阻抗匹配平衡变压器的应用

Application of impedance-matching balance transformer

电力牵引负荷是电力系统的一种重要负荷,以单相工频交流电作为牵引动力的电气化铁路由于自身的工作特点,会使三相供电系统处于不对称运行状态,在系统中引起负序电流,使电力系统的运行受到影响。采用阻抗匹配变压器可有效地解决这一问题。介绍了阻抗匹配平衡变压器的一般原理,对YN/荦接线三相变两相阻抗匹配平衡变压器的电压、电流关系及电气化牵引变电所变压器差动保护的实现方法进行了推导,指出了阻抗匹配平衡变压器的一些特点。现场运行表明其适合于在电气化铁路的电力线路上使用。

Electric power traction is an important load of power system. The electrified railwaytaking single-phase AC as its traction power brings on the asymmetry operation of three-phase power system,which results in negative sequence current in power system and affects its operation. The impedance-matching balance transformer is used to solve this problem. Its principle is intro-duced,the voltage and current of impedance-matching balance transformer for symmetrical trans-forming between three phases and two phases are derived,and the implementation of transformer differential protection is detailed. Some features of impedance-matching balance transformer are pointed out. Site operation shows that it is suitable for the power lines of electrified railway.