Optimal droop offset adjustments for accurate energy trading in rural DC mini-grid clusters
Author(s)
Rodriguez Bernuz, JM
Junyent Ferre, A
Xiang, X
Type
Conference Paper
Abstract
Off-grid micro-grids and solar home systems have become an enabler for the electrification of rural areas in developing countries. Their future integration into full-scale grids poses multiple technical challenges. This paper presents a concept of local DC mini-grid formed by the interconnection of nearby micro-grids. This is envisioned as a step towards the bottom-up development of a larger grid. The paper places special emphasis on the analysis of the controller structure, which is based on a variation of the common droop controller. Generally, decentralised droop schemes present inherent limitations to achieve, simultaneously, DC voltage regulation and accurate energy tracking. The decentralised controller proposed here improves conventional approaches by optimally adjusting the droop controller setpoints based on an Optimal Power Flow (OPF) algorithm that takes into account the characteristics of individual converters and the energy trading commands. This approach can benefit from the communication layer required by the energy trading system. The control design of the mini-grid is customised for its deployment on a variation of the dual active bridge (DAB) power electronic converter. Despite the use of a centralised OPF, the system stability is guaranteed by the decentralised low-level controller. The performance of the control approach and its sensitivity to unknown system parameters is measured and validated through detailed simulation studies.
Date Issued
2021-03-05
Date Acceptance
2020-10-01
Publisher
IEEE
Start Page
453
End Page
458
Journal / Book Title
2020 International Conference on Smart Grids and Energy Systems (SGES)
Copyright Statement
© 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Grant Number
EP/R030235/1
Source
2020 International Conference on Smart Grids and Energy Systems (SGES 2020)
Publication Status
Published
Start Date
2020-11-23
Finish Date
2020-11-26
Coverage Spatial
Perth (Australia)
Date Publish Online
2021-03-05