PUBLICATIONS

A diagnostic method for an open-circuit switch failure in a hybrid active neutral-point clamped (HANPC) inverter is proposed in this

paper. The switching leg of the HANPC inverter consists of four silicon insulated gate bipolar transistors and two silicon carbide

metal-oxide-semiconductor field-effect transistors to achieve higher efficiency and power density compared to conventional neutral-

point clamped inverters. When an open-circuit failure occurs in a switching device, the output current is severely distorted, causing

damage to the inverter and the connected loads. The proposed diagnostic method aims to detect the open-switch failure and protect

the related devices without additional sensors or circuits. The faulty conditions of six different switches are investigated based on the

current distortion in the stationary reference frame. By analyzing the individual characteristic of each switch failure, it is possible to

detect the exact location of the failed switch in a short period. The effectiveness and feasibility of the proposed fault-diagnostic

method are verified using simulation and experimental results.