Investigation Of The Permanent Magnetic Synchronous Motor Control System

Permanent magnetic synchronous motor (PMSM) has its outstanding performance relative to other motors, so it is used so widely in every field of industry. And rare earth which consist the permanent magnet is so rich in our country, so it is very important for us to do research in controlling of PMSM. The motor researched in this paper is used in the system of oil extraction in Da Qing Oil Field. PMSM is be superior to asynchronous motor in the following fact:(a) The efficiency of PMSM is higher than asynchronous motor;(b) The torque of PMSM in the course of start is high and the PMSM has the ability when over loading;(c) The power factor of the PMSM is also high. So the PMSM will be applied in many fields.The plans of controlling the PMSM include the open-loop control and the close-loop control. The open-loop timing control system has no feedback of the current and the position. So the structure of the system is easy. The system can work steadily when the power factor is lagged. But the system can not work steadily when the voltage is invariable and the load is heavy. Besides, the efficiency is low when the load is light and the power factor is low. So in this task we work out the curves of V/f based the performance of the motor and the load first of all. And then we can control the motor based those curves. The experiment has proved that the system can work well in this method.The close-loop control systems include the self-commutating motor drive system, the efficiency-optimizing motor drive system, and the high-factor motor drive system. The power factor of the motor is relative to the current and the efficiency of the motor. So in my task we researched this method. The experiment has proved that we can control the power factor of the motor through controlling the voltage of the transducer.I introduced the process of designing the transducer from software and hardware. Also we do much work in anti-jamming.