300 Mvar空冷调相机转子一点接地保护跳闸故障分析

Analysis on Tripping Fault of One-Point Grounding Protection of 300 Mvar Air-Cooled Synchronous Condenser Rotor

针对某厂站300 Mvar空冷调相机转子一点接地导致的跳闸故障,通过现场检查、返厂拆解、化学成分分析、力学性能测试、金相组织分析、断口形貌分析、温度场仿真等手段对故障原因进行了详细分析。结果表明,连接螺钉压紧区域附近处的引线与绝缘盒之间存在悬空区域,需要使用绝缘配垫进行填充,而装配过程中绝缘配垫未能完全充实该区域,导致引线悬空,引线在离心力的长期作用下最终发生断裂。为此,建议对转子引线绝缘配垫结构进行优化,加强装配工序质量控制,明确工艺质量标准和检查标准,以避免同类型故障再次发生。

Aiming at the fault of the rotor of 300 Mvar air-cooled synchronous condenser in a plant,the author analyzes the cause of the fault in detail by field inspection,disassembly,chemical composition analysis,mechanical property test,metallographic structure analysis,fracture morphology analysis,temperature field simulation and other relevant simulations and tests.The results indicate that there is a suspended area between the lead and the insulation box near the compression area of the connecting screw,which requires to be filled with insulation pads.However,during the assembly process,the insulation pads do not fully fill the area,resulting in the lead being suspended and eventually breaking under the long-term action of centrifugal force.Therefore,it is recommended to optimize the insulated gasket structure of rotor leads and strengthen the quality control of the assembly process,clarify the process quality standards and inspection standards,and avoid the recurrence of similar faults.