Doubly-fed generator turn-to-turn fault diagnosis system and method

Abstract

The invention provides a doubly-fed generator turn-to-turn fault diagnosis system and a doubly-fed generator turn-to-turn fault diagnosis method. The doubly-fed generator turn-to-turn fault diagnosis method comprises the following steps of: collecting generator stator three-phase current waveforms within given time particles; converting the three-phase current to a dq plane and fitting an ellipse; calculating the eccentricity of the ellipse obtained by fitting; and judging whether a turn-to-turn fault of the doubly-fed generator occurs or not according to the obtained eccentricity. According to the Doubly-fed generator turn-to-turn fault diagnosis system and the Doubly-fed generator turn-to-turn fault diagnosis method, diagnosis errors caused by differences of different motors can be effectively avoided, and the diagnosis precision is improved.

Description

technical field [0001] The invention belongs to the field of power generation, and in particular relates to a double-fed generator turn-to-turn fault diagnosis system and method. Background technique [0002] When the inter-turn short circuit of the stator winding of the doubly-fed wind turbine occurs, if the fault is relatively minor, the change of the three-phase stator current is very small. At this time, it is impossible to identify whether there is a stator inter-turn short circuit fault only from the time domain waveform. The vector trajectory of the three-phase current Park changes significantly with the fault. The shape of the vector trajectory and the eccentricity of the elliptical ring can be used to determine whether there is a short circuit and estimate the severity of the inter-turn short circuit. It is generally considered that when a 1% inter-turn short circuit occurs, the elliptical eccentricity The eccentricity of the ellipse changes significantly (increased...

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Problems solved by technology

[0002] When the inter-turn short circuit of the stator winding of the doubly-fed wind turbine occurs, if the fault is relatively minor, the change of the three-phase stator current is very small. At this time, it is impossible to identify whether there is a stator inter-turn short circuit fault only from the time domain waveform

The vector trajectory of the three-phase current Park varies significantly with faults. The shape of the vector trajectory and the eccentricity of the elliptical ring can be used to determine whether there is a short circuit and estimate the severity of the inter-turn short circuit. It is generally considered that when a 1% inter-turn short circuit occurs, the eccentricity of the ellipse The eccentricity of the ellipse changes significantly (increased from 0.009 to 0.213). However, during the actual operation of the generator, the initial ellipse eccentricity is relatively obvious, and the eccentricity cannot be directly used for fault diagnosis.

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