中性点采用两种接地方式的配电网单相接地故障的比较

为了更好地应用小电阻接地方式来提高配电网系统的安全性、可靠性,笔者研究了中性点采用小电阻接地和消弧线圈接地的配电网在发生单相接地故障时的不同特点以及保护方式的差异。首先采用对称分量法对这两种配电网的单相接地故障进行分析,并采用MATLAB进行了仿真。研究结果表明,采用这两种接地方式的配电网在发生单相接地故障时的不同特点导致其继电保护措施也各不相同。因此,随着中性点经小电阻接地的接地方式的推广,其相应的单相接地故障继电保护措施需进一步完善。

Comparison of Single-phase-to-ground Faults in Distribution Network with Two Kinds of Grounding Methods

In order to obtain a better application of low resistance grounding system to improve the safety and reliability of distribution network, the author investigated different characteristics of the power distribution network with neutral grounding through small resistors or petersen coil in the event of single-phase-to-ground fault, as well as the difference between the protecting methods. The symmetrical components method was used to analyze the single-phase-to-ground faults. Then a simulation via MATLAB was conducted. The results show that the different features of the two kinds of networks during single-phase-to-ground fault lead to adopting different relaying methods. With the spreading of low-resistance grounding method, the corresponding relaying methods should be improved.