The crosstalk of the power line to the safety monitoring signal line in the rectangular tunnel leads to the unstable state of the safety monitoring signal, especially producing the misreport or omission which seriously affects the safety of the power equipment. In this paper, the crosstalk shielded cable model is established for the signal line affected by the electromagnetic interference of the power line, based on the actual electrical parameters of cables. The purpose of this paper is to solve the transfer impedance of the shielded cable and calculate the characteristics of crosstalk by the FDTD (Finite-Difference, Time-Domain) method, yielding the law of change in crosstalk terminated resistive load or dynamic component under different line distances. The results have certain reference value for perfecting the theory of monitoring and communication in rectangular tunnel and exerting the safety guarantee function of power safety monitoring equipment.

dynamic components,FDTD,power equipment safety,shielded cable