Method for judging magnetic pole polarity of motor rotor

Abstract

Provided is a method for judging magnetic pole polarity of a motor rotor. Pulsating high frequency voltage signals are injected into a direct axis, high frequency current response values of the directaxis and a quadrature axis are obtained; according to the response currents of the direct axis and quadrature axis, a first direct axis high frequency current corresponding to a phase shown in the description and a second direct axis high frequency current corresponding to a phase shown in the description are calculated; the magnetic pole polarity of the motor rotor is judged by comparing absolute values of the first direct axis high frequency current and second direct axis high frequency current. According to the method, only the pulsating high frequency voltage signals are injected into thedirect axis, an initial estimated value of the rotor position is obtained through calculation, and it is judged whether the initial estimated value is revised or not. The method is compared with theprior art, multiple injection voltages are not needed to acquire the corresponding parameters, the calculation method is simple, and the magnetic pole polarity of the motor rotor can be quickly and accurately obtained.

Description

technical field [0001] The invention belongs to the field of motor control, and in particular relates to a method for judging the magnetic pole polarity of a motor rotor. Background technique [0002] Due to its simple structure, small size, light weight and high efficiency, the permanent magnet synchronous motor has gradually become a research hotspot in the field of AC speed control transmission. The permanent magnet synchronous motor needs accurate rotor position and speed signals to achieve field orientation and speed control. In the vector control of the sensorless permanent magnet synchronous motor, the initial position of the rotor is a very important quantity. If the initial position is not estimated accurately, Otherwise, the reverse rotation may occur when the motor is started, or the motor may fail to start, and it may also affect the running performance of the system after starting. [0003] The method based on pulse vibration high-frequency signal injection is ...

AI Technical Summary

Problems solved by technology

[0004] Using the high-frequency impedance characteristics of permanent magnet synchronous motors to extract the rotor position estimation deviation Δθ input signal Adjust the input signal When approaching zero, there may actually be two solutions, or That is, in this process, due to the symmetry of the salient poles of the rotor, only the electrical angle from 0 to π can be distinguished, so the polarity of the magnetic poles cannot be identified.

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