零序电流是电网系统一种故障状态下的电流，三相电流平衡的常规条件下系统零序电流
Zero-sequence current is a kind of fault current in power system. Under the normal condition of three-phase current balance, the zero-sequence current of power system is zero-sequence current.
理论数值为零，在小电流接地系统出现接地故障后系统出现系统电容电流大小为主的零序电流，但由于各种因素造成的采集设备所获得的零序电流数据误差可能导致保护装置误发告警，导致值班人员作出错误判断，不利于设备的安全可靠运行。
The theoretical value is zero. After the grounding fault occurs in the small current grounding system, the zero-sequence current of the system mainly depends on the capacitive current. However, the error of the zero-sequence current data obtained by the acquisition equipment caused by various factors may lead to the false alarm of the protective device, resulting in the wrong judgment of the duty personnel, which is not conducive to the equipment. Safe and reliable operation.