A sub-region based direct torque control method of matrix converter fed PMSM drive system

In order to suppress the torque and flux ripples with direct torque control (DTC) method of matrix converter, this paper proposed a modified MC-DTC based on a sub-region fed permanent magnet synchronous motor (PMSM) drive systems. With the proposed method, According to amplitude of the output voltage vector of MC, output voltage vectors are divided into large, medium, small and zero vector these four vectors. Compared to the reference output vector meeting the requirements of torque and flux regulator, these discontinuous vectors have deviation. Based on the rules of the deviation between output voltage vectors and the reference, each sector of the output phase voltage vector divided three sub-regions, and determines the sub-region boundary by using a probability statistics method. By dividing the sub-regions, the suitable output voltage vectors can be selected according to the deviation as small as possible between output voltage vectors and the reference voltage vector. Experimental results prove that the proposed method can effectively reduce the torque and flux ripples while retaining the good dynamic performance and the control capacity of input power factor.