Failure gas generation within the oil-paper insulation system of shunt reactor

Power transformers and shunt reactors play an important role in electric power transmission and distribution. They are very expensive capital investments. For these reasons it is necessary to maintain safe, reliable and uninterrupted operation of transformers and shunt reactors. Interaction of operating conditions and degradation factors with key subsystems of transformers/shunt reactors can cause excessive degradation and has a significant impact on their overall lifespan. Factors such as increased loading, temperature and moisture can lead to failure, end their serviceability and can create serious problems. There is a tendency to predict failures, prevent their inception and discover them in time. Routine diagnostics, monitoring systems, and protective and safety devices all contribute to the reliable and safe operation of electrical equipments. Article deals with the gas generation within the paper-oil insulation system during the aging and failures. Production of different gases is typical for particular failures. Furthermore, there is presented post mortem analysis of a shunt reactor failure accompanied by a rapid accumulation of combustible gas. Moreover there is shown the gas generation monitored by several sensors during the failure. Shunt reactor was switched off by dispatch control engineer because of well-timed Buchholz relay tripping.