抽能型高压并联电抗器磁路等效模型及匝间保护方法  

Magnetic Circuit Equivalent Model Construction and Inter-turn Protection for Shunt Reactor With Auxiliary Windings

作　　者：郑涛 田浩宇 杨国生 张浩 詹智华 ZHENG Tao;TIAN Haoyu;YANG Guosheng;ZHANG Hao;ZHAN Zhihua(State Key Laboratory of Alternate Electrical Power System With Renewable Energy Sources(North China Electric Power University),Changping District,Beijing 102206,China;China Electric Power Research Institute,Haidian District,Beijing 100192,China)

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),北京市昌平区102206 [2]中国电力科学研究院有限公司,北京市海淀区100192

出　　处：《电网技术》2023年第5期1837-1844,共8页Power System Technology

基　　金：国家电网有限公司科技项目(5100-202155028A-0-0-00)。

摘　　要：抽能型高压并联电抗器(简称“抽能高抗”)是一种既可以为长距离线路提供无功补偿又可以为开关站提供站内用电的新型并联电抗器。铁心上布置的若干气隙在使抽能高抗获得良好线性伏安特性的同时导致了主电抗绕组与抽能绕组间的弱磁耦合。针对抽能高抗这种特殊结构,采用空心变压器模型只能满足抽能高抗端口特性的要求,难以表达抽能高抗实体结构中具体的电磁耦合关系,该文在分析其电磁耦合特性的基础上,提出基于磁路分解的抽能高抗等效建模方法,通过构建抽能高抗的三段磁路等效模型来模拟抽能高抗在额定运行工况及区外故障发生时的电气特性。在所提模型的基础上,针对抽能绕组匝间故障保护灵敏度不足的问题,进一步研究并提出了基于零序电流比值及相位差异的抽能绕组匝间保护新方法,该方法无需引入电压量且无需整定,能够有效识别主电抗绕组和抽能绕组匝间故障并具有较高的灵敏度。最后通过动模试验和仿真试验对比,验证了所提抽能高抗等效模型的准确性及匝间保护方法的有效性。Shunt reactor with auxiliary windings as a new type of shunt reactor which can provide both the reactive power compensation for the long distance lines and the internal power for the switch stations.A number of air gaps on the core keep shunt reactor with auxiliary windings have a good linear characteristics while lead to the weak magnetic coupling between its power winding and auxiliary windings.In terms of this special structure,the existing air-core transformer model can only meet the simulation requirements of the external characteristics of shunt reactor with auxiliary windings system,but cannot reflect its internal electromagnetic coupling relationship.To solve this problem,through the analysis of its magnetic characteristics,this paper proposes the three-segment magnetic circuit equivalent model of the shunt reactor with auxiliary windings based on magnetic circuit decomposition method.This model can accurately simulate the electrical characteristics of the shunt reactor with auxiliary windings under the conditions of normal operation and various faults.Based on the proposed model and aiming at the problem of insufficient sensitivity of the protection against inter-turn fault of shunt reactor with auxiliary windings,a novel protection based on the zero-sequence current ratio and the phase difference is proposed.This scheme has high sensitivity and can identify the inner-turn faults of each winding without introducing the voltage and presetting any parameter.Finally,the correctness of the proposed three-segment magnetic circuit equivalent model and the novel protection scheme against inner-turn fault are verified by testing the physical model of shunt reactor with auxiliary windings.

关 键 词：抽能高抗 三段磁路模型 零序等值回路 零序电流比值 相位差异 匝间保护 

分 类 号：TM721[电气工程—电力系统及自动化]