Control System Design For Position Sensorless Permanent Magnet Synchronous Motor

In recent years, with the rapid development of power electronic technology, microelectronics technology, new motor control theory and rare earth permanent magnetic materials, the permanent magnet synchronous motor (PMSM) has got rapid popularization and application. PMSM is of small size, low dissipation and high efficiency, as energy saving and environmental protection is valued today, the research to it appear more necessary. In order to realize the control of speed regulation system, it is very important to obtain the rotor positions and speed signals. The traditional PMSM installed position sensors (such as Hall sensors) on through the rotor shaft to obtain the rotor positions and speed signals, but these sensors increased the system cost, reduced the system reliability and durability. Therefore, how to realize the control of speed regulation system without installing position sensors became the focus.The research objects of this paper are position sensorless PMSM and its control system. The paper researches and designs the vector control system which is based on sliding mode variable structure control mode. On the analysis of the working principle and characteristics of PMSM, its mathematical model is constructed. Through detailed research of the technology and waveform generation mechanism of space vector pulse width modulation (SVPWM) and the characteristics of sliding mode variable structure control method, a design method is put forward which applies sliding mode variable structure principle in vector control system of position sensorless PMSM. This method can measure motor current, voltage, etc, use the sliding mode variable structure to estimate rotor position, extract position and velocity information of the rotor.This paper introduces the basic structure and performance of STM32F103 chip, and gives the software and hardware design of speed regulation system which use the chip as the main control chip. Theoretical analysis and simulation results show that the design has stronger robustness and high control precision.