Submit to Energies Review for Energies Propose a Special Issue

Journal Browser

Direct Current (DC) Distribution Grids and Microgrids

Print Special Issue Flyer
Special Issue Editors
Special Issue Information
Published Papers

A special issue of Energies (ISSN 1996-1073). This special issue belongs to the section "A1: Smart Grids and Microgrids".

Deadline for manuscript submissions: closed (21 November 2021) | Viewed by 19516

Share This Special Issue

Special Issue Editors

Dr. Laura Ramírez Elizondo

E-Mail Website
Guest Editor

Department of Electrical Sustainable Energy, Delft University of Technology, Mekelweg 4, 2628 CD Delft, The Netherlands
Interests: microgrid
Special Issues, Collections and Topics in MDPI journals

Dr. Aditya Shekhar

E-Mail Website
Guest Editor

Electrical Sustainable Energy, Delft University of Technology, Mekelweg 4, 2628 CD Delft, The Netherlands
Interests: reliability of power electronic systems; medium DC voltage; modular multilevel converters; renewable energy

Special Issue Information

DC distribution is finding increasing applications in various areas, including off-grid microgrids, transportation electrification, data centres, and residential and industrial purposes. Societal focus on sustainable energy transition, including increasing use of electric vehicles, renewable energy generation, and electric heating, has put pressure on the traditional AC power grid infrastructure. DC-based technologies can play a key role in integrating these emerging grid components. This Special Issue invites original research papers addressing the following topics:

Modelling of DC distribution grids
Control of DC distribution grids
Stability of DC distribution grids
Protection in DC distribution grids
Power electronics converters in dc distribution systems
Shipboard DC Distribution
DC Microgrids
DC microgrids topologies
Hybrid AC-DC microgrids
Integration of storage in DC distribution grids

Dr. Laura Ramírez Elizondo
Dr. Aditya Shekhar
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Energies is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Published Papers (6 papers)

Download All Papers

Research

Jump to: Review, Other

19 pages, 3742 KiB

Open AccessArticle

DC Bus Voltage Selection for a Grid-Connected Low-Voltage DC Residential Nanogrid Using Real Data with Modified Load Profiles

by Saeed Habibi, Ramin Rahimi, Mehdi Ferdowsi and Pourya Shamsi

Energies 2021, 14(21), 7001; https://doi.org/10.3390/en14217001 - 26 Oct 2021

Cited by 13 | Viewed by 2259

Abstract

This study examines various low voltage levels applied to a direct current residential nanogrid (DC-RNG) with respect to the efficiency and component cost of the system. Due to the significant increase in DC-compatible loads, on-site Photovoltaic (PV) generation, and local battery storage, DC distribution has gained considerable attention in buildings. To provide an accurate evaluation of the DC-RNG’s efficiency and component cost, a one-year load profile of a conventional AC-powered house is considered, and AC appliances’ load profiles are scaled to their equivalent available DC appliances. Based on the modified load profiles, proper wiring schemes, converters, and protection devices are chosen to construct a DC-RNG. The constructed DC-RNG is modeled in MATLAB software and simulations are completed to evaluate the efficiency of each LVDC level. Four LVDC levels—24 V, 48 V, 60 V, and 120 V—are chosen to evaluate the DC-RNG’s efficiency and component cost. Additionally, impacts of adding a battery energy storage unit on the DC-RNG’s efficiency are studied. The results indicate that 60 V battery-less DC-RNG is the most efficient one; however, when batteries are added to the DC-RNG, the 48 V DC distribution becomes the most efficient and cost-effective option. Full article

(This article belongs to the Special Issue Direct Current (DC) Distribution Grids and Microgrids)

► Show Figures

Figure 1

22 pages, 1479 KiB

Open AccessEditor’s ChoiceArticle

Comparison of AC and DC Nanogrid for Office Buildings with EV Charging, PV and Battery Storage

by Ilman Sulaeman, Gautham Ram Chandra Mouli, Aditya Shekhar and Pavol Bauer

Energies 2021, 14(18), 5800; https://doi.org/10.3390/en14185800 - 14 Sep 2021

Cited by 13 | Viewed by 2060

Abstract

Future office buildings are expected to be integrated with energy intensive, inherently DC components such as photovoltaic panels (PV), electric vehicles (EV), LED lighting, and battery storage. This paper conceptualizes the interconnection of these components through a 750 V DC nanogrid as against a conventional three-phase 400 V AC system. The factors influencing the performance of a DC-based nanogrid are identified and a comparative analysis with respect to a conventional AC nanogrid is presented in terms of efficiency, stability, and protection. It is proved how the minimization of grid energy exchange through power management is a vital system design choice. Secondly, the trade-off between stability, protection, and cost for sizing of the DC buffer capacitors is explored. The transient system response to different fault conditions for both AC and DC nanogrid is investigated. Finally the differences between the two systems in terms of various safety aspects are highlighted. Full article

(This article belongs to the Special Issue Direct Current (DC) Distribution Grids and Microgrids)

► Show Figures

Figure 1

21 pages, 1078 KiB

Open AccessArticle

A Comprehensive Loss Model and Comparison of AC and DC Boost Converters

by Daniel L. Gerber, Fariborz Musavi, Omkar A. Ghatpande, Stephen M. Frank, Jason Poon, Richard E. Brown and Wei Feng

Energies 2021, 14(11), 3131; https://doi.org/10.3390/en14113131 - 27 May 2021

Cited by 4 | Viewed by 2732

Abstract

DC microgrids have become a prevalent topic in research in part due to the expected superior efficiency of DC/DC converters compared to their AC/DC counterparts. Although numerous side-by-side analyses have quantified the efficiency benefits of DC power distribution, these studies all modeled converter loss based on product data that varied in component quality and operating voltage. To establish a fair efficiency comparison, this work derives a formulaic loss model of a DC/DC and an AC/DC PFC boost converter. These converters are modeled with identical components and an equivalent input and output voltage. Simulated designs with real components show AC/DC boost converters between 100 W to 500 W having up to 2.5 times more loss than DC/DC boost converters. Although boost converters represent a fraction of electronics in buildings, these loss models can eventually work toward establishing a comprehensive model-based full-building analysis. Full article

(This article belongs to the Special Issue Direct Current (DC) Distribution Grids and Microgrids)

► Show Figures

Figure 1

14 pages, 5632 KiB

Open AccessArticle

A New High-Gain DC-DC Converter with Continuous Input Current for DC Microgrid Applications

by Javed Ahmad, Mohammad Zaid, Adil Sarwar, Chang-Hua Lin, Mohammed Asim, Raj Kumar Yadav, Mohd Tariq, Kuntal Satpathi and Basem Alamri

Energies 2021, 14(9), 2629; https://doi.org/10.3390/en14092629 - 04 May 2021

Cited by 38 | Viewed by 3884

Abstract

The growth of renewable energy in the last two decades has led to the development of new power electronic converters. The DC microgrid can operate in standalone mode, or it can be grid-connected. A DC microgrid consists of various distributed generation (DG) units like solar PV arrays, fuel cells, ultracapacitors, and microturbines. The DC-DC converter plays an important role in boosting the output voltage in DC microgrids. DC-DC converters are needed to boost the output voltage so that a common voltage from different sources is available at the DC link. A conventional boost converter (CBC) suffers from the problem of limited voltage gain, and the stress across the switch is usually equal to the output voltage. The output from DG sources is low and requires high-gain boost converters to enhance the output voltage. In this paper, a new high-gain DC-DC converter with quadratic voltage gain and reduced voltage stress across switching devices was proposed. The proposed converter was an improvement over the CBC and quadratic boost converter (QBC). The converter utilized only two switched inductors, two capacitors, and two switches to achieve the gain. The converter was compared with other recently developed topologies in terms of stress, the number of passive components, and voltage stress across switching devices. The loss analysis also was done using the Piecewise Linear Electrical Circuit Simulation (PLCES). The experimental and theoretical analyses closely agreed with each other. Full article

(This article belongs to the Special Issue Direct Current (DC) Distribution Grids and Microgrids)

► Show Figures

Figure 1

Review

Jump to: Research, Other

27 pages, 2517 KiB

Open AccessFeature PaperReview

State of the Art of Low and Medium Voltage Direct Current (DC) Microgrids

by Maria Fotopoulou, Dimitrios Rakopoulos, Dimitrios Trigkas, Fotis Stergiopoulos, Orestis Blanas and Spyros Voutetakis

Energies 2021, 14(18), 5595; https://doi.org/10.3390/en14185595 - 07 Sep 2021

Cited by 41 | Viewed by 5218

Abstract

Direct current (DC) microgrids (MG) constitute a research field that has gained great attention over the past few years, challenging the well-established dominance of their alternating current (AC) counterparts in Low Voltage (LV) (up to 1.5 kV) as well as Medium Voltage (MV) applications (up to 50 kV). The main reasons behind this change are: (i) the ascending amalgamation of Renewable Energy Sources (RES) and Battery Energy Storage Systems (BESS), which predominantly supply DC power to the energy mix that meets electrical power demand and (ii) the ascending use of electronic loads and other DC-powered devices by the end-users. In this sense, DC distribution provides a more efficient interface between the majority of Distributed Energy Resources (DER) and part of the total load of a MG. The early adopters of DC MGs include mostly buildings with high RES production, ships, data centers, electric vehicle (EV) charging stations and traction systems. However, the lack of expertise and the insufficient standards’ framework inhibit their wider spread. This review paper presents the state of the art of LV and MV DC MGs in terms of advantages/disadvantages over their AC counterparts, their interface with the AC main grid, topologies, control, applications, ancillary services and standardization issues. Overall, the aim of this review is to highlight the possibilities provided by DC MG architectures as well as the necessity for a solid/inclusive regulatory framework, which is their main weakness. Full article

(This article belongs to the Special Issue Direct Current (DC) Distribution Grids and Microgrids)

► Show Figures

Figure 1

Other

Jump to: Research, Review

17 pages, 5420 KiB

Open AccessConcept Paper

DC Microgrid Utilizing Artificial Intelligence and Phasor Measurement Unit Assisted Inverter

by Raziq Yaqub, Mohamed Ali and Hassan Ali

Energies 2021, 14(19), 6086; https://doi.org/10.3390/en14196086 - 24 Sep 2021

Cited by 1 | Viewed by 1926

Abstract

Community microgrids are set to change the landscape of future energy markets. The technology is being deployed in many cities around the globe. However, a wide-scale deployment faces three major issues: initial synchronization of microgrids with the utility grids, slip management during its operation, and mitigation of distortions produced by the inverter. This paper proposes a Phasor Measurement Unit (PMU) Assisted Inverter (PAI) that addresses these three issues in a single solution. The proposed PAI continually receives real-time data from a Phasor Measurement Unit installed in the distribution system of a utility company and keeps constructing a real-time reference signal for the inverter. To validate the concept, a unique intelligent DC microgrid architecture that employs the proposed Phasor Measurement Unit (PMU) Assisted Inverter (PAI) is also presented, alongside the cloud-based Artificial Intelligence (AI), which harnesses energy from community shared resources, such as batteries and the community’s rooftop solar resources. The results show that the proposed system produces quality output and is 98.5% efficient. Full article

(This article belongs to the Special Issue Direct Current (DC) Distribution Grids and Microgrids)

► Show Figures