Leg-Shared Fault Tolerant Predictive Control of PMSM Drive Systems Fed by Three-Level Back-To-Back Converters

Abstract

Reliability is one of the most important characteristics of motor drive system, especially after power semiconductor device open-circuit fault occurs. Effective fault tolerant control methods are considered crucial to increase their reliability and availability levels. In this manuscript, a leg-shared fault tolerant control strategy within the model predictive control framework is proposed. In the fault tolerant topology, three TRAICs (TRIod AC switches) are adopted to connect three legs on the machine-side with one shared-leg on the grid-side. This topology makes full use of the feature that both sides of back-To-back converter are active legs, and has little adverse effect on DC-link capacitor voltage. Meanwhile, in order to not increase the complexity of fault-Tolerant control algorithm, more flexible model predictive control (MPC) method is adopted and the calculation efficiency is improved. Simulation results validate the feasibility and effectiveness of the proposed leg-shared fault tolerant control methods.