A NOVEL FAULT TOLERANT TOPOLOGY OF ACTIVE NEUTRAL POINT CLAMPED INVERTER
Manmeet Bhatia, Reshmita Sharma, Rahul Pandey
Multilevel Inverter, Active Neutral Point Clamped, Fault Tolerant.
Amongst all power electronic devices, semiconductor switches are most vulnerable to failure. On the other hand, MLIs incorporate a high device count which combined with their vulnerability characteristic lead to a high probability of failure leading to mal-operation of MLI. There are two types of fault mainly occurring in semiconductor switches, open circuit failure and short circuit failure. A short circuit failure results in shoot through condition through DC voltage source or capacitor, which causes a huge surge current to flow through the remaining healthy part of the inverter, thereby decreasing the reliability of the inverter. This condition can be avoided by connecting the fuses to the legs of the inverter, which results in converting a short circuit failure into an open circuit fault. Therefore, it is necessary to bypass faulty switch in power semiconductor switches to preserve the health of the inverter and avoid total system shutdown. Thus, only the open circuit fault tolerant operation has been studied in the entire length of the paper of the proposed topology. A unique position of redundant switches helps to achieve the fault tolerant operation for the proposed topology.