Evaluating the energy capabilities of transformers

An industry analysis on how to leverage the energy capabilities of distribution transformers in a distribution network.

Power distribution is considered to be one of the most important segments of the Indian power industry. However, high distribution losses, theft of electricity, and poor financial health of utilities have posed big challenges to the sector in recent times. Here, industry experts share their opinions and suggestions on how to achieve potential energy saving of distribution transformers in distribution network.

Achieving energy saving distribution transformers
Distribution transformers (DT) are key assets for any distribution network. Hence, their reliability and efficiency are necessary to reap long-term benefits for the power distribution utilities.

Anil Kadam, General Manager, Business Development, Solution Architect- Smart Grid/Smart Cities, Schneider Electric India, says, “Power distribution serves a great significance as this segment has a direct impact on the sector’s commercial viability, and ultimately on the consumers who pay for power services.”

“While the digital transformation of the energy sector is rapidly gaining traction on a global scale, new opportunities are emerging to help deliver efficient, affordable and reliable electricity to consumers,” he adds.

According to Kadam, digital transformation of grids allows users to take a holistic approach to achieve efficiency, flexibility, transparency and long-term sustainability. “Smart grids create the potential to combat the challenges faced by the power sector, and provide the opportunity for the region to develop its energy capabilities. The smart grid, connected through IoT, facilitates continuous and real-time monitoring of distribution and transmission assets. DTs are vital components in the electrical value chain,” he adds.

Speaking on potential energy savings of DT, Manas Kundu – Director, Energy Solutions, International Copper Association India, suggests that it can be achieved by following National Standard IS 1180 and implementing BEE Star labelling programme as recommended by CEA guidelines for minimum efficiency performance standard observation during new asset procurement.

“As for legacy assets or DTs existing in distribution network, one need to carry proper data analytics to assess the loss levels of the transformers and then take a call for highly deviated DTs to undergo active repair, a concept successfully piloted at Maharashtra and Madhya Pradesh,” he adds. “Active repairing using copper helps improving not only efficiency, but also reliability and safety aspects in distribution system.”

Sanjib Mitra, Country Head & Sr VP – Transformer Division, Electrotherm India, elaborates that transformer losses are generated due to magnetic core inside it and copper conductor resistance in the current flow circuit. Out of these two losses, magnetic circuit loss is less in percentage (approx. 4 to 6 per cent of total loss). However, it remains constant throughout the operation. The resistive circuit loss, on the other hand, increases with increased load and thus varies with loading pattern.

“Typically, DTs were earlier not given much focus by Government of India due to which losses were nearly four per cent. Thanks to BIS, the DTs (up to 2.5 MVA) are now produced with losses less than 0.5 per cent. This has gradually lessened the distribution network loss to a great extent and has helped reduce electricity bills of each customer,” Mitra adds.

Govt programmes to strengthen DTs
As per the Indian Constitution, power is crucial and the responsibility for distribution and supply of power to rural and urban consumers rests with the government. The Government of India provides assistance to states through several central sectors or centrally sponsored schemes for improving the distribution sector.

Anil Kadam states that the government’s Integrated Power Development Scheme (IPDS), which aims at strengthening the sub-transmission and distribution networks in the urban areas, has helped improving the distribution sector. “Government initiatives has propelled the demand for DTs over the years and this is expected to grow further, with the increase in generation capacity of both conventional and non-renewable sources, resulting from the increase in per capita consumption of electricity and new entrants such as electric vehicle charging stations,” says Kadam.

Referring to the Deendayal Upadhyaya Gram Jyoti Yojana (DDUGJY), he says that the scheme also proposes to strengthen the transmission and distribution (T&D) networks in the rural areas to encourage operational and financial turnaround of state-owned power distribution companies (DISCOMs), with an aim to reduce Aggregate Technical & Commercial (AT&C) losses. However, Manas Kundu says that IPDS is another initiative, apart from DDUGJY, that has helped the T&D sector in India.

“Ujwal Discom Assurance Yojana (UDAY) is another flagship scheme that not only addresses turnaround of DISCOMs, but also target reduction of AT&C losses to 15 per cent by 2018-19,” Kundu says, adding that stated objectives are mostly not reached by most of the states, citing recent reports. “24×7 Power For All (PFA) by 2019 – uninterrupted power supply 24×7 is another scheme for comprehensive overall development of power sector including reforms at all-India level,” he adds.

According to Sanjib Mitra, BIS level 1 was the first initiative by Energy Bureau in 2012 – 13, thereafter IS 1180 was amended in 2014 for further efficiency improvement. Further loss reduction programmes were scheduled with help of IEEMA in issuing Level 1, Level 2 and Level 3 in successive years since 2015 onwards.

“The certification of energy efficiency transformers by BIS has also been a great initiative in terms of collecting data across country and publishing online about manufacturer’s database regarding their stage of progress in achieving various certifications from NABL accredited lab,” concludes Mitra.

Active repairing using copper helps improving efficiency, reliability and safety aspects in distribution system
Manas Kundu – Director, Energy Solutions, International Copper Association India

Thanks to BIS, the distribution transformers are now produced with losses less than 0.5 per cent
Sanjib Mitra, Country Head & Sr VP – Transformer Division, Electrotherm India

Distribution transformers are vital components in the electrical value chain
Anil Kadam, General Manager, Business Development | Solution Architect- Smart Grid/Smart Cities, Schneider Electric India