PUBLICATIONS

DC-link capacitor loss with fault-tolerance control in three-level hybrid active neutral point clamped (ANPC) inverters was analyzed in this paper. The three-level hybrid ANPC inverter consisted of 18 switch devices such as silicon insulated-gate bipolar transistors and silicon carbide metal–oxide–semiconductor field effect transistors. The numerous switch devices increased the percentage of switch failures. Switch failure distorted the output current and led to the loss of the DC-link capacitor. The loss is related to the shortened lifetime of the DC-link capacitor. To improve system performance and reliability, fault-tolerance control has been studied. However, fault-tolerance control leads to greater loss of DC-link capacitors because of the high voltage ripples, and secondary system failures can occur. In this paper, DC-link capacitor losses are analyzed with fault-tolerance control in a hybrid ANPC inverter and the expected lifetime of DC-link capacitor was determined according to the fault-tolerance conditions. The validity of the analysis was demonstrated by simulation and experimental results.