Distributed aggregation control of grid-interactive smart buildings for power system frequency support

Abstract

Grid-interactive smart buildings with thermostatically-controlled loads can be modeled as virtual energy storage systems with dissipation, which have great potentials for providing grid ancillary services such as frequency support. In this paper, a new distributed aggregation control method is proposed for multiple grid-interactive smart buildings in one frequency control area (e.g. a residential community) to provide fast frequency support. The proposed method is based on the distributed sliding mode control via a leader-follower communication scheme. A leader control is designed to provide power and comfort/energy level references for the smart building aggregator based on the area frequency deviation, while references are tracked by each smart building using the proposed distributed sliding mode control. The stability of the proposed control method for grid-interactive smart buildings is proved by the Lyapunov method. With the proposed method, the external characteristics of the aggregated smart buildings will have good power tracking and energy recovery capability, which can effectively improve the system frequency response. In the aggregator, fair and efficient power and comfort/energy level sharing are achieved among all participating grid-interactive smart buildings. The proposed control scheme is tested on a three-area power system considering both system contingency and normal operation scenarios.