Energy storage savings depended on recuperation ratio in traction

Abstract

Performance of future electric traction systems can be improved by energy storage system (ESS). Using of ESS is not advantageous in all cases. Additional losses always occur during the ESS operation. If saved energy is relatively low in comparison with these losses, the return of investment will not be reached. This paper is focused on energy storage on-board tram vehicle. Return on investment determination is not trivial for multi-source/load systems like a tram. The main emphasis of proposed research is given to the energy savings in dependency on recuperation ratio in tram line. One of main energy savings influencing factors is power management (PM) strategy of ESS. Therefore five PM strategies were taken in to account for energy savings calculation. Four of PM strategies are basic and one is more sophisticated. This sophisticated strategy is based on the Takagi-Sugeno Fuzzy controller (T-S Fuzzy). T-S Fuzzy strategy uses knowledge of the tram line and tram position by GPS. All these strategies were simulated at the same tram line via stochastic tram line model.