Study Of Motor Direct Torque Control System Of Matrix Converter Multiple Voltage Vectors

In this paper, the topic is " Direct Torque Control of Motor based on the matrix converter multi-voltage vector (long and short, zero)", this paper has studied the principle and advantages of matrix converter, as well as the feasibility of space vector modulation; analyzed the properties, basic algorithms and rules of space vector modulation strategy, and has a more detailed illustrates for multiple voltage vector of matrix converter; based on the theory of direct torque control, use matrix converter supply motor, reasonable apply its long, short and zero voltage vector and the theory of direct torque control to regulate motor speed.The main contents of this paper as follows:From the work principle of matrix converter (MC), analysis the model of matrix converter, inducted double- space vector modulation strategy of matrix converter and equivalent virtual circuit; Faced the commutation problem introduced the four step commutation strategy. Direct Torque Control (DTC) is a novel AC variable speed method after vector control, the paper simply analyzes the basic principles of direct torque control, inducted control method of direct torque control system, the characteristics of Matrix converter and the advantages of Direct Torque Control are combined, format AC adjusting speed control system that is non-polluting, high-performance and "green", and power factor is adjustable, can maintain the power factor is 1.Finally, full utilize big and small input voltage of matrix converter synthesis long , short and zero voltage vector based on direct torque control of motor that fed by matrix converter, through the rational use of long , short and zero voltage vector to reduce torque ripple. The simulation model of main circuit and control circuit is constructed with MATLAB/SIMULINK, and lots of simulations are carried out, and preliminary experimental verification. The results indicate that control strategy effectively reduce torque ripple at low speed, improved flux accuracy and enhance the robustness of the system, the low-speed performance of DTC system was improved.