中文摘要：

文章深入分析了系统电容的放电特性和过渡电阻对直流配电系统极间短路故障特征的影响,在深入挖掘故障特征的基础上,提出了一种基于线路暂态电流突变量的纵联保护新原理。该方法利用线路首末端故障前后暂态电流的变化量来隔离故障线路,能够适用于单端电源系统,尤其适用于双端或多端电源系统,保护原理的速动性不受过渡电阻和系统运行方式的影响,具有很强的适应性。最后,在10k V辐射型直流配电系统中对该方法进行了验证,仿真验证结果表明,在考虑启动元件、断路器动作时间以及通信等因素的情况下,该方法可以在1ms左右切除线路故障,满足系统对保护快速性和抗过渡电阻性能的要求。

英文摘要：

This article analyzes the discharge characteristics of DC-Link capacitor and fault characteristics influenced by transition resistance under the condition of line to line fault of DC distribution system, afterwards proposes a new pilot protection principle based on the saltation of transient current. This method utilizes the transient current variation of head and end of the line to isolate fault, which could be applied to single-terminal power supply system as well as multi-terminal power supply system. The speed of protection is hardly affected by transition resistance and operation mode of systems, which means strong adaptiveness. Finally, the protection is verified in a 10 k V radial DC distribution system, and the results of simulation show that this method could clear the fault in 1ms under the consideration of starting element, operating time of circuit breaker, and other factors caused by communication, meeting the request of high-speed and impregnability under the condition of transition resistance.