Balancing Renewable Energy Source with Vehicle to Grid Services from a Large Fleet of Plug-In Hybrid Electric Vehicles controlled in a Metropolitan Area Distribution Network

摘要

The endeavor for a more sustainable power generation has led to a dramatic increase in powergeneration from renewable energy sources (RES), such as wind and solar. These sources areof fluctuating nature and therefore introduce new challenges to power system operation,which was historically designed for generators with constant infeed. The fluctuations arebalanced by ancillary services contracted from flexible generators or storages. So far, largescale solutions for storage are only provided by pumped hydro. However, one potentialsolution for a large storage could be to aggregate Plug-In Hybrid Electric Vehicles (PHEVs),once they are adopted on a wide scale, into a virtual storage. This storage could then be usedto balance the infeed error of RES. The balancing would imply that the PHEVs could berecharged from emission free sources, thereby enabling an emission free individualtransportation sector. This paper focuses on the realization of an aggregated PHEV storageand the balancing of RES infeed errors. In specific, the paper investigates how a large fleet ofPHEVs can be aggregated over a large, urban electricity distribution network and how thisstorage can be used to balance a wind infeed error while considering the limits of theunderlying infrastructure. The balancing can be achieved through so called vehicle-to-grid(V2G) services which allow PHEVs to act both as loads and as generators. The utilizedaggregation scheme is based on an intelligent PHEV charging control scheme which avoidsnegative network impacts, such as overloading of assets, from excessive PHEV charging.V2G services are added on top of this intelligent recharging infrastructure. The paper showsthat by using a Model Predictive Control (MPC) approach as a controller for the aggregatedPHEV storage, an intrahour wind infeed error from a 500 MW wind park can be fullybalanced while keeping the underlying distribution network in a secure state.