断路器内部SO_2和H_2S含量超标问题的分析

Analysis of Superstandard SO_2 and H_2S Content in Circuit Breaker

在对某热电站断路器的SF6气体中微水及杂质成分进行检测时,发现断路器的SF6气体中SO2和H2S体积分数严重超标,因此对该断路器气室中的SO2和H2S含量进行跟踪监测,并进一步将断路器解体检查。根据检查结果分析,SO2和H2S含量超标的原因是由于断路器开断短路电流后内部结构受到破坏,合金钢导电杆长期高温发热,导电杆与绝缘筒内壁放电,引起SF6分解而产生大量SO2和H2S。最后,针对故障产生的原因提出了预防措施与对策。

The volume fractions of SO2 and H2S in SF6 gas of Circuit Breaker QF101 were found to be seriously superstandard during the detection of micro water and impurities in SF6 gas of circuit breakers in some cogeneration power plant. Therefore the content of SO2 and H2 S in the circuit breaker chamber was tracked and monitored. Strip inspection of the circuit breaker was also conducted. Subsequent analysis showed that the superstandard problem was due to the damage of the circuit breaker inner structure after opening short-circuit current, the long-standing overtemperature of alloy steel conductor pole as well as the discharge of the conductor pole and the inner wall of insulation bushing, which eventually caused SF6 to decompose and produce massive SO2 and H2 S. Precautions and countermeasures are presented accordingly.