At present, the distribution cable lines of State Grid Corporation of China are as long as 900,000 kilometers. However, due to the implementation cost and complexity of the environment, there is almost no application of online monitoring devices in distribution cable lines. The contradiction is very prominent, and it is urgent to develop an economical and reliable online monitoring technology to improve the state perception ability of distribution cable lines.
The operating temperature monitoring technology of distribution cable line based on traveling wave rate studied in this paper includes impedance characteristics, partial discharge and fault location functions. Through the method based on double terminal pulse time interval identification, the independent time synchronization of double terminal device is realized. This kind of pulse signal is high-frequency signal, and its traveling wave propagation speed is affected by operating temperature and cable material characteristics, Therefore, this study believes that the operating temperature of the cable can be monitored and perceived by the way of traveling wave speed, so as to realize the perception of more dimensional states without increasing the cost of sensing and signal processing devices.
Firstly, the influencing factors of cable traveling wave propagation rate are analyzed. Through simulation, the propagation rate variation law and traveling wave characteristics of high-frequency traveling wave signals in cables with different sizes and insulation states under different overall or local temperatures are analyzed. Finally, the measured verification is carried out by using the model cable with equal diameter reduction and the real running cable line.
The research shows that the traveling wave speed will decrease by 0.025 * 108m / s and the change rate will be about 1.3% when the cable insulation temperature rises by 5 ℃. When the state of cable structure and insulating material is known, it is feasible to realize the monitoring of cable operating temperature by timing pulse traveling wave speed when making basic correction.

cable,semiconductor,dielectric properties,traveling wave velocity,temperature monitoring