Fault-tolerant modulation strategy for inverter stage of full bidirectional switches two stage matrix converter

Full bidirectional switches two stage matrix converter (FBS-TSMC), which can be effectively used in critical applications, is presented. Comparing with traditional two stage matrix converter, it adds six additional switches to inverter stage as redundancy hot backup. Meanwhile, its bidirectional switches structure in inverter stage makes it possible to reverse dc bus voltage polarity. The above two features provide FBS-TSMC fault-tolerant capacity in the presence of faults. From the view of modulation, this paper proposes two fault-tolerant strategies for FBS-TSMC to deal with single switch short circuit failure and bidirectional switch open circuit failure in inverter stage respectively. By utilizing the characteristics of fault switch and increasing additional switch times in healthy phases, the proposed fault-tolerant strategies can ensure FBS-TSMC's satisfactory performance without modifying the control technique. A simulation model of FBS-TSMC has been built in Matlab/Simulink and the verification of the proposed fault-tolerant modulation strategy is confirmed using extensive simulation results.