Research on Flux Weakening Control of Single Q-axis Current Regulator Scheme for Long Stator Permanent Magnet Linear Synchronous Motor

The long stator permanent magnet linear synchronous motor (LS-PMLSM) used for the maglev vehicle needs to adopt flux weakening (FW) control to increase its speed due to the limitation of the traction inverter output voltage. In this paper, it is proved that the speed of LS-PMLSM with the feeder cable can be increased by FW control, and an FW control scheme based on the single q-axis current regulator (SQCR) is proposed. Compared with the conventional FW control, the proposed SQCR-FW control scheme can eliminate the coupling between the two current regulators. The hardware-in-the-loop (HIL) experiment shows that LS-PMLSM can achieve the highest target speed and complete the full speed operation. It can reduce current and traction fluctuation and the actual speed of the motor can follow the reference speed curve better when compared with the double current regulator (DCR) method.