When the power system is disturbed or the operation mode is changed, the electromagnetic transient process will occur, which will lead to the high frequency transient component and affect the protection and control of the power system. Therefore, attention should be paid to the analysis of high-frequency transient components when modeling and analyzing the system model. In view of the fact that the symmetrical-component theory is not suitable for asymmetric transmission lines and the phasor method is not suitable for transient analysis and calculation, this paper uses the phase coordinate approach and Laplace transform to derive the node voltage equation of three-phase π type transmission lines in frequency domain, which can be used to calculate the transient response of transmission lines caused by the change of operation mode or disturbance. And vectorized NILT is used to calculate the time domain solution, which greatly improves the calculation speed. The calculated results are basically consistent with those of ATP-EMTP, and can fully reflect the transient characteristics. This method lays a foundation for analyzing the influence of high frequency transient components on power system and fault analysis considering transient process.

当电力系统受到干扰或运行模式改变时，会发生电磁暂态过程，这将导致高频暂态分量，并影响电力系统的保护和控制。因此，在建模和分析系统模型时应注意对高频瞬态分量的分析。鉴于对称分量理论不适用于非对称输电线路，并且相量方法不适用于瞬态分析和计算，本文采用相位坐标法和拉普拉斯变换来推导三端节点电压方程。相位π型传输线在频域中，可用于计算由于操作模式的变化或干扰而引起的传输线的瞬态响应。使用矢量化NILT进行时域求解，大大提高了计算速度。计算结果与ATP-EMTP基本吻合，可以充分反映瞬态特性。该方法为分析高频暂态分量对电力系统的影响以及考虑暂态过程的故障分析奠定了基础。