配电柜中性点直接接地系统接地时零序元件的特性是怎样的呢？这是很多人都不理解的，下面就来讲讲吧。

　　What are the characteristics of the zero sequence elements when the neutral point of the distribution cabinet is directly grounded? This is something that a lot of people don't understand, so let's talk about it.

　　故障点的零序电压高，离故障点越远，零序电压越低，中性点接地变压器的零序电压为零。零序电流的分布主要取决于输电线路的零序阻抗和中性点接地变压器的零序阻抗，与电源的数量和位置无关。当电力系统运行方式发生变化时。

　　The zero sequence voltage of the fault point is high, the farther away from the fault point, the lower the zero sequence voltage, and the zero sequence voltage of the neutral earthed transformer is zero. The distribution of zero-sequence current mainly depends on the zero-sequence impedance of the transmission line and the zero-sequence impedance of the neutral ground transformer, and has nothing to do with the number and position of the power supply. When there is a change in the way the power system operates.

　　如果输电线路和中性点接地的变压器数量不变，则零序阻抗和零序等效网络不变。然而，电力系统的正序阻抗和负序阻抗会随着系统的运行方式而变化，这将间接影响零序分量的大小。对于故障线路，配电柜安装两端零序功率方向与正序功率方向相反，零序功率方向实际上是从线路流向母线。

　　If the number of transformers on the transmission line and the neutral ground is constant, the zero-sequence impedance and zero-sequence equivalent network are constant. However, the positive sequence impedance and negative sequence impedance of power system will change with the operation mode of the system, which will indirectly affect the size of zero sequence component. For faulty lines, the zero-sequence power direction at both ends of the PDC is opposite to the positive sequence power direction. The zero-sequence power direction actually flows from the line to the bus.

　　电气成套人员认为保护的配置小电流接地系统的输电线路一般采用三级电流保护，以应对相间短路故障；由于小电流接地系统没有接地点，单相接地短路只被视为异常运行状态。一般是利用母线上的绝缘监测装置发出信号，操作人员切断电源寻找接地设备。

　　Three-phase current protection is generally used in transmission lines with small current grounding system to cope with phase to phase short circuit fault. Since the system with low current grounding has no ground point, a single phase grounding short circuit is only considered an abnormal operating condition. Generally, the insulation monitoring device on the bus is used to send out signals, and the operator cuts off the power supply to find grounding equipment.

　　配电柜中性点直接接地系统的特性这样了，如果您还有什么问题的话，就来网站www.tongyuhengcheng.com进行咨询吧。

　　Distribution cabinet neutral point direct grounding system characteristics of such, if you have any questions, please come to the website www.tongyuhengcheng.com for consultation.