广域保护中基于能量守恒原理的母线及输电线差动保护

提出一种基于能量守恒原理的纵联差动保护，对线路两端或母线各端的有功功率进行比较，若各端功率的和超出整定值，则判定为区内故障。在典型400 kV输电系统模型上，运用MATLAB仿真软件对所提出的原理进行了仿真验证。仿真结果表明，该方法比传统电流比率差动保护更加可靠且计算量小，因而可缩短动作时间。该方法能检测所有故障类型，适应于超高压远距离输电线路。

Differential Protection of Busbars and Transmission Lines Based on the Energy Conservation Law for Wide Area Protection

This paper presents a unit protection scheme based on the energy conservation law (ECL). The signals of real power measurement at both ends of a line or all the ends of a busbar are compared and if the result is more than a pre-specified value, an internal or in-zone fault is indicated. The proposed technique is evaluated using a MATLAB simulator configured to model the effect of faults on typical 400 kV busbars and transmission lines. Results indicate that the method is more reliable than a conventional biased differential protection algorithm and needs fewer calculations and hence less computation time. It can also detect all fault types, including those on long and/or highly capacitive lines.