接地变压器低压绕组匝间短路故障的电磁特征研究  

Research on electromagnetic characteristics of short circuit faults in low-voltage windings of grounding transformers

作　　者：咸日常[1] 陈蕾 耿凯 范慧芳 张冰倩 高鸿鹏 XIAN Richang;CHEN Lei;GENG Kai;FAN Huifang;ZHANG Bingqian;GAO Hongpeng(School of Electrical and Electronic Engineering,Shandong University of Technology,Zibo 255000,China;Shandong Huineng Electric Co.,Ltd.,Zibo 255000,China)

机构地区：[1]山东理工大学电气与电子工程学院,山东淄博255000 [2]山东汇能电气有限公司,山东淄博255000

出　　处：《电力系统保护与控制》2021年第8期74-82,共9页Power System Protection and Control

基　　金：国家“十三五”重点研发计划项目资助(2016YFB0901303)。

摘　　要：接地变压器具有系统中性点引出和站用电双重功能,在我国大中型变电站中被普遍采用,其运行可靠性直接影响电网的安全稳定。针对接地变压器低压绕组匝间绝缘短路故障检测方法缺失问题,基于磁场-电路耦合原理,利用ANSYS软件建立接地变压器二维有限元模型。通过对比高、低压侧电流的仿真值与计算值,验证模型的正确性。在此基础上分析其低压绕组单匝匝间短路故障时的电磁特征。研究结果表明:当接地变压器低压绕组发生单匝匝间短路故障时,短路环内部有很大的短路电流;电压、电流相位角,功率因数角以及高、低压侧三相电流均会发生变化,但电流波动达不到接地变压器保护的动作定值;同时,短路环附近的磁场也会发生畸变。The grounding transformer is widely used in large and medium-sized substations in China since it has the dual functions of system neutral point extraction and station power consumption.Its operational reliability directly affects the safety and stability of the power grid.There is a problem of the lack of a detection method for an inter-turn insulation short-circuit fault of the low-voltage winding of a grounding transformer.Thus this paper builds a two-dimensional finite element model of the grounding transformer based on the magnetic field-circuit coupling principle and by use of ANSYS software.The correctness of the model is verified by comparing the simulated and calculated values of the high and low side currents.The electromagnetic characteristics of its low-voltage winding single-turn inter-turn short-circuit fault are analyzed.Research indicates that when a single-turn inter-turn short circuit fault occurs in the low-voltage winding of a grounding transformer,there is a large short-circuit current inside the short-circuit ring;the voltage,current phase angle,power factor angle,and three-phase currents on the high and low voltage sides change,but the current fluctuation cannot reach the action setting value of the grounding transformer protection;at the same time,the magnetic field near the short-circuit ring is distorted.

关 键 词：接地变压器 低压绕组 匝间短路 ANSYS 电磁特征 研究 

分 类 号：TM40[电气工程—电器] TM63