In order to ensure the train operation safety, it is necessary to analysis the transient response of track circuit in complex electromagnetic environment. According to the distribution characteristics of transmission lines in traction electric network and the structure of ZPW-2000 jointless track circuit, the multiconductor transmission lines model of the traction electric network combined with the track circuit is established. The model cannot be calculated directly due to the presence of parallel or terminated nonlinear lumped elements in the track circuit. For this problem, the new analytical method is proposed, which is based on finite difference time domain (FDTD) method to solve the transmission line part, Thevenin's theorem with state variable method to solve the equations of the terminated nonlinear track circuit. The solution equation of multiconductor transmission line system is obtained by combining the two parts. The relevant parameters of the model can be calculated by finite element method. In ATP-EMTP, the simulation results verify the correctness of the expression. In addition, through the transient response experiment of track circuit, it is confirmed that the transmission characteristics of transient signal on rail are consistent with the calculation results in this paper. Finally, the influence of signal frequency, ballast resistance on track surface voltage, and the influence of interline coupling voltage by the conductivity (σ) and the permittivity (ε) are studied. It provides theoretical reference for the anti-interference analysis of track circuits. © 2022 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

中文翻译：

---

基于多导体传输线理论的无缝轨道电路暂态响应分析

为保证列车运行安全，有必要对复杂电磁环境下轨道电路的瞬态响应进行分析。根据牵引电网输电线路的分布特点和ZPW-2000无接缝轨道电路的结构，建立了牵引电网结合轨道电路的多导体输电线路模型。由于轨道电路中存在并联或端接的非线性集总元件，该模型无法直接计算。针对该问题，提出了一种新的解析方法，即基于有限差分时域(FDTD)方法求解传输线部分，戴维南定理结合状态变量法求解端接非线性轨道电路方程。将两部分结合起来得到多导体传输线系统的解方程。模型的相关参数可以通过有限元法计算。在 ATP-EMTP 中，仿真结果验证了表达式的正确性。此外，通过轨道电路暂态响应实验，证实暂态信号在轨道上的传输特性与本文计算结果一致。最后，研究了信号频率、镇流器电阻对轨道表面电压的影响，以及线间耦合电压对电导率（σ）和介电常数（ε）的影响。为轨道电路的抗干扰分析提供理论参考。© 2022 日本电气工程师学会。由 Wiley Periodicals LLC 出版。