Control method and device of permanent magnet synchronous motor sensorless for electromobile EHPS

Abstract

The invention relates to a sensorless control method and device of a permanent magnet synchronous motor of an electromobile EHPS (electric hydraulic power steering system). The control method dependson a permanent magnet synchronous motor DC/AC controller; for a demand of the electromobile EHPS, the controller realizes real-time estimation on the rotor location and speed of the permanent magnet synchronous motor by utilizing the control method of the multi-algorithm fused sensorless, thereby realizing the reliable control on the permanent magnet synchronous motor full rotating speed range ofthe EHPS; the controller can realize the current voltage detection, the external communication, high-voltage inversion and like functions, and external interfaces with high-low voltage supply, AC output, enabling signal and communication line; the controller is conducive to an assisting motor for the EHPS without installing a sensor, the system cost can be reduced, the system complexity is lowered, and the system reliability is improved. Furthermore, the controller can properly reduce the power-assisted steering when the vehicle speed is high, the road feel is improved, and the driving stability of the vehicle is improved.

Description

technical field [0001] The invention belongs to the field of permanent magnet synchronous motor control, in particular to a sensorless control method and device for a permanent magnet synchronous motor used in an electric vehicle EHPS. Background technique [0002] Because the permanent magnet synchronous motor has the characteristics of low power loss, high power density and high reliability, it is widely used in the electric hydraulic power steering system (EHPS) of electric commercial vehicles, and the acquisition of the rotor position information of the permanent magnet synchronous motor is a permanent magnet synchronous The basis of motor control is now mostly obtained by transposition measurement of rotor position sensors such as resolvers or encoders. However, for the working environment of EHPS, the installation and maintenance of sensors are very difficult, which will not only increase the system cost, but also reduce the reliability of the system. Therefore, the s...

AI Technical Summary

Problems solved by technology

The "high-frequency signal injection method" is only suitable for salient pole motors, which has poor versatility and is prone to out-of-step problems due to torque fluctuations

However, there is currently no single method that can solve the problem of estimating rotor position and speed in the full speed range, so it is necessary to combine multiple control methods to form a complete control system and method.

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