Shore Wind Research Articles

Noise propagation variations over long distances over water

This paper investigates the short temporal variations of noise propagation over a water surface for long distances. Analysis is formed on the results of a measurement campaign for downwind noise propagation over water for elevated sound sources. Noise propagation over water for elevated noise sources is specifically relevant for offshore wind turbines, near shore wind turbines or wind turbines on land close to large water bodies. The measurement setup is a height-adjustable sound source placed at three different heights 81 m, 50 m and 30 m above ground and microphones positioned downwind at shore and ~100 m inland at three different distances over water from the sound source ~3 km, ~5 km and ~7 km. The meteorological conditions wind speed, wind direction, atmospheric stability, temperature, humidity, etc. were monitored continuously at both ends of the setup, utilizing both a tall met mast, a wind profiler and sonic anemometers at multiple heights. The results are used for improving auralisations of noise from offshore wind turbines and offshore wind farms. In addition to this a semi-analytical model for propagation over water is tested.

Techno-economic evaluation and improved sizing optimization of green hydrogen production and storage under higher wind penetration in Aqaba Gulf

On shore wind farms designed for hydrogen production present a promising avenue for maximizing the utilization of wind energy, achieving decarbonization and energy security objectives across various sectors. However, existing understanding of these systems, particularly in terms of economic and technical considerations, remains challenging. Hence, this paper introduces a comprehensive numerical modeling aimed at assessing the feasibility of hydrogen production from onshore wind farms for the arid costal community south of Aqaba Gulf, Saudi Arabia. This model incorporates formulas to compute wind power output, electrolyzer plant sizing, and hydrogen generation based on fluctuating wind speeds. The objective is to identify the optimal setup for a hydrogen station fueled by high wind resources, while also evaluating its economic feasibility and reliable capacity to reduce hydrogen production cost and minimize carbon emissions. The results show that the optimal Onshore Wind-Hydrogen System (OWHS) consists of 26 units of WT (each is 6.15 MW), Alkaline Electrolyzers plant with a capacity of 120 MW, and a group of hydrogen storage tanks of total size of 300 tones. The hydrogen demand and the subsidiary electric needs are successfully met with the 160 MW of wind generation capacity installed within the system with negligible capacity shortage and unmet demand. The employed set of alkaline electrolyzers has a total rated capacity of 120 MW and can stay in operation for 7335 h/yr to produce a total annual amount of 8,214,152 kg/yr of green hydrogen. The proposed system generates hydrogen with a moderate price since the LCOH obtained is found 5.26 $/kg which falls within the global range that varies from 4 to 6 $/kg. Moreover, the CO2 mitigation of the designated OWHS reaches 3343.72 Mt. with a corresponding $133,748 carbon credit gain. The sensitivity analysis shows that the total net present cost (TNPC) is highly sensitive to wind speed, hydrogen cost, and hydrogen demand but less so to inflation and discount rates. The TNPC increases by 22 % with a 5 % decrease in wind speed, as well as reducing hydrogen costs by 25 % and 50 % decreases TNPC by 14.63 % and 29.26 %, respectively. While, increasing hydrogen demand by 20 % and 40 % raises TNPC by 30.3 % and 51.4 %, respectively. This study aims to assist stakeholders and policymakers in refining onshore wind‑hydrogen systems to economically fulfill the requirements of hydrogen production for the arid costal community in Saudi Arabia.

Classification for transient overvoltages in offshore wind farms based on multi-scale mathematical morphology

At present, the transient overvoltages in o shore wind farms caused by faults or frequent operations of electrical equipment are particularly severe. The quick and accurate classi cation of transient overvoltages is important for protecting electrical equipment from damage. In order to classify the internal transient overvoltages in o shore wind farms, this research rstly proposes a feature extraction method based on mathematical morphology, which proposes a new morphological structure element and utilizes a multi-scale mathematical morphology to extract the high/low-frequency components of transient overvoltages. Then a high-frequency feature and a high/low-frequency energy ratio feature are constructed as identi cation features. Finally, based on the constructed features, a support vector machine is employed to identify di erent types of internal transient overvoltages. Extensive simulations and experiments are performed to verify the superiority of the proposed feature extraction method based on mathematical morphology, which is also compared with the widely used conventional wavelet algorithms. Results show the proposed mathematical morphology feature extraction method is capable of classifying and discriminating among various types of internal transient overvoltages with a simple procedure and an improved accuracy. The proposed method provides a valuable reference for the protection and insulation coordination of electrical equipment in o shore wind farm substations.

A New Fuzzy Based UPFC Topology for Active Power Enhancement in an offshore Wind Farm

The stability of a power system is the ability of a
 power system to restore an operating state of equilibrium for
 a given initial operating condition after it has been subjected
 to a physical disturbance, most of the variables of the system
 being limited so that almost the entire system remains intact.
 To create a MATLAB SIMULINK model of odd shore wind
 energy system having power being transmitted through DC
 transmission system. The first model will have no power flow
 controller and second model will have artificial intelligence
 based controlling technique. To design a controller for
 enhancing the power output from the wind energy system
 using UPFC. This will be made to feed DC transmission
 system. Finally integrating the system with long distance DC
 transmission system and then to the grid so as to make it
 more reliable and efficient. In this work a coordinated
 control based on Fuzzy logic for UPFC for cluster of offshore
 WPP connected to the same HVDC connection is being
 implemented and analyzed. The study is targeting
 coordination of reactive power flow and active power flow
 between HVDC Converter and the WPP cluster while
 providing offshore AC grid voltage control. Thus it can be
 drawn from this work that while designing a power control
 strategy the proposed fuzzy logic based active power
 controller in UPFC can serve the purpose with better results
 in terms of active as well as reactive power. This control can
 also be used in hybrid systems thus making it more reliable
 controlling method. The

Regional Spatial Analysis of the Offshore Wind Potential in Japan

This study presents an approach for estimating the offshore wind potential of Japan. Bathymetry data (1 km mesh) and near shore wind speed data of the year 2018 were used to assess the potential. A turbine with a peak power of 10.6 MW was employed for the analysis. The potential was calculated for multiple regions. These regions are based on the service areas of the major electricity supply companies in Japan. Overall, the results show that Japan has the potential to produce up to 32,028 PJ electricity per year. The electricity demand of 2018 amounts to 3231 PJ. The potential is therefore large enough to cover Japan’s electricity needs ten-times over. The capacity that could theoretically be installed amounts to 2720 GW, which is a multiple of the current worldwide installed capacity of 29.1 GW (2019). In addition to the huge potential, the regional assessment shows that the regions vary greatly in their potential; of all the considered regions, Hokkaido and Kyushu have the highest overall potential.

Smart Wireless sensors for Impairment detection of the offshore Wind Turbines

The maintenance of Wind farms located in the off shores are highly challenging as the preservation and the operational availability are tedious. The insufficiency in the traditional system for monitoring the conditions of the wind turbines located in the off shores has made this topic an attractive area of research. The proposed method in the paper utilizes the multiple intelligent smart sensors to detect the impairments in the structure of the wind turbines. The sensors utilized in the proposed method estimates the damage index in the wind turbine by engaging the embedded software. The effectiveness of the proposed method was measured by applying it to the off shore wind turbines. The results obtained evinces the minimized cost and the down time in maintaining the off shore wind farms.

2354 Published By: Blue Eyes Intelligence Engineering & Sciences Publication Retrieval Number J1160881019/2019©BEIESP DOI: 10.35940/ijitee.J1160.0981119 Journal Website: www.ijitee.org High Voltage DC Transmission Systems for Offshore Wind Farms with Different Topologies

Theoretical review of various topologies of high voltage DC links in application to off shore wind forms has been studied and analysed. In addition to that, various types of high voltage DC links such as back to back, two terminal, multi-terminal systems has been covered under this study. The Line-Commutated Converters, Voltage Source Converter, Modular Multi-Level Converter as well as some of advanced hybrid high voltage DC topologies in application to off shore wind forms has been reviewed. This study covers complication arising from large-scale wind power generation. The review paper also points out the scope of future research in high voltage DC converters.

Numerical simulation of a resistant structural bonding in wind-turbine blade through the use of composite cord stitching

The trailing edge is a critical part of blade because of monolithic bonding, which may lead to separation of edges while wind-turbine is in service. It is easily perceptible that the maintenance is (under harsh environmental conditions) extremely expensive and time consuming for wind turbine blades with excessive length (100 m). From technological point of view, o shore wind generation maintenance teams are targeting zero-maintenance and/or least maintenance in a well-chosen timing. As a matter of fact, the two halves (top and bottom skins) of a wind blade should hold together as long as possible to allow enough time for maintenance in the event of onset of damage. Accordingly, we are suggesting a strategy, which consist the joints with ‘carbon-fiber cord composite stitching’. In order to implement this technique in industrial application, one should take care of lowering stress concentration as much as possible around drilled holes and should prevent indentation to carbon-fiber cords. This paper is addressing the mentioned technologies in detail, using numerical simulation.

Preface: advances in theoretical and practical combinatorial optimization

Preface: Advances in Theoretical and Practical Combinatorial Optimization Said Salhi1, Richard Eglese2, Eleni Hadjiconstantinou3 This issue consists of research papers dedicated, though not limited, to the International Symposium in Combinatorial Optimisation (CO2016), chaired by Said Salhi and held at the University of Kent, Canterbury, 1-3 September 2016. Of the many good papers it attracted, 35 were considered suitable for the next stage of review, resulting in 20 being accepted mostly after two rounds of reviews. We divided the issue into three parts, each covering a wider though well-defined area within combinatorial optimization (CO). These three parts, which are not completely distinct, are referred to for simplicity as Mathematically-Oriented (MO), Heuristically-Based (HB) and Practically-Focussed (PF). MO contains seven papers. These include a paper on the integration of network flows in a coloring algorithm by Koster, Scheidweiler, and Tieves; one on a polynomial time algorithm for the minimum flow problem by Khodayifar, Raayatpanah, and Pardalos, and one on a formulation in multi-level capacitated facility location by Irawan and Jones. A.Salhi, Alsoufi, and Yang provide a mixed integer program combined with an evolutionary approach for seaside operations in container ports, while Zare, Borrero, Zeng and Prokopyev have contributed a note on new linearized formulations in bilevel linear integer problems. Fuzzy logic is explored for portfolio optimization by Liagkouras and Metaxiotis, and for supplier selection by Chang. HB covers six papers. Azizi, using a genetic algorithm, explores hub and spoke networks under disruption. Knust and Xie produce a simulated annealing algorithm for nurse rostering, while Pei, Cheng, Liu, Pardalos, and Kong investigate Variable Neighbourhood Search (VNS) for single and parallel machine serial batching. A skewed VNS is adopted by Derbel, Jarbaoui, and Bhiri for the heterogeneous fleet vehicle routing problem, and an ascent-escent VNS for the detection of community (cluster) structures in a network is discussed by Džamic, Aloise, and Mladenovic. The last paper in this category is by Brimberg, Mladenovic, Todosijevic, and Urosevic, who investigate the capacitated clustering problem using a variant of VNS. PF has seven papers that treat inspiring implementations of CO for real-life applications. For example, in the area of scheduling, the use of spare parts in vessel maintenance is dealt with by Kian, Bektas, and Ouelhadj, while shift scheduling for power station staff is explored by Shuib and Kamarudin. The avoidance of obstacles in off shore wind farms is optimized by Klein and Haugland, and the costing of a product within a supply chain is performed by de Matta. In the health area, the maximization of the expected number of kidney transplants is performed by Alvelos, Klimentova, and Viana; a preventive health care network is designed by Davari; and the layout of an operating theater is produced by Chraibi, Osman, and Kharraja. Finally, we are grateful to Professor E. Boros for trusting our academic judgment in acting as guest editors of the Annals of Operations Research special issue devoted, but not restricted, to CO2016. We are also thankful to the managing editor, Katie D’Agosta, for her patience and valuable support in preparing this special issue. 1 Centre for Logistics and Heuristic Optimisation, Kent Business School, University of Kent, Canterbury, UK 2 Lancaster University Management School, Lancaster, UK 3 School of Business and Law, Frederick University Cyprus, Cyprus.

Comparison of temperature sensitive electrical parameter based methods for junction temperature determination during accelerated aging of power electronics

This paper compares the most common used temperature sensitive electrical parameters towards their aging dependencies as well as to one another. Therefore a mission profile is extracted from an off shore wind park and a test plan is generated. Insulated Gate Bipolar Transistor (IGBT) power modules are tested against that test plan using active power cycling. The selected temperature sensitive electrical parameters (TSEP) are monitored online during the test and correlated to each other. This way the aging dependence can be extracted, so that the most aging independent TSEP can be used for condition monitoring during wind park operation.

2050—An Energetic Odyssey: Understanding ‘Techniques of Futuring’ in the transition towards renewable energy

After the Paris agreement on climate change (2015) climate change politics is no longer about raising awareness but about shaping the sustainability transition itself. It requires us to rethink the role of scientific knowledge, shifting from a tradition of “expected futures” to an approach focusing on “desirable futures” and ways to get there. We argue the sustainability transitions scholarship tends to see constructions of the future (visions, scenarios, predictions etc.) as explanans (that what explains) while constructions of the future are rarely seen as explanandum (that what should be explained). The article introduces the concept of ‘Techniques of Futuring’ defined as practices bringing together actors around one or more imagined futures and through which actors come to share particular orientations for action, to get a grip on the actual acts of ‘futuring’. The empirical focus is on ‘2050—An Energetic Odyssey’, a process centred around an elaborate multimedia installation, introducing large scale exploitation of the North Sea for harvesting off shore wind energy taking place in 2015 and 2016. We examine the Odyssey as example of a Technique of Futuring. We conclude with a reflection what the Odyssey teaches us about effective Techniques of Futuring to further the sustainability transition.

THE STUDY OF SHIPS BEHAVIOR DURING PORT MANEUVERING WITH TUGS

Most of the time, during the turning, the motion of the ship is not a perfect circle because there are several forces acting on the ship and these forces change continuously. In this paper we study the real motion of the ship when a transverse force is applied by a tug at the different points of the moving or stationary ship. The pivot point is useful by seafarers to visualise the rotation of a ship during its combined rotation/translation movement. It is the result of all forces acting on the ship and its position changes continuously during the ship’s displacement, depending on the forces involved.The centre of drift is the point at which the resultant of all hydrodynamic forces acts: underwater resistance, lift and drag as a function of speed and drift angle. The underwater resistance force exists both for pure headway or sternway motion and for all lateral motions. It induces flow velocities below and beside the hull. On a real turning circle the heading is not completely constant as it undergoes small variations due to small changes in the forces acting on the ship: local variations in water depth, variations in distance from the shore line, local currents or wind gusts.

Occupational risk for an onshore wind farm

The aim of the paper is to present the quantification of risk for workers in the construction, operation and maintenance of an on shore wind farm. The method for risk estimation is based on a probabilistic model which has been developed under the WORM (Workgroup Occupational Risk Model) project and is called ORCA (Occupational Risk Calculator). This method assesses workers’ risks, by considering all hazards which may occur during their daily activities and tasks as well as the exposure to these hazards. Risks of all workers, participating in the construction, operation and maintenance of a specific wind farm located in Greece have been assessed, by estimating the risk of recoverable, permanent injury and fatality. Crane operators, fitters, electricians, and maintenance workers have been ranked according to their risk. Fitters have the highest fatality risk, followed by crane operators working in the construction phase, while electrical/mechanical maintenance operators have the highest fatality risk during maintenance. Risk reduction measures for the most important hazards, which are fall from elevation and struck by falling objects, are proposed.

Dynamic Stability Improvement of a Smart Grid Using Neural Network Based STATCOM

Objectives: A micro grid is a cluster of loads and distributed resource units serviced by a distribution grid and capable of operation in a grid –connected mode, in an autonomous mode or a ride-through between the above two modes. Methods: Micro grids are significant for local reliability, considerable reduction of losses, different costs and continuity of service. Smart Grid is formed with the interconnection of different generating resources and loads, the characteristics of the grid can be modified according to the requirements. The major challenges are fault clearing, voltage regulation, islanding, and power quality and interfacing with the utility system in terms of its stability. Findings: This paper describes improvement of dynamic stability in interconnected on and off shore wind turbines with Proposed Artificial Neural Network Controller compared with the discrete Proportional–Integral–Derivative (PID) controller. As per the references indicated, the generators driven by OWF may be modeled as the parallel connection of several Doubly -Fed Induction Generators (DFIGs) and the generators driven by MCFs can be modeled by means of Squirrel Cage Induction Generators (SCIGs) well efficiently. Normally, STATCOMs or different combinations of Flexible AC Transmission System (FACTS) devices are used as large scale control devices in many applications. In the present work, Artificial Neural Network (ANN) based PID controller is used instead of Discrete PID controller for providing control pulses to the STATCOM connected to the grid system. Keywords: Artificial Neural Network, Converter, Power System Stability, Smart Grid, Static Var Compensators

North Atlantic right whale occurrence near wind energy areas along the mid-Atlantic US coast: implications for management

The distribution and seasonal patterns of the North Atlantic right whale, Eubalaena glacialis, inform management decisions that mitigate anthropogenic threats. Based on data from visual surveys, much of the population migrates between winter calving grounds in coastal waters adjacent to the southeast USA and summer feeding and nursery grounds adjacent to the northeast USA. However, little is known about right whale occurrence along the mid-Atlantic US migratory corridor. A better understanding of right whale occurrence in this region is needed prior to off- shore wind energy development activities, which may increase mortality risks and chronic impacts on the population. We conducted an 11 mo passive acoustic survey along coastal North Carolina and Georgia near several wind energy areas to document the acoustic occurrence of right whales in the southern region of the mid-Atlantic US coast. Right whales were acoustically detected across all seasons, with peak seasonal presence occurring during autumn in the Georgia site and during winter in the North Carolina site. A secondary peak in presence also occurred dur- ing June and July in the Georgia site, when right whales were not expected to be in the area. Given the nearly year-round presence of right whales in the survey areas, these results may war- rant an evaluation of current management protocols in order to provide adequate protection to the population in the face of offshore energy development activities.

An extended goal programming model for site selection in the offshore wind farm sector

This paper presents an application of extended goal programming in the field of offshore wind farm site selection. The strategic importance of offshore shore wind farms is outlined, drawing on the case of the United Kingdom proposed round three sites as an example. The use of multi-objective modelling methodologies for the offshore wind farm sector is reviewed. The technique of extended goal programming is outlined and its flexibility in combining different decision maker philosophies described. An extended goal programming model for site selection based on the United Kingdom future sites is then developed and a parametric analysis undertaken at the meta-objective level. The results are discussed and conclusions are drawn.

Autonomous inspection of underwater structures

In the future our resource on land will be over exploited. The exploration of new resources in the ocean is in progress. Mining will be done on the bottom of the sea. The sea is also a big source of renewable energy. Off shore wind parks and tide plants are built. Also, the major world trade is handled over sea routes and several big harbors. All this maritime facilities are getting older and there are effects like corrosion or malfunctions. In general, they need to be inspected frequently. For deep sea applications, security reasons and cost reduction autonomous underwater vehicles (AUVs) will be the first choice.The project “CView” addresses one of these inspection problems, the harbor inspection. But the algorithms, we present in this article can be adapted to many other inspection tasks. One of the main goals in this project is to find cracks or damaged areas at the underwater buildings or to observe critical sections under water with cost effective methods.The platform for developing the guidance algorithms for inspection is the AUV “SeaCat”. This underwater vehicle has a control software system with an user interface for mission planning, a mission control system, a precise navigation system, optimized motor control with an autopilot and sensors for obstacle detection and inspection.For obstacle and inspection target detection, a scanning sonar is used. The sonar images are automatically processed with edge detection and line extraction algorithms to get a simplified environment description, which is used by the guidance methods presented in this article. A pan–tilt enabled sensor head with camera, laser measurement and MBES (Multi Beam Echo Sounder) is used to inspect the detected objects. Additionally, these sensors provide distance information to the inspection object which can be used by the inspection guidance.This article presents methods for inspection using the online information from the vehicle sensors to guide the vehicle efficient and safely. It is also important to handle the interaction between mission planning and execution. During mission planning, the operator will define the type of the inspection object (wall, vessel, sluice, etc.). The algorithms we develop use the information from the mission planning and the online data from the vehicle sensors to guide the vehicle to get the optimal inspection results. Therefore, a precise distance control to the inspection object, collision avoidance and object recognition are needed.

Off shore Wind Power Plant in the Adriatic Sea: An Opportunity for the Croatian Economy

The significant growth of renewable energy production in the past decades is present mainly due to the global depletion of fossil fuel reserves. One of interesting and well developed renewable energy technologies are wind turbines which are mainly built onshore. Due to more favorable wind characteristics at sea, off shore wind power plants are an interesting and challenging option for meeting future energy demands. In particular, less turbulent wind with higher average velocity enhances energy production and reduces structural fatigue of wind energy structures. In this study, benefits and drawbacks of off shore wind turbine units and power plants are pointed out. Based on the available climate data, sea depths and existing sea traffic routes, two possible wind power plants, i.e. one with fixed and another with floating turbines, are proposed for installation in the Croatian part of the Adriatic Sea. Benefits for the Croatian shipbuilding industry and its economy are pointed out.

Online fault location on AC cables in underground transmission systems using sheath currents

This paper studies online travelling wave methods for fault location on a crossbonded cable system using sheath currents. During the construction of the electrical connection to the 400MW off shore wind farm Anholt, it was possible to perform measurements on a 38.4km crossbonded cable system. At 31.4km, all cables were accessible which made it possible to apply a fault using an arc free breaker and measure the travelling waves at each end of the cable.On a crossbonded cable system, the sheaths are short circuited and grounded at both ends. This makes possible the use of low voltage Rogowski coils if the sheath currents contain the necessary information for accurate fault location. In this paper, this is examined by analysis of field measurements and through a study of simulations. The wavelet transform and a visual inspection method are used and the accuracy is compared. Field measurements and simulations are compared for testing the reliability of using simulations for studying fault location methods.

Ripple Current Propagation in Bipole HVDC Cables and Applications to DC Grids

Offshore wind power is attracting increasing levels of research and investment. The use of HVDC transmission and the development of dc grids are topics with similar high levels of interest that go hand in hand with the development of large scale, far from shore wind farms. Technical challenges result from the interaction between power-electronic dc-dc converters and the cables in a dc transmission network. In particular, the propagation of the ripple current in bipole dc transmission cables, constructed with a lead sheath and steel armor, is examined in detail. The finite-element method is used to predict the currents induced in the outer layers of the cable by the ripple current. These results are used along with wave propagation theory to demonstrate that cable design plays a crucial role in the behavior of the dc system. Applications include the prediction of transmission losses, resonance, and high-voltage filter design.