Minimum Power Requirements Research Articles

Surrogate Model-based Multi-Objective Optimization in Early Stages of Ship Design

The abstract is the early stages of ship design, the decision of the ship's main dimensions significantly impacts the ship's performance and the total cost of ownership. This paper focuses on an optimization approach based on surrogate models at the early stages of ship design. The objectives are to minimize power requirements and building costs while still satisfying the constraints. We compare three approaches of surrogate models: Kriging, BPNN-PSO (Backpropagation Neural Network-Particle Swarm Optimizer), and MLP (Multi-Layer Perceptron) in two multi-objective optimization algorithms: MOEA/D (Multi-Objective Evolutionary Algorithm Decomposition) and NSGA-II (Non-Dominated Sorting Genetic Algorithm II). The experimental results show that MLP surrogate models get the best performance with MAE 6.03, and BPNN-PSO gets the second position with MAE 7.2. BPNN-PSO and MLP with MOEA/D and NSGA-II improve the design with around 58% smaller adequate power and 6% less steel weight than the original design. However, BPNN-PSO and MLP have lower hypervolume than Kriging for both optimization algorithms MOEA/D and NSGA-II. On the other hand, Kriging has the most inadequate model accuracy performance, with an MAE of 22.2, but produces the highest hypervolume, lowest computational time, and far lower objective values than BPNN-PSO and MLP for both optimization algorithms, MOEA/D and NSGA-II. Nevertheless, the three surrogate model approaches can significantly improve ship design solutions and reduce work time in the early stages of design.

Sensing Mental States: Way Forward

Flexible electronics has enabled to us reach newer heights. Now, has come the era of wearables. With the advent of advanced fabrication and integration technology, wearables have entered every domain of our life. The ease of use as well as minimal power requirement attract consumer to adopt them more and more as a part of their daily wear regime. These wearables provide direct monitoring many health issues such as sugar level, oxygen level as well as heart pressure etc. Recently, wearables have achieved another feat of sensing the mental state of the wearer. This short communication dwells upon this wearable providing information about the mental health. Along with working principle, the future perspectives are also provided.

The influence of frequency containment reserve flexibilization on the economics of electric vehicle fleet operation

In recent years, the spot and ancillary service markets have become a relevant source of revenue for stationary battery storage systems. During this period, many markets have become increasingly flexible with shorter service periods and lower minimum power requirements. This flexibility makes the markets attractive for pools of electric vehicles (EVs), providing the opportunity to earn additional revenue. In this paper, multi-year measurement data from 22 commercial EVs are used to develop a simulation model to calculate the available power of an EV pool. In addition, the driving logbooks of >460 vehicles from commercial fleets of 14 different economic sectors are analyzed. Based on our simulations, we discuss the influence of shorter service periods on available pool power and power uncertainty. The key findings are that, especially at times with a high pool power, the uncertainty is low. This leads to the conclusion that commercial fleets offer a highly reliable power profile during known idle times depending on the economic sector. All investigated 14 sectors show high and reliable power availability at night and most show this availability also during weekends while others show a regular driving pattern seven days a week. These results are applicable to any energy market. To have a concrete use case, the impact of frequency containment reserve (FCR) flexibilization on the economics of an EV pool is analyzed using the German FCR market design from 2008 to 2022. It is shown that, depending on the fleet, especially the two recent changes in service periods from one week to one day and from one day to 4 h generate the largest increase in available pool power. Further future reductions in FCR service periods will only produce minor benefits, as idle times are often already longer than service periods. According to our analysis, revenues of about 450 €/a to 750 €/a could have been achieved per EV in the German FCR market between mid-2020 and the first quarter of 2022.

On the design of a compact emergency mechanical ventilator with negative expiratory exit pressure for COVID-19 patients

The present work deals with the design of a cylinder-piston arrangement to deliver the required tidal volume (TV) of air to the patient through the respiratory tract especially in the setting of severe acute respiratory syndrome corona virus 2 (SARS CoV-2) or corona virus disease (COVID-19). The design ensures that only the desired volume of air is delivered in each breath and a negative pressure is retained at the delivery point in a separate cylinder. The frequency of piston motion is the same as that of the average human respiratory rate (RR). The effect of negative pressure on time of evacuation under the present condition has been verified. The present design provides a compact ventilator unit with a surface area of 0.8 × 0.4 m2 with a minimal power requirement of 116.48 W. An RR of 16 is obtained with a volume flow rate in lit/s by using a twin cylinder arrangement with bore diameter 0.1 m and length 0.4 m. The ratio of inspiration time to expiration time is designed to be 1:2 by controlling the stroke frequency as 16 and piston speed 0.32 m/s. The present design provides promising quantitative information on the design of an automated continuous mechanical ventilator (CMV), which is different from bag mask valve (BMV) operated ventilators, and on preventing and minimising barotrauma.

Linear pricing game based power control with resource allocation and interference management in device‐to‐device communication for IoT applications

AbstractDevice‐to‐Device (D2D) communication is one of the leading technologies which works under the aegis of fifth generation (5G) communication for the Internet of Things in Healthcare. In D2D communication, power control with resource allocation is the most challenging area for the research to make them suitable for IoT devices. In the present work, power control with resource allocation is done by using the Linear pricing game power allocation method. First, a mathematical min‐function based problem is proposed whilst taking the interference, data rate and minimum power requirement as a constraint to ensure the resource and power allocation. In the next phase, a linear pricing game (LPG) method is utilized to propose the LPG power control with resource allocation (L‐PaRAG). Mathematical analysis and theorem ensure the minimum cost function with global stability for an optimal solution of the proposed problem. Numerical analysis and results show that the proposed algorithm gives the best results for power control and resource management whilst managing the interference to maintain the quality of services (QoS) in D2D communication. Optimized power can be utilized for the communication between the base station and D2D users, especially, during disaster management.

Self-powered Infusion Micropump Fabrication using Xurography and Thermal Lamination Techniques

Point of care testing (POCT) as part of diseases and health monitoring will be very beneficial in resource constrained areas with minimum healthcare expert and power requirement. Elimination of external power source in testing device brought the idea of self-powered infusion micropump. This research aimed to fabricate and investigate the pumping capability of non-mechanical self-powered infusion micropump under the effect of different porous materials. The self-power infusion micropump was successfully fabricated with Xurography and thermal-lamination techniques. The average percentage difference between the measured dimensions of micropump with actual design was 2.30 %. Sandwich layers configuration of the micropump which consisted of PVC sheet and laminating plastic pouch was successfully fabricated and proven to have a leak-proof micropump. Micropump’s flow rate of 0.89, 3.62, and 0.84 μL/min were obtained under the effect of porous material ashless grade Whatman filter paper number W40, W41 and W42 respectively. These flow rate values were influenced by filtration speed as per porous material specifications.

Optimizing the physical design and layout of a resilient wind, solar, and storage hybrid power plant

As wind and solar technologies improve and their costs decrease, the share of power produced by these sources will increase. As the market penetration increases, these power sources will need to provide grid services, such as dispatchability, in addition to providing energy. One way to reduce variability, provide higher quality power to the grid, and address local grid stability issues is through colocating wind and solar power plants. In addition to operating reliably during normal operating conditions, in scenarios with high penetrations of renewable generation, it is important that these hybrid plants can withstand production disruptions and continue to supply power despite prolonged resource reduction, extreme weather events, or other disruptions. In this paper, we present a methodology to optimize a wind–solar-battery hybrid power plant down to the component level that is resilient against production disruptions and that can continually produce some minimum required power. We introduce the models and assumptions we used to simulate a hybrid power plant as well as the design variable parameterization and specific methods we used to optimize the plant. We demonstrate the performance of our method by comparing a plant optimized for different objectives, generation outage durations, minimum power requirements, and power purchase agreements. Although the plant design is sensitive to model parameters and various other assumptions, our results demonstrate some of the optimal designs that occur in different scenarios and what one should expect when designing a hybrid wind–solar-storage power plant.

Socio-Economic Impact Assessment at Sagar Island in Respect of Grid Availability

The focus of the paper is based on the state of West Bengal's Sundarban region. The Sundarban forests lie in the southern part of the state. It comprises 104 island groups out of which 54 are inhabited. Sagar Island, the focus of my study, is the largest island in this area having an area of 286 km2 and a population of more than 1.6 lakhs. This island is situated 5 km adrift on the mainland of India. Due to the presence of River Muriganga (Hooghly), this island could not be connected to the national grid. So, the power requirement was fulfilled by the Diesel Generator sets run by WBSEDCL, 9 Solar Photovoltaic Plants located in the strategic areas, and one Wind- Diesel Hybrid Plant run by WBREDA so that the minimum power requirement could be met. In this paper, the focus of the study will be on the people of Sagar Island on how they will be benefited from the conventional grid in order to improve their lifestyle and economy and also study the future of renewable projects and the existing off-grid system prevalent in this island. Keywords: Grid availability, Socio-economic impact assessment, Decentralized Distributed

Influence of soil moisture on energy requirement of rotary tilling

The rotary tiller with ‘L’ shaped blades was examined for torque, power and specific tilling energy requirements to attain optimum soil-machine operational parameters. The three levels of moisture content (11.4%, 12.8% and 14.6% (d.b)), three speed ratios of 20 (?1), 12 (?2) and 9 (?3) at different passes (first, second and third) with rotational speed of 262 rpm were selected for study. The observations indicated inverse relation between torque and power requirement to moisture content. The lowest value of torque of 16.54 N-m and 26.66 N-m was associated with sandy loam and clay loam soil under third pass and moisture content of 14.6 per cent. Similarly, the minimum power requirement of 0.452 kW and 0.699 kW was observed under analogous conditions of rotary tiller. The energy requirement was found to decrease with higher number of passes due to the breakdown of the hard pan and clod aggregate size. The specific tilling energy is strongly correlated with forward speed and less dependent on the number of the passes of rotary tilling.

Boolean and Elementary Algebra with a Roll‐To‐Roll Printed Electrochemical Memristor

AbstractA non‐volatile conjugated polymer‐based electrochemical memristor (cPECM), derived from sodium 4‐[(2,3‐dihydrothieno[3,4‐b][1,4]dioxin‐2‐yl)methoxy]butane‐2‐sulfonate (S‐EDOT), is fabricated through roll‐to‐roll printing and exhibited neuromorphic properties. The 3‐terminal device employed a “read” channel where conductivity of the water‐soluble, self‐doped S‐PEDOT is equated to synaptic weight and was electrically decoupled from the programming electrode. For the model system, a +2500 mV programming pulse of 100 ms duration resulted in a 0.136 μS resolution in conductivity change, giving over 1000 distinct conductivity states for one cycle. The minimum programming power requirements of the cPECM was 0.31 pJ mm−2 and with advanced printing techniques, a 0.1 fJ requirement for a 20 μm device is achievable. The mathematical operations of addition, subtraction, multiplication, and division are demonstrated with a single cPECM, as well as the logic gates AND, OR, NAND, and NOR. This demonstration of a printed cPECM is the first step toward the implementation of a mass produced electrochemical memristor that combines information storage and processing and may allow for the realization of printable artificial neural networks.

Automatic (Headlight) Beam Controlling module for two-wheelers

Abstract: Automatic High Beam controller is a device made due to the rising number of accidents at night because of LED headlamps temporarily affecting the vision of the driver on the opposite lane. According to AAA, LED lights do a much better job of illuminating the roadway, particularly in the low-beam application versus a halogen reflector at 150 feet more during testing. But, still, that brings the max vehicle speed to about 52 miles an hour, which is still falling short of highway speeds. So, the users are suggested to drive with high beam on if there is no oncoming traffic within a reasonable distance and the roadway is improperly lit. But in practice most people drive with the high beam settings in places with or without traffic great from the user's standpoint. However, even on low beam, they have such a high intensity that on 2-lane roads, especially when the oncoming driver of a car or small pickup approaches the LED equipped truck at night, in rain, fog, or snow the oncoming driver is blinded at a level equal to or greater than if the LED equipped vehicle were using conventional halogen high beams. This device is made without distance or ambient lighting being deciding factors and entirely based on user’s discretion. The transmitter model is fitted with a button that sends a signal to the receiver model using nrf24L01 modules and AT Mega 8 microcontroller (programmed using Arduino UNO). The pressing of button causes the state of the button to be set to HIGH. This signals the receiving circuit to set the LED pin to LOW. Therefore, the High Beam is set to Low Beam for 5 seconds when the impulse is received. Due to the use of H4 C6 headlamps which are rated for 36W with a minimum power requirement of 12W an adapter was connected to convert 220V AC supply to 12V, 3A DC supply for the LED and the rest of the circuit.

Effects of force and moment actuation in active two dimensional VIV control of an elastic circular cylinder in power-law fluid flow

The coupled in-line/crosswise (2-DOF) Vortex-Induced Vibration (VIV) control of a flexibly-supported impenetrable circular cylinder immersed in uniform 2D laminar cross-flow of incompressible non-Newtonian power-law fluids is numerically investigated. Two effective active closed-loop control strategies are separately applied and compared in a real-time collaborative simulation framework that interactively connects the Fluent CFD solver with Matlab/Simulink. Numerical simulations reveal the important effects of power-law rheology and controller configuration on the key cylinder response/aerodynamic parameters and flow structure for a wide range of power-law index parameters (0.4≤n≤1.8). In the absence of the control system, the boundary layer thickness, the attached wake size/strength, and the length/thickness of the associated “shear stretching layer” (vortex shedding frequency) are found to noticeably increase (decrease) with increasing the power law index parameter. As the value of power-law index is largely increased, there is a notable shift of the synchronization (lock-in) region into the higher Reynolds number range besides its marked contraction which can passively complement the cylinder VIV control problem in the highly viscous shear-thickening fluid. When the active control system becomes operative, the superior performance and efficiency of the moment-based controller in effective and rapid mitigation of cylinder VIV and weakening of the vortex intensities through a desynchronization type of action with minimum actuator power requirements is demonstrated.

Rapid optimization of stationary tokamak plasmas in RAPTOR: demonstration for the ITER hybrid scenario with neural network surrogate transport model QLKNN

This work presents a fast and robust method for optimizing the stationary radial distribution of temperature, density and parallel current density in a tokamak plasma and its application to first-principle-based modeling of the ITER hybrid scenario. A new solver is implemented in the RAPTOR transport code, enabling direct evaluation of the stationary solution to which the radial plasma profiles evolve. Coupled to a neural network emulation of the quasi-linear gyrokinetic QuaLiKiz transport model (QLKNN-hyper-10D), a first-principle-based estimate of the stationary state of the core plasma can be found at unprecedented computational speed (typically a few seconds on standard hardware). The stationary state solver is then embedded in a numerical optimization scheme, allowing the optimization of tokamak plasma scenarios in only a few minutes. The proposed method is applied to investigate the performance of ITER hybrid scenarios at different values of total plasma current, plasma density and pedestal height and for different power contributions in a heating mix consisting of electron cyclotron and neutral beam heating. Optimizing the radial distribution of electron cyclotron current drive (ECCD) deposition, the q profile is tailored to maximize the fusion gain Q, by maximizing the energy confinement predicted through the first-principles-based transport model, while satisfying q > 1, avoiding sawtooth oscillations. It is found that optimal use of ECCD in ITER hybrid scenarios is to deposit power as close to the core as possible, while maintaining sufficient off-axis current drive to keep q above 1. Upper limits for the fusion gain Q are shown to be constrained either by minimum power requirements for the separatrix power flow to maintain H-mode or by minimum current drive requirements for q profile tailoring. Finally, it is shown that the ITER hybrid scenario operating window is significantly extended by an upgrade of the electron cyclotron power to 40 MW.

Assessing the benefits of exchanging spinning reserve capacity within the hydro-Dominated nordic market

This paper presents a hydrothermal scheduling toolchain suitable for detailed studies of procurement of spinning reserves in the hydro-dominated Nordic power system. The toolchain combines a long-term model to find the expected marginal value of water in the hydropower reservoirs and initial states for thermal generators, and a short-term model to optimize the daily unit commitment and dispatch. The short-term model has a detailed description of both hydro and thermal generation technologies to realistically constrain their capabilities as reserve capacity providers. The toolchain is applied on a data description representing a 2030 scenario of the Northern European power system to quantify the benefits of exchanging spinning reserve capacity both between bidding zones and between countries within the Nordic market. By allowing 10% of the transmission line capacity for exchange of reserves, we find that the daily average economic benefit is 290 k€ and 102 k€ for reserve exchange between bidding zones and countries, respectively. Moreover, we quantify and illustrate the importance of applying unit commitment for hydropower stations and strictly enforcing their minimum power requirements.

SATPAS: SINR-based adaptive transmission power assignment with scheduling in wireless sensor network

In this work, a centralized metaheuristic algorithm is proposed for assigning minimum transmission power to each sensor node for every transmission link along with a scheduling slot while satisfying the Signal to Interference plus Noise Ratio constraint in the Wireless Sensor Network. Simultaneous communication in all communication links is not possible while maintaining SINR constraints. Thus, the algorithm also tries to maximize the number of concurrent transmission links in each scheduling slot. We formulate the optimization problem with two objective functions as (i) Communication link wise adaptive and minimum transmission power assignment together with scheduling slot number and (ii) Minimization of the required number of scheduling slots. Probabilistic interference model, which is more realistic, is used for calculating the receiver interference, unlike the graph-based interference model mostly described in the literature. Genetic Algorithm with Edge-set and Edge-window-decoder chromosome representation schemes are used for optimization. Extensive simulations are carried out to demonstrate the efficiency of proposed algorithms using different benchmark data sets and special network topologies like spiral, cluster, and mesh. Our proposed algorithm outperforms the existing MST-based algorithm in terms of minimum transmission power requirement, number of scheduling slots required, and rate of convergence.

Thermodynamic analysis and power requirements of CO2 capture, transportation, and storage in the ocean

Carbon capture and storage entails a series of processes for carbon dioxide: separation from the other combustion gases and sequestration; pressurization; transportation; storage; and monitoring. Each one of these processes requires significant quantities of energy. This article offers a holistic view of carbon capture and storage by examining all the processes involved and calculating their work requirements. In addition, the article derives the minimum work (exergy) for separation, which applies to all the separation processes – mechanical, chemical, electrical, etc. This benchmark work is 106.8 kJ/kg for carbon dioxide. A case study is performed for a 1 GW (nominal) coal power plant that is currently in operation. The calculations show that carbon dioxide must be transported in a supercritical state, and that the separation and compression of this gas requires the expense of significant energy. The absolute minimum power requirements for capture, transportation and storage of the produced CO2 account for approximately 16% of the net power generated by the power plant, while the actual power requirements – using current technology and realistic equipment efficiencies – are close to 58% of the generated power.

Conceptual Design of Fuel Cell Based Hybrid Unmanned Air Vehicle

Unmanned air vehicles (UAVs) are used successfully in many different fields mainly various military and civilian applications. Recently electric powered UAVs have become more preferable due to their better accessibility, cost, transportation and silence. However, the batteries used in electric UAVs still do not have enough energy density for long endurance flights. Due to the difficulty of using piston and gas turbine engines in small-sized UAVs, hydrogen fuel cells are seen as one of the considerable options to increase endurance and range. In this study, conceptual design of hybrid UAV including fuel cell, solar unit and battery is presented. Small, light and high endurance UAV was designed using aerodynamic calculations and minimum power requirement for cruise flight was determined. 100 W fuel cell produced by Horizon Fuel Cell Technologies and 3S, 5 Ah of battery were used for main power supplies, moreover solar cells to charge the battery were designed to mount on the surface of the wings. Also, a new power management system is designed for switching between the energy sources. As a result of this work, it is determined that fuel cells and solar units are the significant options which can increase the endurance of UAV up to 8 times depending on the design, solar flux, hydrogen capacity etc.

On the effect of biofouling on the minimum propulsion power of ships for safe navigation in realistic conditions

This study first examines the minimum power requirements of a tanker according to the IMO 2013 Interim Guideline (IMO 2013). For the estimation of the added resistance in waves a recently introduced semi-empirical method is used. Secondly, the influence of the increase in surface roughness of the hull and propeller due to fouling is investigated, reflecting the actual condition of a ship in service. The results show that even if ships are fulfilling the IMO 2013 Guideline, they may become unsafe in operation. Lastly, the uncertainties involved in the assessment procedure are discussed. The investigation conducted is particularly of interest for the assessment of the safety of ships now being idle or used as floating storage due to the impact of the pandemic COVID-19 on the world economy, while they are expected to go again into service once the demand for transport recovers.

PMSG-Based Dual-Port Wind-Energy Conversion System With Reduced Converter Size

In this study, a dual-port wind-energy conversion system has been proposed. A double-fed permanent-magnet synchronous generator (DFPMSG) forms the central part of the system, where the concentrated single-layer winding configuration of the generator enables electric and magnetic isolation between the ports. DFPMSG has two three-phase terminals out of the stator; one is connected directly to the grid, whereas the other is tied to the grid through a back-to-back converter. This study investigates design issues caused by the DFPMSG port with a direct grid connection. The unique design issues of the proposed system include determining the slot/pole combination using wind data and determining the minimum reactive power requirement for the port with a direct grid connection. Next, the load-sharing capability among the ports of the proposed system is presented through a detailed investigation of three schemes. Experimental work is presented for a 5-kW prototype DFPMSG system to illustrate the isolation among the ports, minimized reactive power demand on the port with direct grid connection, and load-sharing ability among the ports for different control schemes.

Estimating the grid payments necessary to compensate additional costs to prospective electric vehicle owners who provide vehicle-to-grid ancillary services

The provision of ancillary services in the smart grid by electric vehicles is attractive to grid operators. Vehicles must be aggregated to meet the minimum power requirements of providing ancillary services to the grid. Likely aggregator revenues are insufficient to cover the additional battery degradation costs which would be borne by an existing electric vehicle owner. Moreover, aggregator revenues are insufficient to make electric vehicles competitive with conventional vehicles and encourage uptake by prospective consumers. Net annual costs and hourly compensation payments to electric vehicle owners were most sensitive to battery cost. The fleet provided firm fast reserve from 1900h for 0.42 hours, up to 2.7 hours in the best cases. At best, likely aggregator revenue was 20 times less than the compensation required, up to 27,500 times at worst. The electric vehicle fleet may not be large enough to meet the firm fast reserve power and duration requirements until 2020. However, it may not be until 2030 that enough vehicles have been sold to provide this service cost-effectively. Even then, many more electric vehicles will be needed to meet the power level and duration requirements, both more often and for longer to enable participation in an all-day, everyday ancillary services market.