利用分布参数等值特高压输电线路，分析不同故障类型情况下暂态高频分量的特征，提出一种基于暂态高频分量频域特征的故障类型识别和保护方案，讨论了实际应用中的关键问题及解决方法。通过多信号分类(multiple signal classification，MUSIC)算法分析故障后三相电流的频谱，计算线路一侧的电流频谱相关性和电流频谱能量，利用其进行故障识别和确定故障相，在此基础上，利用线路两侧故障相的电流频谱相关度判断区内、外故障。利用PSCAD对特高压线路模型进行了仿真验证，仿真结果证明了保护判据的有效性。

The fault-generated transient signals contain a lot of high-frequency components for ultra-high-voltage (UHV) transmission lines with distributed capacitance and long distance. In this paper, distribute parameter model was used to express UHV transmission lines, the spectrum characteristic of high-frequency signals was analyzed firstly, then a protection scheme based on spectrum correlation degree and spectrum energy was proposed. It also discussed the key problems in application and solutions. The scheme performance was proven by using PSCAD simulations of a 1 000 kV power system. The simulation results show that the scheme can identify fault type, internal or external fault quickly and correctly, it does not need synchronously sampling at both ends and phase-mode transformation, further more it is immune to fault resistance, load current, fault time, swing, system operation condition, etc.