Hybrid Transmission Distribution Co-simulation: Frequency Regulation using Battery Energy Storage (1912.07204v1)

Abstract: Battery energy storage systems (BESS) are proving to be an effective solution in providing frequency regulation services to the bulk grid. However, there are several concerns for the transmission/distribution system operators (TSO/DSO) with the frequent dispatching of the distribution-connected fast-responding storage systems. Unfortunately, the existing decoupled models for transmission and distribution (T&D) simulations are unable to capture the complex interactions between the two systems especially concerning frequency regulation problems due to rapidly varying distribution-connected distributed energy resources (DERs). In this paper, an iteratively coupled T&D hybrid co-simulation framework is developed to facilitate the planning studies for the system operators to help integrate distribution-connected BESS in providing frequency regulation services in response to highly variable DERs such as photovoltaic generation (PVs). Specifically, the proposed framework helps evaluate: (1) the effects of distribution-connected DERs/PVs on the response of the system's automatic generation control (AGC) response, and (2) highlights the use of BESS in providing frequency regulation services using integrated T&D model. The proposed framework is demonstrated using the IEEE 9-bus transmission system model (operating in dynamics mode) coupled with multiple EPRI Ckt-24 distribution system models (operating in quasi-static mode). It is shown that the proposed co-simulation framework helps better visualize the system AGC response and frequency regulation especially in the presence of high-levels of DER generation variability requiring frequent dispatch of BESS.