10 kV系统冲击与工频续流联合试验回路设计

为检验10 kV带间隙防雷装置在冲击闪络后熄灭工频续流电弧的能力，设计了一种冲击试验与工频续流试验相结合的试验回路。为了产生较高电压下的高幅值工频续流，采用LC串并联谐振回路产生工频续流，对该回路中各元件的参数进行计算并给出合理数值，最后利用同步控制回路提取冲击信号来导通工频续流回路，实现冲击试验与工频续流试验的同步。计算结果表明，该联合试验回路能在产生1.2/50 μs冲击波的同时产生频率为50 Hz的正弦电流波且电流的振荡能够持续至少100 ms，满足带间隙防雷装置在冲击闪络后，检验工频续流下熄灭电弧能力的要求。

10 kV Combined Test Circuit Design with Impulse and Power Frequency Continuous Current

To test the capability of 10 kV lightning protection device with series gaps to cut off the power frequency continuous current after the device breakdown by lightning, this paper designed a test loop in combination with impulse test and power frequency continuous current test. In order to generate power frequency continuous current with high amplitude under higher voltage, a LC series and parallel resonant circuit was used in which the parameters of each element were calculated and selected and their reasonable values were given. Finally, a synchronization control circuit was chosen to extract the impulse signal to conduct the power frequency continuous current circuit, which could realize the synchronization in impulse test and power frequency continuous current test. The calculation results show that the combined test circuit can generate 1.2/50 μs impulse waveform, and 50 Hz sinusoidal current wave with 100 ms oscillation, which can meet the requirement of testing the capability of lightning protection device with series gaps to cut off electric arc under power frequency continuous current after the device breakdown by lightning.