保定零序电流互感器电气厂

零序电流互感器是一种零序电流过滤器，他的二次侧反应一次系统的零序电流。这种电流互感器用一个铁芯包围住三相的导线（母线或者电缆），一次线圈就是被保护元件的三相导体，二次线圈就绕在铁芯上。

Zero sequence current transformer is a kind of zero sequence current filter, his secondary side reaction system of zero sequence current at a time. The current transformer with a core of encirclement of three-phase wire (bus or cable), a three-phase conductor coil is protected component, the secondary coil is wound on the iron core. 

正常情况下，零序电流互感器一次侧三相电流对称，其向量和为零，铁芯中不会产生磁通，二次线圈中没有电流，当系统中发生单项接地故障时，三相电流之和不为零（等于3倍的零序电流），因此在铁芯中出现零序磁通，该磁通在二次线圈感应出电动势，二次电流流过继电器使之动作。

Under normal circumstances, the zero sequence current transformer primary side three phase current is symmetrical, the vector and zero, won't produce magnetic flux in the core, no current in the secondary coil, when the single ground fault occurred in the system, the sum of three phase current is not zero (equal to three times the zero sequence current), so a zero sequence magnetic flux in the core, the magnetic flux in the secondary coil induction electromotive force, the secondary current flows through the relay action. 

实际上，由于三相导线排列不对称，它们与二次线圈间的互感彼此不相等，零序电流互感器的二次线圈中有不平衡电流流过。零序电流互感器一般有母线型和电缆型两种。

In fact, due to the asymmetric three-phase conductor arrangement, the mutual inductance between them and the secondary coil is not equal to each other, the zero sequence current transformer has unbalance current flows through the secondary coil. Zero sequence current transformer is generally have a mother line and cable type two kinds.