Fault-Tolerant Direct Torque Control of Five-Phase Permanent Magnet Synchronous Motor under Single Open-Phase Fault Based on Virtual Vectors

Abstract

In the existing literature, direct torque control (DTC) by synthesizing virtual vectors can effectively suppress low-order harmonic currents under the single open-phase fault (OPF) of the five-phase permanent magnet synchronous motor (PMSM), but the sectors and the look-up tables need to be redesigned, which makes the control process more complicated. In order to solve this problem, an indirect correction method of virtual vectors is proposed, and the amplitudes of the virtual vectors are maximized. The fault-tolerant DTC strategy under the OPF ensures that there is no need to re-divide the sectors under the fault. And the selection rules of the look-up tables are consistent with the healthy operation. The difference is that the amplitudes of ten virtual vectors in the faulty operation are reduced, which simplifies the control process and is easy to implement. Finally, the correctness and effectiveness of the proposed control strategy were verified by experiments.

Keywords

• five-phase permanent magnet synchronous motor
• virtual voltage vectors
• direct torque control
• single open-phase fault
• harmonic currents