Permanent magnet synchronous motor sensorless control method

Abstract

The invention discloses a sensorless control method for a surface-mounted permanent magnet synchronous motor, and the method comprises the following steps: S1, constructing a sliding-mode current observer based on a continuous, smooth and dynamically variable function under a mathematical model of the surface-mounted permanent magnet synchronous motor under alpha and beta coordinates; s2, taking the observation error Sh = 0 of the stator current as a sliding mode surface of the sliding-mode current observer, and outputting a time-varying counter electromotive force signal under the sliding mode surface; s3, filtering the output counter electromotive force pre-signal of the sliding mode current observer by an RLS adaptive filter, and outputting a counter electromotive force estimated value; and S4, estimating the rotating speed and the rotor position of the motor based on the back electromotive force estimated value. The high-frequency buffeting phenomenon of the system is greatly improved, and the phase delay amplitude of the system is reduced; the problems that the sliding film observer cannot extract the counter electromotive force signal and cannot estimate the rotating speed of the motor and the position of the rotor when the permanent magnet synchronous motor runs at a low speed are solved.

Description

technical field [0001] The invention belongs to the technical field of motor control, and more specifically, the invention relates to a position sensorless control method of a permanent magnet synchronous motor. Background technique [0002] The surface-mounted permanent magnet synchronous motor has become the main drive of electric vehicles due to its small size, high stability, simple structure, and high power density. However, the traditional surface-mounted permanent magnet synchronous motor control needs to rely on photoelectric encoders, resolvers and other components to extract the speed and position information of the motor rotor, which not only increases the economic cost and installation difficulty, but also the mechanical sensor is susceptible to interference from the external environment Detection errors are generated, which can easily lead to safety accidents and affect the safety performance of the vehicle. Therefore, the research on the control strategy of th...

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Problems solved by technology

At this time, the traditional synovial film observer cannot extract the back electromotive force signal, so the traditional synovial film observer fails when the system is running at low speed

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