  This paper proposes a concept of generalized energy storage (GES) to
facilitate the integration of large-scale heterogeneous flexible resources with
electric/thermal energy storage capacity to participate in multiple markets.
First, a generalized state variable referred to as degree of satisfaction (DoS)
is defined, and dynamic models with a unified form are derived for different
types of GESs. Second, a real-time market-based coordination framework is
proposed to facilitate control, and ensure user privacy and device security.
Demand curves of different GESs are then developed based on DoS to express
their demand urgencies as well as flexibilities. Furthermore, a low-dimensional
aggregate dynamic model of a GES cluster is derived thanks to the DoS-equality
control feature provided by the design of demand curve. At last, an
optimization model for a large-scale GESs to participate in both the energy
market and regulation market is established based on the aggregate model.
Simulations results demonstrate that the optimization algorithm could
effectively reduce the total cost of an aggregator. Additionally, the proposed
coordination method has high tracking accuracy and could well satisfy users'
diversified power demand.
