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

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5595
Author(s):  
Maria Fotopoulou ◽  
Dimitrios Rakopoulos ◽  
Dimitrios Trigkas ◽  
Fotis Stergiopoulos ◽  
Orestis Blanas ◽  
...  
Keyword(s):  
Direct Current ◽  
Low Voltage ◽  
State Of The Art ◽  
Renewable Energy Sources ◽  
Electrical Power ◽  
Research Field ◽  
Total Load ◽  
Dc Microgrids ◽  
Medium Voltage ◽  
Battery Energy

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.

scholarly journals STUDI PENGARUH TIDAK BEROPERASINYA PLTSa SUWUNG TERHADAP PROFIL TEGANGAN PADA PENYULANG SERANGAN

2018 ◽  
Vol 5 (2) ◽  
pp. 299
Author(s):  
Gede Endrawadi ◽  
I Wayan Sukerayasa ◽  
Wayan Gede Ariastina
Keyword(s):  
Renewable Energy ◽  
Power Plant ◽  
Distributed Generation ◽  
Power Supply ◽  
Low Voltage ◽  
Renewable Energy Sources ◽  
Electrical Power ◽  
Energy Sources ◽  
Voltage Profile ◽  
Medium Voltage

The power plant with renewable energy sources is needed to reduce the pollution. One of this kind is in Bali, that is PLTSa (Garbage Power Plant) Suwung. However, PLTSa Suwung is no longer operating for now. PLTSa Suwung is connected with Serangan feeder, this connection named Distributed Generation. When PLTSa Suwung doesn’t operate, it will affect the Serangan feeder’s voltage profile. The change of voltage profile will be analyzed with EDSA Technical 2000 Service Pack 3.5 software. The research will give five scenarios with different electrical power supply from each scenario. The gap of the voltage profile between scenario 1 (100% power supply from PLTSa) and scenario 5 (0% power suplly from PLTSa) is 0,0079% for medium voltage bus and 0,0062% for low voltage bus. This small gap shows that the connected PLTSa Suwung doesn’t give effect to voltage profile of Serangan feeder.

scholarly journals An Overview of Bidirectional AC-DC Grid Connected Converter Topologies for Low Voltage Battery Integration

2018 ◽  
Vol 9 (3) ◽  
pp. 1223 ◽  
Author(s):  
Kaspars Kroics ◽  
Oleksandr Husev ◽  
Kostiantyn Tytelmaier ◽  
Janis Zakis ◽  
Oleksandr Veligorskyi
Keyword(s):  
Energy Storage ◽  
High Efficiency ◽  
Low Voltage ◽  
Renewable Energy Sources ◽  
Storage System ◽  
Distribution Grid ◽  
Battery Energy Storage ◽  
Battery Energy Storage Systems ◽  
Converter Topologies ◽  
Battery Energy

<p>Battery energy storage systems are becoming more and more popular solution in the household applications, especially, in combination with renewable energy sources. The bidirectional AC-DC power electronic converter have great impact to the overall efficiency, size, mass and reliability of the storage system. This paper reviews the literature that deals with high efficiency converter technologies for connecting low voltage battery energy storage to an AC distribution grid. Due to low voltage of the battery isolated bidirectional AC-DC converter or a dedicated topology of the non isolated converter is required. Review on single stage, two stage power converters and integrated solutions are done in the paper.</p>

scholarly journals Multiobjective Approach for Medium- and Low-Voltage Planning of Power Distribution Systems Considering Renewable Energy and Robustness

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2517
Author(s):  
Diogo Rupolo ◽  
Benvindo Pereira Junior ◽  
Javier Contreras ◽  
José Mantovani
Keyword(s):  
Renewable Energy ◽  
Power Distribution ◽  
Distribution System ◽  
Distribution Systems ◽  
Low Voltage ◽  
Renewable Energy Sources ◽  
Optimization Techniques ◽  
Neighborhood Search ◽  
Medium Voltage ◽  
Multiobjective Approach

In this paper, a multiobjective approach to carry out the planning of medium-voltage (MV) and low-voltage (LV) distribution systems, considering renewable energy sources (RES) and robustness, is proposed. Due to the uncertainties associated with RES and demand, the proposed planning methodology takes into account a robust planning index (RPI). This RPI allows us to evaluate the robustness estimation associated with each planning solution. The objective function in the mathematical model considers the costs of investment and operation and the robustness of the planning proposals. Due to the computational complexity of this problem, which is difficult to solve by means of classical optimization techniques, MV/LV planning is solved by a decomposition search and a general variable neighborhood search (GVNS) algorithm. To demonstrate the efficiency and robustness of this methodology, tests are performed in an integrated distribution system with 50 MV nodes and 410 LV nodes. Our numerical results show that the proposed methodology makes it possible to minimize costs and improve robustness levels in distribution system planning.

scholarly journals Review and Comparison of Grid-Tied Inverter Controllers in Microgrids

2020 ◽  
Author(s):  
Tommaso Caldognetto
Keyword(s):  
Power Distribution ◽  
Distribution Systems ◽  
Low Voltage ◽  
Control Strategies ◽  
Renewable Energy Sources ◽  
Electrical Power ◽  
Voltage Source ◽  
Smart Power ◽  
Operating Modes ◽  
Grid Connected Inverter

<div><div><div><p>Grid-tied inverters are widely used for interfacing renewable energy sources or storage devices to low-voltage electrical power distribution systems. Lately, a number of different control techniques have been proposed to address the emerging requirements of the smart power system scenario, in terms of both functionalities and performance. This paper reviews the techniques proposed for the implementation of current-controlled or voltage-controlled inverters in microgrids. By referring to a voltage source inverter with LCL output filter, the different control architectures are classified as single-, double-, and triple- loop. Then, the functionalities that are needed or recommended in the grid-connected, islanded, and autonomous operating modes of the grid-tied inverter are identified and their implementation in the different control structures is discussed. To validate the analysis and to better illustrate the merits and limitations of the most effective solutions, six control strategies are finally implemented and experimentally compared on a single-phase, grid-connected inverter setup.</p></div></div></div>

scholarly journals STUDI ANALISIS GANGGUAN PERANGKAT HUBUNG BAGI TEGANGAN RENDAH DAN UPAYA MENGATASINYA DI PLN AREA TANJUNG PRIOK

2018 ◽  
Vol 9 (1) ◽  
pp. 51-59
Author(s):  
Redaksi Tim Jurnal
Keyword(s):  
Low Voltage ◽  
High Reliability ◽  
Electrical Power ◽  
Power Source ◽  
Achievement Level ◽  
Medium Voltage ◽  
Ground Plate ◽  
The Cost ◽  
Over Time

Medium voltage feeders are a means for the distribution of electricity from substations to consumers. But in reality these feeders often experience interference, among other is interference onthe low voltage network, especiallyCircuit For Low Voltage Device. Circuit For Low Voltage Device (PHB-TR) is device used as a liaison, security, and dividers electrical power from an electric power source to the customer. Over time, the PHB-TR also decreased quality of service so that should be their efforts to overcome the problems in order to maintain or restore the initial achievement level and can operate with high reliability so that the continuity of the electrical service will be achieved. The disturbances that can occur in this PHB-TR as damage to the NH fuse, corona contained in ground plate, over current and damage to the measuring instrument.Additionally by overcoming the interference can secure the assets of PLN from the interferences and reduce the cost of replacing broken tools.

scholarly journals Design of a Low Voltage DC Mini-grid for Isolated Healthcare Centres

2021 ◽  
Author(s):  
Vishnu Dhinakaran ◽  
K Akash ◽  
Rakshaa Viswanathan ◽  
S. Arul Daniel ◽  
A. Rakesh Kumar
Keyword(s):  
Primary Healthcare ◽  
Rural Areas ◽  
Low Voltage ◽  
Renewable Energy Sources ◽  
Electrical Power ◽  
Research Work ◽  
Diesel Generator ◽  
Fuel Prices ◽  
Long Run ◽  
Primary Healthcare Centre

Primary healthcare centres are essential to any inhabited place in the world. A lack of electrical power from the grid should not be a reason for people in remote rural areas to miss out on basic healthcare. In developing countries like India, rural healthcare centres usually have intermittent or no grid supply and run on diesel generator-based electricity or other conventional sources, if at all there are such centres established. This, however, contributes to environmental degradation and is also expensive to maintain, considering fluctuating fuel prices. To turn the dependence on renewable energy sources like photovoltaics would pave the way to sustainable energy production and utilization, which costs less in the long run. This research work aims at designing an islanded low voltage DC solar mini-grid that will provide enough power to sustain a primary healthcare centre that has less to no access to the national grid. Previous works in this context tend to rely on varying extents of intermittent supply from the national grid, which may not be the reality in most Indian rural areas. Additionally, an unreliable source of power from the grid which is also difficult to predict would make sensitive and important loads less accessible.

Current and Voltage Choice for North American Railroad Electrifications: 1895-1931

2020 ◽  
Author(s):  
John G. Allen
Keyword(s):  
Direct Current ◽  
North American ◽  
Single Phase ◽  
Low Voltage ◽  
Alternating Current ◽  
Early Adopters ◽  
Medium Voltage ◽  
Medium Voltage Dc

Abstract The variety of currents and voltages adopted by North American railroads between 1895 and 1931 is sometimes seen as confusing. Railroads faced choices between direct current (DC) and alternating current (AC), as well as among different voltages. But closer analysis shows a clear order to the specifications chosen. The technology options available at the time and the intended functions of these installations explain the specifications that railroads chose. Railroads electrifying fell into three basic groups: 1. Early adopters (usually requiring electrification for tunnels), 2. Railroads electrifying after 1910 for commuter service, and 3. Railroads that electrified for, or at least with freight service in mind. Each of these faced very different sets of options, and made their choice of electrical specifications accordingly. There were four basic combinations of current and voltage: 1. Low-voltage DC delivered via third rail, 2. Medium-voltage DC, 3. Higher-voltage DC, and 4. AC (almost always single-phase at 11,000 Volts, 25 Hertz). For railroads in a given category, the practicable choices were in fact limited to one or two options. Contrary to what is sometimes thought, the different electrical specifications reflected an underlying logic, not disorder.

scholarly journals Novel Earth Fault Protection Algorithm Based on MV Cable Screen Zero Sequence Current Filter

Energies ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 3190 ◽  
Author(s):  
Krzysztof Lowczowski ◽  
Jozef Lorenc ◽  
Jerzy Andruszkiewicz ◽  
Zbigniew Nadolny ◽  
Jozef Zawodniak
Keyword(s):  
Distribution System ◽  
Low Voltage ◽  
Renewable Energy Sources ◽  
Simulation Software ◽  
Protection Relay ◽  
Medium Voltage ◽  
Earth Fault ◽  
Fault Protection ◽  
Zero Sequence ◽  
Cable Lines

This paper presents novel zero sequence current filter and earth fault protection relay, which utilize cable screens earthing current in protection algorithm. Different problems connected with state of the art of zero sequence current filters and protection relays are presented and compared with the proposed solution. The presented concept is verified in PowerFactory simulation software, experiment concerning modeling the earth fault current flow in medium voltage (MV) cable supplied from the low voltage (LV) network and measurements in the MV network in the Polish distribution system. The proposed solution is characterized by higher sensitivity and reduced number of erroneous trips. The presented solution is suitable for any MV cable lines. Biggest advantages are observed in power output lines from renewable energy sources, which are often operated under no-load conditions.

scholarly journals Modular Multi-Port Ultra-High Power Level Power Converter Integrated with Energy Storage for High Voltage Direct Current (HVDC) Transmission

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2711 ◽  
Author(s):  
Sen Song ◽  
Wei Li ◽  
Kai Ni ◽  
Hui Xu ◽  
Yihua Hu ◽  
...  
Keyword(s):  
Energy Storage ◽  
High Voltage ◽  
Direct Current ◽  
Power Plants ◽  
High Efficiency ◽  
Low Voltage ◽  
Renewable Energy Sources ◽  
Power Converter ◽  
Hvdc Transmission ◽  
High Voltage Direct Current

To connect renewable energy sources (RESs) with a unity-grid, energy storage (ES) systems are essential to eliminate the weather fluctuation effect, and high voltage direct current (HVDC) transmission is preferred for large-scale RESs power plants due to the merits of low cost and high efficiency. This paper proposes a multi-port bidirectional DC/DC converter consisting of multiple modules that can integrate ES system and HVDC transmission. Thanks to the adoption of three-port converters as submodules (SMs), ES devices, for example, batteries, can be decentralized into SMs and controlled directly by the SMs. Additionally, SMs are connected in a scalable matrix topology, presenting the advantages of flexible power flows, high voltage step-up ratios and low voltage/current ratings of components to satisfy the requirements of HVDC transmission. Furthermore, the control flexibility and fault tolerance capability are increased due to the matrix topology. In this paper, the analysis of the novel modular multi-port converter is introduced, and its functions are verified by the simulation results in PSIM.

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