Fault simulation and diagnostic test for abnormal voltage of secondary coil of capacitor voltage transformer

The transformer protection action is investigated and studied caused by over-excitation due of capacitor voltage transformer secondary coil voltage that is increased. In order to find the reasons of the transformer protection action, routine tests, diagnosis tests are conducted and theses data are accord with national standards. According to infield inspection, faults simulation and analysis method are proposed which results indicated that the protection action caused by electromagnetic interference of the secondary loop. In order that prevent the occurrence of similar failures, some suggestions for operation and maintenance of capacitor voltage transformers are concluded.