Power Loss Research Articles

A Quasi-Binomial Regression Model for Hurricane-Induced Power Outages during Early Warning

A Quasi-Binomial Regression Model for Hurricane-Induced Power Outages during Early Warning

Frequency Stabilizing and Reducing Power Outages of The Islanded Power ‎Network Using a ‎Load Shedding Method in The Presence of Renewable Energy ‎Resources

Frequency Stabilizing and Reducing Power Outages of The Islanded Power ‎Network Using a ‎Load Shedding Method in The Presence of Renewable Energy ‎Resources

High-reliability uninterruptible power supply manager for critical virtualization cluster

Information technology servers are complex, delicate, and expensive systems; power grid interruption is one of the possible causes that can lead to hardware damage or logical disk structure damage, with severe consequences. Moreover, a power grid drop causes a sudden interruption of the services managed by a server. Uninterruptible power supplies (UPS) provide backup power when the regular power grid source drops. UPSs can only maintain a server for a short time. Therefore, it is necessary to introduce a blackout manager who can correctly shut down the server activities. Moreover, the manager must be able to restore the servers' status when the electrical grid power returns to its normal state. This paper proposes a possible UPS power manager able to manage servers during a prolonged electrical blackout. The UPS power manager identifies the blackout and keeps the servers safe by saving their state and shutting them down properly. Following the power grid restoration, the UPS power manager restarts the servers and restores their state. The proposed approach has been evaluated on a virtualization cluster used for critical activities at the Politecnico di Torino.

A hybrid optimization approach for strategically placing electric vehicle charging stations in a radial distribution IEEE-33 bus system

The main objective of this study is to demonstrate the effectiveness of using Hybrid Particle Swarm Optimization (HPSO), a unique methodology, to optimize an IEEE-33 bus system for optimal placement of electric vehicles. This methodology has been specifically designed to effectively regulate voltage fluctuations while reducing power dissipation. The exploration capabilities of PSO and the exploitation capabilities of SA make HPSO a robust algorithm for a specific objective function. HPSO has shown superior performance compared to current traditional methods after careful study. Simulation results illustrate power loss reductions ranging from 1.01% to 8.21% compared to various metaheuristic methodologies. The inclusion of this approach demonstrates that combining the capabilities of PSO and SA facilitates the development of a highly efficient optimization framework by combining their stochastic search and fast convergence capabilities. This methodology not only sets innovative benchmarks for power system development, but also represents a significant paradigm shift in managing and improving durable and efficient electrical networks.

Insulation coating via hydrothermal oxidation for high-frequency FeSiAl soft magnetic composites

Soft magnetic composites (SMCs) play a crucial role in electronic devices owing to their high saturation magnetization. However, conventional insulation methods employed in SMCs exhibit inadequate insulation reliability, thereby restricting their further application in high frequencies. In this study, hydrothermal oxidation is introduced for insulation coating in the preparation of FeSiAl SMCs. When treated at 150 ℃ for 2 h, an insulation layer comprising of Al2O3, SiO2, Fe3O4 and Fe2O3 is formed on the surface of FeSiAl. The most optimal sample is achieved with saturation magnetization of 134.3 emu/g, presenting no significant reduction in saturation magnetization compared to the untreated sample. Cut-off frequency exceeding 300 MHz, and power loss of 503.7 kW/m3 (@7 MHz, 5 mT) are also obtained. This study suggests that hydrothermal oxidation could be a dependable method for fabricating high-frequency SMCs.

High breakdown voltage of 1.3 kV and low turn-on voltage of 0.48 V β-Ga2O3 heterojunction barrier Schottky diode with tungsten Schottky contact

β-Ga2O3 power diodes were expected to possess low turn-on voltage (V on), low reverse leakage (J R), and high blocking capability for low power losses. In this work, a low V on (0.48 V) β-Ga2O3 heterojunction barrier Schottky diode (HJBS) with tungsten Schottky contact was achieved. Benefitting from the lateral depletion of p+-NiO to suppress J R originating from the low Schottky barrier, the blocking capability of β-Ga2O3 HJBS was enhanced. The spacing width of p+-NiO was systematically studied to reveal its modulation effect on forward and reverse characteristics. This work provides a promising strategy for improving rectifier efficiency of β-Ga2O3 diodes.

Power Transformer On-Load Capacity-Regulating Control and Optimization Based on Load Forecasting and Hesitant Fuzzy Control

The operational stability of a power transformer exerts an extremely important impact on the power symmetry, balance, and security of power systems. When the grid load fluctuates greatly, if the load factor of the transformer cannot be maintained within a reasonable range, it leads to increased instability in grid operation. Adjusting the transformer capacity based on load changes is of great significance. The existing control methods for on-load capacity-regulating (OLCR) transformers have low timeliness, and the daily switching frequency of the capacity-regulating switch is not controlled. To ensure the safe and stable operation of transformers, this paper proposes a control method for OLCR transformers based on load prediction and fuzzy control. Firstly, the operating principle of OLCR transformers is analyzed, and a multi-strategy enhanced dung beetle optimizer (MSDBO) combined with a CNN−LSTM model is proposed for load forecasting. On this basis, the daily switching frequency of the capacity-regulating transformer is introduced, and hesitant fuzzy control is used to select the optimal capacity-regulating strategy relying on three factors: loss, economy, and switching frequency. Finally, simulation models are constructed using the MATLAB/SIMULINK platform and simulation analysis is conducted to verify the effectiveness and superiority of the proposed control method. For the three scenarios in this paper, the method reduces daily power loss by 28.5% to 56.3% and daily operating costs by 25.4% to 50.8%. The method used in this paper can sacrifice 3.5% to 9.2% of the loss reduction capability in exchange for reducing the number of switch operations by 28.6% to 57.1%, significantly extending the lifespan of the switches and thereby increasing the operational lifespan of the transformer.

Selection of Power Semiconductor Devices for a Standalone System based on Power Loss Analysis

Selection of Power Semiconductor Devices for a Standalone System based on Power Loss Analysis

Design of higher gain linearly polarized 2×2 microstrip patch array antenna for wireless communication

The fifth-generation technology is popular and best as far as data rates are concerned for wireless applications. To meet the increased demand of the modern world for faithful communication, this research work is carried out. In this approach, a single patch, 1×2 array, and 2×2 array are designed using a low-cost FR4 dielectric substrate ( =4.4) covering the 3.3–3.8 GHz frequency band. Due to the lack of gain from arrays in the present research, an attempt is made to achieve excellent gain from arrays with a minimum number of patches. First, the gain of a single inset-fed antenna is compared with another normal single patch of the same thickness but with an additional air dielectric medium. Next, the second single patch is extended to obtain a rectangular 1×2 array and a 2×2 array antenna. A second single patch measuring 50×32.5×0.8 mm is designed assuming an infinite ground plane. It has 3mm air gap between the patch strip and the ground. Air acts as a second dielectric layer that reduces power loss. This allows a maximum gain of 15.2 dB with a return loss of -22 dB. Also, antenna efficiency and bandwidth are 91% and 267.69 MHz, respectively.

A correction model for the effect of spanwise flow on the viscous force contribution in BEM and Lifting Line methods

Design optimization and aeroelastic load evaluation for wind turbines are still infeasible for CFD due to computational cost. These tasks are carried out using 3D engineering aerodynamic methods, where the local aerodynamic loads are obtained from tabulated 2D aerodynamic polars, which makes the models fast. With recent developments such as highly flexible blades, coned/prebent/swept blades, the relative inflow direction to the “inner” 2D airfoil section systems can have a significant component in the spanwise direction. The Crossflow Principle (CP) is used to treat the effects of this in a physically consistent manner. Cases dominated by pressure forces are described well with the CP method, but it is shown in the paper that CP fails to describe the part of the forces stemming from the friction forces correctly. It is shown in the paper that the power loss due to friction forces will be underestimated with the crossflow principle for rotors with significantly swept blades or other designs with a significant amount of local crossflow on the blades. The present work presents a simple model to correct the baseline crossflow principle method to take into account also the friction force part in a consistent manner. The model is validated with 3D CFD results on a 2D airfoil section. It is shown that the new model successfully corrects for the addition of the viscous forces due to spanwise flow component. The paper includes examples of the effect of using the model on rotor designs with different amounts of blade sweep simulated using a blade element momentum (BEM) and blade element vortex cylinder (BEVC) methods.

Barium titanate–silicon elastomer based body coupled antenna for wearable microwave head imaging applications

This paper presents a flexible monopole antenna fed by a coplanar waveguide (CPW) feeding line with a barium titanate (BaTiO3) silicon-elastomer impedance matching layer for microwave head imaging applications. The operating frequency bandwidth of the proposed antenna is 614 MHz which is from 0.475 GHz to 1.089 GHz. In biomedical microwave sensing and imaging applications, the major challenge is the high power loss due to reflection between the BaTiO3 and the antenna due to impedance mismatch. Therefore, the proposed BaTiO3 silicon-elastomer composite is designed to have dielectric property of 20 which acts as an impedance matching layer for the monopole antenna. The proposed antenna has dimensions of 70×30×6 mm. The flexibility of the antenna is provided by the use of the silicon elastomer. It has been shown that the power radiated into an artificial head phantom improved by almost 160% as compared to antenna without impedance matching layer. Moreover, the SAR level is 0.0286 W/kg when 1 mW of power is transmitted, which is well below the limit set by the regulation. This makes the antenna suitable for wearable biomedical applications due to its wideband characteristic and improved power penetration into human head.

On the impact of different static induction control strategies on a wind turbine wake

This study provides a wind tunnel investigation to identify effective ways of derating an upstream turbine for mitigating wake-induced power losses. Short-range continuous-wave lidar measurements are used to remotely map the time-averaged wake characteristics of a controllable model wind turbine under uniform inflow with negligible turbulence. The analysis focuses on comparing four distinct static induction control (SIC) strategies, each at targeted derating levels of 5 % and 10 %, against a conventional greedy strategy. The results indicate that pitch-to-feather combined with an increased tip-speed ratio is the most favourable approach for minimising wake losses in a two-turbine setup. Notably, power gains of up to 3.8 % are achieved for partial and full wake overlap conditions at 5 % derating and small turbine spacing. These observations are consistent with previous field experiments, suggesting that SIC may be advantageous in wind farms with closely spaced turbines. Overall, these findings underscore the importance of carefully selecting and understanding the implemented derating strategy for supporting wind farm flow control applications.

Feasibility and Techno-Economic Assessment of a 128kWp Grid-Tied SPV System using HOMER Pro

Abstract A substantial amount of the world’s annual CO2 emissions are attributable to the continued consumption of electricity from the grid that is generated from burning fossil fuels. Renewable energy sources could strengthen grid reliability and lessen their effect on the environment, especially in high-demand regions prone to power failures. Investigating the viability of erecting solar power plants in a subtropical area to provide the necessary electricity for an educational building that operates mainly during daylight hours is the main intent of the present study. The purpose of this investigation is to demonstrate and validate a model for enormous-scale commercial HRES applications (such as an educational institution) utilising the HOMER programme to figure out the optimal size. Minimising emissions of carbon dioxide, the main greenhouse gas responsible for accelerating global warming, is also of the utmost importance. Based on the simulation findings, the optimal system configuration consisted of a 120 kW converter and 400 PV arrays (each with 320 Wp = 128 kWp). For regional power generation, the most cost-effective choice is still a combination of solar panels and the grid. Findings show that a HRES can be economically feasible for installation in educational institutions at an initial capital cost of USD $0.068 million with annual operating expenses of USD $0.0447 million—a reduction of 44.11% compared to the existing system. The expected payback for this endeavour is five years. Other locations with identical climates could benefit from these results when considering the deployment of comparable technology. In order to help achieve a zero-carbon target, financial rewards could encourage governments to adopt similar schemes.

Design of Resonant Converter of Trans cutaneous Energy Transfer System to Power Artificial Heart

Wireless technologies have matured to recharge the batteries of consumer devices efficiently. The benefit of the technology is being used by mobile communication devices, personal computation devices, and wearable entertainment devices. The wireless energy transfer techniques employ the transfer of electrical energy between two-tesla coils in surface contact and not by electrical contact through the phenomenon of electromagnetic induction. Many international consortiums have made guidelines for designing and manufacturing these devices. However, for active implantable medical devices such as artificial hearts, a large amount of electrical energy usually in the range of 15W to 30W needs to be transferred across the skin at a depth of 10mm to 30mm. The design needs to be optimized for maximum power transfer with the highest possible efficiency. Any loss in power will be reflected as heat energy and cause burns and tissue death. A transcutaneous energy transfer system is such type of wireless energy transfer mechanism across the skin to power implanted life-saving devices. In this paper, the design of a resonant converter and its performance is investigated to wirelessly transfer electrical power up to a tissue thickness of about 25mm.

Dual-trait genomic analysis in highly stratified Arabidopsis thaliana populations using genome-wide association summary statistics.

Genome-wide association study (GWAS) is a powerful tool to identify genomic loci underlying complex traits. However, the application in natural populations comes with challenges, especially power loss due to population stratification. Here, we introduce a bivariate analysis approach to a GWAS dataset of Arabidopsis thaliana. We demonstrate the efficiency of dual-phenotype analysis to uncover hidden genetic loci masked by population structure via a series of simulations. In real data analysis, a common allele, strongly confounded with population structure, is discovered to be associated with late flowering and slow maturation of the plant. The discovered genetic effect on flowering time is further replicated in independent datasets. Using Mendelian randomization analysis based on summary statistics from our GWAS and expression QTL scans, we predicted and replicated a candidate gene AT1G11560 that potentially causes this association. Further analysis indicates that this locus is co-selected with flowering-time-related genes. The discovered pleiotropic genotype-phenotype map provides new insights into understanding the genetic correlation of complex traits.

Passive and low-energy strategies to improve sleep thermal comfort and energy resilience during heat waves and cold snaps

Sleep is a pillar of human health and wellbeing. In high- and middle-income countries, there is a great reliance on heating, ventilation, and air conditioning systems (HVAC) to control the interior thermal environment in the bedroom. However, these systems are expensive to buy, maintain, and operate while being energy and environmentally intensive—problems that may increase due to climate change. Easily-accessible passive and low-energy strategies, such as fans and electrical heated blankets, address these challenges but their comparative effectiveness for providing comfort in sleep environments has not been studied. We used a thermal manikin to experimentally show that many passive and low-energy strategies are highly effective in supplementing or replacing HVAC systems during sleep. Using passive strategies in combination with low-energy strategies that elevate air movement like ceiling or pedestal fans enhances the cooling effect by three times compared to using fans alone. We extrapolated our experimental findings to estimate heating and cooling effects in two historical case studies: the 2015 Pakistan heat wave and the 2021 Texas power crisis. Passive and low-energy strategies reduced sleep-time heat or cold exposure by 69–91%. The low-energy strategies we tested require one to two orders of magnitude less energy than HVAC systems, and the passive strategies require no energy input. These strategies can also help reduce peak load surges and total energy demand in extreme temperature events. This reduces the need for utility load shedding, which can put individuals at risk of hazardous heat or cold exposure. Our results may serve as a starting point for evidence-based public health guidelines on how individuals can sleep better during heat waves and cold snaps without relying on HVAC.

Using electric vehicles to enhance power outage resilience – An agent-based modeling approach

Power outages can cause severe disruption to critical infrastructure. With the predicted increase in the electrification of the transport sector, society will become even more vulnerable to the effects of power outages. While increased electric vehicle (EV) adoption will contribute to the electrification process, EVs can also offer capabilities to provide services during an outage. This paper studied the use of a fleet of EVs during the aftermath of a disaster to provide disaster relief by donating power to a shelter, delivering critical supplies and people in need, and providing transport for personnel or performing inspections. While the bulk of the past work has focused on using EVs to increase the resilience of the distribution grid, or individual buildings, to a power outage, this paper was novel in its use of an agent-based model to study EVs that are performing functions to increase the resilience of a community to an outage. The fleet of EVs were provided access to a microgrid with a solar array, one or two EV fast chargers, and three possible sizes of a storage. Useful outputs were produced and studied for such features as daily energy donated to a shelter, daily energy used at the microgrid, and the length of outages that can be supported before the energy is depleted at the microgrid. Results showed that increasing storage size at the microgrid led to substantial increases in the outage length that could be support. Additionally, it was found that focusing a fleet on delivery and transport tasks, as opposed to energy donation, could also increase the length of outages that could be supported.

PENYEIMBANGAN BEBAN TRANSFORMATOR DISTRIBUSI PCC-007 UNTUK MENGURANGI RUGI-RUGI JARINGAN PADA TEGANGAN MENENGAH 20KV

The distribution system of electrical power networks serves as a means to distribute electrical energy to both industrial and household consumers. With the increasing population growth, the number of electrical energy users or consumers also increases, potentially impacting the loading on each distribution transformer. If the loading on each transformer increases, it can lead to overload, load imbalance, power losses, and damage to the transformer. Therefore, to ensure the proper operation of distribution transformers, PLN (a state-owned electricity company in Indonesia) has set a standard for the loading on distribution transformers, which should not exceed 80%. This research aims to measure the loading on distribution transformers and analyze the occurrence of power losses caused by load imbalance. Measurements are conducted using a clamp meter and earth tester to obtain current and voltage values as well as the resistance value of grounding. Subsequently, calculations are performed for transformer loading, load imbalance, and power losses on the feeder.

Simulation design of 542kWp DC/480kWp AC Solar Photovoltaic System at Institute of Southern Punjab

Conventional methods of producing electricity are expensive, pollute the environment, need a lot of maintenance, and eventually run out of power. Because of this, it is imperative to take use of the unrealized potential of renewable energy sources that are also ecologically beneficial. At the Institute of Southern Punjab (ISP), Multan, Pakistan geographical location coordinates latitude 30° 17′ 20′′ N and longitude 71° 30′ 1′′ E. Current study developed an effective, long-lasting, and environmentally friendly Grid Tie PV System (GTPVS) to address this issue. One location where solar energy has enormous promise is Multan. At this location, the average yearly horizontal solar irradiance is 1861.8 kWh/m2/year and average diffuse horizontal solar irradiance 898.9 kWh/m2/year. In this study, PVSyst is used to calculate the performance ratio and various power losses, such as inverter, temperature-related losses, and losses from PV modules. Every day, 3026.26 kg of coal are saved, which is the same as growing 29062.87 Teak trees for life time. According to National Electric Power Regulation Authority (NEPRA) rule Tarif A3(66) is applied on universities and schools, where 60 Rs/kWh is unit cost in year 2024. The generated energy costs for Longi solar cell for proposed location in ISP Multan is 0.07 US dollars per kWh, while the standard energy pricing in Pakistan in 2024 is 0.21 US dollars per kWh. The simulation results show that, proposed RTSPVS design energy production is 966.4 MWh/year. Annual performance ratio (PR) for the proposed system is 85.8%.

Simulation design of 542kWp DC/480kWp AC Solar Photovoltaic System at Institute of Southern Punjab

Conventional methods of producing electricity are expensive, pollute the environment, need a lot of maintenance, and eventually run out of power. Because of this, it is imperative to take use of the unrealized potential of renewable energy sources that are also ecologically beneficial. At the Institute of Southern Punjab (ISP), Multan, Pakistan geographical location coordinates latitude 30° 17′ 20′′ N and longitude 71° 30′ 1′′ E. Current study developed an effective, long-lasting, and environmentally friendly Grid Tie PV System (GTPVS) to address this issue. One location where solar energy has enormous promise is Multan. At this location, the average yearly horizontal solar irradiance is 1861.8 kWh/m2/year and average diffuse horizontal solar irradiance 898.9 kWh/m2/year. In this study, PVSyst is used to calculate the performance ratio and various power losses, such as inverter, temperature-related losses, and losses from PV modules. Every day, 3026.26 kg of coal are saved, which is the same as growing 29062.87 Teak trees for life time. According to National Electric Power Regulation Authority (NEPRA) rule Tarif A3(66) is applied on universities and schools, where 60 Rs/kWh is unit cost in year 2024. The generated energy costs for Longi solar cell for proposed location in ISP Multan is 0.07 US dollars per kWh, while the standard energy pricing in Pakistan in 2024 is 0.21 US dollars per kWh. The simulation results show that, proposed RTSPVS design energy production is 966.4 MWh/year. Annual performance ratio (PR) for the proposed system is 85.8%.