Fault tolerant multilevel current source inverter

Abstract

This paper explores the issue of constructing a multilevel current source converter (MCSI) topology with fault tolerant capabilities. A novel modular single rating inductor MCSI topology is analyzed. The MCSI proposed is made by identical modules where all inductors carry the same amount of current. The current balance is achieved by a Phase-Shifted Carrier SPWM proper implementation. A new state machine approach, easy to implement on a FPGA, allows minimizing switching frequency by taking advantage of the three different zero-states of the topology. A protection circuit is proposed to avoid over voltages in case of a failure. The performance of a seven level, four modules, fault tolerant arrangement is analyzed and is thoroughly simulated with Matlab Simulink.