Provision of flexible load control by multi-flywheel-energy-storage system in electrical vehicle charging stations

Electrical vehicle (EV) chargers are going to occupy a considerable portion of total energy consumption in the future smart grid. Fast charging stations (FCS), as the most demanding representatives of charging infrastructure, will be requested to provide some ancillary services to the power system in order to support basic electrical operation. This paper proposes a local implementation of a hysteresis-based aggregation algorithm for coordinated control of multiple stations that can provide functions such as peak shaving, spinning reserves, frequency control, regulation and load following. Local control is achieved by distributed bus signaling control which exploits multiple flywheel energy storage systems to respond to the system-level control signals without compromising EV charging process. Due to switching nature of the system, a common Lyapunov function has been found in order to prove its stability. Finally, corresponding hardware in the loop results based on dSPACE1006 platform have been reported in order to verify the validity of proposed approach.