Improving Grid Current Quality of Direct Matrix Converter for Induction Motor

This paper presents a novel predictive active damping strategy for controlling an induction motor fed by a direct matrix converter. In ac-ac drive applications, the grid current suffers from high distorted harmonics at low power levels. The high distortion negatively affects the power factor resulting in poor power quality. The proposed method offers an improvement in grid current quality when the induction motor operates at a lower than nominal power level. The predictive active damping method is integrated into the predictive torque control strategy, and the objective function is reformulated to achieve an effective damping performance. A comprehensive design step procedure is explained, and all theoretical analyses are verified by the simulation works. The results show that the proposed method is effective in reducing unwanted harmonics in grid current.