Current Sensor Fault Tolerant Control for Encoderless IPMSM Drives Based on Current Space Vector Error Reconstruction

Position and current sensors are required in conventional field-oriented control in permanent magnet synchronous motor (PMSM) drives. However, the current sensors subject to various faults, which decreases the reliability. To solve this problem, a single-phase-current sensor encoderless control scheme using a sliding-mode observer (SMO) for fault diagnosis and fault-tolerant control of PMSM drives is proposed in this article. The reconstruction of the faulted phase current is completed through SMO by using the current space vector error projection as the correction term. Then, the equivalent circuit of extended back electromagnetic force estimation is established, and the effect of parameter variations is analyzed based on the vector diagram. The position deviation effect on the current error reconstruction is evaluated. Finally, the effectiveness of the single-phase-current sensor encoderless control is verified by the experiments on a 1.0-kW PMSM drive platform.