Design and implementation of a hybrid energy supply system for railway vehicles

An energy supply system based on a hybrid energy storage unit combined of batteries and ultracapacitors for a railway vehicle is studied. In order to optimize the energy supply system architecture and to manage the energy distribution the power electronic converters connecting ultracapacitors, batteries and the DC-link are investigated together with control strategies comprising a multiobjective continuous and a discrete optimization. The prospective goal of applying latter optimization techniques via a so-called operator controller module is a self-optimizing energy supply system. Simulated and measured results are presented, revealing that the separation of the dynamic load from batteries yield improvements in lifecycle, availability and long term costs, while the novel control facilitates prospectively large energy savings and obeying set constraints.