Enhanced Bandwidth of Current Loop for Permanent Magnet Synchronous Motor Drives Based on FPGA

In the field of AC permanent magnet synchronous motor control, the current loop is the innermost ring of the servo control system, and its bandwidth represents the dynamic performance of the control system. The main factors that restrict the current loop bandwidth are digital delay and switching frequency. At present, power devices which can sustain the high switching frequency are expensive and some relative technologies are not yet mature. So the main way of expanding the current loop bandwidth is to reduce digital delay of the control loop. In this paper, Multiple stator current sampling and multiple PWM duty cycle update were achieved in a carrier period without changing the switching frequency. Thereby, with the current loop bandwidth extended, the dynamic performance of the current loop is enhanced. Finally, the simulation results all verify the effectiveness of the algorithm.