The Research On PMLSM Control System Based On DSP

With the development of technologies, the requirement on the numerical control machine such as machining accuracy, processing speed and machining efficiency are enhanced. However, the intermediate conversion devices, which are used to convert the rotation of the motor into linear motion, limit the improvement of system performances. Compared with rotary motors, PMLSMs have no intermediate transmission links, so PMLSMs have a fast speed, high thrust, higher precision to satisfy the NC machines which need high speed and high precision. In this paper, the models of PMLSM were derived, the control systems using three strategies were built and the conclusion was proved by experiments.Firstly, the structural characteristics and working principle of permanent magnet synchronous linear motor were studied, and then its mathematical model was built. With the id=0 motor vector control strategy and voltage space vector pulse width adjustment technology, the simulation model of permanent magnet synchronous linear motor control system was completed by using Matlab/Simulink and then the analysis of motor current loop, speed loop and position loop of the control performance was done. Secondly, the three closed loop control system of permanent magnet synchronous linear motor on the speed loop controller was studied as an important part. A fuzzy PID speed controller was designed by combining the advantage of fuzzy control and conventional PID control and a fuzzy neural network PID speed controller was designed in combination with the advantage of a fuzzy neural network control and conventional PID control. Thirdly, the simulation model of speed controller was built by using Matlab/Simulink and then the comparison of the control effect of the control system of permanent magnet synchronous linear motor speed loop based on the speed controller of conventional PID, fuzzy PID and fuzzy neural network PID was done. And the conclusion could be made from the result that the control effect of PID speed controller based on fuzzy neural network control system of speed loop was better compared with two other speed controller.In this paper, the hardware and software design scheme of this control system was described in detail. The hardware included control circuit as control core by using TI company’s TMS320F2812 digital signal processor and the driver circuit by using Mitsubishi intelligent power module. The software included the main program and interrupt program, and the interrupt program was the key point of software design. The SVPWM algorithm, the conventional PID control algorithm and the fuzzy PID control algorithm were analyzed in the interrupt program module, and the corresponding coordinate transformation, AD conversion, the initial phase back to zero, fault interrupt program was introduced. In the end, the PMLSM’s control system test platform was built. And then it was tested on the actual motor control system based on the simulation of the controller parameters through the analysis of the waveforms of SVPWM, phase current slope response, and location ramp response. As a conclusion, the control system has a better control precision and dynamic response performance, and can provides a good technical basis for follow-up studies.