Wayside energy recovery systems (WERS) can increase energy efficiency in DC railway grids. Almost all commercial systems connect energy storage system and grid via power electronics, and most studies investigate this approach. Power electronics increase complexity, space demand, and investment costs.
Our work presents a novel concept for an application in 750 V grids: a direct grid-coupled, uncontrolled WERS based on a commercial lithium-ion-titanate-oxide (LTO) cell.
We present a detailed simulation model to investigate the application of the novel concept on tramline 112 in Oberhausen/Mulheim (Germany). Field measurements on two vehicles support the investigations. We consider the auxiliaries’ specific behaviour and use measured traction power profiles as simulation input. As a result, the application of the proposed WERS could save around 182,500 kWh per year. Economic operation is thus possible with a service life of two years at investment costs of less than 53,000 €.