中文摘要：

当电力系统在功率低频振荡等动态情况下发生故障时，电力信号幅值和频率往往表现出一定的动态特性，影响了传统的T形输电线路故障测距算法的精度。因此，提出了动态条件下T形输电线路故障测距算法。该方法拓展了传统的静态信号模型，建立了时变的信号模型使其能正确表示信号的动态特性，并加入基于同步相量测量单元（PMU）的动态同步相量测量算法估计的信号相量值，从而可以在动态条件下正确判断出故障支路和估计线路参数。最后通过牛顿迭代算法得到准确的故障距离。应用PSCAD／EMTDC软件模拟各种工况对算法进行验证，仿真结果表明所提出的测距算法在动态条件下具有较高的故障测距精度，并且不受过渡电阻和故障类型的影响。

英文摘要：

Magnitude and frequency of pow6r signals always present certain dynamic characteristics, while tault happens during power system is in active power low frequency oscillation. Both above factors reduce the accuracy of traditional fault locating algorithm for three-terminal transmission lines. Thus, a new fault locating algorithm for three-terminal transmission lines under dynamic conditions is proposed. The new algorithm extends traditional static signal model and builds a time-variable signal model in order to properly show dynamic characteristics of the signal. After using the adjoining signal phasor estimated from synchronous phasor measurement units （PMUs）, this algorithm can be used to correctly identify the fault branch and estimate the line parameters under dynamic conditions. And finally an accurate estimate of fault location can be attained via a Newton iteration method. The per{ormance of the proposed algorithm is evaluated by simulation of various operation situation with PSCAD/EMTDC software. Simulation results show that the proposed technique yields a more accurate fault locating algorithm than traditional static state algorithm and is independent of fault locations, fault impedance, and fault types.