Study on Power Factor Behavior in High-Speed Railways Considering Train Timetable

In many traction substations (TSSs) of high-speed railways, the average power factor measured in a 24-h period is usually below the required value of 0.9 that takes huge additional energy penalty from the utility companies. It is urgent to evaluate and improve the average power factor at the point of common coupling in the TSS. Thus, a dynamic power factor assessment and its sensitivity method along with detailed dynamic modeling and solving technology are presented here. The power factor behavior of the traction power supply system (TPSS) and corresponding influencing factors are fully investigated. To quantify the effects of variable factors on the average power factor, an average power factor changing rate (APFCR) index is defined and calculated. In addition, the APFCR-index method and shunt reactive compensation (SRC) technique are combined to improve the average power factor. The numerical dynamic power flow results verify the effectiveness and validity of the presented method in studying power factor issue. The dynamic power factor behaviors caused by high-speed trains, electric devices in TPSS, and train timetable have been studied thoroughly. The train timetable is the most important influential factor and the average power factor can be improved through increasing train quantity and installing SRCs. Finally, a generalized platform is proposed for a convenience assessment of various conditions based on the MATLAB and LabVIEW software.