Fault diagnosis and failure prediction of aluminum electrolytic capacitors in power electronic converters

This paper gives the equivalent circuit model of aluminum electrolytic capacitor, and analyzes the main degradation mechanism, based on which the life model and degradation parameter of aluminum electrolytic capacitor is discussed in detail. To realize online fault diagnosis of aluminum electrolytic capacitor in power electronic converters, a parameter identification method to identify the equivalent series resistance (ESR) based on the circuit model is presented, and the trend of ESR with time is also deduced to realize failure prediction.