直流剩磁对大容量变压器空载合闸特性的影响  

Influence of DC Remnant Magnetism on the No-load Closing Characteristic of Large Capacity Transformer

作　　者：朱小贤 淡淑恒 傅晓飞 ZHU Xiaoxian;DAN Shuheng;FU Xiaofei(Shanghai University of Electric Power,Shanghai 200090,China;State Grid Shanghai Electric Power Company,Shanghai 200122,China)

机构地区：[1]上海电力大学,上海200090 [2]国网上海电力公司,上海200122

出　　处：《高压电器》2020年第4期108-112,共5页High Voltage Apparatus

基　　金：国家自然科学基金项目(50577040);上海绿色能源并网工程技术研究中心(13DZ2251900)。

摘　　要：大容量变压器绕组的直流电阻太大会导致变压器发热严重,进而引起变压器绝缘老化加速,使变压器的使用寿命缩短并有可能危及变压器的安全运行。因此使用部门会定期测量变压器直流电阻。常用的测量方法是恒流法,即给变压器绕组通入直流电流,各个用户所用电流大小不同。检测结束后变压器投入运行。但是测完直流电阻后再空载合闸常常引起断路器跳闸,使变电站送电失败。文中为了从原理上探究该问题,分别计算了直流通流给变压器造成的剩磁;然后提出模型计算在有直流剩磁的情况下空载合闸变压器所形成的涌流大小,分析影响该涌流大小的因素;研究控制该涌流的方法。为变压器空载安全投入运行提供理论基础。The DC resistance of transformer winding is too large,which resulting in serious heat.Heating causes the aging of transformer insulation,and ultimately reduces the service life and safe operation of transformers.Therefore,the user department will regularly measure the DC resistance of the transformer.The common measurement method is the constant current method,that is,the direct current is applied to the transformer winding,and the current used by each user is different.After the test,the transformer is put into operation.However,no-load closing after DC resistance measurement often leads to tripping of circuit breaker and failure of power transmission in substation.In order to explore the problem in principle,this paper calculates the remnant magnetism caused by DC current to the transformer;then puts forward a model to calculate the magnitude of inrush current formed by no-load closing transformer with DC remnant magnetism,analyzes the factors affecting the magnitude of the inrush current;studies the method of controlling the inrush current,provides a theoretical basis for the safety of transformer reliable operation.

关 键 词：大容量变压器 直流电阻 空载关合 剩磁 

分 类 号：TM41[电气工程—电器]