Fault tolerance in active power filters, based on multilevel NPC topology

The use of neutral-point-clamped (NPC) converters in high power systems brings many advantages when compared with traditional ones, and its application in active power filters is no exception. However, since it is needed a greater number of switching devices, the probability of a failure in these devices is higher and must be therefore to be taken into account. Then, in this paper is proposed a method of fault detection and fault tolerance operation in shunt active power filters, based on three-level NPC topology. The effectiveness of these techniques is demonstrated by simulation results.