Impact of Different PQ Models of Wind Turbine Generating Units (WTGUs) on System Voltage Performance

2017 ◽  
Vol 18 (4) ◽  
Author(s):  
Tukaram Moger ◽  
Thukaram Dhadbanjan
Keyword(s):  
Comparative Analysis ◽  
Performance Analysis ◽  
Wind Turbine ◽  
Power Factor ◽  
Power Output ◽  
Reactive Power ◽  
Test System ◽  
Variable Speed ◽  
Voltage Dependent ◽  
Voltage Performance

AbstractThis paper presents the voltage performance analysis of the system with various types of wind turbine generating units (WTGUs). A detailed voltage performance analysis is carried out by considering the different PQ models used for computing the reactive power output of the WTGUs (fixed/semi-variable speed and variable speed WTGUs). The different PQ models of fixed/semi-variable speed WTGUs incorporated for the studies are voltage dependent model, voltage independent model, power factor based model, and PX model. In addition, the variable speed WTGUs are also considered in different fixed power factor mode of operation. Based on these models, a comparative analysis is presented. A modified 27-bus equivalent distribution test system with dispersed wind generation is considered for the studies. Further, the case studies have been carried out by considering the various wind power output levels of WTGUs to examine its impact on system voltage performance. From the comparative analysis, the power factor based model can be the best choice over the other models (which are based on voltages) for the system studies with fixed/semi-variable speed WTGUs.

Research on Switched Reluctance Generator for Off-Grid Variable-Speed Wind Energy Applications

2010 ◽  
Vol 44-47 ◽  
pp. 1672-1676
Author(s):  
Jing Feng Mao ◽  
Guo Qing Wu ◽  
Ai Hua Wu ◽  
Xu Dong Zhang ◽  
Yang Cao ◽  
...  
Keyword(s):  
Wind Energy ◽  
Wind Turbine ◽  
Control Strategy ◽  
Test System ◽  
Variable Speed ◽  
Detailed Model ◽  
Switched Reluctance ◽  
Energy Applications ◽  
Variable Speed Wind Turbine ◽  
Model Control

This paper presents a theoretical analysis and experimental evaluation of the switched reluctance generator (SRG) for off-grid variable-speed wind energy applications. The detailed model, control parameters and operational characteristics of the SRG as well as variable-speed wind turbine are discussed. In order to drive the wind energy conversion system (WECS) to the point of maximum aerodynamic efficiency, a SRG power output feedback control strategy which optimized angle position-current chopping control cooperating PI regulator is proposed. The control strategy is also demonstrated by means of Matlab/Simulink. Moreover, an experimental test system is set up, which a cage induction machine is used to emulate the variable-speed wind turbine. The experimental results validate the proposed control strategy and confirm the SRG performance.

Performance Study of Wind Turbine Generators

Solar Energy ◽  
2003 ◽  
Author(s):  
G. R. Bhagwatikar ◽  
W. Z. Gandhare
Keyword(s):  
Power Consumption ◽  
Wind Turbine ◽  
Wind Power ◽  
Wind Turbines ◽  
Reactive Power ◽  
Variable Speed ◽  
Turbine Generators ◽  
Wind Turbine Generators ◽  
Utility Grid ◽  
Operational Issues

It is well known that the wind power has definitely certain impact on the grid power. Issues associated with the integration of wind power into the utility grid are interface issues, operational issues and planning issues. Interface issues include harmonics, reactive power consumption, voltage regulation and frequency control. Operational issues are intermittent power generation, operating reserve requirements, unit commitment and economic despatch. And planning issues are concerned with intermittent wind resources compared to conventional power resources. An important question, when connecting the wind turbine generators to the utility grid, is how much the power / voltage quality will be influenced, since the power production by wind turbines is intermittent, quantity wise as well as quality wise. This paper is focused on the on comparison between the constant speed wind turbines and variable speed wind turbines, reactive power consumption and harmonics generated by both wind turbines. Total harmonic distortion is calculated by the application of C++ software and a comparison is done between the generators with respect to the harmonics. It is observed that constant speed wind turbine generates low order harmonics and variable speed turbine generates high order harmonics. On the basis of results, some solutions are suggested to improve the wind power quality and to reduce reactive power consumption. It seems that variable speed wind turbines with electronic interface are better with respect to the utility grid point of view.

Dynamic Simulation of a Wind Farm With Variable Speed Wind Turbines

2003 ◽  
Author(s):  
E. Muljadi ◽  
C. P. Butterfield
Keyword(s):  
Wind Turbine ◽  
Wind Power ◽  
Wind Turbines ◽  
Wind Farm ◽  
Reactive Power ◽  
Power Network ◽  
Variable Speed ◽  
Power Capacity ◽  
Advantages And Disadvantages ◽  
The Impact

Wind power generation has increased very rapidly in the past few years. The total U.S. wind power capacity by the end of 2001 was 4,260 megawatts. As wind power capacity increases, it becomes increasingly important to study the impact of wind farm output on the surrounding power networks. In this paper, we attempt to simulate a wind farm by including the properties of the wind turbine, the wind speed time series, the characteristics of surrounding power network, and reactive power compensation. Mechanical stress and fatigue load of the wind turbine components are beyond the scope this paper. The paper emphasizes the impact of the wind farms on the electrical side of the power network. A typical wind farm with variable speed wind turbines connected to an existing power grid is investigated. Different control strategies for feeding wind energy into the power network are investigated, and the advantages and disadvantages are presented.

scholarly journals A Study of the Impact of Pitch Misalignment on Wind Turbine Performance

Machines ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 8 ◽  
Author(s):  
Davide Astolfi
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Power Output ◽  
Wind Farm ◽  
Reactive Power ◽  
Power Production ◽  
Test Case ◽  
Before And After ◽  
Input Variables ◽  
The Impact

Pitch angle control is the most common means of adjusting the torque of wind turbines. The verification of its correct function and the optimization of its control are therefore very important for improving the efficiency of wind kinetic energy conversion. On these grounds, this work is devoted to studying the impact of pitch misalignment on wind turbine power production. A test case wind farm sited onshore, featuring five multi-megawatt wind turbines, was studied. On one wind turbine on the farm, a maximum pitch imbalance between the blades of 4.5 ° was detected; therefore, there was an intervention for recalibration. Operational data were available for assessing production improvement after the intervention. Due to the non-stationary conditions to which wind turbines are subjected, this is generally a non-trivial problem. In this work, a general method was formulated for studying this kind of problem: it is based on the study, before and after the upgrade, of the residuals between the measured power output and a reliable model of the power output itself. A careful formulation of the model is therefore crucial: in this work, an automatic feature selection algorithm based on stepwise multivariate regression was adopted, and it allows identification of the most meaningful input variables for a multivariate linear model whose target is the power of the wind turbine whose pitch has been recalibrated. This method can be useful, in general, for the study of wind turbine power upgrades, which have been recently spreading in the wind energy industry, and for the monitoring of wind turbine performances. For the test case of interest, the power of the recalibrated wind turbine is modeled as a linear function of the active and reactive power of the nearby wind turbines, and it is estimated that, after the intervention, the pitch recalibration provided a 5.5% improvement in the power production below rated power. Wind turbine practitioners, in general, should pay considerable attention to the pitch imbalance, because it increases loads and affects the residue lifetime; in particular, the results of this study indicate that severe pitch misalignment can heavily impact power production.

Voltage stability enhancement using an adaptive hysteresis controlled variable speed wind turbine driven EESG with MPPT

2014 ◽  
Vol 25 (2) ◽  
pp. 48-60
Author(s):  
R. Jeevajothi ◽  
D. Devaraj
Keyword(s):  
Wind Turbine ◽  
Voltage Stability ◽  
Reactive Power ◽  
Synchronous Generator ◽  
Maximum Power ◽  
Induction Generator ◽  
Variable Speed ◽  
Maximum Power Point ◽  
Variable Speed Wind Turbine ◽  
Power Point

This paper investigates the enhancement in voltage stability achieved while connecting a variable speed wind turbine (VSWT) driven electrically excited synchronous generator (EESG) into power systems. The wind energy conversion system (WECS) uses an AC-DC-AC converter system with an uncontrolled rectifier, maximum power point tracking (MPPT) controlled dc-dc boost converter and adaptive hysteresis controlled voltage source converter (VSC). The MPPT controller senses the rectified voltage (VDC) and traces the maximum power point to effectively maximize the output power. With MPPT and adaptive hysteresis band current control in VSC, the DC link voltage is maintained constant under variable wind speeds and transient grid currents.The effectiveness of the proposed WECS in enhancing voltage stability is analysed on a standard IEEE 5 bus system, which includes examining the voltage magnitude, voltage collapse and reactive power injected by the systems. Simulation results show that the proposed WECS has the potential to improve the long-term voltage stability of the grid by injecting reactive power. The performance of this scheme is compared with a fixed speed squirrel cage induction generator (SCIG), a variable speed doubly-fed induction generator (DFIG) and a variable speed permanent magnet synchronous generator (PMSG).

Analysis on Power Output Capability and its Power Control Strategy of DFIG Wind Turbine under Unbalanced Grid Voltage

2013 ◽  
Vol 448-453 ◽  
pp. 1819-1824
Author(s):  
Shu Ju Hu ◽  
Ling Ling Wang ◽  
Ya Deng
Keyword(s):  
Power Control ◽  
Wind Turbine ◽  
Control Strategy ◽  
Power Output ◽  
Reactive Power ◽  
Maximum Output ◽  
Voltage Sags ◽  
Active And Reactive Power ◽  
Unbalanced Voltage ◽  
Power Limit

Wind turbines are required by gird codes that active and reactive power should be fed into power grid during gird faults such as voltage sags. Power output capability is important for DFIG wind turbine to provide active and reactive power support. Constraints of stator, rotor maximum current and maximum output voltage of rotor-side converter (RSC) of DFIG are considered to analyze stator power output limit of the DFIG under unbalanced voltage sags, and newton-raphson method is used to solve the power limits, then the power control strategy based on power limit analysis is proposed. Simulation, calculation and comparison are carried out by a 1.5MW DFIG wind turbine model, and the effectiveness of the analysis and the proposed control strategy is verified.

scholarly journals Dynamic Modeling and Performance Analysis of PMSG- based Variable Speed WTG: Case Study of Adama Wind Farm I, Ethiopia

2021 ◽  
Vol 12 (2) ◽  
pp. 155-172
Author(s):  
Zenachew Muluneh ◽  
Gebremichael Teame
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Power Flow ◽  
Wind Farm ◽  
Reactive Power ◽  
Maximum Energy ◽  
Current Control ◽  
Speed Ratio ◽  
Variable Speed ◽  
Grid Side

In this paper, the performance of Permanent Magnet Synchronous Generator (PMSG) -based Variable Speed Wind Turbine Generator (WTG) at Adama Wind Farm I (WTG), connected to a grid is studied. To study the performance of the WTG, both machine and grid side converters are modeled and analyzed very well. On the machine side, maximum power point tracking (MPPT) for maximum energy extraction is done using the direct speed control (DSC) technique, which is linked with the optimal tip speed ratio for each wind speed value considered. On the grid side, dc-link voltage and reactive power flow to the grid are controlled. For this purpose, first, the simulation model of the system is prepared in MATLAB Simulink considering the dynamic mathematical model of the PMSG, and Wind Turbine Aerodynamic model using the user-defined function blocks. Then, the PI regulators designed for direct speed, torque (current) control, and dc-link voltage are employed in the model. Moreover, to study and analyze the behavior of the system in a variable speed operation, a wind speed starting from cut-in wind speed (3m/s) to the rated wind speed (11m/s) is applied in 4s. The simulation result of the existing system model shows that the actual values of performance variables correspond well with the analytical values of the system. In addition, the chosen control algorithms applied in the control system of the generator-side converter are hence verified.

Simulating the Dynamic and Steady State Response of a Rotor Resistive Controlled 1.5 MW Variable Speed Wind Turbine

2010 ◽  
Author(s):  
Jared B. Garrison ◽  
Michael E. Webber
Keyword(s):  
Steady State ◽  
Wind Speed ◽  
Dynamic Response ◽  
Wind Turbine ◽  
Power Output ◽  
Pitch Angle ◽  
Maximum Power ◽  
Variable Speed ◽  
Wind Speeds ◽  
Variable Speed Wind Turbine

Currently, wind and solar technologies only generate 0.77% and 0.014% of the U.S. electricity consumption, respectively [1]. Though only a small portion of total U.S. electricity production, both sources have seen significant growth recently. For instance, Texas has more than quadrupled its installed wind capacity over the period from 2005–2009 with new installations totaling over 9400 MW [2, 3]. These two resources are globally available and have the potential to generate massive amounts of electricity. As the amount of installed wind turbines continues to grow, gaining better knowledge of their operation and their dynamic response to changing wind conditions is important to ensure their smooth integration and safe operation. The goal of this research is to analyze the dynamic and steady state operations of a 1.5 MW variable speed wind turbine that uses an external rotor resistive control mechanism. The addition of the external generator rotor resistance allows for adjustment of the generator slip and employs a feedback controller that maintains constant power output at all air velocities between the rated wind speed and cut-out wind speed. Using the electronic programming language PSCAD/EMTDC the model simulates the dynamic response to changing wind conditions, as well as the performance under all wind conditions. The first task of the model was to determine which blade pitch angle produces a maximum power output of 1.5 MW. A sweep was used where the simulation runs over the entire range of wind speeds for a selected pitch angle to find which speed resulted in maximum power output. This sweep was used for numerous blade pitch angles until the combination of wind speed and pitch angle at 14.4 m/s and −0.663°, respectively, resulted in a maximum power of 1.5 MW. The second task was to evaluate the model’s dynamic response to changes in wind conditions as well as steady state operation over all wind speeds. The dynamic response to an increase or decrease in wind speed is important to the safety and life expectancy of a wind turbine because unwanted spikes and dips can occur that increase stresses in the wind turbine and possibly lead to failure. In order to minimize these transient effects, multiple controllers were implemented in order to test each ones’ dynamic response to increasing and decreasing changes in wind velocity. These simulations modeled the characteristics of a variable-speed wind turbine with constant power rotor resistive control. First, through calibrating the model the design specifications of blade pitch and wind speed which yield the peak desired output of 1.5 MW were determined. Then, using the method of controlling the external rotor resistance, the simulation was able to maintain the 1.5 MW power output for all wind speeds between the rated and cutout speeds. Also, by using multiple controllers, the dynamic response of the control scheme was improved by reducing the magnitude of the initial response and convergence time that results from changes in wind speed. Finally, by allowing the simulation to converge at each wind speed, the steady state operation, including generator power output and resistive thermal losses, was characterized for all wind speeds.

scholarly journals Fractional Order Sliding Mode Control of PMSG-Wind Turbine Exploiting Clean Energy Resource

2019 ◽  
Vol 8 (1) ◽  
pp. 81 ◽  
Author(s):  
Muhammad Waseem Khan ◽  
Jie Wang ◽  
Linyun Xiong ◽  
Meiling Ma
Keyword(s):  
Sliding Mode Control ◽  
Wind Turbine ◽  
Fractional Order ◽  
Power Output ◽  
Reactive Power ◽  
Sliding Mode ◽  
Energy Resource ◽  
Clean Energy ◽  
Active And Reactive Power ◽  
Control Scheme

The extensive application of permanent magnet synchronous generator (PMSG) based wind energy conversion system (WECS) has attracted growing interests of power researchers on its control and operation. This paper aims to propose a kind of fractional order sliding mode based (FOSM) power output control scheme of PMSG based WECS with fast exponential reaching law (FERL). The FERL based FOSM control technique proves to be better capable of attenuating the level of the chattering phenomenon with faster convergence speed. The boost converter and the neutral point clamped inverter, both of which are utilized to connect the PMSG and the power grid, are controlled with the proposed FOSM control scheme. Furthermore, the direct and quadrature grid current are tracked, which leads to the control of the active and reactive power output. The effectiveness of the proposed method is verified with an 8kW wind turbine simulation and the test results indicate that the proposed method can better track the reference value of active and reactive power. In addition to that, the total harmonic distortion level of the grid current is largely mitigated.©2019.CBIORE-IJRED. All rights reservedArticle History: Received June 2nd  2018; Received in revised form October 6th 2018; Accepted January 7th 2019; Available onlineHow to Cite This Article: Khan, M.W., Wang, J., Xiong, L. and Ma, M. (2019). Fractional Order Sliding Mode Control of PMSG-Wind Turbine Exploiting Clean Energy Resource. International Journal of Renewable Energy Development, 8(1), 81-89.https://doi.org/10.14710/ijred.8.1.81-89

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