基于贝杰龙模型多点联合判断的特高压直流输电线路纵联保护

Pilot Protection of UHVDC Transmission Line Based on Multi-point Joint Judgment of Bergeron Model

摘要:

对于具有明显分布参数特性的特高压、长距离输电线路，分布电容电流对传统以基尔霍夫电流定律为基础的电流差动保护的灵敏性及可靠性有很大影响。提出了基于贝杰龙模型，采用由一端电压、电流推算至另一端得到的电流以及由两端电压、电流推算至中点得到电流分别构造保护判据，形成了多点联合判定的纵联保护方案。保护判据采用比值的形式构造，使得区外故障下，其比值理论上为1，易于构造保护整定值且受故障电阻的影响小。大量仿真表明：考虑了超长特高压直流输电线路的分布参数特性，通过多点联合的判据，可以进一步减小分布电容电流对保护判据的影响，提高了长距离输电线路差动保护的可靠性。

Abstract:

For UHV and longdistance transmission lines with obvious distribution parameter characteristics, the distributed [JP]capacitance current has a great influence on the sensitivity and reliability of the traditional current differential protection based on Kirchhoff current law. Based on Bergeron model, the protection criteria are constructed by using the current calculated from one end voltage and current to the other, and the current calculated from the voltage and current at both ends to the midpoint respectively. And the pilot protection scheme with multipoint joint decision is formed. The protection criterion is constructed by ratio, and the ratio will be 1 theoretically under the outside fault, which is easy to construct the protection setting value and is less affected by the fault resistance. A large number of simulation results show that considering the distribution parameter characteristics of extralong UHVDC transmission lines, the influence of distributed capacitance current on the protection criterion can be further reduced by the criterion of multipoint joint judgement, and the reliability of differential protection of longdistance transmission lines can be improved.