Sensorless control method of permanent magnet synchronous motor

Abstract

The invention provides a sensorless control method of a permanent magnet synchronous motor, and aims to solve the problems of instability and negative influences caused by a digital filter and systemdelay in a voltage injection method used in the traditional zero-low-speed process in the sensorless control of a built-in permanent magnet synchronous motor. The sensorless control method comprises the steps that 1, the operating process of the permanent magnet synchronous motor is controlled by a microprocessor, and a high-frequency orthogonal square-wave voltage is injected into a static shaftsystem of the permanent magnet synchronous motor; 2, according to the high-frequency current information extracted in the static shaft system of the permanent magnet synchronous motor, a signal processing link of a discrete sequence is designed, and the negative effects of the digital filter and a digital control system are considered and eliminated; and 3, a position observer is designed, so thatthe position and the rotating speed of a rotor are obtained for performing motor rotating speed and current closed loop control, so that sensorless control is realized. The invention is used for thetechnical field of motor control.

Description

technical field [0001] The invention relates to the technical field of motor control, in particular to a control method for a permanent magnet synchronous motor without a position sensor. Background technique [0002] Permanent magnet synchronous motors are widely used in various fields because of their high power density, high torque density and good dynamic performance. Traditional vector control technology requires motor rotor position information for decoupling control, but the installation of position sensors not only increases the cost, but also reduces the reliability of the system, so position sensorless technology has become one of the main research directions in the field of motor control. [0003] The position sensorless technology is mainly divided into the high-frequency signal injection method used at zero and low speeds and the model method used at medium and high speeds. Because the model method is greatly affected by noise when the speed is low, so the high...

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Problems solved by technology

[0004] The purpose of the present invention is to solve the problems that the traditional high-frequency signal injection method used at zero and low speeds is unstable and easily affected by digital filters and system delays in the position sensorless control of permanent magnet synchronous motors. Sensorless Control Method of Permanent Magnet Synchronous Motor with Shaft Orthogonal Square Wave Injection

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