Development of the method of determining the location of a short circuit in transmission lines

One of the serious problems of the reliable functioning of energy systems is the disruption of the performance of overhead and cable transmission power lines caused by various reasons. Most of the power outages occur in distribution networks. Particularly dangerous short-circuits in the supply and distribution network, due to unpredictable natural disasters. To ensure uninterrupted and reliable power supply to consumers, it is necessary to identify and eliminate the malfunction in a short time to reduce damage. Finding and troubleshooting a line is an important task. The authors proposed a method for quickly determining the location of a short circuit in power lines. The proposed method allows to reduce search time and increase the accuracy of determining the fault location.

Revisiting nation branding: An infrastructure financing perspective in Zimbabwe

Purpose: This study aimed to reconfigure nation branding theories and concepts through infrastructure financing intervention. Research methodology: Data were collected using a QUAL to QUAN sequential mixed methods. Results: Qualitative research informed that the infrastructure that is required for nation branding to be road networks; airports; Information Communication Technologies (ICTs); reliable power supply; industrial facilities; tourism facilities; healthcare facilities; educational facilities; educational facilities; and residential accommodation. These were then classified into two, namely, economic and social infrastructure. Results from quantitative research showed that there is a positive relationship between nation branding and infrastructure financing. Also, it showed that road infrastructure and airports were the most related to nation branding with public-private partnerships and bilateral/multilateral loans to finance their development, respectively. Limitations: As a result of the COVID-19, the research did not manage to have some focus groups for a depth understanding and comprehensive response of the participants. Contribution: The results will help the Zimbabwean government consider developing the road networks and airports to enhance the nation’s brand.

Economic Load Dispatch using Lambda Iteration, Particle Swarm Optimization & Genetic Algorithm

In economic load dispatch problem scheduling of loads is done in order to achieve reliable power supply with reduced costs. With the increase in load demand with each passing year energy crisis is increasing hence an area of study where fuel costs can be reduced was proposed. This can be achieved using various methods among which the methods discussed in this paper are Lambda Iteration, Particle Swarm Operation and Genetic Algorithm. Based on numerical results the best optimization technique can be figured out among the discussed methods. Keywords: Lambda Iteration, PSO, GA, economic load dispatch, optimization solutions

Autonomous Cooperative Control for Hybrid AC/DC Microgrids Considering Multi-Energy Complementarity

Multi-energy hybrid AC/DC microgrids (MGs), considering ice storage systems (ISSs), can promote the flexible integration and efficient utilization of distributed generators (DGs) and energy storage systems (ESSs), provide a reliable power supply for local loads, and achieve multi-energy complementarity and energy savings at the same time. An autonomous cooperative control of multi-energy MGs is proposed in this paper, which can realize the following targets: 1) In the energy storage period, ice storage systems and energy storage systems can absorb energy in accordance with their rated capacity. 2) In the energy releasing period, ice storage systems are first put into operation, and the rest of the equivalent cooling loads and electrical loads are shared by the energy storage systems according to their rated capacity ratio. Besides, the complete system small signal model is constructed, which can be used to analyze the features and characteristics of the system and guide the optimal design of the control parameters. Finally, the effectiveness of the proposed control is corroborated by several case studies conducted in PSCAD/EMTDC.

Planning of Aegean Archipelago Interconnections to the Continental Power System of Greece

This paper presents the results of a thorough planning investigation carried out by the Transmission System Operator (TSO) and the Distribution Network Operator (DNO) in Greece in order to study the interconnections of the Aegean Islands with the mainland power system. The feasibility of interconnecting islands is based on the need for a reliable power supply to isolated and autonomous islands, reducing the operating costs of the power generation system through the withdrawal of high-cost oil-fired generating units, and the further ability to increase renewable energy source (RES) penetration in the country’s energy mix, according to directions imposed by the National Energy and Climate Plan. Among the alternative topologies and interconnection technologies considered, the final selection of the interconnection scheme selected for inclusion in the development plans of TSO and DNO was based on their detailed comparative evaluation, considering financial and other technical criteria.

Methodology for Determining Time-Dependent Lead Battery Failure Rates from Field Data

The safety requirements in vehicles continuously increase due to more automated functions using electronic components. Besides the reliability of the components themselves, a reliable power supply is crucial for a safe overall system. Different architectures for a safe power supply consider the lead battery as a backup solution for safety-critical applications. Various ageing mechanisms influence the performance of the battery and have an impact on its reliability. In order to qualify the battery with its specific failure modes for use in safety-critical applications, it is necessary to prove this reliability by failure rates. Previous investigations determine the fixed failure rates of lead batteries using data from teardown analyses to identify the battery failure modes but did not include the lifetime of these batteries examined. Alternatively, lifetime values of battery replacements in workshops without knowing the reason for failure were used to determine the overall time-dependent failure rate. This study presents a method for determining reliability models of lead batteries by investigating individual failure modes. Since batteries are subject to ageing, the analysis of lifetime values of different failure modes results in time-dependent failure rates of different magnitudes. The failure rates of the individual failure modes develop with different shapes over time, which allows their ageing behaviour to be evaluated.

Integration Of Underground Pumped Hydro Storage Membrane (UPHSM) System With Hybrid Of Renewables And Diesel Generator In Off-Grid Remote Area Communities of Ontario

Worldwide, off-grid remote areas are facing energy issues. The Canadian remote communities depend on diesel generation posing many issues including high fuel cost and greenhouse gas emissions. The government policy is to connect such communities to electricity grid that requires high cost and long time. In this situation renewable generators, including wind and solar, may be an appropriate solution. However, their intermittent nature is problematic that needs to be addressed. Therefore, this project investigated the integration of underground pumped hydro storage membrane system (UPHSM) to address the intermittency to provide steady and reliable power supply. A four step systematic methodology is proposed to examine the feasibility of UPHSM in a remote community. The case study results show an overall 64 percent reduction in diesel consumption and 295696 t in CO2 emission. The study results also confirmed that the proposed system is a viable solution for off-grid remote areas.

Integration Of Underground Pumped Hydro Storage Membrane (UPHSM) System With Hybrid Of Renewables And Diesel Generator In Off-Grid Remote Area Communities of Ontario

Worldwide, off-grid remote areas are facing energy issues. The Canadian remote communities depend on diesel generation posing many issues including high fuel cost and greenhouse gas emissions. The government policy is to connect such communities to electricity grid that requires high cost and long time. In this situation renewable generators, including wind and solar, may be an appropriate solution. However, their intermittent nature is problematic that needs to be addressed. Therefore, this project investigated the integration of underground pumped hydro storage membrane system (UPHSM) to address the intermittency to provide steady and reliable power supply. A four step systematic methodology is proposed to examine the feasibility of UPHSM in a remote community. The case study results show an overall 64 percent reduction in diesel consumption and 295696 t in CO2 emission. The study results also confirmed that the proposed system is a viable solution for off-grid remote areas.

Bootstrapped Ensemble of Artificial Neural Networks Technique for Quantifying Uncertainty in Prediction of Wind Energy Production

The accurate prediction of wind energy production is crucial for an affordable and reliable power supply to consumers. Prediction models are used as decision-aid tools for electric grid operators to dynamically balance the energy production provided by a pool of diverse sources in the energy mix. However, different sources of uncertainty affect the predictions, providing the decision-makers with non-accurate and possibly misleading information for grid operation. In this regard, this work aims to quantify the possible sources of uncertainty that affect the predictions of wind energy production provided by an ensemble of Artificial Neural Network (ANN) models. The proposed Bootstrap (BS) technique for uncertainty quantification relies on estimating Prediction Intervals (PIs) for a predefined confidence level. The capability of the proposed BS technique is verified, considering a 34 MW wind plant located in Italy. The obtained results show that the BS technique provides a more satisfactory quantification of the uncertainty of wind energy predictions than that of a technique adopted by the wind plant owner and the Mean-Variance Estimation (MVE) technique of literature. The PIs obtained by the BS technique are also analyzed in terms of different weather conditions experienced by the wind plant and time horizons of prediction.

COVID-19 Vaccination in Developing Nations: Challenges and Opportunities for Innovation

Vaccines offer a hope toward ending the global pandemic caused by SARS-CoV2. Mass vaccination of the global population offers hope to curb the spread. Developing nations, however, face monumental challenges in procurement, allocation, distribution and uptake of vaccines. Inequities in vaccine supply are already evident with resource-rich nations having secured a large chunk of the available vaccine doses for 2021. Once supplies are made available, vaccines will have to be distributed and administered to entire populations—with considerations for individual risk level, remote geography, cultural and socio-economic factors. This would require logistical and trained personnel support that can be hard to come by for resource-poor nations. Several vaccines also require ultra-cold temperatures for storage and transport and therefore the need for specialized equipment and reliable power supply which may also not be readily available. Lastly, attention will need to be paid to ensuring adequate uptake of vaccines since vaccine hesitancy has already been reported for COVID vaccines. However, existing strengths of local and regional communities can be leveraged to provide innovative solutions and mitigate some of the challenges. Regional and international cooperation can also play a big role in ensuring equity in vaccine access and vaccination.