特高压电流差动保护方案研究

Scheme of Current Differential Protection in UHV Transmission Lines

特高压1000 kV输电线路分布电容更大,由分布电容引起的暂态电容电流对线路的保护影响更大,因此研究1000 kV输电线路的特点及暂态过程对保护的影响很重要。分析了1000 kV输电线路的特殊性,给出了暂态电压电流的仿真波形,介绍了基于不同电容电流补偿方法的线路差动保护判据,通过分析和大量的仿真验证了几种判据在1000 kV输电线路中应用的优缺点及需要注意的问题,为特高压输电线路电流差动保护方案提供一定的参考。

The 1000 kV UHV transmission line has a bigger distributed capacitance and the transient capacitance current caused by distributed capacitance influences the line current differential protection greatly. So it is important to research the characteristics of 1000 kV transmission line and the influence of transient process on the protection. The particularity of 1000 kV transmission line is analyzed, and the transient V/I simulation waveform is presented. The differential protection criterions based on different capacitance current compensation are introduced. The strong points and disadvantages of each criterion are validated as well as the problems needing attention in a 1000 kV simulation model through the analyses and simulations. The results give a reference for the current differential protection scheme of UHV transmission line.