bluuebunny/crossref_metadata_2025_split huggingface dataset:
Generating long-term sub-hourly wind speed time series by coupling mesoscale models with full-scale spectra
Authors: Schillebeeckx David , Leroy Grégoire 
Published: January 2022

Abstract
Time series-based wind studies are gaining more and more interest and importance within the wind resource community. Benefits of such time series-based analysis being, among others, more accurate production and loss estimations, better representation of ramp-up and extreme events, and improvements in the dimensioning of energy storage systems. While mesoscale Numerical Weather Prediction (NWP) models can simulate long-term winds that capture non-stationary weather patterns, it is known that they are not able to properly resolve sub-scale processes leading to a smoothing effect. Recent studies presented spectral models that describe the full atmospheric spectrum of boundary layer winds which connect the microscale turbulent movements to the large, mesoscale fluctuations. In this work, mesoscale simulations from the Weather Research and Forecasting (WRF) model are coupled with stochastic turbulence simulations using state-of-the-art full-scale boundary-layer spectra to efficiently bridge the spectral gap between the mesoscale and the turbulence fluctuations, without requiring any local measurements nor expensive CFD simulations. The study provides a practical step-by-step approach to generate long wind speed time series at high sampling rate at any desired location and height.
Investigation of the Measurability of Selected Damage to Supporting Structures of Wind Turbines
Authors: Rupfle J , Emiroglu A , Grosse C U 
Published: January 2022

Abstract
The present work deals with a measurability study of damage to supporting structures of wind turbines. The examined hybrid tower consists of a prestressed concrete part with an attached steel section on top. Principal focus is on developing a data preprocessing and analysis concept aiming to investigate the measurability of the two selected failure cases missing pretension of tendons and fatigue based change of Young’s modulus in reinforcement concrete. A simulation deduced out of real world mass and thrust forces provides a comparison with measured data based tower displacements, natural frequencies and mode shapes. The measurability of given deviations is investigated by means of virtual sensors, derived from the measurement setup of a test facility measuring acceleration, velocity, displacement and strain on different positions of the wind turbine tower, aiming the development of detection methods of such cases of damage for condition monitoring systems. The simulation input can be given by strain-based external forces or vibration-based displacements.
Developing a long-lasting offshore wind business case towards a Dutch decarbonised energy system by 2050
Authors: Krishna Swamy S , Gonzalez-Aparicio I , Chrysochoidis-Antsos N 
Published: January 2022

Abstract
The integration of large-scale offshore wind power in the energy system will have a major effect on electricity markets. It may lead to large market price volatility due to the inherent variability of wind energy in terms of power fluctuations, forecast errors and insufficient flexibility on the demand side. This study models future business cases for offshore wind farms in two reference national scenarios for the Netherlands, namely NECP2030 and TRANSFORM. Results show that the value of offshore wind in 2030, according to NECP scenario is 39.9 €/MWh, and that electricity price in the TRANSFORM scenario, which considers aggressive development towards a sustainable economy, is a high 104 €/MWh by 2050. To consider ways of improving the return on investment for offshore wind farms in future markets, an optimisation problem is defined, where the wind farm has the choice to either sell the generated electricity to the spot market or to an electrolyser. Results show a potential advantage in using an electrolyser to produce green hydrogen for offshore wind farms, with net profit of 41.4 M€, compared to when offshore wind farms sell electricity solely to the spot market, where the profits are 36 M€.
Offshore wind farm wake modelling using deep feed forward neural networks for active yaw control and layout optimisation
Authors: Anagnostopoulos S , Piggott MD 
Published: January 2022

Abstract
Offshore wind farm modelling has been an area of rapidly increasing interest over the last two decades, with numerous analytical as well as computational-based approaches developed, in an attempt to produce designs that improve wind farm efficiency in power production. This work presents a Machine Learning (ML) framework for the rapid modelling of wind farm flow fields, using a Deep Neural Network (DNN) neural network architecture, trained here on approximate turbine wake fields, calculated on the state-of-the-art wind farm modelling software FLORIS. The constructed neural model is capable of accurately reproducing single wake deficits at hub-level for a 5MW wind turbine under yaw and a wide range of inlet hub speed and turbulence intensity conditions, at least an order of magnitude faster than the analytical wake-based solution method, yielding results with 1.5% mean absolute error. A superposition algorithm is also developed to construct flow fields over the whole wind farm domain by superimposing individual wakes. A promising advantage of the present approach is that its performance and accuracy are expected to increase even further when trained on high-fidelity CFD or real-world data through transfer learning, while its computational cost remains low.
Deriving an experimental and analytical relation between the core and fiber temperatures of a 3P XLPE cable
Authors: Callewaert Manly , Vanthillo Roel , Fojtek (Marlinks) Christian , Mampaey (Elia) Bart 
Published: January 2022

Every submarine power cable contains a fiber-optic assembly. Most windfarms have a distributed temperature sensing (DTS) device for continuous temperature monitoring. Using real-time thermal rating (RTTR) the performance of subsea cables can be increased or a less expensive cable can be installed.
The experiments aimed to establish the relation between the fiber and core (or conductor) temperatures in the cable. Fiber temperature was obtained using a DTS interrogator; thermocouples installed in the conductors yielded the core temperature data. The cable used in this test was a 20 meter-long 1800 mm2, 1000 A export cable.
These experiments validated a new RTTR model proposed by Marlinks: a thermal RC-ladder model based on finite-element (FEM) calculations. Better suited to the complexity of the spacer geometry and existence of the fiber node, the Marlinks-developed model is considered to be more accurate than the industry standard.
Offshore Wind-to-Hydrogen Production Plant Integrated with an Innovative Hydro-Pneumatic Energy Storage Device
Authors: Settino J , Farrugia R N , Buhagiar D , Sant T 
Published: January 2022

Abstract
One of the main technical challenges of wind-to-hydrogen production plants is to couple intermittent and variable renewable power sources, such as wind turbines, with an electrolyser. Most hydrogen production concepts rely on electrical storage to smoothen the power input to the electrolyser. In this study, the use of a hydro-pneumatic energy storage system is proposed as an interface between the green, fluctuating electricity supply and the electrolyser. The performance of the proposed solution is analysed and compared to that of a conventional offshore wind-to-hydrogen production plant in order to identify potential advantages and drawbacks. The results of the simulations show that the FLASC energy storage system provides a stabilized, yet green power supply. Short-term fluctuations of the power input to the electrolyser can be avoided. A 70% reduction of the On/Off cycles can be obtained. Moreover, if compared to an offshore wind-to-hydrogen production plant with no storage there is no substantial difference in terms of hydrogen production observed over the analysed period of one year in spite of a 70% round-trip efficiency of the energy storage device.
Influence of initial particle configuration upon sphericity of shock loaded density interface in SPH modelling of Richtmyer-Meshkov instability
Authors: Sapozhnikov Filipp A , Rykovanov Vasiliy S 
Published: January 2022

Abstract
The Richtmyer-Meshkov Instability (RMI) occurs when a perturbed interface between two fluids of different densities undergoes impulsive acceleration by, for example, a shock wave. Its study is important for gaining better understanding of processes governing inertial confinement fusion where a spherical solid deuterium-tritium (DT) capsule filled with the DT gas is compressed by a powerful laser [1]. The imploding shock moving to the center of the spherical shell causes the RMI to form on its inner surface due to a large density difference between solid and gaseous DT phases, which leads to a rapid growth of initially present randomperturbations. Usually, the density interface consists of random perturbations (e.g., surface roughness, machining inaccuracies, etc.) which initially grow linearly before nonlinear effects emerge. To improve reliability of shock-driven flow simulations, it is necessary to understand the factors which inuence the RMI growth. Our work aims to find the best initial particle configuration that does not introduce artificial perturbations of the spherical density interface. The shocked interface must preserve spherical symmetry if no perturbations are applied. In order to reduce the number of simulated particles in calculation, it is necessary to adapt spatial resolution, i.e., to increase the concentration of particles in target regions.
Shock induced melting of sapphire
Authors: Ostrik A , Nikolaev D 
Published: January 2022

Abstract
The method for calculation the melting curves of crystalline bodies based on the Debye model of heat capacity and the Lindemann melting rule is proposed. Hugoniot shock adiabate, determined in dynamic experiments and thermophysical characteristics of the substance under normal conditions are used as input data. Mathematically, the calculation of the melting curveis reduced to the Cauchy problem for a system of ordinary differential equations. This system is solved numerically by the Runge-Kutta method. Using the proposed method, the melting curves of copper, silver, gold, and sapphire at high pressures are calculated. The results obtained for copper, silver and gold were compared with available calculated and experimental data to validate the method. Experiments on shock compression of transparent sapphire sampleswere performed, using a Mach-type cumulative explosive generators. Investigated pressure range (280-1350 GPa) covered a region of shock-induced melting. The temperature of shock front was registered by fast optical pyrometer together with shock velocity. Particle velocity andpressure were obtained by impedance matching technique. Satisfactory agreement of calculatedand experimental data on temperature of melting behind the shock wave front in sapphire was obtained.
Prediction of bead geometry on filling cavities in hydroelectric turbine blades by means of robotic welding
Authors: Lázaro Plata J L , Caribé de Carvalho G , Flórez Solano E N 
Published: January 2022

Abstract
This paper presents a methodology of mapping the bead geometry, deposited on a fillet like joint, as a function of the input parameters of the synergic pulsed gas metal arc welding process and the welding position, to allow the planning of repairing hydroelectric turbine runner blades by means of robotic welding. The challenges of automating the repair process; further, to choosing the best welding parameters, include the definition of the path that the robot must follow during the metal deposition, such that it is able to fill completely the damaged blade cavity, by means of producing overlapped layers from several individual weld beads. Thus, this research focused on developing statistical prediction models that could map the geometric variations of the weld bead section as function of the input parameters (wire feed speed, welding speed and bead face rotation angle). For this purpose, the bead section was approximated by a parallelogram whose height, width and inclination angle were considered as dependent variables. Several welding trials were carried out according to a central composite experimental design and three multiple regression models were obtained. Here, the physics is used to interpret the influence of the input parameters on the output results.
Prescribed Performance Voltage Control Strategy of LC Inverter
Authors: Shi Jianqiang , Li Shuang 
Published: January 2022

Abstract
Aiming at the voltage tracking problem of the LC inverter, a new prescribed performance controller is proposed. In order to make the voltage tracking error converge entirely according to the trajectory described by the performance function, a new state variable is introduced referring to the integral sliding surface. The specific form of the voltage controller is obtained according to the voltage equation in the dq coordinate frame and the system stability requirement. The adopted control law is easy to implement. It does not need to adjust the parameters repeatedly so that the inverter’s steady-state and dynamic performance indicators can be close to the prescribed values. The MATLAB/Simulink platform simulation experiment verifies the feasibility and effectiveness of the proposed new prescribed performance control strategy.
Development and Efficiency Test of a 3 MVA Four-port Power Electronic Transformer
Authors: Luo Long , Li Yaohua , Li Zixin , Zhao Cong 
Published: January 2022

Abstract
The development of a 3 MVA four-port, i.e. 10 kV ac port, 380 V ac port, ±750 V dc port, and ±375 V dc port, power electronic transformer (PET) for an integrated energy system is described. For this four-port PET, the efficiency test is a complex problem as each port-to-port efficiencies should be tested. To solve this problem, this paper proposes a data fitting method using only the converter efficiency in each port. The experimental results show a high accuracy of the proposed testing method. The test results of this four-port PET are also analyzed and the efficiency under different power flow directions is explained.
Frequency Domain Characteristic Analysis of Fault Electrical Quantities in HVDC Transmission System
Authors: Cao Hong , Liang Ying , Yu Yue , Wang Zhengmao 
Published: January 2022

Abstract
The transient frequency domain characteristics of different fault electrical quantities in HVDC transmission system are studied in this paper firstly using analytical calculation. Firstly, the equivalent model of LCC converter suitable for DC system fault characteristic analysis and the equivalent model of DC line considering parameter frequency variation effect are established. On this basis, the DC system fault equivalent circuit is constructed. The frequency domain expressions of relevant electrical quantities under different DC line fault conditions are obtained according to the solution of equivalent circuit. On the basis of the frequency domain expression of fault electrical quantity, the frequency component diagram of fault electrical quantity is obtained. Finally, the frequency spectrum of fault voltage under different fault conditions is analyzed and compared.
Efficient Compression Method Based on Object Model for Massive Real-time Data in Power IOT
Authors: Hou Jixin , Zhao JingHu , Wu Zidong , Fan Ying , Wang Xiaochao , Meng Jie 
Published: January 2022

Abstract
With rapid development of the Internet of things (IOT) in power field, equipment of various majors began to access the smart IOT system on a large scale. In this paper, a new data compression algorithm based on object model (CABM) is proposed to solve the problems of large-scale applications of power Internet of Things, such as high-frequency transmission of large quantities, real-time short data can not be effectively compressed, resulting in low efficiency of cloud edge information transmission and serious waste of bandwidth resources. The CABM adds a compression and decompression module between the IOT management platform and the edge agent; the IOT management platform automatically generates a compression dictionary based on the object model file and saves it synchronously in the edge agent. During data transmission, both the sender and receiver complete automatic compression and decompression according to the compression dictionary. The experimental results show that for real-time message data below 1KB, the compression rate using CABM algorithm is 3-5 times higher than that using GZIP compression algorithm; and the compression time is 10-20 times lower than that using GZIP; the efficiency using CABM algorithm is 4.5 times higher than that using GZIP algorithm; that is, CABM can reduce redundant data transmission between cloud edges and improve the efficiency of cloud edge transmission.
Design and Research of Operating Repulsion Mechanism Suitable for 252kV High-Speed Breaking Circuit Breaker
Authors: Cheng Cai , Liu Yingyi , Wei Jianwei , Yuan Haiwen 
Published: January 2022

Abstract
This paper proposes a high-speed operating repulsive force mechanism suitable for 252kV high-voltage circuit breakers. The mechanism draws on the working principle of the electromagnetic repulsion operating mechanism of the medium voltage circuit breaker, and combines the new electromagnetic fast repulsion device with the traditional disc spring hydraulic mechanism to realize the fast action of the circuit breaker. This paper first introduces the working principle of the electromagnetic repulsion operating mechanism, and proposes the initial design scheme of the mechanism. Subsequently, the digital twin technology was used to establish the rigid-flexible coupling multi-body dynamics model of the mechanism, and the defects of the initial scheme were analyzed based on simulation. Finally, the paper optimized the design of the initial scheme and verified it by simulation. The test shows that the 252kV high-voltage circuit breaker with the improved scheme as the operating mechanism works normally and can complete the fault breaking within 20.1ms, which is twice as fast as the current products of the same type.
A Method for Dynamically Identifying Equivalent Mathematical Model Parameters of Power Electronic System Based on Digital Filter
Authors: Peng Huiming , Maksim Popov G , Li Feng , Lu Zhiyu 
Published: January 2022

Abstract
In practice, most mathematical calculations and analysis methods to study the transients of power electrical equipment are based on the use of its idealized mathematical description and, as a result, do not adequately reflect the real dynamic characteristics of the combined power systems. One of the reasons, the use of unreliable initial parameters of the mathematical model during numerical experiments. In this article, a method is developed, the synthesis of equivalent models of a given structure is carried out using methods of parametric identification of dynamic systems. Digital filters designed to increase the reliability of the measurement and information part of modern microprocessor systems are described. There is also an assessment of their speed and error in the numerical solution of the problem of restoring useful and primary electrical signals, as well as methodological and practical recommendations for choosing the sampling frequency of analog-digital transformations in time are given.
Principle of Distributed Bus Protection Based on Directional Impedance Component Comparison
Authors: Zhang Hong , Shiping E , Gong Xiao , Wang Zuowei , Liu Dongchao , Zhang Kanjun , Li Hengxuan , Ding Jie 
Published: January 2022

Abstract
Distributed bus protection is one of the main tasks of smart substation construction to improve the secondary system because it is economical, simple, easy to layout, and easy to realize double. This paper mainly considers that distributed current differential protection is limited by high precision synchronization and high bandwidth and a distributed bus protection based on the directional impedance element comparison principle is proposed. The bus impedance protection constructed by reverse current calculation is proposed, which the impedance protection with positive sequence polarization and the impedance protection with memory polarization are the main components. Further considering the influence of system oscillation, the power frequency variable distance protection is introduced to form a distributed bus protection system, and the setting and time setting principles are given. The principle of the protection system is simple and the action is reliable. The effectiveness of the protection system is verified based on PSCAD simulation software.
Numerical Simulation and Optimal Design of Air Cooling Heat Dissipation of Lithium-ion Battery Energy Storage Cabin
Authors: Xu Song , Wan Tao , Zha Fanglin , He Zhiqiang , Huang Haibo , Zhou Ting 
Published: January 2022

Abstract
Lithium-ion battery energy storage cabin has been widely used today. Due to the thermal characteristics of lithium-ion batteries, safety accidents like fire and explosion will happen under extreme conditions. Effective thermal management can inhibit the accumulation and spread of battery heat. This paper studies the air cooling heat dissipation of the battery cabin and the influence of guide plate on air cooling. Firstly, a simulation model is established according to the actual battery cabin, which divided into two types: with and without guide plate. Then, at the environment temperature of 25°C, the simulation air cooling experiment of the battery cabin was carried out. The working condition of module was 1C, and the air speed was set to 4m/s. The results show that the average temperature, maximum temperature and temperature difference in the battery cabin reduced by 4.57°C, 4.3°C and 3.65°C respectively when guide plate added. The air cooling effect of battery cabin was improved by adding guide plate. There is better consistency between the modules and the modules can operate at more appropriate environment temperature.
Dynamic Identification of Equivalent Parameters of Mathematical Models of Power Electrical Equipment of Electromechanical Power Systems
Authors: Peng Huiming , Maksim Popov G , Li Feng , Lu Zhiyu 
Published: January 2022

Abstract
The article describes a method for dynamic identification of AC and DC hybrid power network parameters. The inaccuracy of the parameters of the electromechanical transient simulation model of the power system has caused the obvious difference between the simulation results and the actual measurement, which has restricted its online application. Over the years, the dynamic parameter identification technology based on field test and test has made great progress, but it is far from satisfactory and accurate. There is still a long research journey for the requirements of performance. The online identification method based on the actual dynamic parameters of the power system is a way to solve the problem. The article includes the main microprocessor modules for system parametric identification of load (SIP L) and an overhead power transmission line (SIP TL). The article will analyze the active electrical network and passive electrical network