Dynamic Current Trajectory Tracking Strategy With Optimized Overmodulation Method for Permanent Magnet Synchronous Motor Drives

Deadbeat predictive current control (DPCC) can track the current command with a two-sample step response. However, voltage insufficiency is common during abrupt torque changes, and the current command tracking performance is inevitably degraded. To address this issue, an optimized overmodulation method is developed in this paper. By predicting the current vector hexagon in the subsequent switching period, the crossing point between the predicted current hexagon boundary and the expected current trajectory is determined as an optimized current reference. The purpose is to mitigate the current trajectory drift in the overmodulation zone, thus ensuring optimal dynamic trajectory tracking performance and voltage utilization. The solution of the crossing point is solved by the dichotomy due to the randomness of the expected trajectory. By combining DPCC with the proposed method, dynamic current reference optimization and deadbeat response in the overmodulation zone can be achieved, and accurate current trajectory tracking can be realized. Taking$i_{d}=0$and$i_{d}=-i_{q}$trajectory tracking as validation examples, the proposed method is compared with the traditional methods. Both simulation and experimental results have verified the effectiveness of the proposed method.