This paper analyzes the influence of a DC-link capacitor under open-switch failures in hybrid active neutral point clamped (ANPC) inverters that consist of Si-IGBTs and SiC-MOSFETs. Open-switch failures cause the current harmonic distortion of DC-link capacitors. This distorted current affects the capacitor loss increase, which in turn affects the lifetime decrement of the DC-link capacitor. These influences of open-switch failures on inverter operation have not been discussed despite the fact that they lead to secondary failures of the system. In this paper, the influence of open-switch failure is analyzed based on the current harmonics of the DC-link capacitor, which experiences the highest failure rate. Simulation and experimental results demonstrate the effects of various open-switch failure scenarios on DC-link capacitors in terms of current harmonics and lifetime.
This work was supported in part by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. 2020R1G1A110040611) and in part by the Korea Institute of Energy Technology Evaluation and Planning (KETEP) and the Ministry of Trade, Industry & Energy (MOTIE) of the Republic of Korea (No. 20206910100160)
