General frequency control with aggregated control reserve capacity from time-varying sources: The case of PHEVs

Herein, the concept of an ancillary service manager is developed for the provision of additional control reserve capacity. The aggregating entity clusters time-varying, aggregated battery capacity from plug-in hybrid electric vehicle (PHEV) fleets and power reserves from conventional generators. It is shown that providing additional control reserve capacity from time-varying sources such as PHEVs is possible and beneficial for power system control. An MPC framework is used as the algorithm of choice for the ancillary service manager. It is able to manage and allocate control reserve power efficiently from its sources, taking into account their constraints on available power, energy and ramping capabilities. The proposed method is applied to the IEEE 14 bus system featuring conventional generation units and several PHEV fleets with different charging patterns and availability profiles. Emergency situations, resulting in frequency deviations on different time-scales, are simulated. The MPC scheme proves to stabilise the grid frequency at all times taking into account the various parameter constraints of the different control sources.