新型电子式电压互感器及其误差分析  

A New Type of Electronic Voltage Transformer and Its Error Analysis

作　　者：吴涛[1] 周有庆[2] 曹志辉[2] 彭红海[2] 

机构地区：[1]中南勘测设计研究院风电研究所,湖南省长沙市410014 [2]湖南大学电气与信息工程学院,湖南省长沙市410082

出　　处：《电网技术》2010年第4期209-213,共5页Power System Technology

摘　　要：提出了以微型电流互感器检测耦合电容器电流,再将电流信号传输至控制室转换为与一次电压成正比的二次电压信号来构成电子式电压互感器(electronic voltage transformer,EVT)的技术方案,详细分析了新型高压EVT的传感原理及特点,建立了EVT的一次侧等值电路,推导出其误差公式,并分析了电网频率、电容器温度及二次负载对一次侧误差的影响,且对所研制的高压EVT进行了高压试验,结果表明,新型EVT具有结构简单、体小质轻、绝缘性能好、抗干扰能力强、测量准确度高等优点。In view of some problems existing in current HV voltage transformers, a technical scheme is proposed, in which the current of coupling capacitor is detected by micro current transformer （CT）, then the detected current signal is sent to the control room via optical fiber and is transformed into a secondary voltage signal that is directly proportional to the primary voltage to construct an electronic voltage transformer （EVT）. The sensing principle and features of this HV EVT are analyzed in detail, then its equivalent circuit at its primary side is built and its error formula is deduced, and then the impacts of power network frequency, temperature of capacitor and secondary load on error at primary side are analyzed. High voltage tests of the developed HV EVT are performed. Test results show that the developed novel HV EVT possesses such advantages as small volume and light in weight, good insulation performance and high performance of counter-interference and high measuring accuracy.

关 键 词：电子式电压互感器 检测电流型电压互感器 电流互感器 耦合电容器 

分 类 号：TM644[电气工程—电力系统及自动化]