Magnetism loss detection method and system of permanent magnet motor and related components

Abstract

The invention discloses a magnetism loss detection method of a permanent magnet motor, the method is applied to a frequency converter for driving the permanent magnet motor to operate, and the methodcomprises the following steps: when the permanent magnet motor is in a shutdown process, obtaining a reference voltage and a rotating speed corresponding to the permanent magnet motor; calculating anactual rotor flux linkage according to the reference voltage and the rotating speed; and determining the state of the permanent magnet motor by using the actual rotor flux linkage, wherein the state comprises a field loss state or a non-field loss state. The excitation loss detection of the permanent magnet motor is realized through an existing frequency converter in the motor control system; extra hardware and instrument equipment are not needed, the permanent magnet motor does not need to be calibrated in advance, the engineering practicability is high, the field loss detection can be carried out on the permanent magnet motor in each shutdown process of the permanent magnet motor, the purpose of repeated detection is achieved, and the reliability and safety of the operation of the permanent magnet motor are improved. The invention further discloses a magnetism loss detection device of the permanent magnet motor, electronic equipment and a computer-readable storage medium which have the above advantages.

Description

Technical field [0001] This application relates to the field of permanent magnet motors, and in particular to a method, system and related components for detecting loss of magnetism of permanent magnet motors. Background technique [0002] Permanent magnet synchronous motors have the advantages of small size, high power density, high efficiency, high power factor, etc. As the frequency conversion technology becomes more and more mature, its application is also more and more extensive. The rotor magnetic field of a permanent magnet synchronous motor is generated by permanent magnet materials. Due to applications such as high temperature and weak magnetic field, the permanent magnet materials will lose magnetism. The electromagnetic torque output by the permanent magnet synchronous motor is closely related to the strength of the rotor magnetic field. The loss of magnetization of the rotor will cause the torque output of the motor to decrease. Under the same load, the current will i...

AI Technical Summary

Problems solved by technology

The electromagnetic torque output by the permanent magnet synchronous motor is closely related to the strength of the rotor magnetic field. The loss of the rotor will cause the output torque of the motor to decrease. Under the same load, the current will increase rapidly, resulting in an increase in stator copper consumption and a decrease in motor efficiency. , the temperature of the motor rises, which leads to further loss of magnetization of the rotor, entering a vicious circle, and eventually damages the motor. Therefore, it is necessary to detect whether the permanent magnet synchronous motor has lost magnetism, so that when the motor loses magnetism, it can be dealt with in time

[0003] At present, in order to solve the above technical problems, generally by increasing the current value when the permanent magnet synchronous motor is in a steady state, the torque change measured by the dynamometer is compared with the calibrated current and torque table to judge the permanent magnet synchronous motor. Whether the motor is demagnetized, this solution requires expensive dynamometer equipment, and before the permanent magnet synchronous motor runs, it is necessary to calibrate the permanent magnet synchronous motor through a separate test, which is complicated to operate

Images