Fault-Tolerant Control Strategy of Dual Three-Level Inverter based on Vector Clamped PWM

Abstract

Aiming at solving the switch open-circuit fault of the dual three-level inverter for open-end winding induction motor (OEW-IM), a fault-tolerant control strategy based on vector clamped PWM (VCPWM) is proposed. When the fault is detected, the topology is reconstructed and the phase where the faulty switch is located is clamped to the ‘o’ level. Meanwhile, combined with VCPWM, one inverter is in the clamped state, while the other inverter performs vector synthesis, so that system switching losses can be reduced. In addition, the method proposed in this paper can achieve the neutral point voltage (NPV) balance in the fault-tolerant process. Simulation results show that the proposed fault-tolerant control strategy can realize the tolerance of the switch open-circuit fault of the dual three-level inverter for OEW-IM.