Research And Development Of Electrical Parameter Detection Device For Track Reflux System

With the acceleration of world urbanization,urban rail transit will be vigorously developed.The urban rail transit DC traction power supply system that uses steel rails as reflux rails generally has problems with stray currents and rail potentials,which have become common problems in Metro operations.Rail is the main carrier of traction reflux and its related electrical parameters are the main factors affecting stray current and rail potential.However,there is little research on the electrical parameter detection device of the track reflux system at present.Therefore,it is of great significance for rail transit construction and operation to develop a set of track reflux system electrical parameter detection device which is suitable for the actual line and meets the accuracy requirements.In this thesis,the influence of various parameters on stray current and rail potential in the reflux system was investigated under the unilateral power supply mode: The rail potential is positively correlated with the rail longitudinal resistance and track-to-earth resistance,especially as the rail longitudinal resistance increases,the greater the rail potential change;The stray current is positively correlated with the longitudinal resistance of the rail,when the track-to-earth resistance is 0 ～ 3Ω·km,as the longitudinal resistance of the rail increases,the stray current leakage increases,and the maximum value can reach 50.60A;The stray current is negatively correlated with the track-to-earth resistance,When the longitudinal resistance of the rail is 0.01Ω·km,as the track-to-earth resistance increases,the stray current gradually decreases and the minimum value can reach 0.995 A.Secondly,the detection methods of the electrical parameters of the rail return system which can be used in the actual line are summarized,which mainly include drainage network resistance,rail longitudinal resistance,track-to-earth resistance,insulation joint and insulation installation performance test of civil air defense door and rail.Based on the high-precision USB-4111 and USB-4115 card,combined with signal isolation and other modules,the electrical parameter detection box of rail return system is developed.The power injection part is composed of megasignal DC stabilized power supply,closed loop LEM current sensor and other components to provide injection power for detection,and the CAN protocol of its communication is also specified.Finally,based on the Visual Studio 2010 platform,using VC as the compilation environment and MFC as the basic framework,the upper computer software for the electrical parameter detection device of the track reflux system is developed.The modularization design makes the software simple and easy to operate,and the detected data can be output to Excel reports with one click,which can effectively reduce the workload of the inspectors.The practicability and accuracy of the software are verified by laboratory experiments and field measurements.