Abstract：The safe running of power system is directly related to the reliability of its core equipment transformer. As the result, condition based maintenance of transformers is essential. When implementing the condition based maintenance, it is necessary to give an accurate state assessment of the transformer which decides whether the transformer need to be repaired. This paper simulates the inter-turn fault of the transformer in order to gain the primary side current data under this condition. Then symbolic dynamic is used to generate a sequence of symbols from the current data and set up the mechanism of signal difference measurement to analyze the data. Results of simulation shows that when the inter-turn impedance becomes lower the method can effectively recognize the difference between the normal and fault signal, which provides asolid foundation of the condition based maintenance. Moreover this paper test the symbolic dynamic method on the field test data of transformer internal fault, the result verifies the validity of the symbolic dynamic on the detection of transform internal fault.
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2015, Vol. 30 
