A Study Of Optimization Control For Induction Motor Drive System Fed By Indirect Matrix Converter

Indirect Matrix Converter (IMC) is a novel type of power electronic converter, it has some characteristics:bidirectional energy flow, small size and light weight, etc. It is very suitable for driving the induction motor. Because the traditional double space vector control method of induction motor drive systems fed by indirect matrix converter have a lot of weakness such us complicated structure and many control parameters etc. This paper has introduced the model predictive control (MPC) method and deeply study the optimal MPC method for induction motor drive system fed by indirect matrix converter. The control target is that make this system meet the requirements of power gird and drive system.To improve the input current quality of IMC, this paper has introduced a novel MPC method for IMC to reduce the harmonics of input current. In this control strategy, the input current of IMC has been measured and it has been a weighting factor in the cost function of the system. When the optimal switching states has been chosen, the drive system performance, the input current harmonics and other input performance can be considered in the cost function. The input current harmonics can be reduced when other performance are satisfactory in this system. Simulation results prove the feasibility and effectiveness of propose method in this paper. The total harmonics distortion (THD) of input current have been reduced. At the same time, other performance of the system have no obvious influence in this method. Other input and output performance still keep the satisfactory waveform.In this paper, a zero current commutation method has been proposed because of the complexity of the traditional MPC commutation method. In this method, the zero vector switching states have been inserted in the end of the last sampling time and the beginning of the next sampling period in the inverter when the switching states are changed in rectifier. The inverter switching state will remain and the DC bus current of IMC is zero when the commutation is happened in rectifier. This method can ensure the safety and greatly simplified the commutation of IMC. And this commutation method is more simple than the traditional method. Simulation results show that this commutation method can make IMC commutation in zero current. It is simple and the results are satisfactory on both input and output of IMC.