Sensorless control method and system for permanent magnet synchronous motor

Abstract

The invention discloses a sensorless control method and a sensorless control system for a permanent magnet synchronous motor, which belong to the field of sensorless control of the permanent magnet synchronous motor and comprise the following steps of: acquiring a flux observer taking an alpha-beta axis first equivalent rotor flux as a target function; eliminating direct-current components and higher harmonics in the alpha-beta axis first equivalent rotor flux linkage by using an adaptive band-pass filter; acquiring the estimated motor rotor angular frequency and the estimated uncompensated motor rotor position angle through a phase-locked loop by means of the per-unit alpha-beta axis second equivalent rotor flux linkage; and compensating the estimated uncompensated motor rotor position angle by using a transfer function of an adaptive band-pass filter. According to the invention, the self-adaptive band-pass filter is adopted to filter direct current components introduced by current sampling and higher harmonics introduced by inverter nonlinearity, compensate the position angle of the motor rotor and estimate the angular frequency of the motor rotor, so that the rotating speed of the motor and the position information of the rotor can be accurately observed.

Description

technical field [0001] The invention belongs to the field of speed sensorless permanent magnet synchronous motors, and more specifically relates to a sensorless control method and system for permanent magnet synchronous motors. Background technique [0002] Permanent magnet synchronous motors are widely used in production and life due to their advantages of high power density, high efficiency, high reliability and simple control. In the field-oriented control of permanent magnet synchronous motors, the speed and rotor position information are indispensable. However, the installation of the mechanical sensor will increase the complexity and cost of the hardware of the permanent magnet synchronous motor system, and the installation of the encoder will increase the axial length of the motor. Therefore, the realization of permanent magnet synchronous motor speed sensorless control has high practical application value, and has received a lot of attention from scholars at home an...

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Problems solved by technology

[0004] Aiming at the defects of the prior art, the object of the present invention is to provide a speed sensorless control method and system for a permanent magnet synchronous motor, which aims to solve the problem that the existing flux linkage observer will introduce DC components and inverter nonlinearity due to current sampling. High-order harmonics will be introduced, resulting in the inability to accurately observe the motor speed and rotor position

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