Real-Time Condition Monitoring of the Electrolytic Capacitors for Power Electronics Applications

The objective of this paper is to propose a new low cost method to detect the changes in equivalent series resistor (ESR) and the capacitance value of an electrolytic capacitor in order to realize the real-time condition monitoring of an electrolytic capacitor. Experimental and simulation results are discussed to illustrate the proposed condition monitoring technique. In addition, it is shown that the proposed method can be used for a non-stationary system where waveforms are continuously varying in amplitude, frequency, and phase. The proposed on-line failure prediction method has the merits of low cost and circuit simplicity.