基于后向预测Prony算法的超高压输电线路暂态量保护方案

EHV power transmission line transient-based protection with backward Prony algorithm

提出了一种基于故障后暂态电流信号的保护方案,利用运算法详细推导了分布参数下超高压输电线路各种故障类型时电流暂态信号的成分,分析结果表明故障后的暂态信号包含谐波形式的高频分量,其频率和相位特征能够可靠区分区内、外故障和各种故障类型。使用后向预测Prony算法作为提取暂态电流特征的工具,并对方程组的求解使用QR分解以缩短算法的计算耗时。在给出完整的选相和保护方案后,使用ATP对各种故障条件进行仿真,仿真结果表明该保护方案能够快速和准确地区分区内、外故障和各种故障类型,且不受过渡电阻、故障初相角等故障条件的影响。

A protection scheme based on fault transient current signals is presented. The components of fault transient current are analyzed with the operation method for EHV power transmission line with distributed parameters, which show that the frequency and phase of its high-frequency harmonic components can be applied to distinguish various fault types,including internal and external faults. The backward Prony algorithm is employed to extract the transients and the QR decomposition to simplify the computation. The complete scheme of faulty phase selection and protection is given and simulations with ATP are carried out for various faults. Simulative results show that the proposed scheme distinguishes various fault types quickly and correctly,immune to the transition resistance and inception angle.