Health Index Assessment of 500 kV Auto-Transformer, CT & C.B Sardar Garh Grid Station, Rahim Yar Khan for Preventive Maintenance

The high voltage equipments like power transformers, circuit breakers and current transformers are the major components of a power system. The reliability of power systems depends on the health index. The health of these equipments is influenced by a number of factors including mechanical, chemical and electrical stresses. In this paper health index of the above mentioned equipments has been calculated and the remaining life estimation has been evaluated through compound method strategy. Insulation resistance (IR) and capacitance & dissipation factor (C&DF) tests have been performed on real-time power transformer and CT using IR tester (MIT515) and C&DF test set (DELTA4000). Contacts timing and contact resistance tests have been performed on circuit breaker using contact resistance tester (MOM200A) and circuit breaker analyzer (TM1700). It has been investigated that the equipments were in good health and only required normal maintenance.