Design of a Three Phase Fault Tolerant Nested Neutral Point Piloted Converter with Active Capacitor Voltage Balancing and Space-Vector Modulation

Abstract

This paper presents a design for a nested neutral point piloted(NNPP) converter. The proposed design incorporates redundantcontrol of each power stage and additional sensing and controlcircuitry required to implement a fault tolerant operation.Additionally, an active capacitor voltage balancing technique isproposed and implemented to enhance the converter's volumetricdensity and improve the output harmonics by mitigating capacitorvoltage imbalance. Simulation results validate the effectiveness ofthe proposed design. Hardware prototype is designed and iscurrently being assembled.