The Fault Analysis And Location Of Airfield Lighting System Circuit Cable

The airfield lighting system is the necessary visual aids that help aircraft for normal takeoff, landing, taxiing from the airport at night, low visibility or other complex weather conditions. As the most important part of airfield lighting system, once the airfield lighting cables malfunction, it will make a part or entire lighting circuit failure,which directly affect the security and airfield lighting safe and reliable operation. Therefore,analyzing the fault characteristics of the lighting cables and researching the methods of fault location have some important theoretical significance and practical value of the project for protecting airfield lighting system up and running. In this paper, the fault analysis and location of airfield lighting system circuit cable are studied, and the main task is as follows:Firstly, the airfield lighting circuit cable fault diagnosis and location for domestic and international are analyzed. The causes of fault were studied and the fault is classified. This paper analyzes the cause of big error when traveling wave method fault location is adopted.Secondly, the airfield lighting circuit cable fault location algorithm is studied. This paper introduces spread process of the electric voltage, electric current wave in the cable, and establish its equivalent circuit model based on the distribution parameters of cable. According to the propagation wave equation of the traveling wave in the cable, the voltage reflection coefficient of the traveling wave in the Airfield lighting cable fault point, and it provides a reliable theoretical for the cable location.Thirdly, the method for fault location based on wavelet analysis is studied. The fault waves are usually got at the broken spot, there is a lot of noise with it, and it is hard to identify the first reflected wave, this measurement has some error. This paper designs a filter that combined by mathematical morphology and wavelet theory, and this filter can filter out the noise effectively. Based on it, using the wavelet theory decompounds the fault signal, gets high and low frequency decomposition of signals. Then using the method of searing modulus maximum line to find out the precise singularity in the high reconstruction signal, realize the cable fault location.Last, simulation and experiment are done for airfield lighting circuit cable fault location.And the results show that this method can achieve high fault location accuracy, and verify the usefulness of this method.