Sensorless Control of Three-Phase Permanent Magnet Synchronous Motor Based on Fundamental Wave Mathematical Model

Abstract

In the case of vector control using magnetic field orientation, in order to achieve high performance three-phase PMSM (Permanent Magnet Synchronous Motor) control system, generally we need to obtain an accurate rotor position and speed information, but the use of mechanical sensors will increase the use of system cost, size and quality, and the use of the environment has a more stringent requirements. Sensorless control technology detects the motor winding and focusing on the relevant electrical signals and uses a certain control algorithm to achieve the rotor position and speed estimates. It represents the three-phase PMSM control system development trend. This paper focuses on the sensorless control of three-phase permanent magnet synchronous motor based on the fundamental wave mathematical model. This method relies on the rotational speed-related quantities (such as the generated back electromotive force) in the three-phase PMSM fundamental excitation mathematical model for rotor position and velocity. It is estimated that since the signal-to-noise ratio of the useful signal is low when the motor is running at zero speed and very low speed, it is usually difficult to extract. Thus, ultimately, dependence on the fundamental excitation ultimately results in failure of rotor position and velocity detection at zero speed and low speed. At present, the commonly used algorithms include sliding mode observer algorithm, model reference adaptive control algorithm and extended Kalman filter algorithm. In this paper, the sliding mode observer algorithm is analyzed and modeled. This paper firstly introduces the basic concept of sliding mode control, and then analyzes the commonly used traditional sliding mode observer algorithm and the sliding mode observer algorithm in synchronous rotating coordinate system. Secondly, the permanent magnet synchronous motor control system based on two algorithms is simulated in Matlab2016 / Simulink environment. The response curves of the two control system simulation models under the condition of external disturbance are analyzed.We can get a conclusion that by selecting the appropriate controller parameters, SMO (sliding mode observer)-based three-phase PMSM sensorless control technology can meet the needs of the actual motor control performance.