Torque Ripple Suppression method of Doubly Salient Electro-Magnetic Machine Based on Direct Instantaneous Torque Control

The doubly salient electro-magnetic motor (DSEM) has a broad application prospect in the aviation DC starting generation system due to its advantages of simple and reliable structure, flexible and convenient control. However, non-ideal electro-magnetic characteristics, current commutation, cogging torque and other factors will produce large torque ripple, which will seriously affect the performance of DSEM. A direct instantaneous torque control strategy for doubly salient electro-magnetic motor is proposed in this paper. Firstly, the static torque characteristic of the motor is analyzed by FEA, the phase torque and cogging torque of the motor are decomposed, and the accurate torque model is established; then, the 3-D LUT of torque, position and current is built off-line according to the established torque model, which is used as the instantaneous torque observer to track and control the instantaneous torque of the motor, so as to realize the efficient torque ripple suppression. Finally, the proposed method is simulated and verified on a 12/8 structure prototype, and compared with the traditional current chopping control method. Experimental results show that the proposed method can effectively suppress torque ripple of DSEM.