不对称接线内熔丝高压并联电容器组的不平衡保护计算

Imbalance Protection Calculation on High Voltage Shunt Capacitor Bank with Internal Fuse and Asymmetric Wiring

本文给出不对称接线大容量内熔丝高压并联电容组中性线不平衡电流保护和桥式差电流保护的通用计算公式,为基层电力部门提供了一种简便的计算方法。通过对称接线和不对称接线桥式差电流保护计算结果的比较,分析对称接线计算结果替代不对称接线桥式差电流保护计算结果的可能性,60 Mvar以上的并联电容器组的不平衡保护替代计算引起的误差小于2%。

In this paper, an universal formula for calculating the neutral line current imbalance pro- tection and bridge differential current protection in large-capacity high voltage shunt capacitor bank with internal fuse and asymmetric wiring is introduced, which provides a simple method for the grass-roots power sector. Throughout comparison of protection calculation of symmetrical and asymmetrical wiring bridge differential current, possibilities of adopting current protection calculation results with symmetrical wiring to replace asymmetrical wiring is analyzed. The imbalance protection error caused by the new calculation for shunt capacitors bank above 60 Mvar is less than 2%.