利用同序负序分量的同杆双回线快速保护

Fast Protection of Parallel Transmission Lines on the Same Tower with Same Directional Negative Sequence Components

提出了同杆双回输电线路的一个保护原理.该原理将同杆双回输电线路看作一个被保护单元,并利用六序分量法分解出的同序负序电压和同序负序电流构成方向元件.在系统发生不对称故障时,此方向元件具有明确的方向性,若配合选相元件和通信通道则保护原理可作为同杆双回线路的主保护.该原理简单、易行,具有基于故障分量的方向纵联保护原理所固有的优点,消除了原有基于每一回线的方向元件在双回线非同名相跨线故障时,受双回线线间互感影响需将保护闭锁的缺点.针对特高压输电线路,采用贝瑞隆模型补偿算法代替传统的补偿算法.通过理论分析和仿真,验证了该原理的正确性.

A protective relaying principle was proposed for parallel transmission lines on the same tower. In the principle, the parallel transmission lines were regarded as one protected unit, and a directional relay was formed with same directional negative sequence voltage and current decomposed by the six seqnence components method. In case of unsymmetrical fault, the directional relay can distinguish the internal fault from external fault fast, and can be used as main protection of parallel transmission lines when worked with phase selector and communication cannel. The principle is simple, and has the advantages that belong to directional pilot protection principle based on fault components. Because of influence of coupled inductance, directional protection on single line has to be latched-up during cross line fault between different phases, but the proposed principle overcomes this shortcoming. The traditional compensation algorithm is replaced by a compensation algorithm based on Bergeron model for ultra-high-voltage transmission lines. Theoretical analysis and numerical simulation proved correctness of the proposed principle.