Method for diagnosing stator turn-to-turn short-circuit fault of doubly-fed asynchronous wind-driven generator

Abstract

The invention provides a method for diagnosing a stator turn-to-turn short-circuit fault of a doubly-fed asynchronous wind-driven generator. The method comprises the steps that 1, a mathematical modelfor short-circuit fault diagnosis of the doubly-fed asynchronous generator is established on an abc coordinate system, the mathematical model is transferred from the abc coordinate system to a dq coordinate system, a voltage and flux linkage equation of the doubly-fed asynchronous generator is solved, and then the voltage and flux linkage equation is expressed into a state-space equation of the doubly-fed asynchronous generator; 2, according to the state-space equation, obtained in the step 1, of the doubly-fed asynchronous generator, a circuit model for fault diagnosis of the doubly-fed asynchronous generator is set up based on a MATLAB / SIMULINK software platform, and stator current time-domain oscillograms corresponding to different mu values are obtained through circuit model simulation; and 3, amplitude changing features of spectrograms when mu is equal to 0 and when mu is not equal to 0 are compared, and fault features for judging a stator turn-to-turn short circuit are extractedand used for short-circuit diagnosis of the doubly-fed asynchronous generator. Through the method, the integrity of motor overall structural operation is guaranteed, and the diagnosis result is highin reliability.

Description

technical field [0001] The invention relates to a method for diagnosing a short-circuit fault between turns of a stator of a doubly-fed asynchronous wind power generator, and belongs to the technical field of state detection and fault diagnosis of a drive motor. Background technique [0002] Damage to the insulation layer of the adjacent turns or several turns of the stator winding of the doubly-fed asynchronous generator will cause a short circuit fault between the turns of the stator. The probability of this kind of fault accounts for more than 15% of all fault types of the motor, and it is one of the main types of motor faults. . A small turn-to-turn fault will form a short-circuit current in the short-circuit ring, which will cause the short-circuit of the motor to become hotter and hotter, damage the adjacent insulation layer and cause a greater coil short-circuit hazard. Therefore, it must be dealt with in time to avoid more serious motor failures in the later stage. ...

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Problems solved by technology

Scholars Mirzoian and Williamson first proposed an online monitoring method for stator winding faults of induction motors in 1985; Jensen B.B. and Popa L.M., scholars at the Timisoara University of Technology in Romania, used experimental methods to simulate short-circuit faults between turns of stator windings with parallel reactance on stator windings, and monitored them in real time. Stator and rotor currents were analyzed accordingly; Scholars Rossi C and Stefani A of the University of Bologna in Italy and Scholars Yazidi A of the University of Picardie in France detected stator winding faults by analyzing rotor current modulation signals; Scholars Nandi S and Shah D of Victoria University in Canada proposed a method based on The method of detecting coil voltage and rotor current harmonics to diagnose short-circuit faults between stator turns is ideal; Dinkhauser V and other scholars aim at the identification of motor faults, build a state observer to reconstruct the internal state of DFIG for diagnosis, the method is novel but difficult to build

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