基于阻容网络的避雷器阻性电流计算方法研究

避雷器是目前防止雷击过电压最为有效的措施,其中应用最为广泛的避雷器类型就是氧化锌避雷器。阻性电流是对氧化锌避雷器的健康状态进行判断的重要依据,但是由于部分电容干扰,现有测量方式很难从全电流中准确得到阻性电流。文中以500 kV氧化锌避雷器为例,利用MATLAB中的Simulink模块对三相避雷器进行简化建模,考虑了避雷器的分节情况,考虑了各节之间的部分电容和各相之间的相间电容,得到了三相分节的避雷器阻容网络路模型,可以有效地滤除全电流中的容性分量,计算得到阻性电流。对于路模型中的各部分电容的取值,通过在Ansoft中利用有限元方法计算得出;对于路模型中的电阻的取值,通过高压试验的方法获得,文中进行了500 kV单节避雷器在工作电压附近的交流高压试验,单节避雷器没有相间干扰和各节之间的部分电容干扰,可以通过现有测量仪器直接测得阻性电流,利用施加电压和阻性电流求得交流电阻。

Research on Resistive Current Calculation Method of MOA Based on RC Network

Arrester is the most effective measure to prevent lightning over?voltage. One of the most widely used arrester type is zinc oxide arrester. Resistive current is an important basis for judging the health status of zinc oxide surge arresters. However, due to partial capacitance interference, the current measuring method is difficult to accurately obtain the resistive current from the total current. Taking the 500 kV Zinc Oxide lightning arrester as an example ,the three-phase arrester resistance RC network model modeled by Simulink module in MATLAB, considering the arrester section conditions, taking into account the partial capacitance between the sections and the phase-to-phase capacitance between the phases, can effectively filter out the capacitive component of the total current, calculate the resistive current. The value of the capacitance of each part in the RC network is calculated by using the finite element method in Ansys;The resistance value of the RC network is obtained by the high voltage test. In this paper, the AC high voltage test of 500 kV single section lightning arrester near working voltage was carried out. Without the interference between phases and partial capacitance between the various sections, the resistance current of single - phase surge arresters can be measured directly through the existing measuring instrument. Then obtained the AC resistance by the voltage applied and the resistive current.