Research On Control And Protection Of Permanent Magnet Synchronous Motor Based On

Permanent magnet synchronous motor has been more and more widely used because of its advantages such as high efficiency, high power factor and high power density. The power electronics technology, sensor technology, micro-computer technology have made tremendous progress. Then, the performance of the speed control system of the permanent magnet synchronous motor is better. Now. vector control and direct torque control have been used in high-performance control situations of permanent magnet synchronous motors. The direct torque control only needs to control the flux linkage and torque in stator coordinates. It doesn’t need complex coordinate transformation and the accurate information of the rotor position. The control algorithm is simple and it has good static and dynamic performance. It is easier to make the motor operate without speed sensors in direct torque control. So, it has the vaule of theory and application to research on the permanent magnet synchronous motor of direct torque control.The status of the DTC in the permanent magnet synchronous motor is described at first. The models both of the permanent magnet synchronous motor and the trapezoidal permanent magnet synchronous motor are introduced, too. The traditional method of DTC and the method of SVM-DTC in the PMSM are analysed by the tool of Matlab/Simulation. The results show that the flux linkage and torque ripple are large in traditional DTC and the modulation of the paramenters of the PI regulators are complex. Then, an improved method of SVM-DTC in the PMSM is proposed after depyh analysis and research. It uses the control of changing the limit of the amplitude in dynamic. The simulation results show that this is a feasible control method. The unit of changing the limit of the amplitude in dynamic can avoid fussy debugging of the parameters of the PI regulators. It makes a contribution to design and realize the system.The change laws of the flux linkage and torque in the BLDC are analyzed. Then, a DTC method without flux linkage close loop in the BLDC is proposed. This method saves the close loop of flux linkage and it is easier to realize. The tool of Matlab/Simulation is used to analyse the steady performance and the dymanic performance of the system. The simulation results show the feasibility and correctness of this method.The general platform of motors is designed based on DSP TMS320F28335 produced by Texas Instruments at last. The designs of the software, hardware and the method of its protection in the platform are introduced, too. The system uses the advanced control method of redundancy control. Two motors can be operated by twelve hall electric circuits at the same time. It instals and debugs the main electric circuits and the control and protection system. Some experiments are taken to verify the protection of the platform and the traditional DTC in the PMSM preliminary. The results verify the reliability of this platform and the performance of traditional method of DTC in the PMSM.