接在电网中性点的接地电阻对过电压有限制作用。在解释这一现象时，有三种说法：

In the neutral grounding resistance have a limited effect on overvoltage. To explain this phenomenon, there are three kinds of view: 

　　1）相位说--间隙性弧光接地过电压的产生，是发生单相接地时相角超前电压90%的大的电容电流所致。在接地电容电流过零熄弧时，适逢电压的峰值，再由于电流较大，周围空气环境游离，耐压强度降低，而极易发生重燃，导致了暂态和稳态过电压的发生。在电网中性点接入电阻后，给接地点加注入了阻性电流。接地点流过的阻容性电流和电压之间的相位角会小于90°。若阻性电流与容性电流相等时，相位角为45°；若阻性电流大于容性电流，则相位角变得更小。这时，接地电流过零时，故障点的电压已经下降很多，降低了重燃的或燃率。

     1) phase, the generation of gap arc grounding overvoltage, occur when the single-phase grounding phase voltage caused by 90% of the large capacitance current in advance. When the zero arc grounding capacitive current, comes at a time when the voltage peak, again because of its high current, ambient air environment free, compressive strength is reduced, renewed and easily happened, lead to the transient and steady-state overvoltage. After the neutral connection resistance, add into the resistance to ground current. Ground through the resistance capacity of phase Angle between current and voltage will be less than 90 °. If the impedance equals the current and capacitive current, phase Angle 45 °; If impedance is greater than the capacitive current, the phase Angle become smaller. At this time, earth current zero, the fault point voltage has dropped a lot, reduces the renewed or burning rate. 

　　2）泄漏说--在不接地系统中，发生单相接地时产生的过电压皆是在电容上聚集的能量无从泄漏所致。电弧的点燃、熄灭、重燃的过程，使中性点不接地电网中积累了多余的能量，加剧了重燃时的电磁振荡，增大了弧光接地过电压。在电网中性点接入适量的电阻，是把积累的能量，在电弧熄灭至重燃前（半个工频周期内），泄入大地。过电压就可以降低。电阻越小，释放的越快。

      2) leak says - in no grounding system, occurs when the single-phase grounding overvoltage are gathered in capacitance caused by energy don't leak. The lighting and extinguishing of arc, the renewed process, accumulated in the neutral point grounding grid excess energy, exacerbating the renewed electromagnetic oscillation, increase the arc grounding overvoltage. In neutral access the right amount of resistance, it is the accumulation of energy, in front of the arc extinguishing to rekindle (half) power frequency cycle, discharged into the earth. Overvoltage can be reduced. The smaller the resistance, the faster the release. 

　　3）阻尼说--这是一种更加宏观的说法。当电网中性点不接地，特别是轻负荷时，可以把电网的构成看做是电感电容的交织网络，虚浮在大地之上。当其受到拨动、袭扰时，将会振荡不已，久久不能平静。线路发生的单相接地便类似于这种情景。在网络的零序回路接入电阻，相当于在网络与大地之间，连接了一支阻尼电阻，阻尼振荡。这一说法的提倡者，建议将电阻接入到一台特制变压器的三角形绕组的开口上，也是在零序回路之中。

     3) damping - this is a more macro. When the neutral point grounding grid, especially in light load, can the composition of the grid as a mixed network of lc, vain upon the earth. When the strike, harassing, will oscillation, once in a very long while can't calm. Line of single-phase grounding is similar to this situation. In zero sequence circuit of the network access resistance equal to between the network and the earth, connect a damping resistor, damped oscillation. The advocates of the claim, it is recommended that the resistance will access to a triangle of special transformer winding openings, also is in the zero sequence circuit.