一起220kV CVT二次电压波形畸变的故障分析

电容式电压互感器运行可靠性直接关系到电网安全,由于其设计、结构等原因,电容式电压互感器电磁单元内部空间及各元件间的绝缘距离相对较小,且运行过程中,经常要承受电网的过电压,运行工况较差,极易发生故障。针对一起220 kV电容式电压互感器运行中二次电压波形畸变的故障,根据其结构特点,结合现场试验,初步判断故障原因为电容式电压互感器中间变压器一次绕组并联避雷器损坏,通过对故障电容式电压互感器的解体检查及避雷器试验,证实了该判断,通过对同类型电容式电压互感器的普查,提出了对此类故障的预防及处理措施。

Fault Analysis on Secondary Voltage Waveform Distribution of 220 kV CVT

The operation reliability of capacitor voltage transformer is directly related to grid safety.The internal space of electromagnetic unit of the capacitor voltage transformer and the insulation between each element is relatively small due to design and structure of the voltage transformer,and it normally with-stands grid overvoltage,the operation condition is weak and fault is easy to happen.In view of the fault of secondary voltage waveform distortion of 220 kV capacitor voltage transformer during the operation period,the reason of the fault is judged preliminarily to be the damage of shunt arrester of primary winding of the capacitor voltage transformer in accordance with its structure feature with combination of site test.The judgment is verified throughout the disassembly inspection and the test of arrester.The precautions and treatment measures for the similar fault are proposed through the fault survey of the similar capacitor voltage transformer.