An Improved T-Type Multiphase Fault Tolerant Inverter With Preserved Rated Output

Abstract

A solution to provide fault-tolerance features and reliability enhancement to the multilevel inverters for remote and emergency load applications is proposed in this work. The proposed configuration can tolerate single and multiswitch faults and provides capacitor balancing features without using any voltage sensor circuitry. The converter proposed is derived by introducing a redundant unit with a resistor-switch circuit to the basic T-type three-level inverter, adding the multiphase fault-tolerant feature and improving the converter's reliability. This work uses level-shifted pulse width modulation, which is implemented in FPGA in driving the hardware prototype. The experimental results of the converter in healthy and different switch fault cases are presented and discussed in detail to validate the converter's fault-tolerant ability. Further, reliability analysis, efficiency analysis, and comprehensive comparison with state-of-art converters are presented to emphasize converter merits in remote and emergency load applications.