PMSM Control System Based On Magnetic Encoder

With the rapid development of magnetic materials technology, power electronic technology, microelectronics technology, and the deepening research of vector control theory and automatic control theory, permanent magnet synchronous motor (PMSM) control system has developed rapidly. Because permanent magnet synchronous motor control is simple, and has good dynamic characteristics, it is suitable for the high-performance servo control system with small and medium-sized power. Magnetic encoder has strong adapting ability, low cost and high reliability. Therefore, permanent magnet synchronous motor control system based on magnetic encoder has a good prospect and application value.Firstly, this paper expounds the background, present situation, development trend, and common control strategy of the permanent magnet synchronous motor control system, then builds the mathematical model of permanent magnet synchronous motor in dq0 synchronous coordinate frame. This paper introduces the vector control and Space Vector PWM principle and digital realization method in this model, and confirms the vector control scheme based on rotor field-oriented is used in the control system.And then, it contains the current detection circuit and the periphery circuit of the controller. According to the modular principle, it shows the C language procedures of angle calculation and working of encoder, main function of microcontroller, interrupt routine and regulator, etc. At the same time it gives the corresponding modules of the software flow chart. Besides, it gives a detailed introduction and analysis of some concrete problems encountered in the actual, and provides the specific solutions.Finally, the simulation waveforms of comparator and speed verify the correctness of the motor vector control theory,and it has important guiding significance to the actual development. It analyses the waveform of switch pulse and closed loop current in the actual, proving that this permanent magnet synchronous motor control system is feasible. It detailedly clarifies the problems existing in the system, and gives the direction of work.