Power Quality Analysis of Weak Power Grid Under the Connection of Bilateral Power Supply Traction Load

Abstract

AbstractSichuan-Tibet Railway is faced with many extremely complex operation conditions, such as super long and large ramp tunnel, high altitude and low temperature, strong sunshine and so on. To improve the power supply capacity of traction power supply system by a wide margin, the power supply arm needs to adopt bilateral power supply full parallel operation mode, and cancel the terminal phase separation of traction substation. However, the external power supply of Sichuan-Tibet Railway is single in type and simple in structure, so the access of traction load with bilateral power supply is bound to have a serious impact on its power quality. If wind power is considered as an external power source, wind power integration puts forward higher requirements for power quality of power grid. Firstly, this paper introduces the principle of bilateral power supply for electrified railway. Then, based on PSCAD/EMTDC simulation software, a co-simulation model of bilateral power supply traction network, electric locomotive and weak power grid is built to simulate and analyze the change of equilibrium current of traction network and power quality index of weak power grid under bilateral power supply mode. Finally, the operation of weak power grid with bilateral power supply traction load and wind power connected at the same time is simulated and analyzed. The simulation results have a guiding role for practical engineering application.KeywordsElectrified railwayBilateral power supplyWeak gridPower qualityWind power