Dynamic Compensation Strategy With Dual Closed-Loop Control for Voltage Drift and Torque Ripple in TPFSI-Fed PMSM Drives

Aiming at capacitor voltage offset (CVO) in permanent magnet synchronous motor (PMSM) driven by three-phase four-switch inverter, this article proposes a strategy to resist voltage drift with dynamic voltage compensation. A correction factor is introduced to adjust the capacitor voltage applied to space vector pulsewidth modulation. Then, the additionally superimposed component controlled by the correction factor will be injected into the component of the actual output voltage vector on the α-axis. The additionally superimposed component is adjusted by setting the appropriate correction factor to cancel the CVO on the α-axis. By setting a controllable variable correction factor, its antioffset characteristics can ensure the continuous and stable operation of the system. However, the scheme introduces torque ripple. The strategy adopts double closed-loop control. Experimental results on a 1-kW PMSM prototype show that the proposed scheme can effectively suppress CVO and torque ripple.