Winding preheating and start-up method of permanent magnetic synchronous motor

Abstract

The invention discloses a winding preheating and start-up method of a permanent magnetic synchronous motor. The motor comprises a stator three-phase winding, a rotor and a frequency converter. The winding preheating method comprises the following steps of: (1) maintaining the F direction of the resultant magnetic field of the stator three-phase winding unchanged by the frequency converter, and outputting torque by the frequency converter to draw the rotor to rotate so as to make the magnetic field direction of the rotor parallel to the F direction of the resultant magnetic field of the statorthree-phase winding, so that the rotor is positioned; and (2) after the rotor is positioned, outputting current by the frequency converter to preheat the stator three-phase winding. According to the permanent magnetic synchronous motor winding preheating method disclosed by the invention, on the premise of not increasing an external auxiliary preheating device, the positioned preheating of the motor winding at a low-temperature environment is realized, so that the motor is ensured to be started-up at appropriate winding temperature, the probability of start-up failure of the motor is reduced,overshoot current at the time of start-up is eliminated, the motor is well protected, the reliability of the motor is improved and the service life of the motor is prolonged.

Description

technical field [0001] The invention relates to a motor, in particular to a winding preheating method of a permanent magnet synchronous motor and a starting method of the permanent magnet synchronous motor. Background technique [0002] At present, the motors of some air-conditioning cooling fans and compressors are position sensorless permanent magnet synchronous motors. After a position sensorless permanent magnet synchronous motor is placed in a low temperature environment (minus 20°C) for a long time in winter, the motor winding coils are frozen at low temperature. Winding parameters change. Since the rotor position is unknown before the motor is started, it is necessary to estimate the rotor position according to its winding parameters. If the winding parameters change and the rotor position is not fixed, if the motor is started forcibly after starting up, the rotor position may not be detected easily, resulting in Failure to start, or even damage to the motor. [000...

AI Technical Summary

Problems solved by technology

Since the rotor position is unknown before the motor is started, it is necessary to estimate the rotor position according to its winding parameters. If the winding parameters change and the rotor position is not fixed, if the motor is started forcibly after starting up, the rotor position may not be detected easily, resulting in Fail to start, or even damage the motor

[0003] In the existing technology, an auxiliary preheating device or heat preservation device is used to preheat the winding to maintain the winding temperature within the startable temperature range. The additional auxiliary preheating device increases the cost and volume of the motor, and at the same time, the preheating of the winding is uncontrollable, which affects the performance of the motor. reliable start

[0004] For motors with winding self-preheating devices, during the winding preheating process, the rotor vibrates, which damages the motor and the winding preheats unevenly

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