Analysis on Reason of Generator Set Complete Power Outage of a Hydropower Plant

Abstract

There was a single-phase high resistance grounding fault on the outgoing line of a 110kV hydropower plant. As a result of the mismatch of protection setting values, misoperations happened outside of the main transformer protection area, which caused generator set complete power outage. This paper used RTDS to carry out simulation analysis on this fault, restored the development process of the fault and figured out the fault reason. Meanwhile, through the investigation and analysis on the configuration status of the main transformer backup protection from high voltage side and the neighborhood transformer protection of 110kV hydropower plants throughout the whole province, we concluded the irrationality of the protection configuration and proposed the solutions to it.