Policy Paper on Refurbishment of Distribution Transformer (DT)
Executive Summary
Distribution Transformer (DT) play a vital role in the power distribution network of the DISCOMs. For overall DISCOM viability, it is imperative that each DT turn into a profit center. It is estimated that out of 21.73% national average AT&C losses in FY 2020, about 5.16% is contributed by Technical losses in DTs, and it can be brought down to 4.20% and below. Under prevailing operational practices of public DISCOMs, the DT’s technical losses are not generally measured unless it fails and further, there is no pro-active asset management approach towards DT’s repair and O&M practices.
The key operational issues that the DISCOMs experience with respect the DT asset management are
- Deviation in technical losses in operating legacy DTs and repaired DTs reinstated into system
- Premature failure of new and repaired DTs
To address the above dual issues (i.e., technical loss deviation and premature failure) in DT asset management, ICA India has carried out pilots on refurbishment of DT in three key utilities (i.e. Madhya Pradesh Poorv Kshetra Vidyut Vitran Company Limited (MPPKVVCL), Maharashtra State Electricity Distribution Company (MSEDCL), Tamil Nadu Generation and Distribution Corporation Limited (TANGEDCO)) in India. It is recognized that, Refurbishment of DTs resulted in helping utilities to address the deviation in technical losses from the rated specifications. DT refurbishment fundamentally involves augmentation or replacement of the active materials in a DT i.e., Core and Winding, depending on the condition, and design of the DT.
The pilot studies conducted in the utilities demonstrated that, the energy performance of DT after refurbishment is equivalent to the newly procured Cu DT at about 50% of cost, and its giving extended life to DT equivalent to that of a new transformer.