输电网分布电容对负序方向元件的影响及对策研究

Effect of Distributed Capacitance in Transmission Network on Negative Sequence Directional Element and Its Countermeasure

摘要:

分布电容会对电力系统的正常运行产生影响。详细分析了输电网中分布电容对负序方向保护的影响机理， 研究表明低电压的输电网中线路分布电容对负序方向元件的影响较大。针对分布电容可能导致负序方向元件误动 的情形，提出了一种新的基于正序基波电流幅值变化趋势的解决措施。大量的 PSCAD/EMTDC 仿真实验验证了结论 的正确性。

Abstract:

The distributed capacitance has effect on the stability of power system． The effect mechanism of distributed capacitance on negative sequence directional element is analyzed in detail． The analysis results show that the distributed capacitance will have a greater effect on negative sequence directional element when the transmission voltage decreases． Then，a novel countermeasure based on the change trend of positive sequence fundamental current is presented． A lot of simulations with PSCAD/EMTDC prove these conclusions to be correct．