Fault Diagnosis Method and Fault Monitoring Method for Turn-to-turn Short Circuit of Double-fed Wind Turbine Generator

Abstract

The invention discloses a double-fed wind power generator interturn short circuit fault diagnosis method and a fault monitoring method. The fault diagnosis method comprises the following steps of 1) when a stator of a target generator is separated from a power grid and a rotor is kept in a stationary state, through a wind power converter which matches with the target generator and is installed, exerting a three-phase symmetrical test voltage on a three-phase winding of a rotor; and 2) acquiring an equivalent turn ratio state between a stator winding and a rotor winding of the target generator under the test voltage and an impedance state of the rotor winding and diagnosing a state of generating a single winding interturn short circuit fault. The monitoring method comprises the following steps that when the wind power converter completes a self-check process and before the target generator is started, interturn short circuit fault diagnosis is performed; and if a fault is diagnosed, fault alarm is emitted. In the invention, an early-stage single winding interturn short circuit fault in a double-fed wind power generator can be timely diagnosed and monitored; and advantages that a realization method is simple, auxiliary equipment and complex operation are not needed, a diagnosis result is accurate and so on are possessed.

Description

technical field [0001] The invention relates to the technical field of fault detection of a doubly-fed asynchronous wind power generator, in particular to a fault diagnosis method and a fault monitoring method for inter-turn short circuit of a doubly-fed wind power generator. Background technique [0002] Doubly-fed asynchronous wind turbines (referred to as doubly-fed wind turbines) adopt doubly-fed induction generators (Doubly-Fed Induction Generator, DFIG), which are currently international mainstream wind turbine products, accounting for more than 50%, which has the advantages of independent adjustment of active power and reactive power, wide speed range and small required excitation converter capacity. After the doubly-fed wind turbine has been in operation for a period of time, the mechanical and electrical components will gradually expose some faults. Therefore, in order to ensure the stable and efficient operation of the wind turbine, it is very important to diagnose...

AI Technical Summary

Problems solved by technology

The implementation of the above-mentioned online detection and diagnosis method is relatively complicated, and usually requires the use of analysis techniques such as fast Fourier transform, wavelet transform, and fuzzy neural network, which has a large amount of calculation and is difficult to diagnose the fault in time; Connected to the grid, there are three-phase unbalanced grid voltage, excessive harmonic content, or voltage fluctuations or drops in wind farm applications, which will seriously affect the accuracy of online diagnosis

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