An Improved Fault-Tolerant Control for PMSM with Current Sensor Fault

At least two current sensors are required to realize high-performance closed-loop control of permanent magnet synchronous motor (PMSM), but current sensors may fail due to harsh operating environments. The existing active fault-tolerant control (FTC) for PMSM with current sensor fault has problems such as difficulty in tuning control parameters and poor robustness. This paper proposes a novel FTC combining with a fault diagnosis strategy. First, three-phase estimated currents are obtained based on the current prediction model. The feedback currents of the faulty phases are estimated currents, while the healthy phase is measured current. Moreover, a faulty phases reference current correction method is proposed to suppress the influence of motor parameter variations on the control performance. It is easy to tune the design parameters of the proposed FTC and its effectiveness is verified by experiment.