Hierarchical control of combined power control resources mitigating local power grid fluctuations

Power grid fluctuations are an increasing concern with the high penetration of intermittent generation sources. This paper describes a hierarchical control scheme defined by the dynamics of de-coupled power units over possibly different business domains into an integrated control scheme providing fluctuation mitigation. Specifically, a method built on the combination of charging control of a variable EV fleet and a small-scale energy storage system in a prioritized control hierarchy is investigated with its impacts on both domains. The control hierarchy uses the EV charging dynamics as prime resource for the mitigation of local generation fluctuations and accommodates the residual lack with local electric storage. The definition of a controllable power range for the charging stations allows for the EV charging infrastructure to serve as a power service. The underlying two-layer control algorithms is evaluated through simulations of the dynamics of a residential grid segment combining different grid resources. The results show significantly enhanced performance for effectively reducing the energy surplus-needs through the prime control layer (here: EV charging), but also the need for careful design of secondary power capacities (here: storage).