The Research Of Sensorless Drive System Base On Vector Control For Permanent Magnet Synchronous Motor

Among a variety of motors, the permanent magnet synchronous motor has a lot of advantages in structure and control performance, which makes it widely used in various industries. In high-performance permanent magnet synchronous motor control system,precise location information is the most important condition to achieve high-precision control. Installing a optical encoder or a resolver on the motor is the main method to detect the position of the rotor. But these mechanical sensors result in high system costs, poor reliability, electromagnetic compatibility and many other issues in some conditions. To solve these problems, various sensorless control strategies start to become the current hot topic in the field of AC drives.Based on the mathematical model and the structure of permanent magnet synchronous motors, sensorless control system has been studied in this article. A rotor speed/position estimation method has been theoretical analyzed and developed including the BEMF estimation method based on PLL and the adaptive estimation method based on model reference. The sensorless estimation method can obtain rotor position and speed information accurately and quickly to complete the double-loop vector control of the entire system except in the condition of zero speed and low speed, because in these conditions, BEMF is too small. The current loop, speed loop PI controllers’design of this double-loop vector control strategy is using engineering methods. The parameters’calculation process has been discussed in this article and bode diagram is used to analyze the control system. The design of the subject, the system software and hardware is introduced after the analysis and describes of the theoretical part.The experimental study of this subject is based on the TMS320F2808permanent magnet synchronous motor vector control system, including the estimation method of the motor current loop, velocity loop and double-loop control of rotor speed/position. The simulation and verification has been done in Matlab/Simulink environment. The software development of the core arithmetic has been completed by model-based design. Finally, the steady-state and dynamic experimental test on the permanent magnet synchronous motor control system experimental platform and the system test with, load on the dynamometer experimental platform show that the system is simple, reliable, and has feasibility and practicability in many cases.