Current-Loop Bandwidth Extension for PMSM Servo System Based on SiC Inverter and FPGA

The current-loop bandwidth should be extended to improve the dynamic performance of the servo system. Based on the mathematical model, it is proved that the digital system delay is the main limitation factor for the current-loop bandwidth. Using $\text{SiC}$ power device, a platform of PMSM servo system is established to improve switching frequency. This paper proposes a piecewise and instant PWM update method based on FPGA, which effectively reduces digital delay. Experiments on different conditions are performed, to verify the feasibility of the method.