Simulation And Research Of Regenerative Braking Energy Storage In Urban Rail Based On Super Capacitor

In urban rail transit, when train is in regenerative braking condition, part of the energy from train feedback to traction nets, causing voltage the voltage increasing. At present, resistances will be used to absorb the regenerative braking energy produced by train. But, it also causes temperature of tunnel increasing and energy wasting. How to use regenerative braking energy circularly will be the focus.Firstly, this paper introduces the principle of urban rail transit regenerative braking. After the simulations, it found that amplitude is large, time is short, and recycling value is enormous. In this paper, super capacitor is used into urban rail energy storage system. It introduces Super capacitor's structure and equivalent model, the charging and discharging characteristics are researched through the simulation.Secondly, this paper introduces half bridge Bi-directional DC-DC Converter (BDC), the regenerative braking energy can flowed between urban rail trains and super capacitors through it. According to urban rail trains'traction and braking conditions, this paper established BDC's mathematical model and proposed control strategy.Then, energy storage device's parameters are designed, which is based on Guangzhou metro line 4 vehicles. After simulation and energy recovery efficiency analysis, it found that super capacitor energy storage device which is applied in turban rail transit is feasible.Finally, the article puts forward an improved energy storage device. It can prevent the voltage secondary increasing because of regenerative braking energy leak. In addition, for domestic 750V,1500V two different voltage system urban rail power supply systems, the paper also puts forward an energy storage solutions can adapt to different voltage systems.