特高压长线路电流差动保护自适应电容电流补偿方法

Adaptive compensation scheme of capacitance current to differential protection in UHV lines

分析了线路电流差动保护中两端各补偿一半电容电流的传统补偿方法,指出该方法在区内故障时存在受故障点影响补偿不精确、降低灵敏度的缺点。提出了一种自适应电容电流补偿方法,在保证相同的区外故障可靠性基础上,大大提高了区内故障的灵敏度。对一条1000kV线路故障和电流差动保护进行了仿真试验,证明该自适应补偿方法的有效性和正确性,适合作为特高压输电线路电流差动保护电容电流补偿方法。

The traditional capacitance current compensation is influenced by different fault locations and has lower sensitivity when internal faults occur in one end. An improved adaptive compensation scheme is proposed in this paper. The scheme combines the traditional compensation with compensation utilizing fault distance. The performances of two compensations are compared in the analytical way, showing that, when they have same security on external faults, the improved one has higher sensitivity when internal fault in one end. According to the simulations on the faults and the two compensations in a 1000 kV line, the results verify that the proposed method has achieved a great improvement on sensitivity of internal faults. It is a proper capacitance current compensation scheme for UHV transmission lines.