A Hybrid Two-Stage Control Solution for Six-Phase PMSM Motor with Improved Performance

This article proposes a hybrid two-stage control solution for a six-phase permanent magnet synchronous machine (PMSM) motor with enhanced control performance. The original direct torque control (DTC) and model predictive control (MPC) are artfully integrated together to alleviate the computational burden and the harmonic currents. The proposed method is implemented in two steps. First, the original DTC method is adopted to determine the orientation vector from six existing vectors. It is worthy to mention that the orientation vector is different from the commonly used reference vector calculated through the deadbeat control theory. Second, the prediction vectors located in the same sector with the orientation vector will be evaluated in the original MPC manner. In this way, the enumeration of all the prediction vectors is avoided and the computational burden is avoided. In addition, discrete duty ratios are assigned to define other two groups of virtual vectors to enhance the current quality. In this way, high-performance control of a six-phase motor can be achieved by simply combining the standard DTC and MPC control structure. Experimental results have been used to assess the goodness of the proposed method.