Method for measuring position and speed of rotor of electrically excited synchronous motor and control device

Abstract

The invention discloses a method for measuring position and speed of a rotor of an electrically excited synchronous motor and a control device, and belongs to the measurement method and a control device for the synchronous motor. The method comprises the following steps of: injecting a high-frequency voltage signal at the U phase of a stator of the electrically excited synchronous motor; generating a high-frequency pulsating magnetic field by the high-frequency voltage signal, wherein a high-frequency potential signal induced in a rotor winding by the high-frequency pulsating magnetic field also changes along with position change of the motor rotor; acquiring the signal by a voltage transformer and determining the position of the rotor and the rotation speed of a synchronizer; feeding the measured rotor position signal and rotation speed signal back to a controller; and accurately controlling the speed of the electrically excited synchronous motor by the controller according to a given signal. The method and the device have the advantages that: the device is not provided with a mechanical speed sensor; by using the electromagnetic structure of the synchronous motor, the rotation speed of the motor is directly measured by injecting the high-frequency signal at one phase of the stator; and the composition of the system is simplified, and the reliability of the system and the accuracy for the speed control are improved.

Description

technical field [0001] The invention relates to a measuring method and a control device of a synchronous motor, in particular to a measuring method and a control device of a rotor position and speed of an electrically excited synchronous motor. Background technique [0002] In the high-performance synchronous motor vector control system, the closed-loop control link of rotor position and speed is essential. The speed sensor-based control system uses mechanical speed sensors such as photoelectric encoders and tachometer generators to detect the motor speed and feed back the speed signal. These systems have poor rotor position detection capabilities, mechanical speed sensors have installation problems, and increase the maintenance workload of the system. [0003] The current speed sensorless control system uses the detection of physical quantities such as motor stator voltage and current, and combines the asymmetry of the rotor magnetic circuit to estimate the position and sp...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a method and control device for measuring the rotor position and speed of an electric excitation synchronous motor, which solves the problem of complex hardware structure of the closed-loop control system of the synchronous motor speed, and at the same time improves the reliability and accuracy of the control system

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