One new model based predictive torque control algorithm for doubly salient permanent magnet synchronous machines

The doubly salient permanent-magnet synchronous machine (DSPMSM) is a new type of brushless machine with permanent magnet locating in its stator pole. Compared with other traditional PMSMs, it can offer advantages of high power/torque density, simple mechanical structure and wide speed range for high speed cruising, which is attractive to the applications of wind energy, plug-in hybrid electrical vehicle, etc. However, due to the nature of salient poles in both the stator and rotor, the DSPMSM suffers from severe torque and flux ripples for its variable magnetic circuits and equivalent air gap length. The conventional switching-table-based direct torque control (DTC) receives increasing attention for its merits of quick dynamic response, strong robustness and simple control structure. However, during the conventional DTC algorithm, large ripple of both torque and air gap flux often occurs for its hysteresis control based on Bang-Bang modification principle. This paper presents one improved strategy to reduce the torque ripple of DSPMSM drive system by the help of model based predictive torque control (MPTC), which is an improved algorithm in the base of conventional DTC. Similar as the traditional MPTC strategy, the new algorithm still requires one completely decoupling control scheme. By selecting the best voltage vector to satisfy the demands of torque and flux, the new method can obviously reduce both torque and flux ripples. Comprehensive simulation results are finally presented to validate theoretical analysis, and further experiments will be available in the near future.