接地电阻模型对冲击电流回路输出特性影响的仿真

Simulation of Effect of Grounding Resistance Model on Output Characteristics of Impulse Current Circuit

在ATP-EMTP中建立了常电阻模型、非线性电阻模型、电容阻抗模型、混合模型4种杆塔接地仿真模型,研究了这些杆塔接地模型对8/20?s冲击电流回路输出电流波形参数的影响。结果表明:1当充电电压大于某个值时,非线性电阻模型和混合模型对应的输出波形开始受充电电压影响;2临界击穿场强Ec和土壤电阻率?主要影响接地模型中的非线性电阻部分。大的土壤电阻率?和小的临界场强Ec更有利于提高输出波形幅值并且使得波尾与波头的比值更接近2.5;3接地模型中的电容部分越大,输出波形幅值越大,但波尾和波头比值越偏离2.5;4Ri/R0对电容模型和混合模型中的冲击电流回路输出波形参数的影响差别不大。

Four kinds of tower grounding simulation model （constant resistance model, nonlinear resistance model, capacitance impedance model, combination model） were set up to study the influence law of these models on 8/20gs impulse current waveform parameters. The following results are obtained Firstly, when the charging voltage is larger than a certain value, the output impulse current waveform parameters of the nonlinear resistance model and the combination model are affected by the charging voltage. Secondly, critical breakdown electric field intensity Ec and soil resistivity p mainly affect the nonlinear resistor part of the grounding model. Larger soil resistivity p and smaller critical breakdown electric field intensity Ec can improve the amplitude of the output waveform and make the ratio of wave tail and wave head closer to 2.5. Thirdly, the larger the capacitor part of the grounding is, the greater the output waveform amplitude would be, but the further the ratio of wave tail and wave head would deviate from 2.5. Fourthly, the ratio of Ri and R0 has little impact on the output waveform parameters of the capacitance impedance model and combination model.