Frequency Regulation With Heterogeneous Energy Resources: A Realization Using Distributed Control

Abstract

This paper presents one of the first real-life demonstrations of coordinated and distributed resource control for secondary frequency response in a power distribution grid. A series of tests involved up to 69 heterogeneous active distributed energy resources consisting of air handling units, unidirectional and bidirectional electric vehicle charging stations, a battery energy storage system, and 107 passive distributed energy resources consisting of building loads and solar photovoltaic systems. The distributed control setup consists of a set of Raspberry Pi endpoints exchanging messages via an ethernet switch. Actuation commands for the distributed energy resources are obtained by solving a power allocation problem at every regulation instant using distributed ratio-consensus, primal-dual, and Newton-like algorithms. The problem formulation minimizes the sum of distributed energy resource costs while tracking the aggregate setpoint provided by the system operator. We demonstrate accurate and fast real-time distributed computation of the optimization solution and effective tracking of the regulation signal over 40minute time horizons. An economic benefit analysis confirms eligibility to participate in an ancillary services market and demonstrates up to $49k of potential annual revenue for the selected population of distributed energy resources.

Optimization-Based Ramping Reserve Allocation of BESS for AGC Enhancement

“…In (3) To ensure the proper functioning of the power system with an increasing share of RESs, Fast Frequency Reserve (FFR) based on under-frequency load shedding, energy storage [34], [35], direct load control [36], [37], etc. have been proposed in the literature, where common control measures include droop [34], [37] (sometimes with dead-zone), sectional droop [36], [38], and nonlinear droop [35], [39].…”

“…To achieve this goal, the Area Control Error (ACE) has played an important role [1]. However, with the growing use of intermittent and stochastic RESs, the regulation burden has become more challenging due to the immature management of these resources [2], [3]. As a result, policymakers and Independent System Operators (ISOs) worldwide are actively exploring the commercial use of Battery Energy Storage Systems (BESSs) to provide grid services.…”

DERConnect

“…Based on earlier work in the ARPA-E NODES program [3] , In 2020 the University of California, San Diego was awarded a National Science Foundation Mid-Scale Research Infrastructure (RI) grant to construct a testbed that is dedicated towards the control and optimization of millions of DERs. The testbed will open in 2025.…”

Optimization-Based Ramping Reserve Allocation of BESS for AGC Enhancement

“…T HE ambitious aim of replacing coal-based generation with Renewable Energy Sources (RESs) has aggravated the burden on frequency regulation due to immature management of RES [1], [2]. Recognizing the operational challenges faced by existing power systems, policymakers and Independent System Operators (ISOs) around the world have actively engaged in the commercial use of Battery Energy Storage Systems (BESSs) in the provision of grid services.…”