Direct axis judgment method of permanent magnet synchronous motor

Abstract

The invention discloses a direct axis judgment method of a permanent magnet synchronous motor. A pulse vibration high frequency current injection method is adopted to construct a rotor closed loop system, and direct axis voltage response is obtained; the amplitudes of the direct axis voltage response when the injected current signal phases are Pi/2 and 3 Pi/2 are recorded; and the two amplitude values are compared, the direct axis positive direction is judged, and a compensation value after the direct axis positive direction judgment is obtained. According to the direct axis judgment method inthe invention, in the process of judging the direct axis positive direction, the injected current is always a sinusoidal high-frequency signal, and other forms of signals such as positive and negative pulses do not need to be injected, such that the estimation process is simplified; the operation of the motor is not influenced, the structure is simple, the reliability is high, the operation complexity is reduced, and the initial position estimation process is simplified.

Description

technical field [0001] The invention relates to the field of motors, in particular to a method for judging the positive direction of a direct axis of a permanent magnet synchronous motor. Background technique [0002] Under normal circumstances, due to the uniqueness of the rotor structure design of the surface-mounted permanent magnet synchronous motor, its rotor does not have structural saliency, which limits the application of the rotating high-frequency signal injection method. However, when artificially using the inverter circuit to inject a high-frequency sinusoidal signal into the fundamental wave of the motor in the two-phase synchronous rotating coordinate system, the direct-axis magnetic circuit of the surface-mounted permanent magnet synchronous motor changes, so that the AC of the motor , The direct axis inductance is no longer equal, this phenomenon is called the nonlinear saturation characteristic of the stator inductance. At the same time, since the motor rot...

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Problems solved by technology

Liu Ying, Zhou Bo, Zhao Chengliang, et al. Low-speed position sensorless control of SPMSM based on pulsating high-frequency current injection[J]. Chinese Journal of Electrotechnical Society, 2012, 7(27): 139-145. The first use of pulsating high-frequency current injection The SPMSM rotor position estimation method is realized, but there is no mention of how to judge the positive direction of the direct axis

[0004] According to the existing literature review, there is no article dedicated to the judgment of the positive direction of the straight axis in the pulse vibration high-frequency current injection method.

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