Design Of The Online Railway Track Insulation Tester System Based On DSP

Railway transportation is a great event related to the livelihood of the people.If it does not work normally,it will affect every aspect of the society.Now the most failures of the track circuit are caused by the insulation failure of the track.Because of the complex characteristics of railway lines,the maintenance of track insulation is a very complicated and arduous task,and it is also important to judge and prevent the damage of track insulation.The detection result must be accurate,and the detection rate is also highly efficient.At present,the measurement of rail insulation is based on the combination of naked eye observation and the polarity interleaving method of multimeter to determine whether the track insulation is damaged.This method is not only inefficient but also has high misjudgment rate,which can not meet the requirements of high-speed development of China's railways at present.So it is urgent to develop a handheld instrument that can measure the insulation status of track quickly and accurately to meet the measurement requirements of railway electric system.The tester can realize online measurement without interruption of railway transportation,and it can not produce harmful effects on railway track circuit.The main purpose of this paper is to design an instrument that can measure the insulation of track quickly.The high frequency pulsating constant current signal is emitted to the track insulation detection section,and the feedback signal is collected.Through the DSP processing circuit inside the tester,the FFT transformation analysis filters out traction current reflux and various frequency signals,so the signal components,which can characterize the change of insulation resistance,are separated,and the impedance values of the high frequency pulse constant current signal inside the track insulation joint are calculated to judge the insulation of the track.The test shows that the track insulation on-line tester has achieved the expected effect.It can quickly and accurately measure all kinds of insulation resistance on the track,reduce the work intensity of railway personnel and improve the working efficiency,and it has a certain prospect of application.