On-line fault monitoring system for hydroelectric generators based on spectrum analysis of the neutral current

An on-line fault monitoring diagnostic system for hydroelectric generators based on spectrum analysis of neutral current is presented. Hydroelectric generators are fundamental elements in the power train at hydroelectric power plants and require an adequate diagnostic analysis. Unexpected generator failures can lead to a significant financial effect owing to the elevated costs of emergency repairs and lost revenues caused by forced outage extended periods. Determining the actual operating conditions of a generator is a crucial phase in assessing the risk of failures. The on-line instrumentation fault monitoring diagnostic system uses a simplified electrical model of fault simulation in order to help interpret the harmonic sources in the neutral current. Field measurement results proved that the spectrum analysis model for detecting mechanical faults is effective.