Hierarchical, Grid-Aware, and Economically Optimal Coordination of Distributed Energy Resources in Realistic Distribution Systems

Abstract

Renewable portfolio standards are targeting high levels of variable solar photovoltaics (PV) in electric distribution systems, which makes reliability more challenging to maintain for distribution system operators (DSOs). Distributed energy resources (DERs), including smart, connected appliances and PV inverters, represent responsive grid resources that can provide flexibility to support the DSO in actively managing their networks to facilitate reliability under extreme levels of solar PV. This flexibility can also be used to optimize system operations with respect to economic signals from wholesale energy and ancillary service markets. Here, we present a novel hierarchical scheme that actively controls behind-the-meter DERs to reliably manage each unbalanced distribution feeder and exploits the available flexibility to ensure reliable operation and economically optimizes the entire distribution network. Each layer of the scheme employs advanced optimization methods at different timescales to ensure that the system operates within both grid and device limits. The hierarchy is validated in a large-scale realistic simulation based on data from the industry. Simulation results show that coordination of flexibility improves both system reliability and economics, and enables greater penetration of solar PV. Discussion is also provided on the practical viability of the required communications and controls to implement the presented scheme within a large DSO.

A Survey on Smart Buildings Integration with 5G and Cloud Technologies towards Energy Efficiency

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“…In this work, we consider a hierarchical and modular microgrid control architecture, [10], [14], [16], which allows system-level dispatch of power set-points to inverterbased resources, accommodating only limited data exchange between the (neighboring) inverter modules. Our objective is to design bounds on dispatched control set-points at the inverter buses, that guarantee, in a distributed sense, the safe excursions of local voltage and frequency within the specified limits while tolerating uncertainty in the neighboring buses.…”

Decentralized Frequency Control using Packet-based Energy Coordination

“…In addition, the expected value of the power of the accepted requests corresponding to tracking P nom is n u =P nom /(n p ) [16]. Therefore, using (18), q + has a Gaussian distribution with mean and standard deviation given by ( 14) and (15).…”

“…Moreover, adaptive controllers have been shown to reduce problems with actuation delay. Finally, hierarchical optimization-based DER coordination schemes were developed in [15] with the advantage that AC network constraints can be considered. This is the so-called grid-aware coordination.…”