Research On The Position-sensorless Control Of PMSM For EHPS

The development of the electric vehicle technology for the auxiliary system has resulted in the research of the electric hydraulic power steering system(EHPS). In the traditional permanent magnet synchronous motor drive system, mechanical sensor is installed on the rotor shaft, in order to obtain the rotor of the motor speed and position, due to the shortcomings of mechanical sensors, limits the development of variable speed drive system. This paper considers the application of sensorless control technology in motor EHPS system, to cancel the Holzer effect or traditional photoelectric position sensor, can effectively reduce the cost, simplify the structure, which makes the permanent magnet synchronous motor sensorless control to do further research has very important significance.According to the structure and characteristics of EHPS power system and the control requirements of the system for the power assisted motor, this paper research on the sensorless control of permanent magnet synchronous motor in EHPS system. Firstly the EHPS system principle of work and power characteristics, to establish the mathematical model of the system, by Matlab / Simulink simulation model of the EHPS system.Simulation analysis on the relationship between the EHPS system and the motor speed of hydraulic power, research the control requirements of the motor for electric power system EHPS. Then according to the control requirements of the power of the motor, the EHPS system with permanent magnet synchronous motor, and the matched control scheme was proposed in this paper, selected for the motor control strategy and control method without position sensor, and analyze of selected no position sensor control method basic principle and control model. Finally, through the motor control scheme, a high frequency signal injection method of permanent magnet synchronous motor(PMSM) simulation model of the sensor system, complete the motor speed control. Simulation results show that the pulsating high frequency voltage injection method sensorless control system can realize the regulation of motor speed. To verify the feasibility of the motor selection and application of permanent magnet synchronous motor sensorless control method in EHPS system.