Design Wind Research Articles

Optimization Design of a 40-kJ HTSPPT Module for Inductive Pulsed Power Supply

The topology category based on high-temperature superconducting pulse power transformer (HTSPPT) is an important branch of inductive pulse power supply (IPPS) for rail guns. Optimization design of the HTSPPT can improve the overall performance of the IPPS system. The purpose of this article is to design a 40-kJ air-core HTSPPT module with a high-temperature superconducting (HTS) primary winding and a normally conducting secondary winding. According to the application characteristics of the HTSPPT, under the constraints of the three main performance indicators of critical current, stored energy, and coupling coefficient, the amount of HTS tapes and the volume of the entire HTSPPT are reduced as much as possible. The design of the secondary winding combines the electromagnetic launch requirements for the current pulse in the approximate flat waveform and steep pulse rising edge. With this optimized design, a 43-kJ HTSPPT module with a primary inductance of 79.4 mH, a secondary inductance of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$255.4~\mu \text{H}$ </tex-math></inline-formula> , and a coupling coefficient of 0.97 was obtained. Finally, the maximum stress and strain of the designed HTSPPT in the energy storage state are analyzed through the electromagnetic (EM) structure coupling field.

Fusion wind and solar generation prototype design with Neural Network

Wind and solar power are the most common renewable resources of energy and their usage for power generation is quickly growing all over the world. However, both wind and solar power are difficult to predict manually due to every time changes in weather condition; therefore, power output of wind and solar is associated with some uncertainty. A reliable wind-solar day ahead load prediction with neural network was proposed to support a small microgrids system. All the system performance measurement such as sensitivity, specificity and accuracy give higher than 90%.

Predicting load capacity of shear walls using SVR–RSM model

Accurate prediction of the shear capacity of reinforced concrete shear walls (RCSW) is essential for the wind and seismic design of buildings. However, due to the diverse structural configurations, multitude of load scenarios, and highly nonlinear relations between the design parameters and the shear load capacity, this prediction is very complex. Existing pertinent design code provisions such as the American Concrete Institute ACI-318 and the Eurocode rely on empirical expressions that have various limitations and attain low predictive accuracy. Hence, in this paper, we pioneer a novel hybrid intelligent model to predict the ultimate shear capacity of RCSW. The support vector regression (SVR) and response surface model (RSM) were coupled based on two calibrating strategies in a novel hybrid modeling approach called RSM–SVR. The accuracy, tendency and uncertainty of the proposed SVR–RSM model along with that of three existing empirical relations and two design code provisions were assessed using various statistical metrics based on a comprehensive experimental database retrieved from the open literature. The existing design codes and empirical models were found to be inflicted with high variability and did not capture the influence of the key design parameters on the shear capacity in a robust and rational manner. Conversely, it is shown that the proposed RSM–SVR modeling approach achieved superior accurate predictions for the shear strength of RCSW. The proposed RSM–SVRmodel enhanced RMSE for the training (testing) dataset by 510% (150%) compared to the Baghi et al. model, 550% (190%) compared to the ACI 318-14 design code, 530% (155%) compared to the Chandra et al. model, 320% (145%) compared to the RSM model, and 450% (90%) compared to the SVR model. The novel approach also better captured the influence of the key design parameters, demonstrating robust tendency and much lower uncertainty. Thus, the proposed novel model could be harvested in intelligent generative design and for the enhancement of pertinent provisions in design codes. The proposed method achieves outstanding performance, while maintaining superior computational efficiency and low run time.

Starting forces of the traction linear induction motor with adjustable resistance of the short-circuited winding of the secondary element

Background: Development and research of linear traction drives for Maglev transport is an urgent task. Linear induction motors can be used as traction machines for advanced rolling stock. Aim: Study of the starting characteristics of an adjustable traction linear induction motor with variable resistance by a short-circuited winding of the secondary element. Methods: Theoretically, relations were obtained for calculating the traction starting forces of an adjustable linear induction motor with various designs of a short-circuited winding of the secondary element. Results: Based on the obtained ratios, the calculations of the starting traction forces of linear induction motors intended for use in promising modes of transport were performed. Conclusion: The results of calculating the starting traction forces of adjustable linear induction motors make it possible to reasonably select the modes of starting the motor depending on the design of the secondary winding.

On probability distributions of wind speed data in Malaysia

The rapid depletion of fossil fuel resources leads to environmental issues and impacts, making alternative resources such as wind energy to be one of the important renewable sources. The statistical characteristics of wind speed and the selection of suitable wind turbines are essential to evaluate wind energy potential and design wind farms effectively. Hence, an accurate assessment of wind energy and wind data analysis is crucial before a detailed analysis of energy potential is conducted. The probability distributions of wind speed data are considered, and its parameters are precisely estimated to achieve this aim. This study considers the most selected distribution, namely, Weibull, Gamma, and Logistic distributions. These distributions are fitted to the wind speed data for sixteen stations in Malaysia. The parameter estimation is performed by the maximum likelihood method. The efficiency of the model distribution is analysed. The goodness of fit test is performed using the Kolmogorov-Smirnov test. The results show that Gamma distribution is the most suitable distribution for the wind speed data in Malaysia as it fits the data well for thirteen stations. The Logistic distribution is found to be the best distribution for the other three stations. The graphical method also agrees with the analytical result.

A new lidar design for operational atmospheric wind and cloud/aerosol survey from space

Abstract. Global wind profile measurement has, for a long time, been a first priority for numerical weather prediction. The demonstration, from ground-based observations, that a double-edge Fabry–Pérot interferometer could be efficiently used for deriving wind profiles from the molecular scattered signal in a very large atmospheric vertical domain has led to the choice of the direct detection technique in space and the selection of the Atmospheric Dynamics Mission (ADM)-Aeolus by the European Space Agency (ESA) in 1999. ADM-Aeolus was successfully launched in 2018, after the technical issues raised by the lidar development had been solved, providing the first global wind profiles from space in the whole troposphere. Simulated and real-time assimilation of the projected horizontal wind information was able to confirm the expected improvements in the forecast score, validating the concept of a wind profiler using a single line-of-sight lidar from space. The question is raised here about consolidating the results gained from ADM-Aeolus mission with a potential operational follow-on instrument. Maintaining the configuration of the instrument as close as possible to the one achieved (UV emission lidar with a single line of sight), we revisit the concept of the receiver by replacing the arrangement of the Fizeau and Fabry–Pérot interferometers with a unique quadri-channel Mach–Zehnder (QMZ) interferometer, which relaxes the system's operational constraints and extends the observation capabilities to recover the radiative properties of clouds. This ability to profile wind and cloud/aerosol radiative properties enables the meeting of the two highest priorities of the meteorological forecasting community regarding atmospheric dynamics and radiation. We discuss the optimization of the key parameters necessary in the selection of a high-performance system, as based on previous work and development of our airborne QMZ lidar. The selected optical path difference (3.2 cm) of the QMZ leads to a very compact design, allowing the realization of a high-quality interferometer and offering a large field angle acceptance. Performance simulation of horizontal wind speed measurements with different backscatter profiles shows results in agreement with the targeted ADM-Aeolus random errors, using an optimal 45∘ line-of-sight angle. The Doppler measurement is, in principle, unbiased by the atmospheric conditions (temperature, pressure, and particle scattering) and only weakly affected by the instrument calibration errors. The study of the errors arising from the uncertainties in the instrumental calibration and in the modeled atmospheric parameters used for the backscattered signal analysis shows a limited impact under realistic conditions. The particle backscatter coefficients can be retrieved with uncertainties better than a few percent when the scattering ratio exceeds 2, such as in the boundary layer and in semi-transparent clouds. Extinction coefficients can be derived accordingly. The chosen design further allows the addition of a dedicated channel for aerosol and cloud polarization analysis.

Design and performance simulation comparison of a wave energy-powered and wind-powered modular desalination system

A new method is presented for the design and operation of wind and wave-energy-powered modular seawater reverse osmosis (SWRO) desalination plants. The SWRO modules are designed to achieve discrete adaptation of their power consumption to the estimated power output of the renewable energy technologies. The mean, mode and median power output values are proposed as statistical parameters to select the size of the single-stage SWRO modules. The aim is to select the system configurations which provide the minimum specific product water cost, the highest annual freshwater production, and the most efficient exploitation of the energy resource. A statistical inference analysis determined the existence of significant differences between their results. A discussion is conducted on the optimal systems obtained with both renewable technologies, and an economic sensitivity analysis of the variables employed is performed. The method is applied to a case study in Gran Canaria island (Spain), using local climate data measurements to assess the energy resource. Results show that the median was the best statistical parameter for the design of the wind-powered desalination system and the mode for the wave-based system. In the case study, the wind-powered system obtained better results despite a lower installed power than the wave-powered system.

Novel formulation for optimized winding and core design for improved induction machine performance

Novel formulation for optimized winding and core design for improved induction machine performance

Wind Electric System (WES) Design Using General and Simple Algorithm.(Dept.E)

It is intended in this paper to find the optimum design of a wind electric system by a general, but simple algorithm. It is a general since the proposal can be applied to any wind regime, site and design parameters. Its simplicity stems from the direct solution of the optimization problem without hard and numerous calculations. This is obtained although several parameters are involved. Thus, an objective cost function is deduced to express mathematically the energy cost figure against the foregoing variables. It will be minimized subjected to the most effective technical constraints. Two models are derived also, to describe the optimum normalized rated wind speed and the minimum energy cost figure in explicit forms as functions of wind regime parameters and the wind speeds ratios. A comparative study has been carried out to validate the proposed algorithm and the deduced models. The results are compared with those attained by applying the previously published methodology which depends on step-by-step calculations for specific conditions. The comparison demonstrates the flexibility of the proposal to any change in data and accuracy in estimating the optimum solution despite of its simplicity.

Analysis and Design of a New Relieving-DC-Saturation Transverse-Flux Tubular Motor With Complementary Magnetic Circuit

Due to the flux leakage and large detent force, the thrust force ripple of transverse-flux linear motor is relatively large, which restricts its further application. Also, the field of most existing transverse-flux machines is hard to be altered and regulated considering the permanent magnet (PM) excitation. Therefore, to suppress the force ripple and strengthen the flux regulation capability of transverse-flux machines, a novel hybrid excitation transverse-flux tubular motor with complementary structure is proposed in this article. The key is that a complementary and parallel structure is constructed in this motor, and hybrid excitation of both dc windings and small auxiliary PMs installed at opening of the slot is adopted in this motor as well. In addition, unequal teeth design of dc winding and ac winding is also employed to increase the thrust force density. Finite element calculation results verify the effectiveness of the proposed machine.

Precise appraisement of the harmonic loads impact on hysteresis losses in a 3-phase HTS transformer

Nowadays, the application of non-linear loads such as, rectifiers, electronic phase control, PWM drives, gives rise to a vastly increased level of harmonics in the power network. As such, the transport currents of transformers are non-sinusoidal alternating currents. On the other hand, AC losses are one of the most critical characteristics for the design and operation of high-temperature superconducting (HTS) transformers. The amount of hysteresis losses is a key parameter for the design of HTS windings affecting equipment, cooling cost, efficiency, and transformer economic feasibility. The computation of AC losses by traditional techniques, is suitable for the sinusoidal current condition. While, non-linear loads brings about different number of peaks and amplitudes in the current waveform passing through the HTS transformer windings. So that, in addition to the major hysteresis loop, a number of minor hysteresis loops are also formed changing the hysterical nature of the AC losses.Hence, this paper proposes an accurate, yet efficient analytical algorithm, for calculating hysteresis losses in a three-phase HTS transformer's windings in the presence of the harmonic loads accounting for the AC losses estimation. This is accomplished by performing a numerical Finite Element Method to verify the analytical results. The analysis of the hysteresis losses in an exemplary 315 kVA three-phase HTS distribution transformer for different harmonic loads, is another object of this paper.

Wind shielding in refining and petrochemical facilities

Arguably the most influential climatic load affecting the structural design of gulf coast refining and petrochemical facilities is wind. Despite this fact, little has been done to customize wind design for these unique facilities. This paper proposes a probabilistic model to predict the magnitude of shielding that is provided by the vast network of pipe rack structures that encircle these densely arranged facilities. The probabilistic model is built from data obtained through a broad sampling of pipe rack configurations simulated with hurricane force winds using computational fluid dynamics (CFD). The CFD simulation approach is validated against published wind tunnel data that relate the proposed methodology to code recognized procedures (i.e. wind load reductions corroborated by wind tunnel testing). A reliability analysis is then carried out to re-calibrate the LRFD design equation to include the proposed shielding effects while maintaining the code specified level of reliability. • CFD simulations are used to investiage shielding effects in refining and petrochemical facilities. • A reliability analysis is conducted to ensure the proposed model is in line with target reliability levels. • To aid incorporation into design, an LRFD re-calibration is provided.

Slot-PM-Assisted Hybrid Reluctance Generator With Self-Excited DC Source for Stand-Alone Wind Power Generation

This article proposed a new slot-permanent-magnet (PM)-assisted hybrid reluctance generator (SPMa-HRG) with self-excited dc source for stand-alone wind power generation system. By introducing PM excitation in stator slot openings, enhanced torque density due to flux modulation effect can be achieved compared with the original reluctance topology. Moreover, the introduced PMs make it feasible to build a self-excited dc source to fed dc field winding without using extra power supply. In particular, a simple design of ac supply winding is proposed, by splitting a small portion of ac armature winding to provide electrical power to dc field winding through a diode rectifier and small-capacity H-bridge converter. Compared with using separate dc source, the device cost is reduced, and the system reliability is improved. In this article, the generator structure and operation principle are introduced. PM usage is optimized to obtain the optimal torque. The feasibility of the optimal design with self-excited dc source is verified by field-circuit coupled finite element analysis.

High-Efficiency Push–Pull Resonant Converter Solution for Auxiliary Power Supply in 70-kV Isolated Applications

This paper presented a high-efficiency push-pull resonant converter solution for auxiliary power supply in 70 kV isolated applications. This power supply consists of a two-stage structure with a resonant push-pull inverter and a buck regulator. A series resonance is introduced in the inverter with its operation and parameter design to achieve high-efficiency voltage isolation. A buck converter with feedforward control is presented with the small-signal model and controller design to regulate the output voltage. Besides, the transformer is another challenge as a crucial part of the voltage isolation. Specifically, the optimization design of toroidal core and sector windings is presented, including the analysis of isolation, loss analysis, and leakage inductance. The paper presents comprehensive converter and transformer models, describing the proposed power supply’s design process. Furthermore, a case study is demonstrated under 70 kV isolation with 36 V-84 V input and 48 V output. A prototype of a 200 W, 1.4 L isolated power supply has been built to demonstrate the design model’s validity and process. Results convincingly indicate that the proposed converter has the highest efficiency of 93.1% and can maintain the 70 kV isolation voltage with good regulation performance.

Quasi‐static response of a bottom‐fixed wind turbine subject to various incident wind fields

AbstractIn the design of offshore wind farms the simulated dynamic response of the wind turbine structure includes loading from turbulent wind. The International Electrotechnical Commission (IEC) standard for wind turbine design recommends both the Mann spectral tensor model and the Kaimal spectral model combined with an exponential coherence formulation. These models give deviating wind loads. This study compares these two models to a large eddy simulations model and a model based on offshore wind measurements. The comparisons are performed for three situations, covering unstable, neutral and stable atmospheric conditions. The impact of the differences in the wind fields on the quasi‐static response of a large bottom‐fixed wind turbine is investigated. The findings are supported by an assessment of the impact of individual wind characteristics on the turbine responses. The wind model based on measurements causes high tower bottom and blade root flapwise bending moments due to a high wind load at very low frequencies. Low and negative horizontal coherence is obtained using the Mann spectral tensor model. This causes relatively large yaw moments as compared to the results using the other wind models. The largest differences in response are seen in the stable situation. We furthermore show that the quasi‐static wind load has great impact on the total damage equivalent moments of the structure. From the results, we conclude that in the design of large offshore wind turbines one should carefully consider the structure of the turbulent wind. Further, longer simulations than recommended by the standards should be used to reduce uncertainty in estimated response.

Preface

The 23 papers in this volume constitute the proceedings of the 2021 Wake Conference. The Wake Conference series began in Visby, where it was held in 2009 and 2011. In 2013 the conference took place in Copenhagen where it was combined with the International Conference on Offshore Wind Energy and Ocean Energy. In 2015 and 2017 it went back to where it started, Visby. This year the conference will be held online due to the restrictions for Covid-19. Hosts for the conference are Professor Stefan Ivanell, Uppsala University and Professor Jens Nørkær Sørensen, Technical University of Denmark.Modern wind turbines are today clustered in large farms with a total production capacity reaching those of a nuclear power plant. When placed in a wind farm, the turbines will be fully or partially influenced by the wake of upstream turbines. This wake interaction results in a decreased power production, caused by the lower kinetic energy in the wind, and an increase in the turbulence intensity. Therefore, understanding the physical nature of vortices and their dynamics in the wake of a turbine is important for the optimal design of wind farms.The increased importance and interest in the field of wake and wind farm aerodynamics can be seen in the increased number of scientific articles on the subject. This citation growth essentially shows that the growth in the global production of electrical energy has become a scientific problem to be solved by scientists and engineers. In order to make a substantial impact on one of the most significant challenges of our time, global climate change, the wind industry’s growth must continue. A part of making this growth possible will require research into the physics of wind turbine wakes and wind farms.This conference is aimed at scientists and PhD students working in the field of wake dynamics. The conference covers the following subject areas: Wake and vortex dynamics, instabilities in trailing vortices and wakes, simulation and measurements of wakes, analytical approaches for modeling wakes, wake interaction and other wind farm investigations.We would like to thank all those that assisted in the review process for these proceedings and we are also thankful for the help we have received from the editorial team at IOP Publishing during the process.Visby, Sweden May 2021 Stefan Ivanell and Jens Nørkær Sørensen

Multiobjective Optimization of a Hybrid Wind/Solar Battery Energy System in the Arctic

This paper presents an optimal design of a hybrid wind turbine/PV/battery energy system for a household application using a multiobjective optimization approach, namely, particle swarm optimization (PSO). The ultimately optimal component selection of the hybrid renewable energy system (HRES) is suggested by comprehensively investigating the effects of various factors on the cost-reliability relation, such as the mounting orientation, temperature on the PV modules, wind turbine hub height, different types of batteries, and different load profiles. The optimization results show the feasibility of HRES for a single-family household demand in the arctic region of Tromsø, Norway. As we will discuss in the results, an HRES operating in such a region can achieve great energy-autonomous levels at a reasonable cost partially thanks to the cold climate. The mounting structure and temperature effects on the PV modules and the battery type can significantly change the system performance in terms of cost and reliability, while a higher wind turbine hub offers little improvement. The result suggests an optimal HRES consisting of a wind turbine with a swept area of 21 m2 and a hub height of 12 m, a PV system of 12 m2 with 2-axis tracking, and a battery bank of 3 kWh. This system will achieve 98.2% in self-reliance. Assuming that the system lifetime is 20 years, the annual cost is about 900 USD. Even though this study focuses on an HRES for a single-family application in the arctic, such an approach can be extended for other applications and in other geographical areas.

Wind load and structural analysis for standalone solar parabolic trough collector

Solar energy is one of the emerging technologies and the use of concentrating power technology is increasing in solar power plants. Parabolic trough collector is a concentrating solar power technology that is situated in the open terrain and subjected to wind loads. The structural stability of these devices under such loads determines the ability to accurately concentrate the rays at the absorber tube, which affects the overall optical and thermal efficiencies. A detailed numerical analysis is carried out at different wind loads and design conditions. It is observed that for a change in velocity from 5 m/s to 25 m/s, slope deviations increase from 1.21 mrad to 3.11 mrad at the surface of the reflector exceeding the shape quality of the mirror panels. Higher yaw angles and pitch angles of 60° and 120° are observed to be decisive in the design of collectors. Roof-mounted collectors experience a 40% higher drag force than ground-mounted collectors at a 0° pitch angle. For the Aluminium trough, the slope deviation at the surface of the reflector is higher by 4.62% than glass. The study will be helpful for engineers and scientists in the design of the parabolic trough collectors.

Optimization of hybrid renewable energy system in radial distribution networks considering uncertainty using meta-heuristic crow search algorithm

In this paper, probabilistic design and placement of hybrid wind–photovoltaic​ system based on battery storage (PV/WT/Batt) in distribution networks with the aim of minimizing active losses and voltage deviations considering renewable units generation uncertainty and network load demand. The uncertainties are modeled with Monte Carlo simulation (MCS) using probability distribution function (PDF). It is assumed that the total load of hybrid system is supplied via the PV/WT/Batt system without the use of the power grid and the hybrid system extra power is transferred to the distribution network. The decision variables include the optimal installation location and hybrid system components size, i.e. the number of PVs, WTs and batteries, which is determined using an optimization method named improved crow search algorithm (ICSA) using behavior of crows searching for food hidden by them and the pursuit of other crows. In the ICSA, performance of traditional CSA is improved based on decreasing inertia weight method to increase the exploration capability. The proposed method is simulated on IEEE 33 and 69 bus distribution networks. The net present cost of the hybrid system is also assessed for its load supply as well as the improvement of the distribution network characteristics. The deterministic results indicated that design and placement of PV/WT/Batt system in the networks, optimally causes reduction of active losses and voltage deviations significantly. The superiority of the ICSA is compared with traditional CSA, well-known method of particle swarm optimization (PSO) and manta ray foraging optimization (MRFO) that the proposed method is resulted less power losses and less voltage deviations and more net saving the other methods. The results cleared that the designing cost of hybrid system is increased, reduced losses and voltage deviations considering uncertainty. So the probabilistic results indicated that considering uncertainty determines the worst possible events of the network for the operator and creates the possibility of logical decision making to improve the network characteristics.

Performance-based wind design framework proposal for tall buildings

Performance-based seismic design (PBSD) is currently used for retrofitting of older buildings and the design of new buildings. Whereas, application of performance-based design for wind load is still under development. The tendency has been in the codes to increase wind hazard based on recent recorded events. Since tall buildings are highly susceptible to wind load, necessity for developing a framework for performance-based wind design (PBWD) has intensified. Only a few guidelines such as ASCE (2019) provide information on using PBWD as an alternative for code prescriptive wind design. Though wind hazards, performance objectives, analysis techniques, and acceptance criteria are explained, no recommendations are provided for several aspects like how to select a proper level of wind hazard for each target performance criterion. This paper is an attempt to explain current design philosophy for wind and seismic loads and inherent connection between the components of PBSD for development of a framework for PBWD of tall buildings. Recognizing this connection, a framework for PBWD based on limits set for serviceability and strength is also proposed. Also, the potential for carrying out PBWD in line with ASCE 7-16 is investigated and proposed in this paper.