一种特征相角关系调谐法在配电网对地参数测量中的应用

To-grounded Parameters Measurement Method Based on the Tuning of Various Phase Angles about Grid Distribution

针对中性点经消弧线圈接地的中低压配电网,为了改善配电网分布电容和对地绝缘电阻的测量精度,提出了一种基于多种特征相角调谐的配电网对地参数测量方法。该方法通过微调工况下的消弧线圈电感量,第一次测得中性点零序电压幅值和相对于线电压的相位角θ1;投入阻尼电阻后,配合调节消弧线圈电感量,实时跟踪测量中性点零序电压相对于线电压的相位角θ2,当θ1与θ2的和或者差的绝对值满足0o、90o这样一些特征关系时,可以精确地计算出系统的分布电容C∑与绝缘电阻G∑,从而为消弧线圈的全补偿调谐以及升级改造提供了重要依据。本文通过理论分析和PSCAD仿真实验,验证了该方法能够较为准确的计算出配电网的对地参数。该方法操作方便,测量精度高,可以用于消弧线圈的调谐以及线路整体绝缘水平的判定。

For the neutral point with arc suppression coil grounded in low voltage distribution network,In order to improve the measurement accuracy of distributed capacitance and insulation resistance,proposed a measurement method of distribution network to-grounded parameters based on multiple phase angles relationship.By trimming Petersen coil inductance under normal condition,measure the amplitude and phase angle of zero-sequence voltage relative to the line voltage for the first time;then access the damping resistor,with adjusting arc suppression coil inductance,real-time tracking and measuring phase angle of the neutral point voltage relative to the line voltage.When the difference between the two meets some relationships,we can calculate the distributed capacitance and insulation resistance accurately,which provides an important basis for full compensation tuning.Through theoretical analysis and PSCAD simulation,verifying that the method can accurately calculate the togrounded parameters of the distribution network which can be used to determine the overall insulation level and the arc suppression coil tuning.