Found 6 results
Article
12 June 2024Optimized Real Time Single-Drone Path Planning for Harvesting Information from a Wireless Sensor Network
We consider a remote sensing system in which fixed sensors are placed in a region, and a single drone flies over the region to collect information from cluster heads. We assume that the drone has a fixed maximum range and that the energy consumption for information transmission from the cluster heads increases with distance according to a power law. Given these assumptions, we derive local optimum conditions for a drone path that either minimizes the total or maximum energy required by the cluster heads to transmit information to the drone. We show how a homotopy approach can produce a family of solutions for different drone path lengths so that a locally optimal solution can be found for any drone range. We implement the homotopy solution in Python and demonstrate the tradeoff between drone range and cluster head power consumption for several geometries. Execution time is sufficiently rapid for the computation to be performed in real time so that the drone path can be recalculated on the fly. The solution is shown to be globally optimal for sufficiently long drone path lengths. A proof of concept implementation in Python is available on GitHub. For future work, we indicate how the solution can be modified to accommodate moving sensors.
Article
04 June 2024Investigating and Analyzing the Impact of a Bidirectional Multiport Power Electronic Transformer Interface on the Power Quality and Stability of Interconnected Microgrids
This paper investigates the potential benefits of a bidirectional multi-port power electronic transformer (MPPET) to interface multiple microgrids with utility distribution networks in terms of power quality and stability. The main concept is based on the interaction between the utility grid, the connected microgrids, and the MPPET in controlling the disturbances that lead to grid instability and power quality issues. The proposed MPPET does not require any serious communication infrastructure for operation. In addition, the MPPET can respond to reverse power flow caused by excess power generation on the grid. Due to the intermittent nature of the renewable energy sources and the different stages involved in the design of the proposed MPPET, the system is liable to internal DC voltage fluctuation, causing grid instability; thus, an energy storage system (ESS) is incorporated to avert the challenges. The networks under investigation and the proposed MPPET are designed and simulated using MATLAB and Simulink software. The electrical isolation capability of the proposed bidirectional MPPET is verified through simulation. Several case studies have been carried out to evaluate the behavior of the system under different operating conditions and to check the feasibility of MPPET for power quality improvements. It was observed that the MPPET is proficient in regulating power quality issues, thus enhancing grid stability. It is also varied that the proposed MPPET prevents the escalation of the impact of faults or disturbances all over the grid. At the same time, it is verified that the proposed bidirectional energy storage systems enhance energy transfer between the utility grid and microgrids, which improves the system’s stability.
Article
22 March 2024Community Sport, Australian Sport Policy and Advocacy: A Qualitative Study of Stakeholder Perspectives
This article explored aspects of the community sport policy process in rural New South Wales, Australia, focusing on the views of community sport club (CSC) officials relating to policy matters. Community sport represents a complicated policy arena, and rural communities face a level of disparity compared with better-resourced urban CSCs, particularly concerning policy implementation and advocacy issues. Officials at CSCs from ten different sports (n = 10) in a rural setting participated in semi-structured interviews to pinpoint themes common in the community sport policy process. Further, the research identified aspects of the connections that impact CSCs, including those with government and National Sporting Organisations (NSOs). To highlight the beliefs and attitudes of the CSC officials, the interviews had two key thematic foci—implementation and advocacy—and the findings highlighted sub-themes relating to the fundamental interests of CSCs. Overall, the research accentuated the hierarchical nature—a power imbalance—of sport policy processes, the potential for CSCs to have a bottom-up role in policy creation, and the consideration of a policy analysis and evaluation structure such as the Advocacy Coalition Framework. Finally, the outcome points to enthusiasm for strengthening community sport by giving CSCs a voice through localized advocacy.
Review
29 February 2024Conceptualizing an Informational Paradigm in the Pursuit of Sustainable Cities and Communities
This study seeks to conceptualize ‘Informational Sustainability’ by examining the dynamic relationship between Sustainable Development and the Information and Communication Technologies (ICT) Revolution through the exploration of two prominent urban theories—Lefebvre’s ‘Right to the City’ and Castells’ ‘Rise of the Network Society’—to underscore the importance of knowledge integration in the development of informed, sustainable communities. Conducting a cross-country comparison between developed and developing nations, the study underscores the critical role of informational transformation in enabling resource efficiency, knowledge sharing, innovation, and informed decision-making—key for achieving Sustainable Development Goals (SDGs), while also highlighting potential risks associated with resisting ICT adoption, including hindered growth, increased inequalities, and reduced social engagement and environmental stewardship. The core focus of this conceptual framework is to validate the precursor role of ICT in building sustainable cities and communities by identifying synergies in Sustainable Development, defining dimensions for effective ICT application within the dynamic interplay of global and local levels, and identifying implementation gaps and necessary presumptions for its effective use.
Article
23 February 2024Influence of Separation Gap on the Performance of Savonius Hydrokinetic Turbine
Despite that ocean current energy is one of the promising sources of electricity produced in the ocean, the development of ocean current energy is far behind compared to other ocean energy due to the low efficiency and high cost of installation and maintenance. Among many converting devices, the Savonius turbine has been proven to be effective and competitive in harnessing ocean current energy. The primary purpose of the present study is to search for the optimum shape of a Savonius rotor based on CFD simulation (Star-CCM+). A Savonius turbine composed of two rotating cup-shaped rotors is selected as a numerical model. We focus on the effect of two geometry parameters such as the overlap and gap ratio on the power coefficient. Throughout the parametric study, the shape of a Savonius rotor affects the power performance, and two geometry parameters with an overlap ratio of 0.15 and a gap ratio of −0.03 are found to be the optimum design. It demonstrates stable performance within the wide TSR (Tip Speed Ratio) range of 0.6 to 1.6, with the maximum power coefficient Cp of 0.34 achieved at a TSR of 0.8. According to the numerical results based on the new CFD model, the presence of a bottom wall does not significantly affect the performance of a Savonius turbine. It means that the present unbounded CFD model can be acceptable in the initial design stage for the determination of the geometry parameters of a Savonius turbine.
Review
14 November 2023Microgrids Overview and Performance Evaluation on Low-voltage Distribution Network
Besides the increase in global energy demand, access to clean energy, reduction in greenhouse gas emissions caused by conventional power generation techniques, energy security, and availability of electricity in remote villages in emerging nations are some of the factors that foster the use of renewable energy sources (RESs) in generating electricity. One of the aims of initiating microgrids (MGs) is to maximize the benefits of RES while alleviating grid-connect issues. Microgrids are interconnected RESs and electrical loads within clearly delineated electrical limits that operate as individual controllable units on the electrical network. It can operate independently and be grid-connected. The paper presents a review and performance assessment of renewable energy-based microgrids under various operating scenarios in stand-alone, grid-connected, and transitioning modes of operation. Fault occurrences, an increase in micro-source generation, a load increase, and the sudden disconnection of a micro-source are some of the simulated scenarios. Microgrid network components’ performance, such as the bidirectional DC-DC converter and energy storage system (ESS), was evaluated. The simulated microgrid architecture includes a small hydroelectric plant, wind farm, and ESS. The work provides valuable information to energy stakeholders on the performance of microgrids in low-voltage distribution networks. The microgrid is coupled to a low-voltage distribution network (0.415 kV) via a PCC. The system under investigation is modeled and simulated using MATLAB/Simulink. From the simulation analysis, the fault effect was felt on the utility and did not escalate to the microgrid side during stand-alone operation. Power quality issues, such as voltage rise, are some of the challenges identified during the transition from one mode of operation to another. However, the energy storage system responds to disturbances and maintains system stability. The originality of this paper is based on evaluating different modes of operation of microgrids and comparing system performances under various operating conditions.
