An Effective Predictive Torque Control Scheme for PMSM Drive without Involvement of Weighting Factors

In this project, Finite Control Set Model Predictive Control (FCS-MPC) methods are emerging as a powerful control technique for power electronic converters and drives. FCS-MPC methods work on the principle of minimizing a single cost function. The cost function consists of multiple control objectives with different magnitudes and requires weighting factors for optimization. The calculation of the weighting factor is a cumbersome process and it depends on the system parameters and operating conditions. In this paper, a new approach for eliminating the weighting factors in Predictive Torque Control (PTC) method for two-level Voltage Source Inverter (VSI) fed Permanent Magnet Synchronous Motor (PMSM) drive is developed. In the proposed PTC method, the torque and flux objectives are considered as separate cost functions and evaluated with all seven different Voltage Vectors (VVs). The top three VVs corresponding to minimized torque and flux objective cost functions are considered individually. Among these, optimal VV is selected for minimizing both torque and flux ripples. As a result, monotonous flux weighting factors tuning is not required and reduction in switching frequency is also achieved.

Keywords:  Predictive Torque Control (PTC), Permanent Magnet Synchronous Motor Drive (PMSM), Weighting Factors (WF).