文聆安,林永源,熊华兵
WEN Ling'an, LIN Yongyuan, XIONG Huabin

• 1:广东粤电大亚湾综合能源有限公司，广东 惠州 516000
• 2:广东惠州平海发电厂有限公司，广东 惠州 516000

摘要(Abstract)：

针对某电厂2号发电机机端零序电压突然出现阶梯式增加的异常变化，经现场试验及排查，排除了出口断路器外侧故障和发电机定子绝缘击穿引起的接地故障；进入发电机和出口断路器内部检查，发现出口断路器V相发电机侧电容器出线套管伞裙上有明显黑褐色积油，判断电容器内部已放电击穿。对三相电容器全部换新处理，机组重新并网，运行参数正常。最后就故障原因进行分析，确定原因为：电容器出线套管与油箱锡焊密封处有裂纹漏油，触发发电机90%定子接地保护动作，机端零序电压呈阶梯式增加，造成电容器内部放电击穿，并对此提出了处理建议。
In view of the abnormal change of the zero sequence voltage at the end of the No.2 generator in a power plant, the outboard fault of the exit circuit breaker and the grounding fault caused by the breakdown of the insulation of the generator stator are eliminated by data analysis and field test. After the main transformer is shut down, the generator and the exit circuit breaker are checked inside, and it is found that there is obvious black and brown oil on the umbrella skirt of outlet tube of capacitor at the V phase generator side of the exit circuit breaker. It is judged that the capacitor has been discharged and broken down. All three-phase capacitors are replaced and the unit is connected to the grid again, and the operating parameters are normal. Finally, the causes and countermeasures of two cracks in the soldering seals between the outlet tube of the faulted capacitor and the fuel tank are analyzed.

关键词(KeyWords)： 出口断路器;发电机;接地保护;电容器;漏油;零序电压;阶梯式增加
exit circuit breaker;generator;grounding protection;capacitor;oil leak;zero sequence voltage;step increasing

Abstract:

Keywords:

基金项目(Foundation):

作者(Author): 文聆安,林永源,熊华兵
WEN Ling'an, LIN Yongyuan, XIONG Huabin

DOI: 10.19929/j.cnki.nmgdljs.2021.0082

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