基于优化模型的直流电缆雷电冲击电压试验波形参数控制

雷电冲击试验中的直流电缆为大电容试品,试验回路中电感对冲击波形的影响不可忽略,冲击电压发生器电阻参数设置不当将会导致波形过冲和振荡,为此提出一种基于优化模型的雷电冲击电压试验波形参数控制方法。首先,对试验回路进行理论推导,并分析波前时间和过冲率之间的关系,在此基础上引入一个可用于表征波形过冲率的变量Δ_m;其次,以波前时间最小为目标函数,通过限制Δ_m的数值对波形过冲率进行约束,建立电阻参数优化模型;最后,设置不同的Δ_m对模型进行求解,并通过仿真计算和实际试验验证其有效性。结果表明,随着Δ_m设置值的增加,过冲率呈上升趋势,波前时间呈下降趋势,优化模型能够对波形参数进行有效控制。为确定Δ_m的合理设置范围,研究了不同试品电容、不同回路电感下Δ_m设置值对过冲率、波前时间的影响。结果表明,Δ_m取值为0.9~1时,能够保证波形过冲率不超过标准规定的10%。

Parameter Control of Lightning Impulse Voltage Test Waveform for DC Power Cable Based on Optimization Model

In a lightning impulse voltage test for DC cable,voltage waveform may contain overshoot and oscillation due to the large capacitance of DC cable and the loop inductance of the test circuit if the resistance parameters of impulse voltage generator are not set properly.To solve this problem,a parameter control method of lightning impulse voltage test waveform based on optimization model was proposed in this paper.At first,based on the theoretical derivation of test circuit and the analysis of the relationship between the wave front time and the overshoot rate,a variable denoted by △m that can be used to characterize the waveform overshoot rate was introduced.Secondly,the resistance parameters optimization model with the objective function of minimizing the front time was established,in which the overshoot rate constraint can be achieved by limiting the value of △m·Finally,the model was solved by using various values of △m,and then the simulation and experimental studies were carried out to verify its validity.The results show that overshoot rate increases and front time decreases with the increase of △m,so the optimization model can effectively control the parameters of the impulse waveform.In order to determine the reasonable range of △m,the effect of △m on overshoot rate and front time with different values of cable capacitance and loop inductance was studied.The result indicates that the reasonable range of △m should be 0.9 ～ 1 which can ensure that the overshoot rate does not exceed the standard limit of 10％.