Cascade PI Controller Designs for Speed Control of Permanent Magnet Synchronous Motor Drive Using Direct Torque Approach

This paper presents a direct torque control (DTC) scheme using space vector modulation (SVM) to achieve high performance speed control of a permanent magnet synchronous motor. Based on the concept of a field-oriented control principle, a Proportional-integral (PI) flux controller is first established to achieve fast direct flux control and then cascade schemes of PI torque and speed controllers are presented to enhance the objective of speed control by the direct torque method. The effectiveness of the proposed control scheme under the load disturbance and parameter uncertainties is verified by simulation results.