Research On Rotor Position Estimation Of Elevator Traction Machine Based On High-Frequency Signal Injection

Permanent magnet synchronous motors (PMSM) being traction machine has become the mainstream of new elevator traction system, but high performance elevator traction system requires high accurate rotor position and speed message to realize field orientation. In conventional elevator controls, high accurate sensors of position and speed are used for this purpose. However these additional sensors increase the cost of system and decrease the reliability. With this background, elevator traction system based on sensorless has been an attractive prospect of elevator systems. At present, most detection methods only depend on the fundamental machine equations, which limits the low speed and zero speed operation of the machine, and are sensitive to the machine parameters. Therefore, this thesis takes PMSM as subject investigated and focuses on detecting rotor position in the whole speed region.In this thesis, the work concentrates on the study of permanent magnet synchronous motor (PMSM) as traction machine. Firstly, three different mathematical models of PMSM and the conversion methods each other are set up based on motor electromagnetism. Based on these models, the vector control and theory are discussed. The principle of vector control method is analyzed systematically. Vector control system is set up. Space vector PWM technology (SVPWM) is introduced.According to the characteristics of elevator traction system, the rotor position detection based on hypothetical rotate frame strategy is introduced. And electric steady also is introduced to estimation of rotor position, which solves effectively the problem of big error on rotor position estimation in process of dynamic. This method is realized easily.Considering above method is low accurate in the whole speed region, rotor position detection of elevator traction machine based on high-frequency voltage signal injection is discussed. Motor mathematical models on high-frequency voltage signal injection is set up and simulated. Simulation results indicate that this method has good dynamic performance, static characteristic and strong robustness. Elevator control system meets the requirements in the whole speed.