Condition Monitoring of Electrolytic Capacitors for Power Electronics Applications
Imam, Afroz M.
MetadataShow full item record
The objective of this research is to advance the field of condition monitoring of electrolytic capacitors used in power electronics circuits. The construction process of an electrolytic capacitor is presented. Descriptions of various kinds of faults that can occur in an electrolytic capacitor are discussed. The methods available to detect electrolytic capacitor faults are discussed. The effects of the capacitor faults on the capacitor voltage and current waveforms are investigated through experiments. It is also experimentally demonstrated that faults in the capacitor can be detected by monitoring the capacitor voltage and current. Various ESR estimation based detection techniques available to detect capacitor failures in power electronics circuits are reviewed. Three algorithms are proposed to track and detect capacitor failures: an FFT based algorithm, a system modeling based detection scheme, and finally a parameter estimation based algorithm. The parameter estimation based algorithm is a low-cost real-time scheme, and it is inexpensive to implement. Finally, a detailed study is carried out to understand the failure mechanism of an electrolytic capacitor due to inrush current.