电网中常用变压器零序阻抗计算方法及实例  

Method of calculating zero sequence impedance of transformer in power grid and its application

作　　者：王莉[1] 刘明予 张予鄂[2] 李立杰 

机构地区：[1]河南省郑州供电公司,河南郑州450006 [2]河南省电力公司,河南郑州450052 [3]河南电力物资公司,河南郑州450000

出　　处：《电力系统保护与控制》2008年第24期118-120,共3页Power System Protection and Control

摘　　要：电网中运行的变压器为保证电网零序网络的稳定性,一般规定220kV及以上电压等级的大接地系统中运行的变压器中性点直接接地。在保护配置上,220kV及以上电压等级的变压器配有反应系统不对称故障的零序电流保护或接地距离保护。因此在保护设备参数的计算上,220kV及以上电压等级的变压器不仅要计算变压器的正序电抗值,还要计算零序电抗值。将对大接地系统中不同接线型式的变压器零序电抗标幺值的计算进行总结。To ensure the stability of the zero sequence networks in power grid it is stipulated that the neutral point of transformer should be earthed directly in all the 220kV and higher voltage systems. In protection design the reaction system of transformer zero sequence current protection or earthing distance protection is arranged in 220kV and higher voltage systems. When deciding the parameters of protection equipments not only the positive sequence impedance but also the zero sequence impedance of a transformer in 220kV or above systems should be calculated. This paper surveys the zero sequence impedance calculation of transformers in different types of earthing system in reference value.

关 键 词：变压器 等值电路 试验值 零序电抗 标幺值 

分 类 号：TM401.1[电气工程—电器]