准确高效的高压输电线故障诊断对加快故障后系统的恢复、确保系统安全稳定运行具有重要意义.高压输电线故障诊断问题主要包括故障类型识别、故障测距和故障时间识别.文中将该问题描述为优化问题,即将故障诊断问题中待求解的量（如故障距离）和待估计的量（如过渡电阻）作为故障假设里的未知参数,以故障后的实际波形和期望波形的差异度最小作为优化目标,在此基础上构建了包括离散和连续优化变量的混合优化模型,采用启发式优化算法——和声搜索算法来求解这一优化问题,并根据问题的特点对该算法进行了改进.算例表明,所提出的方法是正确的和有效的.

Accurate and effective fault diagnosis of high-voltage transmission line （ FDHVTL） is vital for the rapid restoration,as well as for maintaining the security and reliability of the power systems concerned. In this paper,the FDHVTL is formulated as an optimization problem with the fault location,fault type identification and fault time estimation involved. Then,by setting the variables to be solved （ such as the fault location） and the parameters to be determined （ such as the transition resistance） as the unknown parameters in a fault hypothesis,and the minimum discrepancy degree between the actual and the expected waveforms as the optimization objective. Then,a hybrid optimization model with discrete and continuous variables is established and solved with a heuristic optimization algorithm,i. e. ,the harmony search （ HS） algorithm. Some improvements of the HS algorithm are made next. Finally,it is demonstrated by sample results that the proposed method is correct and effective.