Frequent Changes in the guidelines, specifications w.r.t mandatory certification of Distribution Transformers By Mayur Karmarkar in IEEMA Journal May 2019
The total installed power generation in India a reported by IEEMA around 375 GW as on 31.10.2020, Out of which the total installed renewable energy capacity stood at GW of which contributed 36 GW an 38 GW, The Goverment of India has an vary ambitious plan al generating solar energy of 114 GW by 2022, So lot of solar inter transformers and medium and large power transformers are added in the power system. reported that quite a Woocant numbers of these transformers have problems in the systems due to variou jessons descibed in the following causes.
Causes for failure of transformers
- Faulty design-Improper understanding of system operating conditions
- Use of poor quality of materials
- Improper manufacturing and testing processes
- Improper commissioning and inadequate maintenance
- Inadequate / Improper protection
- Frequent short circuits (Earth Faults) and over voltages coming on the transformers due to system disturbances and operating conditions
- Magnetic inrush due to frequent switching on and switching off
Improper understanding of system operating conditions
Since these transformers are getting loaded for about 6-9 hours in a day (may be 8 AM to 5 PM), there is a tendency to under estimate the operating conditions and choose design parameters in such a way that the design becomes more competitive to meet the competitive price demand. This results in over heating of windings, development of hot spots in windings and generation of gases resulting in tipping of transformers under OTI/WTI operation