500kV油浸式电力变压器内部绝缘击穿故障分析

Fault Analysis of Internal Insulation Breakdown in 500 kV Oil Immersed Transformer

分析一起500 kV油浸式电力变压器内部绝缘击穿故障。通过对故障变压器的油箱、高压套管及内部进行检查,并结合故障录波图进行分析,确定了放电主通道、放电诱发原因以及故障发生过程,认为变压器高压套管下均压球和铁轭之间油隙击穿是导致变压器发生爆炸的主要原因。根据故障原因制定了同类故障的防范措施,建议对采用类似设计的变压器进行整改。

The internal insulation breakdown fault in a 500 kV oil immersed transformer is analyzed. By the inspection of oil box of the fault transformer and high voltage bushing and its interior, and the analysis of fault recoding wave, the main discharging path and reason induced the discharging and the process of the fault are determined. The oil gap breakdown between the grading ball and the iron yoke under the high voltage bushing of the transformer and is thought to be the main reason that caused the explosion of the transformer. Preventive measures for same type fault are developed based on the fault reason, and it is suggested that transformers with similar design should he reformed.