避雷器在线监测的影响因素

The influence factors of arrester online monitoring 

在实际运行中，有些干扰因素会对MOA特征量的监测产生影响。主要有以下几个方面的干扰需要考虑。

In the actual operation, some interference factors affect monitoring of earth-sized feature. Interference basically has the following several aspects to consider. 

1、电网谐波电压对金属氧化物避雷器在线监测的影响

1, power grid harmonic voltage impact on on-line monitoring of metal oxide surge arrester 

在电网中，由于使用的各种各样的电力电子设备与日俱增，虽然有抑制谐波的各种措施，但不可避免地存在谐波电压。谐波电压加在MOA上，会使其总电流的谐波电流中也含有容性成分并且与阻性泄漏电流中的谐波成分混合。给从总电流中将阻性电流分离出来造成困难。

In power grid, the use of a variety of power electronic devices is growing, though there are all kinds of measures to restrain the harmonics, but inevitably exists harmonic voltage. Harmonic voltage on the earth-sized, can make the total current also contain yu-jong sex composition in the harmonic current and impedance leakage current harmonic components in the mix. For impedance current separated from the total current. 

2、相间干扰对金属氧化物避雷器在线监测的影响

2, interphase interference influence on on-line monitoring of metal oxide surge arrester 

当三相MOA按一字行排列同事带电运行时，各相MOA之间存在杂散电容，通过相间杂散电容各相MOA之间就有了电气联系，即各相MOA不仅受到自身相电压的作用，同时还通过相间杂散电容而受到邻相电压的作用，他们之间的距离和电压等级决定了这种作用的大小。这使MOA底部泄漏电流与单独一相运行时相比会发生幅值和相位变化。

When three-phase earth-sized arrange colleagues live in the word line is running, the stray capacitance between each phase earth-sized, markings are scattered through phase capacitor is an electrical connection between earth-sized in that each phase earth-sized phase voltage not only by themselves, but also by phase markings bulk capacitance under the effect of phase voltage, the distance between them and the voltage level determines the size of this effect. The leakage current at the bottom of the earth-sized compared with a single phase operation in amplitude and phase change will happen. 

3、表面污秽泄漏电流对MOA阀片泄漏电流监测的影响

3, surface leakage current of earth-sized valve leakage current monitoring 

在MOA表面存在污秽时，无间隙金属氧化物避雷器的等效电路可以看作是在非线性电阻旁并联了一个分流电阻——表面污层电阻，此时在避雷器的接地引下线上测得的泄漏电流将包含有避雷器表面因污层电阻产生的沿面泄漏电流，使得MOA阀片泄漏电流的测量受到影响。对于这种干扰因素，可以采用在避雷器底座上安装屏蔽环使得沿面电流不经过引下线入地，而不会产生对阀片泄漏电流监测的影响。

In earth-sized surface filth, no clearance equivalent circuit of metal oxide surge arrester can be thought of as beside the nonlinear resistor in parallel with a shunt resistance, surface fouling layer resistance, at this point in the lightning arrester on the ground down lead of measured leakage current will contain caused by lightning arrester surface fouling resistance layer along the surface leakage current, make the earth-sized valve leakage current measurement is affected. For this kind of interference factors, can be used in the arrester base install shield ring that without down lead into the ground surface current, without influence on valve leakage current monitoring. 

4、电压波动对金属氧化物避雷器在线监测的影响

4, voltage fluctuation influence on on-line monitoring of metal oxide surge arrester 

在电网运行中电压波动是不可避免的。在电压波动时，NOA的泄漏电流将会相应地产生波动，导致监测到的趋势曲线发生波动。对于这种情况，对三相MOA进行横向比较可以排除干扰。

In in the operation of the power grid voltage fluctuation is inevitable. When the voltage fluctuation, NOA leakage current will fluctuate accordingly, lead to detect change trend curve of them. In this case, the three-phase earth-sized transverse comparison can eliminate interference. 

5、环境因素对金属氧化物避雷器在线监测的影响

5, environmental factors impact on the on-line monitoring of metal oxide surge arrester 

这里的环境因素主要包括温度和湿度。MOA运行的环境条件每天都会有周期性的变化，这将会导致泄漏电流也随之发生周期性的波动，即使在MOA阀片正常条件下监测到的特征量也会发生周期性的波动。对于这种波动，可以经过长期监测和纵横比较来排除其影响。

The environment factors including temperature and humidity. Earth-sized running conditions of cyclical changes every day, and this will lead to leakage current is cyclical fluctuations, accordingly even in earth-sized valve plates under normal conditions to detect characteristics will be cyclical fluctuations. For this kind of fluctuation, can after a long-term monitoring and vertical and horizontal comparison to eliminate its influence.