Development Of DC Microgrid Research Articles

Development of multiple input supply based modified SEPIC DC–DC converter for efficient management of DC microgrid

The development of DC microgrids is reliant on multi-input converters, which offer several advantages, including enhanced DC power generation and consumption efficiency, simplified quality, and stability. This paper describes the development of a multiple input supply based modified SEPIC DC–DC Converter for efficient management of DC microgrid that is powered by two DC sources. Here Multi-Input SEPIC converter offers both versatility in handling output voltage ranges and efficiency in power flow, even under challenging operating conditions like lower duty cycle values. These features contribute to the converter's effectiveness in managing power within a DC microgrid. In this configuration, the DC sources can supply energy to the load together or separately, depending on how the power switches operate. The detailed working states with equivalent circuit diagrams and theoretical waveforms, under steady-state conditions, are shown along with the current direction equations. This paper also demonstrates the typical analysis of large-signal, small-signal, steady-state modeling techniques and detailed design equations. The proposed configuration is validated through the conceptual examination using theoretical and comprehensive MATLAB simulation results. Detailed performance analysis has been done for different cases with various duty ratios. Finally, to show the competitiveness, the multi-input SEPIC topology is compared with similar recent converters.

Design of prototype for the short circuit protection of DC bus using Arduino Uno and DSP controller

Micro-grids (MGs) play a prominent role in the exchange of bulk power between loads and the central grid. MG can run in an islanding mode or grid-connected mode. When the central grid fails to provide power in such situations, MGs serves as power sources for critical facilities such as coordination facilities in railway stations and airports, transportation, university and research facilities. MGs use energy sources such as solar, wind, hydro, geothermal, and biomass to produce electricity along with rechargeable batteries, aircraft applications is continuously increasing. This leads to the development of DC MGs. A model of DC MG is located at the disaster management lab in the Department of Electrical and Electronics Engineering. The MG consists of step-downed and rectified DC power supply from conventional 230 V AC source, a PV array, wind, and a battery bank a source supplying power to a set of nine DC loads. Although DC MGs have many advantages compared to AC MGs, one of the challenges faced is the study of faults and protection of the DC MG. In this paper, a prototype for the existing system in the disaster management lab is designed in hardware and tested.

Review of Voltage Control Strategies for DC Microgrids

With the continuous development of the global economic level, global energy consumption is also on the rise, and the global power industry is faced with a number of formidable challenges including load growth, low energy efficiency, high power quality, and environmental protection. Despite the fact that distributed energy cannot be directly connected to the power grid, the concept of the microgrid (MG) is proposed to make better use of distributed energy and reduce its effect on the power grid. The low cost and high controllability of DC MGs have piqued the interest of academicians both at home and abroad. If DC MGs are to be implemented in real-world engineering, a stability control strategy is required; therefore, research on voltage stability and coordinated control of DC MGs is extremely important and promising. This paper summarizes the current research on the voltage control strategy of the DC MG from the perspective of the voltage control strategy of the DC MG. Lastly, it is proposed that the future development of DC MGs will be more focused on intelligence and control precision and that the consistency algorithm combined with the benefits of centralized control and distributed control can effectively aid the future development of DC MGs, taking into account the grid’s dependability and control precision.

The Fault Analysis of PV Cable Fault in DC Microgrids

Compared to the AC microgrids, the advantages of DC microgrids are notable. However, the development of DC microgrids is being constrained by the lack of mature protection schemes. For the foundation of designing protection schemes, the existing fault analysis focused on the fault characteristics of voltage source converters and ignored other generators. However, in DC microgrids with high permeability of photovoltaic (PV) powers, the effects of PV powers should be paid considerable attention. In this paper, the cable fault characteristics of the PV powers are analyzed in detail, and both the pole-to-ground fault and the pole-to-pole fault are considered. The fault processes are divided into several stages, and the fault circuits and main equations are described for each stage. All of the analyses are verified by the simulation model based on the PSCAD/EMTDC, and with the help of simulation results, the two main challenges the protection system confronted with are emphasized and the impacts of fault distance are analyzed. Finally, this paper proposes to employ a more reasonable converter structure and a transverse differential protection to overcome the main challenges; the effectiveness of the methods is verified by the simulation.

High-gain-high-power (HGHP) DC-DC converter for DC microgrid applications: Design and testing

The use of green energy sources to feed DC microgrids is gaining prominence over traditional centralised AC systems. DC microgrids are characterised by the use of intermediate DC-DC converter which acts as power conditioning units. Hence, the choice of an appropriate DC-DC converter becomes significant as the overall system efficiency is strongly dependent on the converter’s performance. This paper proposes a novel high gain high power (HGHP) DC-DC converter for DC microgrid, which is of one of the significant step forward in the development of DC microgrids. The suitability of the proposed HGHP DC-DC converter is demonstrated by experimental tests of the 60V/1.1kV, 3kW converter; test results validate the converter’s suitability for DC distribution. A significant number of performance parameters of the proposed converter is compared with state of the art converter topologies demonstrating the superior capabilities of the proposed converter. This paper also portrays the potential benefits that could be reaped by trending towards DC instead of existing AC system. The advantages and challenges to be confronted in the foreseeable future while implementing sustainable DC microgrids are also highlighted. Finally, this paper encapsulates renewable energy fed DC microgrid system as an appropriate, technically feasible, economically viable and competent solution for efficiently utilising the sustainable energy sources.