An Improved Control Strategy for the Ultra-high-speed Permanent Magnet Synchronous Motor Based on the Current Source Inverter

In order to solve the problems of high order of control objects and difficulty in current regulator design in traditional current source inverter (CSI) ultra-high-speed motor drive systems, an improved control strategy based on hybrid two-stage CSI was proposed. The basic idea is: the wide band gap (WBG) devices are used to adjust the amplitude of stator current with high frequency in the front stage. The ordinary silicon devices are used to adjust the current phase in the rear stage. On this basis, in order to achieve the maximum torque-to-current ratio control, a single current sensor phase-locked loop (PLL) scheme was proposed, which realized automatic current phase correction by phase-locking the rotor position signal and the phase current. The front and rear stages of the hybrid CSI were controlled cooperatively through the improved control strategy, reducing the order of the closed loop system. At the same time, considering the control delay problem of the hybrid CSI under the ultra-high fundamental frequency operation condition, the current control loop model was further improved, and the stability and dynamic performance of the current loop were deeply analyzed and compared with the traditional CSI topology and its control strategy. Finally, a hybrid CSI drive platform was developed, and a (550 000r/min)/110Wultra-high-speed permanent magnet synchronous motor (UHSPMSM) was used for simulation and experimental verification. The results show that the hybrid drive topology and its improved strategy have higher stability margin and dynamic performance. © 2022 Chin. Soc. for Elec. Eng.