外部短路冲击下瓦斯保护动作性能研究  

Research on the Gas Protection Performance Under External Short-circuit Faults

作　　者：周丹 李正圆 孙文星 林春耀 杨贤 郝治国[2] ZHOU Dan;LI Zhengyuan;SUN Wenxing;LIN Chunyao;YANG Xian;HAO Zhiguo(Electric Power Research Institute of Guangdong Power Grid Co.,Ltd.,Guangzhou 510080,China;State Key Laboratory of Electrical Insulation and Power Equipment,Xi'an Jiaotong University,Xi'an 710049,China)

机构地区：[1]广东电网有限责任公司电力科学研究院,广州510080 [2]西安交通大学电力设备与电气绝缘国家重点实验室,西安710049

出　　处：《高压电器》2019年第1期120-127,134,共9页High Voltage Apparatus

摘　　要：作为变压器的非电量主保护,瓦斯保护动作可靠性一直处于较低水平。近年来,外部短路冲击下瓦斯继电器误动跳闸的事故屡次发生,威胁变压器运行效率。为揭示瓦斯保护误动的本质原因,从绕组发热和振动入手,仿真研究了短路穿越电流对变压器内部油流和瓦斯保护的影响。为研究短路电流热效应对变压器内部油流的影响,采用有限体积法仿真计算了外部故障状态下变压器内部热场与流场耦合作用下的散热过程及流场变化。为分析绕组振动对油流的影响,仿真计算了外部短路情况下绕组的动态电磁力及振动位移,考虑流固耦合作用,计算求解了绕组振动引起的流场变化。结果表明,部件发热对变压器内部油流的驱动是持续性的,但短路电流的热效应对油流的驱动尚不足以引起瓦斯保护误动;绕组振动对油流的冲击更强烈且迅速,可能导致瓦斯保护误动。外部短路冲击下变压器的瞬态热场及流场的仿真计算分析在国内外均属首次开展,相关研究方法及结果可为瓦斯保护性能改进及提高提供参考依据。As the main non-electricity protection of power transformers,gas protection is not reliable enough. Themaloperation accident of gas protection occurs frequently during external short-circuit faults in recent years,whichdamages operation efficiency of transformers. Two factors which may result in the oil surging,namely heating and vi-bration of transformer components,are considered to analyze the influence of external short-circuit current on gasprotection. The simulation of heat generating and dissipating in the transformers under the fault state is conducted bythe flow field analysis method based on the finite volume method(FVM),and the simulation of the winding vibrationeffect on transformer oil is also conducted. The results show that transformer oil flow is driven continuously but notdrastically by the heat generated during the external short-circuit fault. The heat effect of external short-circuit faultsis not strong enough to lead to maloperation of gas protection. However,the winding vibration resulted from externalshort-circuit current has more drastic and rapid influence on transformer oil flow,which may lead to maloperation of gas relay.

关 键 词：油浸式变压器 瓦斯保护 外部短路 温度场 流场 

分 类 号：TM407[电气工程—电器]