The Impact Of The Development Of Short-circuit Fault On The Transformer Differential Protection

The phenomenon of turn to turn fault developing as time go on,a model of transformer progressive short circuit fault put forward , the model based on a trigonometric function with the amplitude increasing with the time was proposed to simulate the progressive fault current . The change rules of the secondary harmonics and dead angle of the fault current waveform under various developing rates were analyzed and the effect of the fault current on two kinds of transformer relay protection of different principles was obtained, which will provide a correct concept on analysis of the protest of differential protection during a progressive failure in the transformer. Due to the development of the transformer protection theory , some better design of the transformer protection device was advanced.