Research And Application Of The Direct Torque Control System Based On Permanent Magnet Synchronous Motor

Permanent Magnet Synchronous Motor(PMSM) drive by triphase sinusoidal current is research object in this thesis. This thesis further investigated the basic principle of controlling the method of direct torque of the PMSM. Based on evaluating the PMSM for organization and characteristic, its mathematics models in several coordinate were set up. The thesis analyzed the principle of PMSM DTC and proposed the PMSM DTC strategy.In the paper, an adaptive fuzzy controller is designed in order to improve the static and dynamic performances of permanent magnet synchronous motors (PMSM) under direct torque control (DTC) techniques. The fuzzy control and adaptive mechanism makes the whole control system more robust and adaptive. Some simplified and optimized algorithm is proposed in the paper by which the controller is realized easily and the real-time feature is better. By the theory analysis and simulation based on MatLab6.5/Simulink.The proposed strategy is proved to enable diminishing the torque ripple. Especially in low speed rang. In addition, both the precision of controlling and high dynamic performance was achieved.Based on the analysis of the principle of PMSM DTC, the thesis proposed a soft-start strategy for PMSM DTC system and set up the modules with MATLAB. The simulation and experiment results shows that the method can low the starter current effectively and make PMSM start smoothly.Based on the principle and structure of the direct torque control of PMSM, This thesis proposed two improved PMSM DTC systems and set up the modules of these systems with MATLAB/Simulink. Through the simulation of these improved system. The results were concordant with the theory analysis.