scholarly journals Analysis of the Wind System Operation in the Optimal Energetic Area at Variable Wind Speed over Time

2019 ◽  
Vol 11 (5) ◽  
pp. 1249 ◽  
Author(s):  
Ciprian Sorandaru ◽  
Sorin Musuroi ◽  
Flaviu Frigura-Iliasa ◽  
Doru Vatau ◽  
Marian Dordescu
Keyword(s):  
Wind Speed ◽  
Angular Velocity ◽  
Optimal Operation ◽  
Wind System ◽  
Optimal Velocity ◽  
Electric Generator ◽  
Wind Speeds ◽  
Power Point ◽  
Variable Wind ◽  
Over Time

Due to high mechanical inertia and rapid variations in wind speed over time, at variable wind speeds, the problem of operation in the optimal energetic area becomes complex and in due time it is not always solvable. No work has been found that analyzes the energy-optimal operation of a wind system operating at variable wind speeds over time and that considers the variation of the wind speed over time. In this paper, we take into account the evolution of wind speed over time and its measurement with a low-power turbine, which operates with no load at the mechanical angular velocity ωMAX. The optimal velocity is calculated. The energy that is captured by the wind turbine significantly depends on the mechanical angular velocity. In order to perform a function in the maximum power point (MPP) power point area, the load on the electric generator is changed, and the optimum mechanical velocity is estimated, ωOPTIM, knowing that the ratio ωOPTIM/ωMAX does not depend on the time variation of the wind speed.

scholarly journals Wind Turbines Optimal Operation at Time Variable Wind Speeds

2020 ◽  
Vol 10 (12) ◽  
pp. 4232
Author(s):  
Mihaela-Codruta Ancuti ◽  
Sorin Musuroi ◽  
Ciprian Sorandaru ◽  
Marian Dordescu ◽  
Geza Mihai Erdodi
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Optimal Operation ◽  
Time Variable ◽  
Total Power ◽  
Proportional Integral ◽  
Wind Speeds ◽  
Variable Wind ◽  
Power Curves ◽  
Large Moment

The wind turbine’s operation is affected by the wind speed variations, which cannot be followed by the wind turbine due to the large moment of the power plant’s inertia. The method proposed in this paper belongs to the wind turbine power curves (WTPC) approach, which expresses the power curve of the permanent magnet synchronous generator (PMSG) by a set of mathematical equations. The WTPC research papers published before now have not taken into consideration the total power plant inertia at time-variable wind speeds, when the wind turbine’s optimal operation is very difficult to be reached, and its efficiency is thus threatened. The study is based on a wind turbine having a large moment of total inertia, and demonstrates, through extensive simulation results, that the optimal values of the PMSG’s power can be determined based on the kinetic motion equation. This PMSG’s optimal power represents an ideal time-varying curve, and the wind turbine should be controlled so as to closely follow it. For this purpose, proportional integral (PI) and proportional integral derivative (PID) type-based control methods were implemented and analyzed, so that the PMSG’s power oscillations could be reduced, and the PMSG’s angular speed value made comparable to the optimal one, meaning that the wind turbine operates within the optimal operation area, and is efficient. The simulations are actually the numerical solutions obtained by using the Scientific Workplace simulation environment, and they are based on the wind speed measurements collected from a wind farm located in Dobrogea, Romania.

scholarly journals Extreme wind speed prediction in mountainous area with mixed wind climates

2022 ◽  
Author(s):  
Teng Ma ◽  
Wei Cui ◽  
Lin Zhao ◽  
Yejun Ding ◽  
Genshen Fang ◽  
...  
Keyword(s):  
Wind Speed ◽  
Mountainous Area ◽  
Construction Site ◽  
Wind System ◽  
Mountainous Areas ◽  
Wind Speeds ◽  
Extreme Wind ◽  
Synoptic Wind ◽  
Extreme Wind Speed ◽  
Extreme Wind Speeds

Abstract In addition to common synoptic wind system, the mountainous terrain forms a local thermally driven wind system, which makes the mountain wind system have strong terrain dependence. Therefore, in order to estimate the reliable design wind speeds for structural safety, the samples for extreme wind speeds for certain return periods at mountainous areas can only come from field measurements at construction site. However, wind speeds measuring duration is usually short in real practice. This work proposes a novel method for calculating extreme wind speeds in mountainous areas by using short-term field measurement data and long-term nearby meteorological observatory data. Extreme wind speeds in mountainous area are affected by mixed climates composed by local-scale wind and large scale synoptic wind. The local winds can be recorded at construction site with short observatory time, while the extreme wind speeds samples from synoptic wind climate from nearby meteorological station with long observatory time is extracted for data augmentation. The bridge construction site at Hengduan Mountains in southwestern China is taken as an example in this study. A 10-month dataset of field measurement wind speeds is recorded at this location. This study firstly provides a new method to extract wind speed time series of windstorms. Based on the different windstorm features, the local and synoptic winds are separated. Next, the synoptic wind speeds from nearby meteorological stations are converted and combined with local winds to derive the extreme wind speeds probability distribution function. The calculation results shows that the extreme wind speed in the short return period is controlled by the local wind system, and the long-period extreme wind speed is determined by the synoptic wind system in the mountain area.

scholarly journals Comparative Analysis of Danger Zone Ranges Determined for LNG in the Coastal Area

2018 ◽  
Vol 1 (1) ◽  
pp. 829-834
Author(s):  
Agnieszka Kalbarczyk-Jedynak ◽  
Dorota Stochła ◽  
Marek Patsch
Keyword(s):  
Wind Speed ◽  
Coastal Area ◽  
Human Life ◽  
Weather Conditions ◽  
Atmospheric Conditions ◽  
Wind Force ◽  
Danger Zone ◽  
Wind Speeds ◽  
Variable Wind ◽  
Neutral Conditions

Abstract The analysis of danger zone ranges for LNG in the coastal area is an important task on account of, inter alia, the safety of human life. It is not an easy process, which is why we consider an danger situation for various weather conditions in the function of constant wind speeds and for various wind speeds in constant weather stability. Pasquill weather stability scale and Beaufort scale with regard to terrain roughness were adopted for the analysis. Both scenarios were considered in the example of Q-flex type vessels in the Świnoujście terminal for two methods of LNG release, i.e. related to a sudden explosion and slow release caused by a leak. The analysis was conducted and considered for the values in the top and bottom flammability limit. Modelling of the danger zone range was analysed with DNV PHAST software, version 7.11. In the process of comparison of the situation related to the risk of explosion in the function of various weather stabilities according to Pasquill scale and constant wind speeds, the values of 1.5 m/s and 5 m/s were adopted, corresponding to 1 and 3 wind force on the Beaufort scale. Those speeds correspond to the water conditions featuring tiny ripples and small waves, the crests of which start to break. The adopted weather stabilities analysed for wind speed equal to 1.5 m/s are A, B, D. A-type stability signifies the least stable atmospheric conditions, and D-type means neutral conditions. In turn, for the wind speed of 5 m/s B, D and F parameters in Pasquill scale were selected. Furthermore, ranges for variable wind speed values were analysed for the selected Pasquill stability.

scholarly journals The Impact of Variable Wind Shear Coefficients on Risk Reduction of Wind Energy Projects

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Kenneth W. Corscadden ◽  
Allan Thomson ◽  
Behrang Yoonesi ◽  
Josiah McNutt
Keyword(s):  
Wind Speed ◽  
Wind Shear ◽  
Mean Squared Error ◽  
Resource Assessment ◽  
Accurate Estimate ◽  
The Body ◽  
Shear Coefficient ◽  
Wind Speeds ◽  
Variable Wind ◽  
The Impact

Estimation of wind speed at proposed hub heights is typically achieved using a wind shear exponent or wind shear coefficient (WSC), variation in wind speed as a function of height. The WSC is subject to temporal variation at low and high frequencies, ranging from diurnal and seasonal variations to disturbance caused by weather patterns; however, in many cases, it is assumed that the WSC remains constant. This assumption creates significant error in resource assessment, increasing uncertainty in projects and potentially significantly impacting the ability to control gird connected wind generators. This paper contributes to the body of knowledge relating to the evaluation and assessment of wind speed, with particular emphasis on the development of techniques to improve the accuracy of estimated wind speed above measurement height. It presents an evaluation of the use of a variable wind shear coefficient methodology based on a distribution of wind shear coefficients which have been implemented in real time. The results indicate that a VWSC provides a more accurate estimate of wind at hub height, ranging from 41% to 4% reduction in root mean squared error (RMSE) between predicted and actual wind speeds when using a variable wind shear coefficient at heights ranging from 33% to 100% above the highest actual wind measurement.

Indirect Power Control (IDPC) of DFIG Using Classical & Adaptive Controllers Under MPPT Strategy

2019 ◽  
pp. 26-85
Keyword(s):  
Wind Speed ◽  
Response Time ◽  
Power Control ◽  
Wind Turbine ◽  
Switching Frequency ◽  
Wind System ◽  
Matlab Simulink ◽  
Speed Variation ◽  
Operation Modes ◽  
Power Point

In this chapter, we present a comparative study of conventional Indirect Power Control (IDPC) algorithm of DFIG-Wind turbine in grid-connection mode, using PI and PID controllers via Maximum power point tracking (MPPT) strategy. Firstly, the conventional IDPC based on PI controllers will be described using simplified model of DFIG through stator flux orientation and wind-turbine model. The MPPT strategy is developed using Matlab/Simulink® with two wind speed profiles in order to ensure the robustness of wind-system by maintaining the Power coefficient (Cp) at maximum value and reactive power at zero level; regardless unexpectedF wind speed variation. Secondly, the rotor side converter (RSC) and Grid side converter (GSC) are illustrated and developed using Space vector modulation (SVM) in order to minimize the stress and the harmonics and to have a fixed switching frequency. In this context, the switching frequency generated by IDPC to control the six IGBTs of the inverter (RSC), and this control algorithm works under both Sub- and Supersynchronous operation modes and depending to the wind speed profiles. The quadrants operation modes of the DFIG are described in details using real DFIG to show the power flow under both modes (motor and generator in the four (04) quadrants. Finally, the conventional IDPC have several drawbacks as: response time, power error and overshoot. In this context, the PID and MRAC (adaptive regulator) controllers are proposed instead of the PI to improve the wind-system performances via MPPT strategy with/without robustness tests. The obtained simulation results under Matlab/Simulink® show high performances (in terms of power error, power tracking and response time) in steady and transient states despite sudden wind speed variation, whereas big power error and remarkable overshoot are noted using robustness tests, so the proposed IDPC can not offer big improvement under parameter variation.

Wind Turbine Power Optimization: Experimental Validation of Extremum Seeking and Perturb/Observe Strategies

2016 ◽  
Author(s):  
Fa Wang ◽  
Laura Wheeler ◽  
Mario Garcia-Sanz
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Extremum Seeking ◽  
Experimental Methodology ◽  
Fast Tracking ◽  
Point Tracking ◽  
Power Point Tracking ◽  
Perturb And Observe ◽  
Power Point ◽  
Variable Wind

This paper presents an experimental methodology to test and validate two Maximum Power Point Tracking (MPPT) strategies on variable speed wind turbines. The first technique of this study is an Extremum Seeking (ES) control strategy which does not require any wind turbine model or wind speed measurements. The analysis shows that its convergence can be quite slow in some cases. For this reason, we improve the ES control with a specific inner-loop that speeds up the convergence of the strategy. Additionally a conventional Perturb and Observe (P&O) algorithm is also implemented for comparison purposes. The proposed ES strategy with an additional inner loop controller shows fast tracking capability and high stability under both constant and variable wind speed in simulations and experiments. Both approaches are verified in Matlab simulations and experiments with a lab-scale wind turbine and a fully instrumented wind tunnel at CWRU-CESC.

scholarly journals Dynamic Analysis of a Single-Rotor Wind Turbine with Counter-Rotating Electric Generator under Variable Wind Speed

2021 ◽  
Vol 11 (19) ◽  
pp. 8834
Author(s):  
Mircea Neagoe ◽  
Radu Saulescu ◽  
Codruta Jaliu ◽  
Ion Neagoe
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Mechanical Characteristics ◽  
Mechanical Efficiency ◽  
Rigid Bodies ◽  
Kinematic Parameters ◽  
Electric Generator ◽  
Variable Wind ◽  
Transient And Steady State

This paper presents a theoretical study of the dynamic behaviour of a wind turbine consisting of a wind rotor, a speed increaser with fixed axes, and a counter-rotating electric generator, operating in variable wind conditions. In the first part, the dynamic analytical model of the wind turbine mechanical system is elaborated based on the dynamic equations associated with the component rigid bodies and the linear mechanical characteristics associated with the direct current (DC) generator and wind rotor. The paper proposes a method for identifying the coefficients of the wind rotor mechanical characteristics depending on the wind speed. The numerical simulations performed in Simulink-MATLAB by MathWorks on a case study of a 10 kW wind turbine highlight the variation with the time of the kinematic parameters (angular speeds and accelerations), torques and powers for wind system shafts, as well as the mechanical efficiency, both in transient and steady-state regimes, considering variable wind speed. The analytical and numerical results are helpful for researchers, designers, developers, and practitioners of wind turbines aiming to optimise their construction and functionality through virtual prototyping.

scholarly journals Determining the optimal operating parameters of a wind system

2018 ◽  
Vol 184 ◽  
pp. 02005
Author(s):  
Cornel Cătălin Gavrilă ◽  
Radu Săulescu
Keyword(s):  
Wind Speed ◽  
Wind Velocity ◽  
Power Factor ◽  
High Capacity ◽  
Operating Parameters ◽  
Power Curve ◽  
Wind System ◽  
Optimal Operating ◽  
Electric Generator

The paper main objective is to determine the representative parameters for the geometrical modeling of the speed amplifiers used in the high-capacity wind systems, taking into account the assembling and also the neighboring conditions of the satellite wheels in the planetary units. The analysis is based on a case study taken from a representative producer in this field - a speed amplifier for which is known: wind rotor diameter, type of speed amplifier and electric generator. Starting from these data and from the power curve offered by each wind device producer, the paper presents the synthesis of the number of teeth and the efficiency of such an amplifier taking into account the electrical and wind parameters (wind velocity, density air, wind rotor diameter). Based on the electrical and wind parameters, the system's power factor is determined to determine the efficiency of the speed amplifier and the wind speed at which the system can work best.

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