Hierarchical Control of Heterogeneous Inverter Air-Conditionings for Primary Frequency Regulation

The expanding penetration of renewable generation challenges system frequency regulation with short-term power-demand mismatches and reduced system inertia. This paper presents a hierarchical control strategy which use inverter air-conditionings (IACs) for primary frequency regulation (PFR). Considering the heterogeneity of IACs, a clustering method is proposed to divide different types of IACs into different clusters to control. Thus, the proposed control system consists of a central controller, clusters and IACs. The cluster sends information of setpoint and frequency responsive band to the IACs. A random number generation method is proposed to trigger IACs to implement PFR, where decentralized control is adopted to help realize a fast response. A corresponding recovery method is presented to restore the IACs to the initial operating state quickly and stably. Dynamic simulations verify the effectiveness of the control strategy.