Enhanced Sufficient Battery Model for Aggregate Flexibility of Thermostatically Controlled Loads Considering Coupling Constraints

This letter proposes an enhanced sufficient battery model (ESBM) as well as a binary search algorithm for an improved inner-approximation of the aggregate flexibility of thermostatically controlled load (TCL) arrays. Compared with the previous work on generalized battery models, our ESBM preserves the merits of being sufficient and reduces conservativity. Moreover, unlike the works ignoring the coupling constraints (e.g., the constraints regarding the distribution network where TCL individuals are physically connected) that may significantly restrict TCLs' aggregate flexibility, our ESBM can readily handle these constraints. Numerical tests validate the merits and significance of using our ESBM for power system operations.