Analysis of Typical Faults and Defects of Capacitive Voltage Transformer
Capacitive voltage transformer is an important detection and protection equipment in substation.In this paper,related suggestions of such aspects as design,operation and maintenance of the capacitive voltage transformer are provided through analysis of the multiple types of faults of the capacitive voltage transformer in operation.Firstly,5 types of typical fault and 1 type of misdiagnosis phenomena of capacitive voltage transformers in 500 kV、±500 kV and 1 000 kV substations are analyzed.Then,the causes of such faults as oil leakage of the capacitive voltage transformer,abnormity of capacitor unit and electromagnetic unit are deeply analyzed in accordance with the real fault example of the voltage transformer at site and also in combination with its working principle,operating condition,diagnostic data and disassembly at the factory etc.Finally,as for the misjudgement of self excitation of dielectric electric bridge,the cause of its occurrence is analyzed by reasonable calculation,and verified by Matlab/Simulink simulation model and field test.The experimental results are consistent with the theoretical calculation.
capacitive voltage transformerfaultcapacitor unitelectromagnetic unitabnormal voltageself-excitation