极性转换电路在XLPE电缆超低频耐压试验中的优化设计

0.1 Hz超低频余弦方波耐压系统,由于与工频耐压系统有良好的等效性且具备体积小,重量轻,能有效的检测出交联聚乙烯电力电缆(简称XLPE电力电缆)的绝缘缺陷等优点,在XLPE电力电缆耐压试验的应用越来越多。但现有超低频设备的极性转换电路设计有二阶阻尼震荡,造成能量损失,使得极性转换后正负电压不一致;由于XLPE电缆的特殊空间结构,这样会增加XLPE电力电缆的空间电荷积累量,最终对电缆造成隐性伤害。针对以上问题,提出了采用反向可馈电的极性转换电路的设计方法来解决此问题。通过Matlab/Simulink仿真表明:此方法能够补充极性转换过程的能量损失,使得极性转换后正负电压一致;仿真结果与理论分析一致,验证了设计的正确性。

The#$NBSDesign#$NBSfor#$NBSApplication#$NBSof#$NBSVoltage#$NBSPolarity#$NBSSwitch#$NBSCircuit#$NBSin#$NBS Ultralow#$NBSFrequency Withstand#$NBSVoltage#$NBSTest With#$NBSXLPE#$NBSCable

The 0.1 Hz VLF cosine square-wave puncture test system , owing to have good equivalence with the system of power frequency withstand voltage and have small size , light weight, etc., can effectively detect the deficiency of XLPE insulated power cables , and applies more and more in the withstand voltage test .But now , polarity switching circuit of ultra-low frequency device is designed with second order damped shocks with energy loss , resulting in incon-sistent positive and negative polarity voltage .That will lead to the accumulation of space charge of XLPE power cable , thus making the whole performance of the system decreases .To solve the above problem , this paper proposes to make use of reverse feedback in polarity switching circuit to solve this problem .The Matlab/Simulink simulation shows that this method can complement the loss of polarity energy , making positive and negative polarity of the voltage reach agreement.Simulation results and theoretical analysis of the design are the same .