Electrical India_July 2015

Publisher's Letter Mahadevan Iyer R epeated replacement of online distribution transformers has Editor-in-chief, Publisher & Managing Director been a common thing in our country. However, besides the direct cost factor that is borne by the distribution companies, [email protected] there are other economic impacts that are shared by the users. So, it is a loss for both sides: supply and demand, and ultimately it is aFailure rate of national loss.distributiontransformers in our During 2014-15, against the target of 20,882 ckm (Circuit-Kilometre)public sector utilities of transmission lines and 47,871MVA of transmission capacity, weis in the range achieved a 22,100ckm and 65,554 MVA respectively, which is theof 8 to 16%... highest achievement ever in a year. Also, the government is committed to provide affordable, 24 x 7 power to all households by 2019. In India, private utilities prefer copper-wound distribution transformers while public sector utilities prefer aluminium wound distribution transformers. Average rate of failure of the al-wound transformers is more than that of the cu-wound transformers. Thus, failure rate of distribution transformers in the private sector utilities is in the range of 1 to 2% whereas that in public sector utilities is in the range of 8 to 16%. Now the question is – with such a weak distribution system, will we be able to sustain the plan just by increasing our generation capacity? Power transformers and the distribution transformers are the main components of any Transmission & Distribution (T&D) system. Their failure leads to power outage, which hinders productivity of the country. There lies the value or importance of these devices. Thus, it is high time that our decision makers from utilities seek solutions to reduce the transformer failure rate. Do send in your comments at [email protected] Vol. 55 • No. 7 • July 2015 Directors Advertisement Department Single Issue: ` 100 Pravita Iyer Yasmeen Kazi Annual Subscription: ` 1000 Office Address: Mahadevan Iyer [email protected] Kaushalya Kadam Disclaimer Editorial, Subscription and Publisher [email protected] Advertisement Office: Mahadevan Iyer Chary Publications does not take responsibility for claims 201, Premalaya, Design made by advertisers relating to ownership, patents, and use Next to Cafe Coffee Day, Editor-in-chief Rakesh Sutar of trademarks, copyrights and such other rights. While all Opp. Telecom Factory, Mahadevan Iyer efforts have been made to ensure the accuracy of the Deonar, Mumbai - 400 088. [email protected] Subscription Department information in this magazine, opinions expressed and images Tel.: (022) 2507 3300 / 01 Hemant Yelave are those of the authors, and do not necessarily reflect the www.electricalindia.in Editor Nafisa Khan views/ collection of the owner, publisher, editor or the editorial P K Chatterjee [email protected] team. Chary Publications shall not be held responsible/ liable4 JULY 2015 [email protected] for any consequences; in the event, such claims are found - not to be true. All objections, disputes, differences, claims & Editorial Co-ordinator Accounts proceedings are subject to Mumbai jurisdiction only. Nafisa Kaisar Dattakumar Barge [email protected] Bharati Solanki Printed, Published and owned by Mahadevan Iyer from 201, Premalaya, Opp. Telecom Factory, Deonar, Mumbai 400088 and Printed at Print Tech., C-18, Royal Ind. Est., Naigaum Cross Road, Wadala, Mumbai 400031. Editor : P K Chatterjee ELECTRICAL INDIA



Vol 55 | No 7 | July 2015 34 5226 38 66 Cover Image Courtesy: Siemens26 On A Threshold Of Transformation 38 Comparison Of Supercapacitors Based On Carbon 56 Trends In The Standards For Dry Type - IndiaÊs Transformer Industry Derived From Leaves Of Tree Transformers - Amol Kotwal - Gaurav Shekhar, Ashutosh Phatak, - Sailesh Purohit, Thomas Lim & Dr PB Karandikar & Prof Swati Shirish More Rados aw Szewczyk30 Smart Transformer For Distribution System 46 Case Studies Of The Transformers Failure Analyses 66 Improving Energy Efficiency - Narendiran S & - Manish N Sinha, Palak Patel, Parth Shah, - Dr G S Grewal & Bhavesh Vasiyani Dr Sarat Kumar Sahoo Maulik Doshi & Nishith Bhalodiya 72 Discrete Wavelet Transform Based34 High Efficiency Distribution Transformers 52 Solar Power Generation: Only Eternal Energy Differential Protection for Power Transformers - S V Varadarajan Source On The Earth - Narri Yadaiah & Nagireddy Ravi - Bandal S DDepartments Publisher’s Note....................................................... 04 Tom King joins the Board of Editorial.................................................................... 08 Directors of Energy Savvy AppointmentsNational News.......................................................... 10 Company News........................................................14 NR Mohanty takes over as CMD International News....................................................18 of NALCO Appointments........................................................... 22 Market Potential....................................................... 24 Praburaman R takes over as Awards..................................................................... 54 quality manager MMI Event Report...................................................... 78, 80 Statistics...................................................................84 Product Avenue........................................................88 Index to Advertisers..................................................926 JULY 2015 ELECTRICAL INDIA



Editorial Embrace Updated TechnologyFocus of our M ore than rushing for more power generation with the traditionalpower distribution methods, it is important for us to plug the holes of power waste. Incompanies is this context, we should remember that in developed countries the lossshifting from of energy expected in electric grids is generally less than 15%, whereas inbenefits of India, the figure goes beyond 30%.replacementcontracts – While talking about the overall energy loss, there are several components oftowards buying this. It is not only the technical loss, power theft and metering challenges arebetter quality also there. Most of our power generation plants are away from the main cities,transformers... thus, our transmission and distribution systems have to be very robust – as long as we remain dependent on the centralised power supply.P K Chatterjee (PK) However, there are some almost unavoidable challenges due to our age-old plans of the cities, for example: small lanes or access points to large slums; where fixing, maintaining and repairing distribution transformers is a challenging task. Also, it increases the risk factor, especially the oil-cooled transformers, which lack regular monitoring and maintenance, often lead to devastating fire. Parts of old cities like Delhi, Mumbai, Chennai or Kolkata cannot be changed overnight. Also, in a democratic country, public opinion (objection) often decelerates the development plans. Thus, at this moment, we have no alternative but to depend on the latest technologies. DRY type transformers are slowly making their ways in the Indian T&D sector. Also, focus of our distribution companies is shifting from benefits of replacement contracts – towards buying better quality transformers that will last longer with complete efficiency. Although erection of the traditional fossil fuel based power plants is still cheaper, and its demand is growing globally, too much addition of such utilities in our country at this moment is not a prudent decision – as we have to eventually take the route of distributive generation. Please e-mail me your views at [email protected] Follow us on www.facebook.com/electricalindiamagazine www.twitter.com/electricalindia www.linkedin.com/in/electricalindia www.google.com/+electricalindia8 JULY 2015 ELECTRICAL INDIA



National NewsMSEs need to be more quality Subject: \"Can't we act on our own?\" Article on ELECTRICALconscious INDIA June 2015 Edition (Issue) Recently at Hello Sir, Kakrapar, First of all it was a great article and in fact a topic where we should Nuclear Power actually focus in todayÊs energy scenario. I was just hovering over the Corporation of magazines in my office pigeon hole post and found this interesting India Limited magazine „ELECTRICAL INDIA.‰ (NPCIL) organized its Vendor Meet- I stay in Pune, and the way I have seen the apartment culture of 2015 for Micro & residents growing, this idea when implemented by default (as in many Small societies compulsory maintenance fee includes PARK, SWIMMING Enterprises(MSEs) POOL, WI-FI. etc. and many other amenities), initially in small amounts, in association with will make people acquainted to investing in small amounts towards a world-changing initiative. I would love to have (see) more of your articles. S C Gupta, AGM (CMM) is delivering the welcome speech... Thanks & Regards, the Southern Sagarika Dash, Accounts Specialist - TELECOMGujarat Chamber of Commerce & Industries [SGCCI]-Surat, SuratEngineering Vikas Association [SEVA]- Surat and MSME- Power Generation Business UnitDevelopment Institute-Ahmedabad. Cummins India Limited, Cummins India Office Campus Tower-A , 6th Floor, S. No. 21, Balewadi, Pune - 411 045 (India) In his inaugural welcome address, S. C. Gupta, AGM (C&MM)emphasised the achievement made by Kakrapar Gujarat Site. He EditorÊs reply:highlighted that more than 20% business originating from the sitehas been provided to MSEs during the year 2014-15 against the set Madam,target of Government of India. The same was appreciated by the Thanks for your attention on the issue. When everyone talks aboutMSME as well as SEVA branch of Surat. power shortage and blames the government, I feel, itÊs high time that we start taking small initiatives at individual or (housing) society level. With LK Jain (Site Director, Kakrapar Gujarat Site), during his Advanced Metering technology that will be implemented throughout thekeynote address, explicitly expressed that quality is the foremost country in a few years, every consumer or group of consumers willfactor for procurement of material by NPCIL from MSEs. He urged benefit from such efforts. Everybody has to think seriously then only theall the participants to develop the suitable quality testing facility in change will come.nearby Surat area that shall be helpful for NPCIL. Regards, In the programme, V. K. Jain, Station Director, KAPS-1&2 PK - Editor, ELECTRICAL INDIAexpressed that MSEs would fulfill NPCILÊs requirement, andinformed that KAPS-1&2 has bagged the ÂGold ShieldÊ award in thecategory of ÂPerformance of Nuclear Power StationsÊ for the year2013-14, conferred by Central Electricity Authority (CEA), Ministryof Power, Government of India.New PV power plant is coming up in Southern IndiaRecently, juwi India Renewable Energies Image courtesy: juwi Group Roth-Deblon continued. Covering an area of Pvt. Ltd., a subsidiary of juwi group, has around 250,000 square metres in the vicinitystarted constructing a ground-mounted power generating capacity. With its Indian of the village Samudram, powerful poly-utility-scale PV power plant with 39 branch, established in 2010 in the high-tech- crystalline solar modules are mounted onMegawatts capacity. The project is located in mecca Bangalore, juwi is ideally positioned fixed racks. \"Because of the quality of theTamil Nadu. Grid connection is scheduled for on the subcontinent. \"In addition to our modules and the strong irradiation at thisthe end of this year. impressive track record, we also have a well- location, we expect an annual electricity filled project pipeline for the upcoming years,\" production of almost 64 million kilowatt- „Around the globe the demand for cost- hours. Carbon-free PV power can alreadyeffective solar energy is increasing. This is compete in terms of cost with climate-especially true for Asia and India,‰ says damaging electricity from coal or other fossilAmiram Roth-Deblon, juwi's Regional fuels,\" says Rajesh Bhat, Managing DirectorDirector for Asia Pacific. By 2022, India is of juwi India.committed to install 100 gigawatts of PV10 JULY 2015 ELECTRICAL INDIA



National NewsIndia has immense potential in the J&K to get centreÊs help to improveLED industry power scenario The LED market Image courtesy: PIB India In a review meeting on the power has emerged as sector of J&K, in presence of Dy. one of the fastest growing industries Chief Minister, J&K, Dr. Nirmal Singh; in India. This industry has been Finance Minister, J&K, Dr. Haseeb A. majorly driven by factors such as Drabu; Sajjad Gani Lone, Minister forfalling prices of LED lights, increasing initiatives taken by thegovernment and rising concerns with respect to energy conservation. S&T & Animal Husbandry, J&K; andResearch and Markets has recently released a research reporttitled, India LED Lighting Market Outlook to 2019 - Next Wave of Piyush Goyal MoS (Power), Mohammad Ashraf MirGrowth Driven by Government Initiatives. at Sher-E-Kashmir International A number of facilities for manufacturing and assembling LEDlights have sprung up in India over the past few years. Also, a Convention Centre (SKICC), at Srinagar on 15 06 2015 Unionnumber of LED exhibitions have been held in the country ever sincethe advent of LED lights. Minister of State (IC) for Power, Coal and Renewable Energy, Piyush The government is also playing an important role in increasingLED penetration in the country with new initiatives such as Goyal has assured all help from Central Govt. for expeditiousDomestic Efficient Lighting Programme (DELP). As per the report, the LED market is at a nascent stage in India, development of conventional and nonconventional energy sources ofprimarily due to low awareness regarding benefits of LED lights inthe country. India has immense potential in the LED industry, which J&K State.is evident from the fact that the market has displayed a CAGR of56.1% in the last 5 years. The meeting was also attended by the Chief Secretary, J&K, and senior officers from Ministry of Power, J&K government and Central PSUs. During the meeting , a presentation was given by the Principal Secretary P.D.D. J&K Govt., on power scenario of J&K state and discussions were held on various issues pertaining to transmission, distribution generation and renewable energy-solar. During the meeting, a Joint Venture (JV) agreement between NTPC JKSPC was signed for development of thermal power for J&K State and an MOU between J&K State and JKPDD- BEE (Govt. of India) was signed to bring out energy efficiency in power transmission and distribution in J&K state.WindStream to help MNRE in defining SWES standardsIn February 2015, the Ministry of New and with the remainder being academic I could not be happier that WindStream India Renewable Energy (MNRE) solicited for institutions and government research has been chosen and that the SolarMill will beproposals to help define the Small Wind programs. The MNRE has developed officially evaluated and tested by thisEnergy and Hybrid Systems (SWES) the standards and has a process in place for esteemed organisation,\" said Venkat Kumarnew and growing sector in India and to approving solar and large wind, utility scale, Tangirala, President of WindStream India.assist it with developing a specification that products but not small scale distributed \"Should the project be successful, it wouldwill be the benchmark for all companies going energy solutions. The MNRE is attempting to open up a vast sales channel for our products,forward. WindStream Energy Technologies find technologies that address its energy not only for rural use but across the entirePvt. Ltd., the Indian subsidiary of WindStream challenges in rural and remote areas and has Indian electrical spectrum,\" he continued.Technologies, Inc., has been shortlisted by adopted the use of hybrid technologies. Thisthe ministry to participate in the R&D project project, when concluded, is expected to WindStream India's response to the RFP(SWES) to help define the standards that will certify a variety of technologies that are was to provide a technology that was a fullybe adopted by the MNRE for all manufacturers deemed viable for use in off-grid areas. integrated, hybrid solution, which producesof hybrid energy solutions. the greatest amount of energy in the smallest There are greater than 400 million people footprint possible, what the company calls, WindStream India's proposal was in India who are without a grid connection, ÂEnergy Density.Ê \"We are confident that ourselected for the small wind sector using and this MNRE initiative is an attempt to SolarMill technology will be found suitable byvertical axis turbines and solar panels. address the problem. \"When we first heard the MNRE for the SWES and become aSeventeen respondents were chosen out of that this programme was being launched by benchmark for hybrid products,\" saidthe many submissions and WindStream was MNRE, we believed we had the most viable Timmaraju Venu Gopal, Head of Productionone of two commercial companies chosen, solution and had to become a part of it. and Engineering, WindStream India.12 JULY 2015 ELECTRICAL INDIA



Company NewsL&T bags huge order in Transmission & Distribution segmentThe Power Transmission and Distribution LLC, a fully owned subsidiary of L&T, has A major order has come from a govt (T&D) Business, under Larsen & bagged a contract from National Grid agency to design and build 66 kV sub-Toubro (L&T) Construction, has won orders Saudi Arabia (a subsidiary of Saudi stations with associated cabling works inworth ` 1,258 crores in the international Electricity Company) for Engineering, the GCC market. Further, L&T Oman LLC,markets recently. Procurement and Construction (EPC) of a subsidiary of L&T, has received an order 132 kV cabling work in Hail city and a 132 from Oman Electricity Transmission Overall, the construction arm of L&T kV double circuit transmission line in Company for engineering, procurementhas won orders worth ` 2278 crores across Turaif, Qaseem and Hail areas of Saudi and construction of a new 132/33 kVvarious business segments in May and Arabia against stiff competition. Salalah Free Zone-2 grid station.June 2015. Larsen & Toubro Saudi ArabiaPhilips India to focus on LED market Intertek to help in testing LEDs, batteries Philips India is demerging its biggest business, lighting, to Quality solutions provider, Intertek has launched focus on the fast-growing LED lighting market in the country in its first Electrical Centre of line with its global strategy to drive Excellence laboratory for value in its core business areas. LEDs and Batteries in, Delhi. Accordingly, 40,000-odd public The new laboratory wasA sample LED tubelight made by Philips shareholders in Philips India, who inaugurated by Andréin China… hold about 3% stake, will get Lacroix, CEO, Intertek Groupshares in the new demerged lighting business on 1:1 basis. The Dutch André Lacroix, Chief Executive Officer, plc., along with senior Intertek Group plc., is inaugurating officials from Bureau ofparent Royal Philips holds the balance 97% in the Indian entity, which Indian Standards (BIS), Intertek's first LED and batteries lab...was delisted 11 years ago from Indian bourses with minority publicshareholding. The diversified technology company has also set up an Department of Electronics & Information Technology (DeitY),independent company - Philips Lighting India Ltd. It has appointed National Accreditation Board for Testing and CalibrationHarsh Chitale, former managing director of HCL Infosystems, as its Laboratories (NABL) and Bureau of Energy Efficiency (BEE) andMD. Philips India, which will continue with healthcare and consumer important stakeholders from regulatory bodies and industry.lifestyle, will continue to be led by its existing CEO Krishna Kumar. Considering the initiative by BIS and DeitY requirement for\"The estimated 8,000 employees in India will get split equally ÂCompulsory Registration Order,Ê which underlined 30 categoriesbetween the two companies and there will be no job losses. The of electronics items to be tested on Indian soil for compliance todemerger process is underway and we soon expect to receive court Indian safety standards, Intertek sees a huge potential to addapproval. India figures among the top five markets for lighting business value and strength to the governmentÊs plans.of Philips and we expect to grow further under the new arrangement Speaking on the future prospects of Intertek, Rajesh Saigal,with dedicated focus on LED lighting,\" said Chitale. Regional MD, South Asia, Intertek, said, „Intertek has alwaysThe company is going to launch intelligent LED lighting solutions. been a partner to the Indian govt; 10 years ago we've fast tracked\"We have started local manufacturing of LED tube lights and the countryÊs standards and labeling programme by putting up theluminaires. Once we are able to meet local demand, we will export 1st laboratory for HVAC. In the same way, we're glad to supportLED lamps. Philips will also expand its LED manufacturing capacity at the govtÊs regulations that are coming up in LED and battery withits two plants at Vadodara and Mohali\" said Chitale. the necessary capacity and capability for testing these products. Follow us on The well-equipped laboratory planned is aligned to the ÂMake inwww.facebook.com/electricalindiamagazine IndiaÊ initiative launched by the Prime Minister Narendra Modi.‰ André Lacroix, CEO, Intertek Group plc. added, „IntertekÊs commitment to the electrical sector has a very strong legacywww.linkedin.com/in/electricalindia associated with Thomas Alva Edison, the father of the electricwww.twitter.com/electricalindia bulb. Considering the growth of the lighting industry backed by the govtÊs focus, with the launch of the new laboratory Intertek willwww.google.com/+electricalindia play a vital role in verifying the products being used.‰14 JULY 2015 ELECTRICAL INDIA



Company NewsTata Power receives Central Electricity Authority's awardTata Power has been honoured by the Tata Power is receiving the award... strived towards achieving world class Central Electricity Authority (CEA) in standards in the industry. We are honouredtwo categories under its ÂComprehensive meritorious performances in the Indian and proud to be recognised as one of theAward SchemeÊ. The company has power sector and felicitates various power leading companies in the space ofreceived a Silver Shield in the category of utilities in the sector with the prestigious Generation and Distribution and veryÂPerformance of Distribution CompaniesÊ and commendable projects undertaken in thankful that our efforts are fruitful to theand Consolation Award in the category of the year. community. As a company, we haveÂPerformance of Thermal Power StationsÊ committed to provide our customersfor Trombay Thermal Power Station Speaking on the occasion, Anil reliable and uninterrupted power supply at(750 MW). Sardana, Managing Director and CEO, competitive prices in years to come.‰ Tata Power, said, „Tata Power has always The award was handed over by Piyush He further added, „Tata Power has wonGoyal, HonÊble Union Minister of State for the National Award in areas of GenerationPower, Coal & Renewable Energy. On & Distribution consecutively in the lastbehalf of Tata Power, Ramchandran Pillai, three years. These awards make the teamSharad Baijal, Pradeep Manjrekar and more committed and enthusiastic aboutVishwas Shrikhande received the award. working relentlessly and striving forCEA under Ministry of Power recognises excellence in our business.‰BHEL receives India Pride Award Waaree Energies completes solar2014-15 power project before schedule Bharat Heavy Electricals Mumbai-based Waaree Energies has commissioned a 10 MW solar Limited (BHEL) the power plant for Sharda Construction and Corporation Pvt Ltd (SCCPL), a construction company based in Nanded, Maharashtra. The integrated power plant project located at Latur, Maharashtra was allotted to SCCPL under the Domestic Content Requirement (DCR) category of Jawaharlal Nehru equipment manufacturer National Solar Mission's (JNNSM) Phase 2, Batch 1. The EPC contract was awarded to Waaree Energies to design and execute the project by and one of the largest SCCPL. The project was completed by Waaree Energies in less than 90 days even in the face of challenging conditions. engineering and Speaking at the occasion, Hitesh Doshi, CMD, Waaree Energies manufacturing companies of Ltd, said, \"We had to face few challenges like undulated land and an extreme slope with a catchment area at the bottom, which added to the its kind in India engaged in design complexity. We are proud to share that the plant performance till date is as expected and it is a proof of Waaree's design and engineering the design, engineering, capability. This project is a hallmark of our growing capability in the field of solar.\" manufacture, construction, CORRIGENDUMAtul Sobti, Director (Power), BHEL (L) is testing, commissioning andreceiving the award from Union Minister, servicing of a wide range of Referring to the May 2015 issue of Electrical India In the article titled \"Switch To Switchgears, And Circuit Arun Jaitley (R)… Breakers With Relays,\" (Page 60, 2nd paragraph), by typographical error, we printed, \"Electricity was invented about products and services for two decades back.\" Kindly read it as: \"Electricity was invented about two centuries back.\" - Editor, Electrical Indiathe core sectors of the economy, viz. power, transmission,industry, transportation (railway), renewable energy, oil & gasand defence with over 180 products offerings to meet the needsof these sectors has once again been recognised for itsengineering efficiency.For the sixth consecutive time, BHEL has been conferred theIndia Pride Award 2014-15 for Excellence in Heavy Industries.Significantly, BHEL has been winning this award every year sincethe award was instituted.In addition, Atul Sobti, Director (Power), BHEL, was awardedthe India Pride Award 2014-15 for Excellence as 'Head ofDepartment' among Central PSUs.The awards were received by Sobti from Arun Jaitley, Hon'bleUnion Minister of Finance, Corporate Affairs and Informationand Broadcasting.16 JULY 2015 ELECTRICAL INDIA



International News Nuclear energy prevented release of EPRI receives grant for power ~56 Gt of CO2 since 1971 plant cooling researchPhoto: C.Brady/IAEA Acomparison of median values The U.S. Department of of gCO2eq/kWh for different Energy has granted a $3 sources of power generation million award to the Electric shows that the lifecycle CO2 Power Research Institute equivalent (including albedo (EPRI) to develop a novel dry effect) from coal and nuclear cooling technology for Yukiya Amano, Director General, IAEA (R) sources stands at 205: 3. Thus The team will research a novel micro thermoelectric power plants. emulsion adsorption system for This new cooling technology with French Nuclear Safety Authority was echoed recently when IAEA has the potential to (ASN) President Pierre-Franck Chevet supplemental power plant cooling... Director General Yukiya Amano told in Paris that nuclear power is one of the lowest-carbon technologies significantly reduce fan power consumption and steam available to generate electricity, and it can play a significant role in condensation temperatures compared to current dry cooling mitigating climate change. During his recent two-day-long visit to systems, and produce a more cost-effective option for reducing France, Amano met with the Minister of Foreign Affairs and International water use at thermoelectric plants. Development Laurent Fabius, Minister of Ecology, Sustainable EPRI is teaming with Drexel University, University of Memphis, Development and Energy Ségolène Royal and other government Evapco, WorleyParsons, Maulbetsch Consulting, and its utility officials and representatives of the nuclear industry. advisors to develop, manufacture and demonstrate a cost- Amano said to the ministers, \"Climate change is the biggest effective, 50 kW indirect dry cooling system that would use environmental challenge of our time. As governments around the world advanced phase change materials to improve heat transfer. The prepare to negotiate a legally bound, universal agreement on climate at proposed design is anticipated to be compact, optimised for the United Nations Climate Change Conference in Paris at the end of various geographic and weather conditions and would have the the year, it is important that the contributions that nuclear science and potential for integration into existing power plants. technology can make to combating climate change are recognised. \"Successful scale-up and demonstration of this technology The use of nuclear power has already prevented the release of will help determine if it could be a competitive water conserving around 56 Gt of carbon dioxide since 1971, equivalent to two years of option for the next generation in power plant cooling,‰ said Sean global emissions at current rates, according to World Energy Outlook Bushart, Director, Generation Environmental Sciences, EPRI. statistics, published by the Paris-based International Energy Agency. DOEÊs Advanced Research Projects Agency-Energy (ARPA-E) Amano and French officials discussed changes in nuclear energy is funding the project under its Advanced Research In Dry cooling policy throughout the world following the accident at the Fukushima (ARID) programme. The EPRI project is one of 14 totalling $30 Daiichi Nuclear Power Plant in Japan in 2011. \"It is the sovereign million to support development of transformative new power plant decision of each country whether or not to add nuclear power to its cooling technologies that can cost-effectively and efficiently reject energy mix. For countries that choose nuclear power, our job is to help waste heat with minimal water evaporation. ARPA-E project teams them in using nuclear technology in a safe, secure and environmentally will work to design kilowatt-scale testing prototypes to help ensure friendly manner,\" he added. He and his French hosts also discussed the the technologies can be scaled up to megawatt-cooling capacity status of the negotiations between Iran and the P5+1 group of countries, without significant performance loss. and the implementation of IAEA safeguards in Iran. Yingli expands its partnership with Vivint Solar Yingli Green Energy Americas (Yingli provides great products and has been a nation's (AmericaÊs) top home solar Americas) a wholly owned beneficial supplier to Vivint Solar this companies. We value our true partnership past year and we are glad to continue with Vivint and their dedicated team. subsidiary of Yingli Green Energy Holding working with them moving forward,\" said Through this renewed supply agreement, Jan Newman, Vice President, Business we are helping in driving job creation in Company Limited (Yingli), which markets Development, Vivint Solar. the flourishing American solar marketplace, as well as solidifying Yingli's its solar panels under the brand name \"With the U.S. residential solar market position as a leading PV supplier,\" poised to reach nearly 3 gigawatts by the commented Robert Petrina, Managing ÂYingli Solar,Ê has been chosen again as a end of 2016, we are thrilled to expand our Director, Yingli Americas. partnership with Vivint Solar, one of the preferred supplier to Vivint Solar (VSLR) in 2015. \"We, as Vivint Solar, are excited to continue our relationship with Yingli. Yingli18 JULY 2015 ELECTRICAL INDIA



International NewsPV modules from JA Solar Egypt to have worldÊs largestHoldings get certified CC power plants soonThe PV modules of JA Solar Holdings Co. Ltd., one of the Two state-of-the-art Combined Cycle (CC) power world's largest manufacturers of high-performance solar plants are coming up in Egypt soon. Once completed,power products, have passed the high-grade Class 4 Hail Testconducted by RETC in May at its facility located at Fremont, each power plant will be the largest in the world and theCalifornia. This success of the company is followed by itssuccessful pass of the similar test conducted by TÜV Rheinland most efficient in Egypt. One of them will be located on thein early March this year. Mediterranean coast, north of Borolos Lake in Kafr El The Class 4 hail test uses solid ice balls frozen at -17degrees Celsius with a diameter of two inches (50.8 millimetres) Sheikh Governorate, and the other in the new capital cityto strike different locations of the glass surface of a PV modulethat include centre, one corner, and one edge along the metal Joe Kaeser, CEO and development. Both will operate on natural gas with lightframe, as well as some random places, at various impact President, Siemens AGvelocities with the maximum reaching 76 metres per second fuel as a backup.(274 kilometers per hour). The kinetic impact energy of thisClass 4 Hail Test carried out by RETC this time on JA's PV Orascom Construction (OC) will build them. Eachmodules is more than eight times higher compared to theenergy registered in the previous hail test conducted by TÜV plant will have a power generation capacity of 4,800 MW, and has a contractRheinland Lab in March when 45-mm hailstones with a strikingspeed of 30.7 m/sec were used. value of EUR 2 billion. They will be constructed in a consortium with Siemens. Wei Shan, Chief Technology Officer of JA Solar, said, \"In OCÊs combined share of the contracts totals EUR 1.6 billion. Siemens and OCorder for our products to withstand harsher weather conditions,it is a necessity that our modules pass the hail impact test under previously collaborated on a 1,000 MW natural gas-fired power plant in Baiji,more stringent conditions. Passing the Class 4 Hail Test atRETC is a testament that further demonstrates the high quality Iraq, where OC installed Siemens equipment and received technical support onand reliability of JA Solar's PV modules, as well as our tirelesslydevoted efforts to meet the needs of our customers through the EPC scope. OC arranged a competitive 15-year financing package for itscontinuous performance improvement, product innovation, andvigorous quality control.\" portion of the contracts on behalf of the Egyptian Electricity Holding Company. Joe Kaeser, CEO and President of Siemens AG, commented, „With these unprecedented contracts, Siemens and its partner are supporting the EgyptÊs economic development by using efficient natural gas and renewable technologies to build an affordable, reliable and sustainable energy mix for EgyptÊs future.‰ Osama Bishai, CEO, OC, said, „This is another milestone that reflects our leadership in the power sector in Egypt and the region. Not only did our people achieve a world record in the construction of a GF dual fuel power plant last week, but we also signed contracts for two of the largest power plants in the world as an EPC partner with Siemens. We are looking forward to establishing a solid long term strategic relationship with Siemens that will go beyond Egypt.‰Eighty six MW solar park is coming up in South AfricaDiggers are rolling, access roads are Image courtesy: juwi projects in South Africa and built up a great being established, posts rammed and reputation as a leading specialist for greenfences erected: There is a lot of activity going „We are delighted to finally realize this energies in the country.on at juwiÊs biggest construction site at the milestone project after a long an intensivemoment. No wonder, close to the city of planning period. With the construction of the The Prieska project was selected by thePrieska in South AfricaÊs Northern Cape solar park we are again playing a key role in Department of Energy of South Africa underProvince the utility-scale Mulilo Sonnedix adding substantial amounts of clean energy the third bidding window of the nationalPrieska PV solar park is scheduled to be to the South African electricity grid‰, says Renewable Energy Procurement Programmecompleted by late summer 2016. Greg Austin, juwi South AfricaÊs Managing in October 2013. Director. Over the past years, juwi Renewable The mega project will then have a size of Energies has realized four utility-scale PV „We are also proud that our efforts inmore than 200 football pitches and an designing the economic development aspectsinstalled capacity of 86 megawatt. For juwi of the project brought the desired outcome,‰the solar park is the largest individual continues Austin.project in the company history. It is managedand executed by juwi Renewable Energies Of all six projects in bidding round three,Pty Ltd., the South African branch of the the Mulilo Sonnedix Prieska PV solar parkjuwi Group. had the highest economic development score. juwi will also provide Operations and Maintenance (O&M) services for the plant.20 JULY 2015 ELECTRICAL INDIA



Appointments Tom King joins the Board of Directors of Energy SavvyTom King Tom King has joined the Board of Directors engagement, analytics and automation. of Energy Savvy, a utility and industry „Tom has run two of the worldÊs leading“Tom King’s leadership and insights partner for energy efficiency (cloudwill help enable us to continue to software). With more than two decades of utility utilities that operate in the #1, #2, #3 and #7provide breakthrough and increasingly senior management experience in roles ranked states for energy efficiency. Hisvaluable solutions to our rapidly including CEO of Pacific Gas and Electric experience is only matched by his passion forchanging industry,” said Aaron Company and more recently National Grid industry progress. His leadership and insightsGoldfeder, CEO Energy Savvy... U.S., Tom brings invaluable expertise and a will help enable Energy Savvy to continue to unique perspective to Energy Savvy. provide breakthrough and increasingly valuable solutions to our rapidly changing Energy Savvy continues to scale its demand- industry. WeÊre honoured to have him join us,‰ side management software and solutions for said Aaron Goldfeder, CEO and Co-founder of utilities, powered by modern customer EnergySavvy. NR Mohanty takes over as CMD of NALCONR Mohanty National Aluminium Company Limited from Larsen & Toubro and worked in BALCO (NALCO) is a Navratna CPSE under before joining Nalco in 1986.Mohanty has rich and varied Ministry of Mines, Government of India.experiences of more than 33 years in The company is a group ÂAÊ CPSE having He has rich and varied experiences of morealuminium industry. He has worked in integrated and diversified operations in mining, than 33 years in aluminium industry. He hasvarious capacities in NALCO’s metal and power. Government of India holds worked in various capacities in NALCOÊssmelter plant and corporate office... 80.93% equity of NALCO. smelter plant and corporate office. He has been instrumental in creating new vision and mission N R Mohanty, Director (Projects & Technical) of plan for the company. NALCO, has been given additional charge of the Chairman-cum-Managing Director of the company. Besides, he has also initiated various growth-oriented greenfield and brownfield Mohanty graduated in B.Sc Engg (Hons) in projects and has successfully steered NALCO Mechanical Engineering from NIT Rourkela in into Âgreen energyÊ with the commissioning of 1980, and was honoured as the best graduate wind power projects at Gandikota, AP and of Sambalpur University. He started his career Jaisalmer, Rajasthan. Praburaman R takes over as quality manager MMIPraburaman R P raburaman Rengaramanujam has been for ISO 9001:2008. recently named Global Quality Manager Commenting on his vision as the Global“My ultimate goal is to satisfy 100% for Michigan Manufacturingof MMI customers. This can be International. In this role, he will be responsible Quality Manager, Praburaman said, „Myachieved through managing the for quality systems at all MMI locations. ultimate goal is to satisfy 100% of MMIcompany’s quality systems customers. This can be achieved througheffectively,” said Praburaman He has 14 years of experience in the managing the companyÊs quality systemsRengaramanujam… quality assurance industry. He specialises in effectively.‰ quality management systems, measurement system analysis and statistical process control. MMIÊs CEO, Jacob Prak said, „I am very pleased to have Praburaman join our firm. He Previously Praburaman was the Quality brings a wealth of quality and management Manager at Modine Thermal Systems. He experience, which will significantly enhance holds a Master of Science in Quality our knowledge base and enable our quality Management, and is a qualified internal auditor systems to reach the highest level.‰22 JULY 2015 ELECTRICAL INDIA



Market Potential Witnessing Growing Demand The demand for coal fired power generation is mainly driven by high demand for electricity for an array of industrial, commercial and residential applications...Image Courtesy: www.transparencymarketresearch.com According to a recent report by Transparency Market Research a The construction of new plants for coal fired global market intelligence company providing business information power generation across the Asia Pacific reports and service, the coal fired power generation market is region will pave the way for further expansion projected to grow at a positive 3.1% CAGR between 2013 and 2019. The of the market... report, titled „Coal Fired Power Generation Market Global Industry Analysis, Size, Share, Growth, Trends and Forecast, 2013 2019,‰ also by the end of 2019. In terms of technology, the global market for coal fired informs that the global coal fired power generation market exhibited an power generation is categorised into pulverised coal systems, cyclone installed capacity of 1,673.1 GW in 2012. The demand for coal fired power furnaces and others (fluidised bed combustion and coal gasification). generation is mainly drivenby high demand for electricity for an array of Geographically, the market can be segmented into North America, industrial, commercial and residential applications. Such factors are likely Europe, Asia Pacific and Rest of the World. Of the key geographic to boost the overall capacity of coal fired power generation to 2,057.6 GW segments, Asia Pacific dominated the market for coal fired power generation in 2012, accounting for a significant 56% share of the overall Global coal fired power generation market shares, installed capacity registered by the market. by technology, 2012 According to the report, the market for coal fired power generation in Source: Primary Interviews. Transparency Market Research Asia Pacific is expected to grow exponentially during the forecast period. The construction of new plants for coal fired power generation across the region will pave the way for further expansion of the market. North America dominated the global coal fired power market in 2012 on the basis of revenue, accounting for 21% of the total market. On the basis of application, the commercial sector dominated the market with a 56% share of the global industry. The residential sector will register tremendous growth in the demand for solar and hydro power, thereby adversely affecting the demand for power generated from coal from the sector. Pulverised coal systems led the market in 2012, accounting for more than half of the total market. High availability of raw materials together with increasing demand for power drove the demand for pulverised coal systems in coal fired power generation market.24 JULY 2015 ELECTRICAL INDIA



Cover StoryOn A Threshold Of Transformation - India’s Transformer IndustryImage Courtesy: Siemens India is on the verge of becoming an 271.7 Giga Watt (GW). Acute fuel shortage emerging power nation among developing (both coal and natural gas), project clearancesThe Transformer market in economies. The availability of electricity is and delay in commissioning of new units,India can be pegged at more directly linked to the Gross Domestic Product affected capacity addition plans.than INR 12,000 Crores. (GDP) growth of developing economies, IndiaPower Transformers being no exception. Growth of the Indian Although India has the 5th largest powercontribute 45 percent of the electrical industry and its investment appeal generation capacity, globally (trailing behindtotal market and distribution primarily depends on government policies. China, US, Japan and Russia), a power deficittransformers, 55 percent. Timely capacity additions to electricity scenario has been plaguing the sector for moreOver the last two years, the generation, transmission & distribution (T&D) than a decade. IndiaÊs per capita powermarket has grown at a very are necessary to improve and sustain GDP consumption of around 1010 kilowatt hourmoderate rate at less than growth and reduce the electricity demand- (kWH) per annum (as at the end of FY2014-15)4 percent... supply gap. is significantly below the world average of 2,600 kWH and developed countriesÊ average The Indian Power Sector of 8,000 kWH. India needs to rapidly increase its generation capacity, in order to achieve the IndiaÊs power generation of installed goal set by the Ministry of Power ÂPower for capacity at the end of FY2014-15 stood at AllÊ by 2019.26 JULY 2015 ELECTRICAL INDIA

Cover Story Power deficit at the end of the 11th five India’s transformer market is predominantly unorganized withyear plan reached 3.6 percent, whereas peak many small participants catering to the smaller distributiondeficit was to the tune of 4.7 percent. Key transformer markets...reasons (apart from missing out on powergeneration capacity addition targets) for the distribution transformer markets. However, power generation capacity addition and T&Dcontinued power deficit scenario in the many are slowly graduating to the medium- infrastructure expansion.country are: sized category, thus expanding the organized• Dismal conditions and inappropriate participantsÊ base. Anticipating the huge domestic (due to a power deficit scenario, requirement of power maintenance of existing T&D equipment / There are approximately 300+ transformer sector expansion) and overseas demand, the infrastructure companies in India, with an overall installed transformer industry in India has more than• Rampant power theft, leading to high capacity of over 370,000 Megavolt Amperes, doubled its manufacturing capacity over the T&D losses (at the end of FY2014-15, (MVA) per annum. The market is fragmented last five years. Transformer manufacturing T&D losses were to the tune of 20.8 with 20 organized players including Bharat capacity in India stands at ~370 GVA with percent) impacting financial condition of Heavy Electricals Limited (BHEL), ABB Ltd, capacity utilization rates hovering around Power T&D utilities (DISCOMs & Crompton Greaves Ltd (CGL), Areva T&D, 60-70 percent on an average over the last 5 TRANSCOs). EMCO Ltd, Bharat Bijlee Ltd (BBL), Vijai years. Transformer over-capacity in the Indian A robust and efficient power T&D Electricals, Transformers and Rectifiers India market has led to immense pricing pressureinfrastructure is imperative for effective Limited (TRIL), Voltamp Transformers Ltd, scenario severely impacting the profitabilitytransfer of power from generation source to among others. of the market players.the consumption points / demand centres.Thus, expanding the T&D infrastructure to In the power transformers category, New Entrantstransmit the power generated to consumer companies in the high-end segment (400 kVpoints across the length and breadth of the and above) mainly include international IndiaÊs huge power shortage, need tocountry becomes imperative. players such as ABB Ltd, Alstom T&D ramp up power T&D infrastructure, economic Transformers are critical components of (erstwhile Areva T&D India), and Siemens; slowdown of developed markets like Europethe Power T&D network that are used to and Indian manufacturers such as BHEL, and North America and excess transformerchange voltage in the power transmission CGL, TRIL, and Toshiba Transmission & manufacturing capacity in China has resultedand distribution process, and hence play a Distribution Systems India (Entity formed by in India being an attractive destination forkey role. acquisition of Vijai Electricals by Toshiba transformer companies globally to tap the Transformers can be broadly classified, Corporation, Japan). Majority of other Indian market opportunity. Anticipating this,based on the output rating as: companies in this sector are present in the many foreign players are already in the• Distribution Transformers (31.5 to 5,000 220 kV segment in power and distribution process of setting up base in India. Over the KVA) transformers. Leading players have significant last 18-30 months, new players have entered• Power Transformers (5.1 to 500 MVA) presence in both power and distribution the market either through acquisitions or• Special Transformers (depending on the transformer market. through setting up of facilities within India. A type of application like welding, traction, few notable examples are: furnace, etc.). Apart from catering to domestic demand, • Canadian company, Hammond Power India exports transformers to over 100Transformer Industry in India nations including the US, Europe, Malaysia, Solutions Inc. had acquired 70 percent Singapore, Bangladesh, African countries, equity stake in the Hyderabad based The Indian transformer industry is more and Gulf countries. India is also an importer transformer supplier Pan-Electro Technicthan five decades old, hence mature. of transformers; the major source countries Enterprises Pvt. Ltd in FebÊ 2012Domestic manufacturers have developed include China, Germany, USA, Korea, • Chinese manufacturer, TBEA has set upcapabilities to manufacture all types of and Japan. transformer manufacturing unit inequipment to meet the countryÊs demand for Gujarat in order to qualify for the bidstransformers up to 800 Kilovolts (kV) and Indian Transformer Market Size from PGCIL.going up to 1,200 kV. The industry enjoys agood reputation in terms of quality, price, The Transformer market in India can be Market Driversand delivery in the domestic as well as pegged at more than INR 12,000 Crores.overseas markets. Power Transformers contribute 45 percent of • Power Generation Capacity augmentation the total market and distribution transformers, and Power T&D infrastructure expansion IndiaÊs transformer market is 55 percent. Over the last two years, the to be in-line with Power generationpredominantly unorganized with many small market has grown at a very moderate rate at capacity addition. According to the 12thparticipants catering to the smaller less than 4 percent, due to the slowdown of plan, INR 1200K-1300K Crores likely toELECTRICAL INDIA JULY 2015 27

Cover Story be invested in the power sector. This concern for the transformer industry in Way Forward spending on the power sector is expected India. The average operational life of a to be equally distributed between transformer is between 25 to 30 years; The Indian power and distribution generation and T&D. Spending on Power however, transformers are known to be transformer markets are highly dependent on T&D infrastructure is expected to boost recalled for repair in as early as three investments planned by the Government of demand for transformers years. The failure rate of distribution India for the T&D segment and reform• Rajiv Gandhi Grameen Vidyutikaran Yojna transformers in India is estimated at programmes like the Revised Accelerated (RGGVY) scheme to improve rural 10-15 percent (in stark contrast to the Power Development and Reform Program electricity infrastructure and rural less than 2 percent failure rate in and Rajiv Gandhi Grameen Vidyutikaran household electrification. The developing countries). This is due to the Yojna. These programmes, when fully electrification drive is expected to provide low entry barriers in the distribution implemented as scheduled, are expected to impetus to demand for distribution transformer market leading to drive the demand for both power and transformers unorganized players entering the market, distribution transformers. The Government of• Increasing focus on Rural Electrification and competing on the price factor. SEBs India currently plans to strengthen Accelerated Power Development and historically follow a L1 vendor selection transmission lines and create a National Grid Reform Program (APDRP 1-2) in order to criteria, which has led to proliferation of interconnecting the five regions (northern, minimize Aggregate Technical and many small players, that compromise on southern, eastern, western and north- Commercial (AT&C) losses at the the quality of transformers manufactured eastern) through the creation of 'Transmission distribution level and improve the financial • Financial Condition of SEBs - SEBs have Super Highways;' this is expected to drive the health of the State Electricity Boards been facing losses due to the supply of demand for higher-rated power transformers. (SEBs) subsidized power to agricultural farmers, With T&D companies actively striving to• Industrial sector growth theft of power, and inefficient T&D reduce Aggregate Technical and Commercial• Replacement of ageing equipment infrastructure. This has restricted private (AT&C) losses, the demand for energy- These reforms are expected to investment in the power T&D sector, efficient transformers would get a boost.significantly affect demand for transformers thereby reducing the quality of serviceover the next 4 to 5 years. from SEBs. This, in turn, is affecting the With huge investments proposed across capacity building program and sectors such as power, infrastructure, etc.,Market Challenges transmission of power the transformers market in India is slated for • Lack of testing facilities The growth in strong growth. The excess capacity in the• Inadequate supply of prime quality Cold testing infrastructure has not kept pace Transformer industry in India, and entry of Rolled Grain Oriented (CRGO) steel is with that of production, both, quantitatively new players is further expected to increase the biggest challenge faced by and qualitatively. Testing infrastructure market competitiveness. Market consolidation transformer manufacturers in the country. available at India's premier agency, the over the next few years is inevitable. CRGO requirement is completely met Central Power Research Institute (CPRI) through imports; it is in fact challenging to is proving short of demand. Manufacturers Amol Kotwal assess the true quality of the material of large power transformers at times Director, Energy & Environment that is used by the transformer need to send their equipment for testing Practice, Frost & Sullivan manufacturers in India. India needs 2.5 to overseas facilities like Korea lakh tons of CRGO every year and an Electrotechnology Research Institute appalling 70 percent of this is scrap (KERI) and KEMA which is expensive. grade material Apart from this, huge logistical costs and lead times are also involved.• Failure rate of Transformers High failure rate of distribution transformers, is a big Now SUBSCRIBE/RENEW Online Just Log on: www.electricalindia.in28 JULY 2015 ELECTRICAL INDIA



Smart TransformerSmart Transformer For Distribution SystemSmart transformers work independently to constantly regulate voltage and maintain contact with the smart grid inorder to allow remote administration (if needed), and to provide information and feedback about the power supply and the transformer...Asmart transformer (ST) provides the power supply and the transformer. Moreover • ST act as a voltage regulator and it exact amount of power that is needed, this type of transformers are used in Point of ensures that the optimised voltage is and responds instantly to fluctuations Common Coupling (PCC) in a microgrid for undisturbed, because they directlywithin the power grid, acting as a voltage voltage control and it acts as a protecting reduce energy consumption & greenregulator to ensure that the optimized voltage device for electrical equipments during house gas emissionsis undisturbed. STs are programmed to, as a power fluctuations.default, provide an voltage optimized power • ST immediately reduce powersupply that directly addresses their facilityÊs The ST has to have some intelligence to consumption by providing a stable,energy needs. ST can help large commercial meet the requirement of future power optimal power supply that suppliesfacilities use power more efficiently to save systems. A possible idea of ST, based on electrical equipment with its ideal voltagemoney, power and go greener. power electronics and communication technology is depicted in Fig.1. The main aim • They also protect electrical equipments A solid state transformer (SST) with of this article is to show the role of ST in with its ideal voltagemanagerial role in the electric distribution distribution grid system with its hardwaregrid is generally called Smart Transformer control and communication topology with its • ST as a default, provide a voltage(ST). Smart transformers work independently role in distribution system. optimised power supply that directlyto constantly regulate voltage and maintain addresses their energy needs.contact with the smart grid in order to allow Some important characteristics of ST are:remote administration (if needed) and to • They give exact amount of power that's Power converter cells for STprovide information and feedback about the needed and respond instantly to Once chosen the ST, the next step is fluctuations within the grid choosing, which should be the basic block of the ST, the power converter cell.30 JULY 2015 ELECTRICAL INDIA

Smart TransformerFig. 1: Smart transformer concept... The interface module blocks are data Communication topology for ST in converters, which convert variables and events distribution system The following goals are achieved using of the control system and send them to thepower converter cells with ST: master module. In the master module the data This system is designed for applications• Isolation for the different voltage level of all the interface modules are packed and in rural distribution networks. This system• Reduced core size sent to the Programmable Logic Control (PLC) consist of a distribution transformer equipped• Minimal loss. interface which converts the data to be sent with an electronic OLTC for automatic voltage through the medium voltage line. The data regulation and a communication system.ST hardware control system coming from a set of transformers are received by the gateway block, which concentrates and The PLC channel is used to establish a The set of hardware control blocks include sends them to the wireless interface. From this path between the distant locations, where theST, instrumentation, control gate drives, block, the data are sent to the power utility transformer is installed, and the gateway thatelectronic On Load Tap Changer (OLTC), where it is received and processed as in Fig. 2. concentrates the data from other smarttransformer builds the voltage regulation block, transformer installed in that region. Thewhich is also responsible for the secondary gateway also converts the data into a wirelessvoltage regulation. communication channel.Fig. 2: Smart transformer hardware control ... The amount of data transferred and received by the smart transformer makes the PLC suitable for this application, since it does not need a high data transmission rate. on the other hand, the wireless channel needs a higher data transmission rate, since it concentrates the data from a set of smart transformers, which prompts cell phone and internet topologies a good choice. A communication topology for employment in smart transformer in distribution system in shown in Fig. 3. Area of applicability These days, controlling the power transfer through the PCC has become a major issue. • Smart transformers when used at the PCC, it controls the active power exchange between a microgrid and the utility grid dependent on the state of both networks and other information communicated to the ST • To control the active power, the ST uses its taps that change the microgrid side voltage at the PCC. This voltage based control of the ST is compatible with the voltage based droop control of the units in the microgrid • ST is a more powerful component providing faster and superior voltage regulation, as it can regulate the voltage, the frequency and the harmonic behaviour of each feeder • A smart transformer enables to control the power exchange between a microgrid and the utility network by controlling the voltage at the microgrid side within certain limits.ELECTRICAL INDIA JULY 2015 31

Smart Transformer PLC Channel PLC Channel Wireless channel Smart transformer N Smart transformer 1 Gateway and wireless wireless module modulewith Control system and with Control system and PLC interface PLC interface Data center and grid management in Power UtilityFig. 3: Communication topology for smart transformer...• The distributed generation units in the identical phase current even for determine its set point of power microgrid are equipped with a voltage unbalanced loads exchange based droop control strategy. This • Providing unity power factor with sinusoidal • ST enables to exploit the microgrid as a controller reacts on the voltage change currents under non-linear loads controllable entity, because the utility making the smart transformer an element • Coordinate fault re-closing over sub-grids network only needs to communicate to that controls power exchange without the zones when connecting to other STs the ST instead of all microgrid elements need for communication to other elements • Accept direct connection to future • Sustainable, Reliable, Reduced overall in the microgrid. medium voltage DC power transmission, weight & volume. low voltage DC grid, storage systems andRole of ST in the distribution system renewable energy systems. Narendiran S Doctoral student in VIT University, In grid connectivity: Issues solved through ST in Vellore• ST are controlled dynamically allowing distribution system Dr Sarat Kumar Sahoo facilities to monitor and manage the The ST can also help in overcoming Associate Professor in the School of transformers directly during the period of several issues associated with distribution Electrical Engineering, VIT University power fluctuations and helping them network, which are difficult to deal with ensure that their power supply remains conventional off-load and on-load tap changer voltage optimised even when new transformers, some of the attributes of smart demands are being placed upon it transformers are listed below,• The power transfer between a microgrid • Reduction in grid losses and the utility grid is actively controlled • Improved power quality & supply reliability. without the need for communication to all microgrid elements Merits of smart transformer• Protect the power system from load disturbances by isolating source and Smart transformer receives attention by load harmonics, transients and researchers due to the following advantages: voltage sags • ST controls the bidirectional power• Enhance the power quality by summarizing the loads to the mains with transfer between utility grid and microgrid • ST is able to aggregate information to www.facebook.com/electricalindiamagazine www.twitter.com/electricalindia www.linkedin.com/in/electricalindia www.google.com/+electricalindia32 JULY 2015 ELECTRICAL INDIA



Efficiency Enhancement Due to use of better grade materials and optimum design, suddenHigh failures are reduced along withEfficiency lower cost of maintenance, leadingDistribution to increased life expectancy. TheseTransformers benefits add up and balance against the inevitable increase in purchase cost as additional copper in the windings and better materials in the core will be used in the manufacture of high efficiency transformers...34 JULY 2015 ELECTRICAL INDIA

Efficiency EnhancementTransformers convert electrical power The cost of energy losses (iron, copper and stray) can be reduced from one circuit to another in the same by improving the efficiency of the transformer. This in turn frequency. In this process, they can reduces the life cycle cost...raise or lower the voltage in one of the circuitswith corresponding decrease or increase in the transformer. This in turn reduces the life Australia. The above BIS standard (for thecurrent. Transformers achieve the above cycle cost. first time) stipulates standard total lossthorough mutual induction between the two (no-load + load losses) levels against specificcircuits that are linked by a common magnetic Also, due to use of better grade materials rating of transformers both at 50% loading andflux in its core. and optimum design, sudden failures are at 100% loading.The invention of transformer reduced along with lower cost of maintenance, BEE's star rated transformers leading to increased life expectancy. These Transformers range in size from radio benefits add up and balance against the Bureau of Energy Efficiency (BEE),frequency transformers less than a few grams inevitable increase in purchase cost as Government of India, has brought out 'starin weight to industrial transformers additional copper in the windings and better rating plan,' through which the distributioninterconnecting the power grid, weighing materials in the core will be used in the transformers (for the first time) are classifiedhundreds of tons. A wide range of transformer manufacture of high efficiency transformers. into '1star' to '5star' classifications. Thedesigns is encountered in electronic and electric Urgent need to increase efficiency transformers under '5Star' grade are the mostpower applications. Since their invention in efficient. Total loss figures are stipulated both1886, transformers have become the back bone The demand for distribution transformers at 50% loading and at 100% loading for eachof AC transmission, distribution, and utilisation has been increasing at a rapid pace due to star classification.of electrical energy. rising population and migration of people fromImportance of transformers rural areas to urban cities. This has further led Electricity networks to increased demand for reliable power supply Transformers play an indispensable role in systems within the country. Power is generated at generating stationsthe power distribution network. After at voltage level ranging from 10 to 30kV. Thistransmission lines, transformers are the second Reduction in transmission and distribution power is converted to typically 230kV* tolarge loss making equipment in electricity losses and providing reliable uninterrupted 400kV* by step-up transformers for transmissionnetworks. Failure of a transformer causes power supply have gained top most attention in to the consumers' distribution networks, whichsudden outage in the power supply, leading to our government's thinking. The emission of are located at urban areas far away. At theloss in industrial production. High efficiency green house gas is reduced with decrease in distribution substations, the transformers steptransformers create economic benefits in terms energy loss. Also, every unit of energy saved is down the power to more usable levels of 110kV*of lower operating costs besides reduced equivalent to about two units of energy for industries. For shorter distances, powergreenhouse gas emissions, improved reliability generated. It is well known that the electrical flows at 110kV* level and at urban substations,and potentially longer service life. In view of energy tariffs are subsidised in certain voltage is again reduced to 11kV. Further alongthese important benefits, many countries segments in our country. The distribution the streets/roads distribution is carried out atincluding India have taken policy initiatives to transformers are special and critical as they 11kV and distribution transformers are used toestablish mandatory and voluntary programmes are the final equipment through which each step down from 11kV to user voltage levels ofto conserve energy and help domestic markets unit of electricity consumed by the end user 415/240V at the street level, very close to thebe competitive by adopting high efficiency has to be delivered. Hence, it is essential that consumers. Thus on an average, electricaltransformers. Moreover, it is relatively easy to every unit of electricity reaches the consumer power is transformed approximately 4 timesreplace the inefficient transformers with the in a reliable and efficient way for ensuring a from the generating station down to theefficient ones when compared with laborious viable distribution. consumer. [* Note: The voltage levels indicated/ time consuming efforts needed for change in The role of BIS in this paragraph are typical values. The exactlines or cables. levels are determined by the quantum of powerHigh efficiency vs life cycle cost Bureau of Indian Standards (BIS) has to be transmitted and the distance between the brought out the revised standard IS 1180:2014, two sub-stations (based on economics)] Life cycle cost of a transformer is calculated 'Outdoor Type Oil Immersed Distributionby adding the purchase cost (investment cost Transformers up to and including 2500 kVA, Network lossesincluding bank interest), the cost of energy 33kV - Specification Part 1 Mineral Oillosses, cost of failure / repairs, cost of Immersed.' This standard extends the scope Technical losses are present in all electricalmaintenance and de-commissioning cost after of coverage beyond 200 kVA and up to and equipments as all equipments offer someproviding for resale price (residual value) of the including 2500 kVA and 33 kilovolts. This resistance to the flow of current causing, I2Rtransformer at the time of its replacement. The extension of the scope would bring IndiaÊs losses. Integrated over a period of time, 't', thiscost of energy losses (iron, copper and stray) norms on efficiency more at par with other constitutes energy loss, namely, I2Rt. Technicalcan be reduced by improving the efficiency of major countries such as USA, China andELECTRICAL INDIA JULY 2015 35

Efficiency Enhancementlosses are categorized and discussed in factors may be seen as per the representative Due to this the core loss is assumed practicallyparagraphs below. list given below: constant for a given transformer. • Industrial distribution transformers have a Load loss Line loss comprises energy loss inconductors and cables (due to selection of higher capacity range of 630 to 4000kVA. Also called as copper loss or short circuitlower size), unbalanced loading (more than The public distribution transformers are loss, this loss is due to resistive losses in thedesigned value of current flowing in one of the rated from 15kVA to about 1000kVA windings/leads and stray losses that are due tophase conductors), neutral conductor loading • The average load on an industrial flow of eddy currents in the structural steel workdue to pre-dominant single phase loads, transformer is higher when compared to the and windings. This loss is proportional to theloosening of strands in ACSR conductors etc average load on an public distribution square of current. transformers, due to constant load Cooling fan loss Losses at joints and terminations including monitoring practice adapted in the industrymid-span joints caused due to improper choice • There is a huge tendency to go in for dry This is caused by the power consumed byof materials and fasteners. type transformers in the industrial network, the fans that cool the radiator bank / body of the which reduces the maintenance time and transformer. Higher the transformer losses, Losses in transformers (apply more to servicing cost when compared with oil larger will be size of the fan. This will result indistribution transformers) such as: cooled transformers till now almost increased losses in the cooling units.• Loose connection at the bushings exclusively used in public networks• Bend in jumpers at the connectors where • Even though the loads have a high Improving efficiency harmonic content (caused by non-linear the strands are not tightly held loads) in an industrial transformer, suitable The losses are to be reduced in order to• High no-load losses due to the type of core harmonic reduction circuits are employed to improve the efficiency. The major areas are (a) bring down the harmonic content. The Core and (b) Windings. However, it will not be used and/or improperly tightened cores in public distribution networks also suffer due easy to work exclusively on core and windings the case of repaired units to loads like UPS, computer power supplies ignoring the other considerations. Transformer• High copper losses due to sub-optimal and various other electronic gadgets used design is complex and let us look into some loading. in households. However, harmonic of the important requirements besides the Losses in service cables and connections reduction circuits are almost absent in losses, which are also to be optimised by theare caused due to under sizing of service public distribution networks, even though design engineer.cables, losses in joints in the poles and in schemes are on the anvil to monitor and • Leakage fieldjunction boxes due to use of inappropriate penalise polluting loads • Short circuit impedancefasteners, missing spring washers and non-use • Load fluctuations are lower in an industrial • In rush currentof torque spanners. network • Stresses and dynamic behaviour under Loss due to high impedance faults occur • Public network transformers suffer fromdue to the overhead wires touching trees, large unchecked unbalanced loads short circuitsgrowth of creepers over the pole / the wires and • In industrial networks, the transformers are • Noisebird nesting, broken insulators and tracking. serviced or maintained better • InsulationLosses in rewired fuses and joints due to poor • Accessibility for servicing / monitoring the • Coolingconnections and inadequate sizing of the fuse transformers is poor in public networks • Transformer DC Biaswires leading to development of hot spot. As • Smaller rating transformers are • Monitoring and diagnosticsexplained before, losses contributed by the predominantly used in the public distribution • Incorporation of latest software (numericaltransformers can be controlled through better networks. When compared with higherdesign and installation practices besides proper ratings, these small transformers have a methods) for design optimisationevaluation of the load demand and choosing the higher no-load and load losses • Weight and cost minimisationright kVA rating to suit the demand requirement. • Thus, we find that transformers in public Reduction in no-load losses distribution network needs more attention.Industrial vs public distribution networks Better selection of the core material will Losses in distribution transformers minimise the core losses. The use modern Cold Even though a large number of distribution Rolled Grain Oriented (CRGO) Silicon Steeltransformers are used both in industrial and No-load losses laminations have reduced core loss. Moredistribution networks, the quality of design, It includes both hysteresis loss and eddy recently the emergence of amorphous metalmaintenance and application are considered has demonstrated significant reduction insuperior in an industrial environment. The current loss. The core flux in a transformer is no-load losses and capacity to tackle non-linearpopulation of transformers in public networks is practically constant for all loads - about 1 to 3% (harmonic) loads.very high compared to the industrial networks. variation from no-load to full load conditions. Apart from the type of core material, the At the same time, their working atmosphere method employed in the design, cutting,is harsh both in the physical sense and in the fabrication and assembly of the core materialselectrical circuit point of view. Some of these also play an important role.36 JULY 2015 ELECTRICAL INDIA

Efficiency Enhancement Increasing the size of the core will reduce the flux density, which will • Introduction of auto voltage boosters in areas of recurrent low voltagereduce the losses, as hysteresis loss is proportional to Bmax1.6 max and • Re-arrangement of LT feeders to avoid overloading as well as undereddy current loss is proportional to Bmax2. But this method has to beoptimised with respect to the attendant increase the weight of the loading of distribution transformerstransformer and the increase in transport and installation costs. • Reducing length of LT lines by suitable relocation of the distributionReduction in load losses transformers Load losses are proportional to the square of the load current. Hence, • Balancing of loads on distribution feeders through regular monitoringthe load current has to be monitored continuously and a fairly accurate • Frequency energy audits at the transformer level.estimation of the loads are needed to select the proper size of thetransformer as a fully loaded transformer achieves higher efficiency. Conclusion The size of the conductor can be increased thereby reducing the High efficiency distribution transformers are the need of the day, ascurrent density and hence the losses, with attendant higher manufacturing we have seen in this article. However, the transformers alone cannotcost. Increased quality control on the making of the windings through reduce the losses. They must be provided with a sound environmentautomated machines and their insertion into the cores also favour including a network devoid of overloads, under voltage, single phasing,reduction in load losses. Superconducting windings with nitrogen cooling unbalance, harmonics, etc., as discussed. Supervision with monitoringhave been developed for special applications as their cost is high for the transformers' health on a continuous basis including periodic checksnormal applications or installations. on the loads and load pattern will enhance their life and ensure continuous performance near to designed parameters.Points of concern S V Varadarajan The high efficiency transformer apart from being an expensive Former Technical Director,purchase, also comes with a few other issues listed below, which are to M. N. Dastur & Company (P) Ltdbe taken care by the designer or end user for extracting the advantages Chennaiof the reduces losses. The higher initial cost of the transformer as suchcan be recovered over a period of time as the lower losses will result inlower operating costs. Increase in size and weight occurs due toenlargement of the core as well as increase in conductor size. Foramorphous iron transformers, the core size increases by about 50%over the conventional design. Hot spots developed due to non-linearloads (such as variable speed drives, computer power supplies,uninterruptible power supplies etc) can bring down the lifeexpectancy of all the transformers. As the financial burden is more in the case of high efficiencydistribution transformers, the problem of hot spot is to be tackledvigorously. Non-linear loads cause harmonics, which increase thelosses many fold, leading to the requirement of a higher sizedtransformer. Analysis of the loads prior to selection of the transformeris a prudent way to avoid failures. Mere installation of high efficiencydistribution transformers alone is not sufficient. The following checklist suggests some of the efforts to be taken at the distribution levelto improve the voltage profile, reduce the single phase loads,balancing of loads, reduce the line losses etc., for ensuring thecorrect and optimum functioning of the high efficiency transformers.Check list:• Construction of more high voltage distribution lines, which will improve the HT-LT ratio as well as reduce the distribution loss• Strengthening of the sub-transmission network by upgrading voltage levels of distribution feeders from 11 to 33kV• Replacement of conductors in the old LT lines• Use of higher sized conductors at the substation end of 11kV feeders• Power factor compensation through installation of shunt and/ or series capacitorsELECTRICAL INDIA JULY 2015 37

New Technology Comparison Of Supercapacitors Based On Carbon Derived From Leaves Of TreeSupercapacitor also known as electric double layer capacitor is emerging as a new energy storage device.Due to its high power density, wide thermal operating range, low cost, and long cycle life, it bridges the gapbetween battery and conventional capacitor. However, it has lower energy density than batteries. Electrodematerial plays a key role for improving the capacitance, and hence energy density of supercapacitor. Inleading research and development organisations in the world, research works are going on in search of newelectrode materials for improving the capacitance of the supercapacitors. This article presents a newapproach to synthesise activated carbon from leaves of trees as an electrode material for supercapacitors.Activated carbon obtained by such process can be cost effective and also environmental friendly...38 JULY 2015 ELECTRICAL INDIA

New TechnologyStorage of energy has a major problem in Supercapacitors are made up of two electrodes of highly porous recent years. Battery, fuel cells and material, which are immersed in an electrolytic solution and capacitor are some of the examples of separated by a separator...energy storage devices in which electricalenergy is stored. In the last decade, the electrodes of supercapacitors. Electrode is made on the parameters of area basedsupercapacitor has come up as a new energy material determines the capacitance of capacitance, specific capacitance, pulsestorage device. In battery and fuel cells, supercapacitor and hybrid capacitor. Scientists current, energy density and power density.chemical energy is transformed into electrical have tried several methods to synthesise highenergy while in supercapacitor charge storage quality carbon, which includes vapour Experimentation with leaves of treemainly takes place by electrostatic principle. deposition, carbonisation of organic precursors,Every energy storage device has its own arc discharge synthesis etc. High capacitance For the development of supercapacitor,advantage and disadvantage and so is true supercapacitors are also developed from multi- activated carbon plays an important role. It isfor the supercapacitor. As compared to capacitor walled carbon nano-tubes,synthesised from used as main electrode material inand battery, supercapacitor has moderately petroleum based precursor. Activated carbon supercapacitors. There are several processeshigh power density and energy density. obtained by petroleum precursor is very of obtaining activated carbon. A recent expensive and also it will not be available after method of obtaining activated carbon is from Supercapacitors are made up of two few decades. Therefore, it is not commercially dead leaves of trees. For this purpose,electrodes of highly porous material, which are viable. A recent method of synthesising composition of various leaves of trees wereimmersed in an electrolytic solution and activated carbon is by burning dead leaves of studied and it was found that neem treeseparated by a separator. Electrolytes provide trees at high temperature, which can be used leaves and coconut shell have relatively highconducting medium while separator prevents as an electrode material for the supercapacitor. carbon content as compared to others. So,internal short circuit between the electrodes. for obtaining activated carbon, neem treeVoltage rating and internal resistance of Waste management is a major problem leaves are collected, and those are thoroughlysupercapacitor are determined by electrolytes. faced by big cities. Several environmental washed. After washing, it is kept in sunlightElectrolytes of any energy storage device are communities are taking initiatives for separating for drying purpose and then it is crushed withbasically of two types: i) aqueous electrolyte out waste material. Carbon content in such the help of a grinder. To synthesise activatedand ii) non-aqueous electrolyte. Aqueous waste material is comparatively high. By burning carbon, neem tree leaves powder is heated inelectrolytes such as potassium sulphate, these waste materials, harmful gases are a furnace at 300OC and 500OC respectivelypotassium hydroxide are non-toxic, highly produced along with ash. Dead leaves of trees, in presence of nitrogen. Initially temperatureconductive, and they have efficient charge which are also a waste material, can be used is increased at a rate of 10OC/min from roomtransfer mechanism. So,they are gaining more for obtaining activated carbon. Activated carbon temperature. After attaining 300OC, it ispopularity for the electrolyte of supercapacitor. obtained by burning dead leaves at high heated continuously for 5 hours. After heatingOn the other hand, non-aqueous electrolyte temperature can be cost-effective and for 5 hours, colour of neem tree leavessuch as aceonitrile is flammable, toxic in nature. environmental friendly. To synthesise activated powder changes from light green to blackMoreover, they are costly and hence they are carbon, dead leaves are burnt at high colour carbon. After cooling the sample, it isnot preferred. Based on electrode design, temperature in absence of oxygen. After washed with 3 molar strength sulphuric acidsupercapacitors are divided into three types (i) heating, it is washed with sulphuric acid and the solution so that ash content gets dissolvedelectric double layer, (ii) hybrid capacitor and solution is then filtered. This article presents a in acid and the samples are then filtered with(iii) pseudocapacitor. Electric double layer and new methodology of synthesising activated the help of filter paper. After filtering, thesepseudocapacitor are symmetric in nature i.e., carbon from neem tree leaves and coconut samples are kept in oven at 100OC for half anboth electrodes have same material. For hybrid shell. The activated carbon derived from neem hour for drying purpose. These samples arecapacitor, one electrode is made up of carbon tree leaves and coconut shell at various then crushed into fine powder with the help ofmaterial and the other of composite material temperatures is compared along with mortar pestle. Similar type of procedure isconsisting of carbon and other metal oxides. commercially available Vulcun XC-72R activated repeated for heating neem tree leaves atCarbon with high specific surface area, low carbon. Area based capacitance is important 500OC for 2 hours. The obtained activatedimpurity and high porosity is suitable for when volume and shape are design parameters. carbon is ready for use in electrodes ofelectrodes of supercapacitor. Carbon materials Specific capacitance is important when weight supercapacitor. A flow chart shown in Fig. 1like activated carbon, carbon nano-tubes, of the electrode material is significant. Pulse gives the detail process of obtaining activatedgraphene, carbon aerogels etc., are used as current, energy density and power density of carbon from neem tree leaves. This processmaterials for the electrodes of supercapacitor supercapacitor are most significant factors for of obtaining activated carbon is generic andand hybrid capacitor. By mixing graphene or automobiles applications. Therefore, can also be applicable to other dead leavesmetal oxide with activated carbon, composite comparison of various derived activated carbon with minor changes.materials are formed, which are also suitable forELECTRICAL INDIA JULY 2015 39

New Technology made on the basis of specific capacitance, under the curve gives the charge stored by the energy density, area based capacitance, pulse supercapacitor, which determines the current, internal resistance, and power density. capacitance. Neem tree leaves derived carbon Parameters Vulcun Neem tree leaves derived Coconut shell XC-72R carbon heated derived carbon at 500OC for at 300OC for heated at 2hrs 5hrs 1000OC for 1hr Pulse current (mA) 32.11 39.35 28.8 16.89 Area based capacitance (F/cm2) 0.039 0.086 0.025 0.08 Specific capacitance (F/gm.) 0.48 1.08 0.305 1.0 Energy density (Wh/gm.) 1.18 2.62 0.74 2.42 Internal resistance (Ω.) 42.73 38.61 57.53 79.16 Power density (Kw/gm.) 0.118 0.13 0.087 0.063 Table 1: Comparison of supercapacitor of various carbon materials...Fig. 1: Flow chart for the synthesis of On comparing supercapacitor of various heated at 500OC has more area under theactivated carbon from neem tree leaves... activated carbons, it was found that neem tree leaves derived activated carbon heated at curve as compared to others. So, it has high For obtaining activated carbon from coconut 500OC for two hours gives much bettershell, it is crushed in to small pieces and then performance. However, specific capacitance capacitance. Also, it has high pulse current andphosphoric acid is mixed in it in the ratio of 1:2. and energy density of coconut shell derivedThe sample is then kept in a rotary kiln at a carbon heated at 1000OC is equivalent to that low internal resistance, which results in hightemperature of 1000OC for 1 hour in the of neem tree leaves derived carbon heated atabsence of air. After 1 hour, sample is then 500OC. From these, it can be concluded that power density. Coconut shell derived carbontaken out and is washed with demineralized functional properties such as specific surface heated at 1000OC has low pulse current as itwater. Another commercially available activated area and porosity of neem tree leaves derivedcarbon i.e., Vulcun XC-72R is used in carbon heated at 500OC for 2 hours sample is has high internal resistance, & hence low powerexperimentation. It is generally obtained by similar to that of coconut shell derived carbon.pyrolysis process in which carbonaceous density compared to other activated carbon. Butmaterial is heated at a very high temperature in Discharge currentabsence of air. Vulcun XC-72R is used along it has almost same capacitance as that of neemwith coconut shell derived carbon and neem A discharge current characteristic of various tree leaves derived carbon heated at 500OC astree leaves derived carbon for trails. The derived activated carbons is shown in Fig. 2. Areaactivated carbon by various methods is used for its discharge current characteristics after firstmaking electrodes of supercapacitor. few seconds almost matches with neem tree For development of prototype, wiremesh leaves derived carbon heated at 500OC.SS316 is used as current collector. Loading onthe wire mesh is done by mixing 20% Vulcun Discharge rate of neem tree leaves derivedXC-72R with 80% derived carbon and a paste carbon heated at 300OC is faster as comparedof two are formed by using iso-propyl alcohol.Then the wire mesh loaded with carbon material to other activated carbon. So, it has less areais sandwich in between three separators. Afterdeveloping the prototype of various activated under curve, which results in lowest capacitance.carbons, they are put in an electrolyte solution.Results Fig. 2: Discharge current characteristics for various carbon derived supercapacitor... Various prototypes of supecapacitor aremade with the activated carbon. Comparison ofactivated carbon derived from neem tree leavesat various temperatures, coconut shell andcommercially available Vulcun XC-72R are40 JULY 2015 ELECTRICAL INDIA



New TechnologyArea based capacitance & power densityFig. 3 shows area based capacitance andpower density of various activated carbons. Asper parameters shown in Table 1, neem treeleaves derived carbon heated at 500OC andcoconut shell derived carbon heated at 1000OChas almost same area based capacitance. Butdue to low pulse current,coconut shell derivedcarbon has high internal resistance, whichresults in poor power density among allactivated carbon. However, dischargecharacteristic of Vulcun XC-72R is above theneem tree leaves derived carbon at 300OC.Therefore, it has high capacitance and powerdensity than neem tree leaves derived carbon Fig. 4: Specific capacitance (F/gm.) and energy density (Wh/gm) for various carbon derivedheated at 300OC. supercapacitors... Pulse current and internal resistance Pulse current and internal resistance of various activated carbons are shown in Fig.5. Internal resistance depend on the electrode and electrolyte materials. On comparing pulse current and internal resistance of various activated carbons, it was found that coconut shell derived carbon has low pulse current and high internal resistance which is undesirable. Vulcun XC-72R has high pulse current and low internal resistance than coconut shell and neem tree leaves derived carbon heated at 300OC.Fig. 3: Area based capacitance (F/cm2) and power density (kW/gm) for various carbon derived Neem tree leaves derived carbon heated atsupercapacitor... 500OC has high pulse current and low internal resistance compared to other activated carbons.Specific capacitance and energy density Fig. 5: Pulse current (mA) & internal resistance (Ω) for various carbon derived supercapacitor... Specific capacitance and energy density ofvarious activated carbons are shown in Fig.4.As per parameter in Table 1,Vulcun XC-72R andneem tree leaves derived carbon heated at300OC has low specific capacitance & energydensity compared to coconut shell derivedcarbon and neem tree leaves derived carbonheated at 500OC. However, coconut shell derived carbonheated at 1000OC has almost same specificcapacitance and energy density as that of neemtree leaves derived carbon heated at 500OC.But the process of synthesizing activatedcarbon from neem tree leaves is much easierthan coconut shell derived carbon. So, it will bepreferred for making electrodes ofsupercapacitor. Thus, in future neem tree leavesderived carbon can be a better option thancoconut shell based carbon.42 JULY 2015 ELECTRICAL INDIA





New TechnologyThe process of obtaining activated carbon from carbon obtained from neem tree leaves involve and energy density can be further increased byneem tree leaves is much easier compared to heating at low temperature, which is cost effective mixing metal oxide in proper proportion alongVulcun XC-72R. Moreover, it can be cost and environmentally friendly.Specific capacitance with the derived activated carbon.effective and enviornmental friendly. So, it willbe the preferred more. Gaurav ShekharConclusion BE (Electrical) University of Pune Activated carbon synthesised from leaves ofneem tree and coconut shell along with Ashutosh Phatakcommercially available activated carbon i.e. ,Vulcun XC-72R is studied for supercapacitor BE (Electrical)applications. On comparing these carbons Mumbai Universitymaterials at various temperatures, it was foundthat neem tree leaves derived carbon heated at Dr PB Karandikar500OC for two hours gives better specificcapacitance, energy density, power density and Associate Professorpulse current as compared to other activated Army Institute of Technology, Punecarbons. However, coconut shell derived carbonheated at 1000OC has almost same energy Prof Swati Shirish Moredensity and capacitance as that of neem treeleaves derived activated carbon heated at Professor and Head of Department - Electrical Engineering500OC. But the process of synthesising carbon Bharati Vidyapeeth Deemed University College of Engineering, Pune.from neem tree leaves is much easier ascompared to coconut derived carbon. ActivatedELECTRICAL INDIA JULY 2015 45

Case StudiesCase Studies Of TheTransformersFailure AnalysesCollection of failure data is the first major task. In free repair service or in repair contract, very little effort ismade by utilities to find out the root cause of failure, which could be one of the reasons why a damagedtransformer is replaced by a new one without removing the cause of damage, leading to failure immediatelyor within a very short period...46 JULY 2015 ELECTRICAL INDIA

Case StudiesIndiaÊs manufacturing sector, heavy Right kind of design, manufacture, test, operation and protection industries, various global service centres increase normal life of a transformer... are all dependent on reliable power supply.This underlines the principle that ÂNo Power- Company details coverings of conductors. The type of coveringNo BusinessÊ. This makes it utmost important The projects has been done at Royal depends upon the type of use and basicthat ÂTransformersÊ, the heart of substation, insulation of the transformer. It is very commonmust function reliably. Failures of critical Electricals Pvt. Ltd. plot no 1405, phase 5, to see a conductor with lost wrapping. Also, thetransformer-assets not only impact industries GIDC Estate,Vithal Udhyognagar 388121, Dist. conductors have single covering instead ofbut other consumer categories also affect the Anand, Under the IDP Scheme Gujarat double covering. The quality of paper is alsoeconomy of the country and have social and Technological University. one of the causes of failure.political ramifications. Classification of failures of a The workmen should be properly trained for WeÊll study the transformers, which come transformer proper insulation of winding and identity badfor repairs after failure in the industry and material of insulation during the process ofanalyse the various causes of failure of power For the purpose of discussion, we have coil making.transformer and distribution transformer in divided faults into three classes:detail. By knowing the causes of failure, we can Failure attributed by users Fig. 1: Winding insulating process...take steps to overcome it and thus reduce the • Prolonged over loading Improper joints or connectionsfault occurrence in transformers and make the • Single phase loadingpower supply more reliable. • Un-balanced loading The local heating generated by improper • Faulty terminations joints or connections may slowly lead to a A transformer is a vital equipment that • Power theft by hooking deterioration of the oil if the joints are oilconnects the generation to various types of • Faulty earth connection to tank body as well immersed. The oil temperature indicator and/orloads. The right kind of design, manufacture, winding temperature indicator (both with alarmtest, operation and protection increase normal as LV terminal contacts) can be used to insulate suchlife of transformer. • Failures due to external short-circuit problems. Gas operated relay, can also be used • Less maintenance to sound an alarm and actuate the trip circuit All power utilities are much worried these • Improper installation if the condition calls for it.days due to high rate of failure of distribution Failure causes at the manufacturerÊs end Case study: (improper joints or connections)transformers and service. The failure rate of • Faulty designtransformers in India is in the order of 12 to15% • Poor quality of material 11kV/415V, distribution transformer: inas against less than 1% in developed countries. • Bad workmanship distribution transformer, the linemen sometimesNo one wants to share responsibility of failure. • Improper transportation make improper terminal connection. This resultsManufacturers often blame the users for • Sharp edges of conductor in to overheating of transformer near the joints,running the transformers in overload for single • Incomplete drying resulting in to failure.phasing or unbalancing. Users are of the • Bad insulation covering on conductoropinion that the cause of failure is due to faulty • Improper joints or connectiondesign or bad materials or poor workmanship. Failure during working conditionBut the fact is responsibility should be shared • Deterioration of oilequally by both. • Faults in magnetic circuit • Inadequate pre shrinkage of the winding The manufacturer should accept the • Inter turn faultsfeedback from the utilities without any prejudice Major failures in power transformers • Oil leakage and take remedial measures, while the users, • Deterioration of oilon their part, should ensure that the equipment • Ventilation failureis not abused, and correct feedback on the • Loose clampingproductÊs performance is passed to the • Bushing flashovermanufacturer. • Fault in OLTC • Inter-turn fault Collection of failure data is the first majortask. In free repair service or in repair contract, Case studies Fig. 2: Improper joint...very little effort is made by utilities to find outthe root cause of failure, which could be one of Failure due to bad insulation of conductorthe reasons why a damaged transformer is Various types of insulation are used asreplaced by a new one without removing thecause of damage, leading to failure immediatelyor within a very short period.ELECTRICAL INDIA JULY 2015 47

Case StudiesDeterioration of the insulating oil Case study : (Deterioration of the insulating Case study: (Fault in magnetic circuit) The insulating oil deteriorates gradually with oil) Rating: 11kV/440V, 30 KVA Cause of failureuse. The main cause is the absorption of the Moisture content in the oil increases, andmoisture in the oil. Each time the moisture is when the transformer is energized, water begins Insulation between lamination got damaged,doubled in a transformer, the life of the insulation to migrate to the coolest part of the transformer which resulted into local overheating and due tois cut by one-half. Failures due to moisture are and the site of the greatest electrical stress. which many laminations got short circuited.the most common causes of transformer failures. This location is normally the insulation in the Thus, winding temperature got increases andReasons for moisture influx lower one-third of the winding. Paper insulation its insulation failed.• Moisture can be in the insulation when it is has a much greater affinity for water than does the oil. The water will distribute itself unequally, Fig. 5: Core insulation failure... delivered from the factory. If the transformer with much more water being in the paper than Inadequate pre shrinkage of the winding is opened for inspection, the insulation can in the oil. The paper will partially dry the oil by absorb moisture from the atmosphere absorbing water out of the oil. Temperature is Insulating paper blocks used for horizontal• If there is a leak, moisture can enter in the also a big factor in how the water distributes and vertical supports of coil are bound to shrink form of water or humidity in air. Small oil itself between the oil and paper. during service due to generation of heat. This leaks, especially in the oil cooling piping, shrinkage is more in case of disk coil. Shrinkage will also allow moisture ingress There is almost twice the moisture near may cause looseness in coil assembly, which• Moisture is also formed by the degradation bottom as there is at the top.So, this transformer may result in failure due to short circuit forces. of insulation as the transformer ages failed in the lower one-third of the windings due• Most water penetration is flow of wet air to paper insulation breakdown. To overcome such failure, it is recommended through poor gasket seals due to pressure that good quality of insulating bolt must be difference caused by transformer cooling. Fig. 3: Failure due to moisture content in oil... used. After heating coils to the required level, The most common moisture ingress points Case study : (Inter turn fault) coils are compressed judiciously by a skilled are gaskets between bushing bottoms and workman till it reaches the required shrunk the transformer top and the pressure relief 50 KVA, 11kV/440 V height. device gasket Cause of failure Case study :( Inadequate pre shrinkage of the• If in breather the moist silica is not replaced winding) by dry silica gel. Then moisture can enter Failure of transformer took place due to from atmosphere. shorting of few turns of winding of the same Rating:11KV/440V,40 KVAEffect of moisture phase. This was due to overloading of Cause of failure Paper insulation has a much greater affinity transformer, which results into insulation failurefor water than does the oil. The water will due to overheating. As shown in the figurer (below), due todistribute itself unequally, with much more water shrinkage of paper blocks, the coil got loose.being in the paper than in the oil. The paper will Fig. 4: Interturn faults... During external short circuit fault, failure of thepartially dry the oil by absorbing water out of the transformer occurred due to movement of discs.oil. Moisture and oxygen cause the paperinsulation to decay much faster than normal. Fig.6: Failure due to paper block shrinkage... Due to moisture oxidation takes place.Oxidation results in the formation of acids in theinsulating oil, which in turn, contributes to theformation of sludge. The rate of oxidation also depends on thetemperature of the oil; the higher thetemperature, faster is the oxidative breakdown.Sludge settles on windings and inside thestructure, causing transformer cooling to beless efficient, and slowly over time temperaturerises. Acids cause an increase in the rate ofdecay, which forms more acid, sludge, andmoisture at a faster rate. This is a vicious cycleof increasing speed forming more acid andcausing more decay.48 JULY 2015 ELECTRICAL INDIA



Case StudiesOil leakage aged, lost elasticity and cracked as it cooled (There is no need to take any cautionary steps Oil in addition to serving as insulating much further than its normal operating range. in the case of nonflammable oil). This is often a slow weeping rather than ameans serves to transfer the heat generated in catastrophic failure; however, over a time, the Conclusionthe windings and the core toward the walls of weeping can cause a serious amount of oil loss.the tank and the radiators. Due to this it has: From case studies of Royal Transformers• High dielectric breakdown It is better to use the gasket without a joint, Pvt. Ltd. on transformers, we conclude that• Low viscosity but it is not possible as the gasket is too large. major failures that occur are mainly on There are round, square, rectangular and oval- distribution transformer of rating 11kV/433V. If the oil leaks from the transformer tank shaped gaskets, but in any case try to join the The major causes of failure on this range ofdue to some reason, the oil level in the tank will gaskets by using a flat portion of the gasket. If transformers are unbalanced loading, singledrop. In the worst case, the connections to this is not done, then there are more chances of phasing, overloading and some user attributedbushings and parts of the winding will get gasket failure. If the element (or a component to reasons. The major failures on powerexposed to air.This will increase the temperature seal that) adopted for the gasket, is not of thin transformers are due to insulation damage,of the windings. This in turn, would damage the layer or not dried with air than the oil can leak deterioration of oil, leakage of oil and also dueinsulation of the winding. Apart from this through the gasket. to bushing failures.moisture can get in through the leak, anddegrade the transformer oil leading to an Many times even after correct adjustment, Manish N Sinhaoverheated transformer. the gasket oil leak is not stopped, then the Assistant Professor, EE Dept. gasket will have to be replaced with a new one. BVM Engineering College In power transformer, the conservator tank A gasket with low elasticity such as lead typeis provided with an oil level indicator having an must always be changed with a new. Do not use Palak Patelalarm facility. If the oil level drops below a the old one again. BE (Electrical), Final Year Studentpredetermined level, the alarm will ring. It allows EE Dept., BVM Engineering Collegethe operator to initiate necessary actions. Fig. 8: Gaskets... Oil leakage from radiator Parth Shah But in distribution transformer, oil level BE (Electrical) Final Year Studentindicator with alarm facility is not provided. Only Radiator fins are a common area for oil EE Dept., BVM Engineering Collegea small transparent window (gauge) placed leaks. Fins are made from thin metal to aid heatconservator tank to see the oil level is provided. transfer. The downside of that thinness is thatIt shows the level of the oil directly, being able internal corrosion due to water ingress andto see from the outside. When the crystal is separation or external environmental corrosiondirty, you can wipe it off with a rag. Periodic can quickly penetrate and spill the oil.checking of this window is not done in India. So,many of small transformers fail due to decrease This leakage must be repaired by welding,in oil level. to make sure that the heat from the welding is not going to produce an explosive gas mixture.Fig. 7: Oil level window... Maulik Doshi BE (Electrical) Final Year StudentCauses of oil leakage EE Dept., BVM Engineering College Oil leaks can occur from many parts of Nishith Bhalodiyatransformer tank: BE (Electrical) Final Year Student Radiator fins, Bad welds, Cracked voltage EE Dept., BVM Engineering Collegebushings, Gaskets, Butterfly valves controlling Fig. 9: Oil leakage from radiator...the flow of oil between the radiator and mainoil tank.Oil leaks in gaskets Oil leaks from transformer gasket, if it has50 JULY 2015 ELECTRICAL INDIA