A PWM Scheme for a Fault-Tolerant Three-Level Quasi-Switched Boost T-Type Inverter

In this paper, a new optimal pulsewidth modulation (PWM) scheme for a three-level quasi-switched boost T-type inverter (TL qSBT(2)I) under normal and failure modes is proposed. The proposed method reveals its semiconductor fault tolerance capability in open-circuit fault condition situations as described in this paper. The PWM control algorithm for the fault-tolerant qSBT(2)I is implemented by selecting appropriate values for the modulation index, shoot-through (ST) duty cycle, and duty cycles of two additional switches. The steady-state analysis and operating principles of the fault-tolerant qSBT(2)I are presented. A laboratory prototype was built to verify the operating principles of the qSBT(2)I with the proposed modulation scheme before and after fault conditions.