Distributed Apportioning in a Power Network for providing Demand Response Services

TL;DR

This paper presents a distributed, consensus-based scheme for power apportioning among DERs in a power network, enabling self-adjustment, prioritization of renewable sources, and finite-time termination despite communication delays, validated through hardware-in-the-loop simulations.

Contribution

It introduces a novel distributed finite-time algorithm for power reference allocation in DER networks that accounts for local constraints and prioritizes renewable energy sources.

Findings

The scheme ensures DERs meet grid demand while respecting local constraints.

It achieves finite-time convergence despite communication delays.

Hardware-in-the-loop tests validate real-time applicability.

Abstract

Greater penetration of Distributed Energy Resources (DERs) in power networks requires coordination strategies that allow for self-adjustment of contributions in a network of DERs, owing to variability in generation and demand. In this article, a distributed scheme is proposed that enables a DER in a network to arrive at viable power reference commands that satisfies the DERs local constraints on its generation and loads it has to service, while, the aggregated behavior of multiple DERs in the network and their respective loads meet the ancillary services demanded by the grid. The Net-load Management system for a single unit is referred to as the Local Inverter System (LIS) in this article . A distinguishing feature of the proposed consensus based solution is the distributed finite time termination of the algorithm that allows each LIS unit in the network to determine power reference commands in the presence of communication delays in a distributed manner. The proposed scheme allows prioritization of Renewable Energy Sources (RES) in the network and also enables auto-adjustment of contributions from LIS units with lower priority resources (non-RES). The methods are validated using hardware-in-the-loop simulations with Raspberry PI devices as distributed control units, implementing the proposed distributed algorithm and responsible for determining and dispatching realtime power reference commands to simulated power electronics interface emulating LIS units for demand response.