基于虚拟等效电感的特高压调压变压器励磁涌流判别算法  

A Discriminating Algorithm for Identifying Inrush of UHV Voltage-Regulating Transformer Based on Virtual Equivalent Inductance

作　　者：郑涛 陆格野 赵彦杰 陈水耀[3] 

机构地区：[1]新能源电力系统国家重点实验室(华北电力大学),北京102206 [2]国网南京市供电公司,南京210019 [3]国网浙江省电力公司,杭州310007

出　　处：《电工技术学报》2016年第7期118-125,共8页Transactions of China Electrotechnical Society

基　　金：国家重点基础研究发展计划(973)资助项目(2012CB215206)

摘　　要：针对1 000 k V特高压试验示范工程现场调试过程中特高压调压变压器差动保护的典型误动案例,分析了现阶段采用的二次谐波分相闭锁判据在识别调压变压器励磁涌流时存在的局限性。为解决实际工程中无法直接测量调压变压器一次绕组端口电压问题,基于特高压变压器的本体结构特点设计一种获取调压变压器一次绕组端口电压的方法,同时提出一种基于虚拟等效电感分布特性识别调压变压器励磁涌流的判别算法。基于数字仿真对比分析了二次谐波分相闭锁判据和波形对称制动原理应用于调压变压器差动保护存在的不足,而基于虚拟等效电感分布特性的算法识别特征明显,能够可靠灵敏地识别励磁涌流和内部匝间短路,有效地解决了传统判据在调压变压器差动保护中存在的误动和拒动问题。Aiming at a typical mal-operation case of the differential protection of the ultra-high voltage（ UHV） voltage-regulating transformer（ VRT） in the 1 000 k V UHV experimental demonstration project,this paper analyzes the limitations of the 2nd harmonics with split-phrase lockout criterion on the spot for discriminating the VRT inrush. On the other hand,the terminal voltage of the VRT is unable to be measured,which limits the application of the equivalent instantaneous inductance. This paper suggests a method to obtain the terminal voltage of the VRT according to the structure of the UHV transformer. Meanwhile,it puts forward a discriminating algorithm for identifying inrush based on the distribution characteristics of the virtual equivalent inductance. By simulation,the 2nd harmonics with split-phrase lockout criterion and the waveform symmetry restraint principle are found to be inadequate for the VRT＇s differential protection. Meanwhile,the proposed algorithm based on the virtual equivalent inductance has clear discriminating property. So it can distinguish inrush and a slight turn-to-turn fault reliably,which solves the miss-operation and mal-operation problems of the traditional methods in the VRT differential protection.

关 键 词：特高压调压变压器 励磁涌流 虚拟等效电感 二次谐波 波形对称 

分 类 号：TM406[电气工程—电器]