基于阻抗特征的高速铁路供电臂联跳保护方案

为了快速有选择性的实现高速铁路全并联AT供电牵引网的保护,提出了一种基于阻抗特征的联跳保护方案.应用回路电压方程和基尔霍夫电流定律推导了发生故障时变电所、AT所、分区所处的短路阻抗表达式,分析了各处阻抗与故障位置的关系,在变电所、AT所、分区所配置距离Ⅰ段保护,并用联跳命令将同一供电臂的保护构成一个整体的保护方案.当任一供电臂的保护检出故障时,跳开对应的所内断路器,并向同一供电臂的其它保护发送联跳命令,实现供电臂的快速保护.仿真结果表明,所提方案能在故障后100 ms内隔离故障供电臂,同时不中断并联供电臂的供电,实现了保护的选择性和速动性. 

Inter-tripping Protection Scheme for Feeding Sections of High-Speed Railway Based on Impedance Features

In order to achieve a rapid and selective protection of cross-coupling AT feeding systems for high-speed railways, an inter-tripping protection scheme for feeding system based on impedance features was proposed. According to loop voltage equations and Kirchhoff's current law, the short-circuit impedance in substation, AT station, and section station was derived;and the relation between short-circuit impedances and fault position was analyzed. In the novel protection scheme, protection elements of distance zone Ⅰ are respectively installed in substation, AT station, and section station, and integrated via inter-tripping signals. When any protection element detects a fault, it will trip the related circuit breaker in the station and send an inter-tripping signal to the other protection elements for the same feeding section to complete fast fault isolation. Simulation results show that the proposed scheme can isolate the fault feeding section within 100 ms after fault, while at the same time not interrupting the power supply of the parallel feeding section. Therefore, the requirement of selectivity and speediness for protection are both satisfied.