The System Development And Data Analysis Of Traction Network Voltage Quality Monitoring

At present,the existing national standards and related research focus more on the power quality problems of public power grids or public connection points,but not paid enough attention to the research on power quality inside traction power grids.With some high-order harmonic resonance accidents in the traction power supply system(TPSS)occur in recent years,the problems of locomotive-network electrical coupling and voltage quality have become more and more prominent.These can damage or shorten service life to the train-mounted or ground equipment,even make trains out of service.All of these would bring serious risks to the safety of traction power supply and reliability of transportation on the electrified railways.Meantime,it is hard to find causes of faults in a short time,because the locomotive-network electrical coupling problem in the TPSS has the characteristics of randomness,concealment,damage accumulation,and existing monitoring techniques are also not applicable.Therefore,real-time voltage monitoring and quality assessment for traction network under this background is becoming necessary.This paper researches the system development and data analysis of traction network voltage quality online monitoring,then works from fault mechanism,analysis method,evaluation index,system design and practical application these aspects.The research results can effectively realize the safety and reliability assessment of the TPSS,and it is of great significance in intelligent monitoring,accident warning,health management and power Internet of things system construction in the future.(1)Due to the difference between the voltage quality problem of traction network and public power grid,and combined with the national standards and the relevant specifications,a set of evaluation index system for the voltage quality characteristics of the traction network is designed.The system is the stratified multi-index voltage evaluation which considers from the angles of the power supply stability and the degree of electrical damage accumulation.It provides an analytical basis for fault prediction and health management(PHM)of TPSS.(2)In order to meet the requirements of traction network monitoring environment and functional technical indicators,the hardware and software implementation scheme of the system is proposed.It adopts the design idea of combining monitoring terminal device with upper computer software system,and can realize the functions of visual monitoring and auxiliary decision-making effectively.(3)In the monitoring terminal device,in order to achieve the purposes of continuous acquisition,transient capture,feature waveform extraction and uploading,abnormal warning and positioning,it chooses the algorithm based on DSP chip during the hardware development process.Besides,the early warning through SMS and GPS positioning function modules are added,which make the monitoring data more diversified.For the device package design,it follows the principle of miniaturization and integration,which makes the device portable and easy to install.(4)In the PC software system,in order to achieve the purposes of intelligent monitoring and human-computer interaction,the C#-based visual monitoring interface development and algorithm design are selected.It integrates the function of data analysis processing,over-voltage type identification,abnormal map positioning and database.Meantime,it also can provide sufficient data support for voltage quality assessment.(5)Finally,through the system on-site installation test and measured data analysis,the system's expected goal is achieved.It also proves that the system has the practical application feasibility,the value of voltage quality assessment and research significance.