电流差动保护的电容电流补偿方法研究

为确保超高压输电线路安全稳定运行,要求输电线路主保护能够可靠快速的切除线路首次发生的故障,输电线路保护的动作时间应安排2个周波以内。电流差动保护原理,理论上基于基尔霍夫电流定律,所需电气量少,原理简单,灵敏度高,动作速度快,是输电线路最理想的主保护之一。但在超高压输电线路中,分布电容电流的存在是影响电流差动保护灵敏度和选择性的主要因素。目前这个问题仍未被很好解决。因此,研究超高压输电线路中分布电容电流对差动保护的影响以及对策的研究是继电保护研究领域中的一个重要课题。

In order to ensure the safe and stable operation of the EHV transmission line, it is required that the main protectionof the transmission line can reliably and quickly remove the first fault of the transmission line. The operation time of the transmissionline protection should be arranged within2 Zhou Bo. The principle of current differential protection is based on Kirchhoff＇s law ofcurrent in theory. It needs less electrical quantity, simple principle, high sensitivity and high speed of action, so it is one of themost ideal main protection for transmission lines. However, in EHV transmission lines, the existence of distributed capacitance currentis the main factor that affects the sensitivity and selectivity of current differential protection. At present, this problem has not beensolved very well. Therefore, it is an important subject in the field of relay protection to study the effect of distributed capacitancecurrent on differential protection in EHV transmission line and its countermeasures.