Direct-torque control system design using maximum torque per ampere method for interior permanent magnet synchronous motors

Abstract

The paper proposes a method for controlling interior Permanent Magnet Synchronous Motor (IPMSM) drives, that combines Direct-Torque control (DTC) and Maximum Torque Per Ampere (MTPA) in a synchronously rotating (d-q) frame. It has been proven that the increase of electromagnetic torque is proportional to the increase of angle between rotor and stator flux linkages. The use of the DTC method for controlling IPMSM shows a quick and robust response with torque and flux ripples. Combined with MPTA the efficiency of the system is increased as there is no need for prior estimation of flux. Also, speed control loop with PI controller is also introduced to the system for speed regulation. Here, we introduce a simple MTPA-based DTC scheme with speed control with satisfied performance. The feasibility of the system is confirmed by Simulink model, the results of which are presented in the paper.