Optimization design of current loop for permanent magnet synchronous servo system

The goal of this paper is to optimize the current loop of permanent magnet synchronous servo system. The current control loop form and the suitable parameters have been discussed first. Then the over modulation in PWM modulation has been introduced to improve the performance of current control loop, especially when the speed of motor is high. A prototype motor is designed and the experiment and simulation show that the feedback current follows the reference current exactly and fast. The over modulation can restrain the EMF, and improve the performance of current control loop, which provides a basis for realizing high performance permanent magnet synchronous servo system. The PCB design is also discussed to eliminate the EMI effects on the current loop.