scholarly journals LSTM-NN Yaw Control of Wind Turbines Based on Upstream Wind Information

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1482 ◽  
Author(s):  
Wenting Chen ◽  
Hang Liu ◽  
Yonggang Lin ◽  
Wei Li ◽  
Yong Sun ◽  
...  
Keyword(s):  
Control Strategy ◽  
Wind Direction ◽  
Power Loss ◽  
Measurement Data ◽  
Load Range ◽  
Yaw Control ◽  
Partial Load ◽  
Accurate Forecast ◽  
Inherent Error ◽  
Wind Lidar

Based on wind lidar, a novel yaw control scheme was designed that utilizes forecast wind information. The new scheme can reduce the power loss caused by the lag of accurate measurement data in the traditional yaw control strategy. A theoretical analysis of the power loss caused by the traditional wind measurement inherent error and the wind direction based traditional yaw control strategy was conducted. The yaw angle error and yaw stop/start frequency in an actual wind field were statistically analyzed, and a novel Long Short Term-Neural Network (LSTM-NN) yaw control strategy based on wind lidar information was proposed. An accurate forecast of the wind direction could reduce the power loss caused by the inherent yaw misalignment, while an accurate forecast of wind speed could increase the stop/start frequency in the medium speed section within the partial load range and reduce the frequency in the low speed section within the partial load range. Thus, the power captured could be increased by 3.5% under certain wind conditions without increasing the yaw duty. Based on a simple wind evolution model and a novel yaw control strategy, the validity of the yaw control strategy was verified in a FAST/Simulink simulation model.

scholarly journals Optimization of the Yaw Control Error of Wind Turbine

2021 ◽  
Vol 9 ◽  
Author(s):  
Yan Liu ◽  
Shu Liu ◽  
Lihong Zhang ◽  
Fuyi Cao ◽  
Liming Wang
Keyword(s):  
Power Generation ◽  
Control System ◽  
Wind Turbine ◽  
Control Strategy ◽  
Wind Direction ◽  
Performance Index ◽  
Great Influence ◽  
Control Error ◽  
Wind Turbine Control ◽  
Yaw Control

Yaw system is an important part of wind turbine control system, yaw error is an important performance index of wind turbine, which has great influence on power generation. The wind utilization and the output of the power generation have been determined by the yaw error. In order to make the wind turbine better aligned toward the wind direction, reduce the yaw error, and increase the power generated by the unit, the angle errors of yaw control of wind turbine have been analyzed, in this paper, and the method of wind test, the strategy of yaw control have been studied respectively. Based on the results of the study, the method of wind test, the restart control strategy of yaw system and the performance of control strategy of yaw system have been optimized in this paper. In this way, the three important links are optimized, it will effectively reduce the yaw error as well as significantly improve the wind turbine generating electricity.

Energieeffizienz beim Spanen/Energy efficiency at machining - Investigations about the influence of minimun quantity lubrication (MQL) at final cutting

2017 ◽  
Vol 107 (05) ◽  
pp. 352-358
Author(s):  
S. Prof. Simon ◽  
S. Wichmann ◽  
A. Brill
Keyword(s):  
Energy Efficiency ◽  
Minimum Quantity Lubrication ◽  
Stress Conditions ◽  
Cutting Performance ◽  
Workpiece Material ◽  
Load Range ◽  
University Of Technology ◽  
Partial Load ◽  
Longitudinal Turning

Von der Brandenburgischen Technischen Universität (BTU) sind in Zusammenarbeit mit der TU Liberec Untersuchungen zur Verbesserung der Energieeffizienz an spanenden Werkzeugmaschinen durchgeführt worden. Im Gegensatz zu bereits durchgeführten Untersuchungen wurde der Fokus hier auf das Belastungsverhalten im Teillastbereich gerichtet. Die durchgeführten Untersuchungen beschränkten sich auf das Längsdrehen mit geringen Schnitttiefen. Als Werkstoffe kamen ein Baustahl und ein Vergütungsstahl zum Einsatz. Durch die Bestimmung der Leerlaufleistung der verwendeten Drehmaschine waren tatsächliche Aussagen über die Schnittleistung möglich. Für das Ermitteln des Wirkungsgrades wurden auch die Schnittleistungen bei verschiedenen Drehzahlen aufgenommen. Alle weiteren Spanungsbedingungen blieben für die Untersuchungen konstant. Im Ergebnis der Untersuchung bestätigte sich das Potenzial der Minimalmengenschmierung. Der Wirkungsgrad verbesserte sich durchschnittlich um 5 %. Beachtenswert ist der Einfluss des Einstellwinkels. Hier liegt das Optimierungspotenzial der Energieeffizienz in Summe bei 14 %. Die Untersuchungen ergaben weiterhin eine hohe Korrelation von Spanungsbedingungen, Werkstückwerkstoff und verwendetem Schmiermittel.   The Brandenburg University of Technology has carried out investigations in cooperation with the technical University of Liberec to improve the energy efficiency of cutting machine tools. In contrast to investigations already carried out, the focus here was on the loading behavior in the partial load range. The investigations carried out were limited to longitudinal turning with low cutting depths. A structural steel and a tempering steel were used as materials. By determining the no-load power of the used lathe, actual statements about the cutting performance were possible. For the determination of the efficiency, the cutting performance was recorded at different speeds. All further stress conditions remained constant for the investigations. As a result of the investigation, the potential of minimum quantity lubrication was confirmed. The efficiency improved by an average of 5 %. The influence of the angle of setting was remarkable. The optimization potential of energy efficiency was at 14 %. The investigations also revealed a high correlation between stress conditions, workpiece material and lubricant used.

scholarly journals Better turbulence spectra from velocity–azimuth display scanning wind lidar

2019 ◽  
Vol 12 (3) ◽  
pp. 1871-1888 ◽  
Author(s):  
Felix Kelberlau ◽  
Jakob Mann
Keyword(s):  
Data Processing ◽  
Resonance Effect ◽  
Measurement Data ◽  
Cross Contamination ◽  
Raw Data ◽  
Combined Use ◽  
Beam Method ◽  
Wind Lidar ◽  
Velocity Spectra ◽  
Methods Numerical

Abstract. Turbulent velocity spectra derived from velocity–azimuth display (VAD) scanning wind lidars deviate from spectra derived from one-point measurements due to averaging effects and cross-contamination among the velocity components. This work presents two novel methods for minimizing these effects through advanced raw data processing. The squeezing method is based on the assumption of frozen turbulence and introduces a time delay into the raw data processing in order to reduce cross-contamination. The two-beam method uses only certain laser beams in the reconstruction of wind vector components to overcome averaging along the measurement circle. Models are developed for conventional VAD scanning and for both new data processing methods to predict the spectra and identify systematic differences between the methods. Numerical modeling and comparison with measurement data were both used to assess the performance of the methods. We found that the squeezing method reduces cross-contamination by eliminating the resonance effect caused by the longitudinal separation of measurement points and also considerably reduces the averaging along the measurement circle. The two-beam method eliminates this averaging effect completely. The combined use of the squeezing and two-beam methods substantially improves the ability of VAD scanning wind lidars to measure in-wind (u) and vertical (w) fluctuations.

Control Strategy for the Optimal Operation of a Solar Cooling Installation

2012 ◽  
Author(s):  
Vittorio Verda ◽  
Giorgia Baccino ◽  
Stefano Pizzuti
Keyword(s):  
Energy Consumption ◽  
Solar Radiation ◽  
Control Strategy ◽  
Primary Energy ◽  
Optimal Operation ◽  
Hot Water ◽  
Objective Functions ◽  
Solar Cooling ◽  
Partial Load ◽  
Input Variables

In this paper, a solar cooling installation is analyzed with the aim of optimizing its performances. The system consists of vacuum solar collectors, which supply hot water to a LiBr absorption chiller. A boiler can be used to supply an additional amount of hot water in the case of insufficient solar radiation. In addition, a vapor compression chiller operates as a backup system and integrates the solar driven system in the case of large cooling request. Such system gives multiple operating options, especially at partial load. A model of the system is presented and applied to the real plant. It is shown that if a multi-objective optimization is performed, considering minimum primary energy consumption from fossil fuel and maximum utilization of the absorption system, a Pareto front is obtained. This occurs because the two objective functions are competing. A control strategy based on the use of neural networks is presented. Input variables are the solar radiation, ambient temperature and the cooling request. In this work the control strategy is adjusted in order to reach the minimum fossil energy consumption, but the same approach can be applied with other objective functions.

Scaling algorithms in modelling of power loss in soft magnetic composites

2019 ◽  
Vol 38 (4) ◽  
pp. 1064-1074 ◽  
Author(s):  
Mariusz Najgebauer ◽  
Jan Szczyglowski ◽  
Barbara Slusarek ◽  
Marek Przybylski
Keyword(s):  
Power Loss ◽  
Measurement Data ◽  
Soft Magnetic Materials ◽  
Scaling Analysis ◽  
Soft Magnetic ◽  
Magnetic Composites ◽  
Content Type ◽  
Soft Magnetic Composites ◽  
Loss Modelling ◽  
Scaling Algorithms

Purpose The purpose of this paper is to examine scaling algorithms in the description and modelling of power loss in soft magnetic composites (SMCs). Design/methodology/approach Three scaling algorithms are examined to determine the most appropriate description of power loss in magnetic composites. The scaling coefficients are estimated in such a way that all measurement data should be collapsed onto a single curve, given in the scaled coordinates. The coefficient estimation is based on a non-linear optimization using the generalized reduced gradient method. The obtained formulae are then used in the power loss modelling. Findings It is revealed that only two-component formulae are suitable for the scaling analysis of power loss because these allow obtaining of the collapse of measurement data. Research limitations/implications This study considers just one type of SMC (Somaloy 700). Further research will be devoted to the verification of the scaling approach to the power loss modelling for other types of magnetic composites. Practical implications The power loss is a basic property of soft magnetic materials, which determines their practical applications. The scaling approach to the power loss modelling gives quite simple models that require a reduced number of measurement data to estimate coefficients. Originality/value The scaling algorithms can be a useful tool in the analysis and designing of magnetic circuits made of SMCs.

scholarly journals Improving the effective efficiency of a spark ignition engine through the use of a fully independent valve control system

2021 ◽  
Author(s):  
Zbigniew Żmudka ◽  
Stefan Postrzednik
Keyword(s):  
Charge Exchange ◽  
Spark Ignition Engine ◽  
Theoretical Research ◽  
Si Engine ◽  
Load Range ◽  
Engine Operation ◽  
Engine Load ◽  
Effective Work ◽  
Partial Load ◽  
Valve Control

The article presents theoretical research of the proposed system of fully independent valve control (FIVC) of the SI engine. The analysis included controlling the movement of the intake valves, which results in adjusting the mass of the fresh charge to the current engine load, as well as the movement of the exhaust valves, where the main aim is to keep the rest of the exhaust gas in the cylinder, i.e. implementation of internal EGR. The open theoretical Seiliger-Sabathe cycle with the classic throttle regulation of load is the reference cycle for assessment of benefits and study of the effectiveness of obtaining work as a result of application of the FIVC system. A comparative analysis of the effectiveness of application of the proposed system was carried out based on the selected quantities: fuel dose, cycle work, relative work of charge exchange and cycle efficiency. The use of the FIVC to regulate the SI engine load makes it possible to eliminate the throttle and thus reduce the charge exchange work, especially in the partial load range. And this then leads to an increase in internal and effective work, which in turn results in an increase in the effective energy efficiency of an engine operation.

Research on wind field characteristics measured in inland city by Lidar

2021 ◽  
Author(s):  
LI Jiawu ◽  
Jun WANG ◽  
WANG Feng
Keyword(s):  
Wind Speed ◽  
Probability Density ◽  
Density Function ◽  
Linear Correlation ◽  
Wind Direction ◽  
Measurement Data ◽  
Attack Angle ◽  
Average Value ◽  
Original Measurement ◽  
Positive Linear Correlation

Abstract In order to study the wind characteristics in inland cities, a Wind3D 6000 Lidar which has many advantages in measuring wind parameters was placed on a campus in Xi’an city. Then, through filtering the original measurement data, the wind speed, wind direction, wind attack angle and turbulence intensity were analyzed using the data of nearly four months ranging from 64m to 610m. It is found that during the field measurement period, there is a linear correlation and Lorentz density function distribution between wind speed and height, but the power index law is not obvious. The wind direction changes obviously with the time and season but less along the height. The probability density of wind attack angle presents Gauss distribution, with an average value of about 1.35°, which is negatively linear correlated with height and wind speed. The probability density of turbulence shows the distribution characteristic of LogNormal density function, which increases first and then decreases with the height, and has a positive linear correlation with the wind attack angle.

scholarly journals Wind reconstruction algorithm for Viking Lander 1

2017 ◽  
Vol 6 (1) ◽  
pp. 217-229 ◽  
Author(s):  
Tuomas Kynkäänniemi ◽  
Osku Kemppinen ◽  
Ari-Matti Harri ◽  
Walter Schmidt
Keyword(s):  
Wind Direction ◽  
Measurement Data ◽  
Reconstruction Algorithm ◽  
Wind Data ◽  
Wind Measurement ◽  
Heater Element ◽  
Measurement Sensor ◽  
Sensor Failures ◽  
Wind Measurements

Abstract. The wind measurement sensors of Viking Lander 1 (VL1) were only fully operational for the first 45 sols of the mission. We have developed an algorithm for reconstructing the wind measurement data after the wind measurement sensor failures. The algorithm for wind reconstruction enables the processing of wind data during the complete VL1 mission. The heater element of the quadrant sensor, which provided auxiliary measurement for wind direction, failed during the 45th sol of the VL1 mission. Additionally, one of the wind sensors of VL1 broke down during sol 378. Regardless of the failures, it was still possible to reconstruct the wind measurement data, because the failed components of the sensors did not prevent the determination of the wind direction and speed, as some of the components of the wind measurement setup remained intact for the complete mission. This article concentrates on presenting the wind reconstruction algorithm and methods for validating the operation of the algorithm. The algorithm enables the reconstruction of wind measurements for the complete VL1 mission. The amount of available sols is extended from 350 to 2245 sols.

Method for Quick Prediction of Windage Power Loss

2014 ◽  
Author(s):  
Qide Zhang ◽  
Kannan Sundaravadivelu ◽  
Ningyu Liu ◽  
Quan Jiang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Empirical Formula ◽  
Power Loss ◽  
Hard Disk Drives ◽  
Measurement Data ◽  
Disk Drives ◽  
Cfd Simulations ◽  
Computational Fluid Dynamics Cfd ◽  
Good Agreement

This work introduces a method by using an empirical formula to quickly predict windage caused power loss of hard disk drives. The results obtained by the empirical formula are compared with those obtained by computational fluid dynamics (CFD) simulations and validated by the experimental measurement data. Good agreement is observed among these three sets of data.

Study on Control Strategy of Shape Set up System for HSM

2012 ◽  
Vol 236-237 ◽  
pp. 247-250
Author(s):  
Zhong Feng Guo ◽  
Jun Hong Hu ◽  
Xue Yan Sun
Keyword(s):  
Control Strategy ◽  
Measurement Data ◽  
Mathematic Model ◽  
Hot Strip Mill ◽  
Key Technology ◽  
Strip Flatness ◽  
Hot Strip ◽  
Strip Profile ◽  
Set Up ◽  
Strip Quality

Shape Set Up (SSU) system is the key technology for Hot Strip Mill (HSM). Precise SSU system is applied to improve the strip quality for HSM. The function of SSU, Setup and Feedback, is introduced. The main mathematic model of strip profile is set up. SSU system strategy is studied of a certain domestic 1700mm HSM. The SSU system is carried out in produce and the measurement data show that strip flatness deviant and strip profile deviant could be controlled in target scope. The study has set a sound base to improve the setting accuracy and develop SSU system for HSM further.

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