Multi-Objective Control Strategy for Switched Reluctance Machine with On-Line Efficiency Estimation and Improved On-Line Instantaneous Torque Estimation

Torque ripple and system efficiency are two major limitations for further application of switched reluctance machines (SRM). Due to the highly non-linear characteristic of SRM, it is hard to estimate system efficiency and instantaneous torque with traditional analytical methods. Thus, an average torque estimator is proposed in this paper and the average torque is estimated according to the energy conversion loop on the flux linkage-current plane of each stroke. For torque ripple estimation, an improved instantaneous torque estimation method is proposed, which estimates the instantaneous torque based on the fluctuation of the instantaneous rotor speed. Then, a multi-objective control method consisting of a rotor speed controller and a multi-objective optimizer is proposed for multi-objective control. In the proposed multi-objective control strategy, the motor control is divided into two steps. First, the rotor speed control is set as the top priority, which ensures the rotor speed response. Then, a multi-objective controller that considers both system efficiency and torque ripple will be activated to improve overall performance according to the on-line multi-objective evaluation result. In the end, to verify the effectiveness of proposed method, simulation and experimental results are performed under different operating conditions. IEEE