中文摘要：

在已知故障类型的前提下，基于线路的丌型集中参数等效模型，利用线路两端从故障发生后到断路器跳闸前的时域信号，通过求解描述线路短路状态的微分方程组，对过渡电阻值进行在线实时计算。从单相系统入手推导了过渡电阻的计算表达式，结合相模变换和复合模网络，给出了三相系统的过渡电阻计算方法。该方法计算响应速度快，具有计算结果不受故障位置、直流信号衰减、谐波信号影响等特点，且具有较高的准确性。采用PSCAD／EMTDC进行了算例仿真仿真结果表明了该方法的有效性和准确性。

英文摘要：

When fault type is known,the time-domain signals of both line ends,from fault occurrence to breaker trip,can be used to online calculate the transition resistance by solving the differential equation of line short circuit states based on the n-type equivalent model. The expression of transition resistance calculation is deduced for single-phase system and,combined with the phase-modulus transformation and composite modal network, the method of transition resistance calculation for three-phase system is introduced,which,immune to fault location,DC signal attenuation and harmonics,has fast response and high accuracy. Case study with PSCAD/EMTDC shows its effectiveness and accuracy.