A fault-tolerant inverter with auxiliary switch and its control method

As multi-level inverters are widely used in high-power applications, the fault-tolerant control of multi-level inverters is also paid more and more attention, because it is very important to ensure the stability and reliability of the system. In this paper, a fault-tolerant inverter with auxiliary switch (FIAS) and its control method are put forward. In order to reduce the damage of Insulated Gate Bipolar Transistor (IGBT) failure of cascaded H-bridge (CHB) inverter, added fault isolation switches and relays on five-level CHB. Using the above switches can complete fault isolation and health bridge reconfiguration after the system receives the fault signal, so that the CHB will keep fault tolerant operation with voltage peak. The effectiveness of proposed method is verified by simulation and experiment of five-level CHB.