Novel Cooperative Controller Design of Heterogeneous Energy Storages for Economic Applications in Electric Railway Systems

Owing to the consistently increased request about efficiency improvement through utilization of regenerative energy from braking railway vehicle in the DC electric railway systems, there are a lot of researches about energy storage applications. However, the feasibility of ESS technology application is usually limited by economic factors rather than technical factors of it. Therefore, this paper proposes the application of heterogeneous energy storage system based on ramp-rate-considered cooperative controller in order to improve economics. The heterogeneous combination of energy storage devices with different technical advantages can gives a more economical solution to respond to individual specifications required by the system. A ramp-rate-considered cooperative controller for the heterogeneous ESS application is presented numerically, and effectiveness of the proposed method has been verified through electromagnetic transient simulation.