Transformer Fault Diagnosis Method Based on Gross Error Examination

This paper proposes a gross error judgment criterion and diagnoses the transformer fault by integrating the gross error judgment criterion and the characteristic gas ratio method. In this way it is possible to judge whether the transformer is in face of an incipient fault by examining the gross errors of the measured values of the fault characteristic gases, at the same time the fault probability could be calculated according to the remarkable level. And then in combination with the characteristic gas ratio method, the fault category and fault cause of the transformer could be figured out. The method has been validated by an actual example of fault diagnosis.