The Experts below are selected from a list of 64980 Experts worldwide ranked by ideXlab platform
Gabriele Michalke - One of the best experts on this subject based on the ideXlab platform.
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Grid Support capabilities of wind turbines
Handbook of Wind Power Systems, 2013Co-Authors: Gabriele Michalke, Anca Daniela HansenAbstract:Wind power has gained a significant penetration level in several power systems all over the world. Due to this reason modern wind turbines are requested to contribute to power system Support. Power system operators have thus introduced Grid codes, which specify a set of requirements for wind turbines, such as fault ride-through and reactive power supply during voltage sags. To date different wind turbine concepts exist on the market comprising different control features in order to provide ancillary services to the power system. In the first place the present chapter emphasizes the most important issues related to wind power Grid integration. Then different wind turbine concepts are characterized and their Grid Support capabilities are analysed and compared. Simulation cases are presented in which the respective wind turbine concepts are subjected to a voltage dip specified in a Grid code.
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multi pole permanent magnet synchronous generator wind turbines Grid Support capability in uninterrupted operation during Grid faults
Iet Renewable Power Generation, 2009Co-Authors: Anca Daniela Hansen, Gabriele MichalkeAbstract:Emphasis in this paper is on the fault ride-through and Grid Support capabilities of multi-pole permanent magnet synchronous generator (PMSG) wind turbines with a full-scale frequency converter. These wind turbines are announced to be very attractive, especially for large offshore wind farms. A control strategy is presented, which enhances the fault ride-through and voltage Support capability of such wind turbines during Grid faults. Its design has special focus on power converters' protection and voltage control aspects. The performance of the presented control strategy is assessed and discussed by means of simulations with the use of a transmission power system generic model developed and delivered by the Danish Transmission System Operator Energinet.dk. The simulation results show how a PMSG wind farm equipped with an additional voltage control can help a nearby active stall wind farm to ride through a Grid fault, without implementation of any additional ride-through control strategy in the active stall wind farm.
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multi pole permanent magnet synchronous generator wind turbines Grid Support capability in uninterrupted operation during Grid faults
Iet Renewable Power Generation, 2009Co-Authors: Anca Daniela Hanse, Gabriele MichalkeAbstract:Emphasis in this paper is on the fault ride-through and Grid Support capabilities of multi-pole permanent magnet synchronous generator (PMSG) wind turbines with a full-scale frequency converter. These wind turbines are announced to be very attractive, especially for large offshore wind farms. A control strategy is presented, which enhances the fault ride-through and voltage Support capability of such wind turbines during Grid faults. Its design has special focus on power converters' protection and voltage control aspects. The performance of the presented control strategy is assessed and discussed by means of simulations with the use of a transmission power system generic model developed and delivered by the Danish Transmission System Operator Energinet.dk. The simulation results show how a PMSG wind farm equipped with an additional voltage control can help a nearby active stall wind farm to ride through a Grid fault, without implementation of any additional ride-through control strategy in the active stall wind farm.
Anca Daniela Hansen - One of the best experts on this subject based on the ideXlab platform.
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Grid Support capabilities of wind turbines
Handbook of Wind Power Systems, 2013Co-Authors: Gabriele Michalke, Anca Daniela HansenAbstract:Wind power has gained a significant penetration level in several power systems all over the world. Due to this reason modern wind turbines are requested to contribute to power system Support. Power system operators have thus introduced Grid codes, which specify a set of requirements for wind turbines, such as fault ride-through and reactive power supply during voltage sags. To date different wind turbine concepts exist on the market comprising different control features in order to provide ancillary services to the power system. In the first place the present chapter emphasizes the most important issues related to wind power Grid integration. Then different wind turbine concepts are characterized and their Grid Support capabilities are analysed and compared. Simulation cases are presented in which the respective wind turbine concepts are subjected to a voltage dip specified in a Grid code.
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multi pole permanent magnet synchronous generator wind turbines Grid Support capability in uninterrupted operation during Grid faults
Iet Renewable Power Generation, 2009Co-Authors: Anca Daniela Hansen, Gabriele MichalkeAbstract:Emphasis in this paper is on the fault ride-through and Grid Support capabilities of multi-pole permanent magnet synchronous generator (PMSG) wind turbines with a full-scale frequency converter. These wind turbines are announced to be very attractive, especially for large offshore wind farms. A control strategy is presented, which enhances the fault ride-through and voltage Support capability of such wind turbines during Grid faults. Its design has special focus on power converters' protection and voltage control aspects. The performance of the presented control strategy is assessed and discussed by means of simulations with the use of a transmission power system generic model developed and delivered by the Danish Transmission System Operator Energinet.dk. The simulation results show how a PMSG wind farm equipped with an additional voltage control can help a nearby active stall wind farm to ride through a Grid fault, without implementation of any additional ride-through control strategy in the active stall wind farm.
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Grid Support of a wind farm with active stall wind turbines and AC Grid connection
Wind Energy, 2006Co-Authors: Anca Daniela Hansen, Poul Ejnar Sorensen, Florin Iov, Frede BlaabjergAbstract:One of the main concerns in the Grid integration of large wind farms is their ability to behave as active controllable components in the power system. This article presents the design of a new integrated power control system for a wind farm made up exclusively of active stall wind turbines with AC Grid connection. The designed control system has the task of enabling such a wind farm to provide the best Grid Support. It is based on two control levels: a supervisory control level, which controls the power production of the whole farm by sending out reference signals to each individual wind turbine, and a local control level, which ensures that the reference power signals at the wind turbine level are reached. The ability of active stall wind farms with AC Grid connection to control the power production to the reference power ordered by the operators is assessed and discussed by means of simulations. Copyright © 2005 John Wiley & Sons, Ltd.
Yasser Abdel-rady I. Mohamed - One of the best experts on this subject based on the ideXlab platform.
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Autonomous Coordinated Control Scheme for Cooperative Asymmetric Low-Voltage Ride-Through and Grid Support in Active Distribution Networks With Multiple DG Units
IEEE Transactions on Smart Grid, 2020Co-Authors: Masoud M. Shabestary, Yasser Abdel-rady I. MohamedAbstract:This paper proposes a comprehensive autonomous coordination control scheme to achieve cooperative asymmetric low-voltage ride-through and Grid Support by multiple distributed generation units in an active distribution network. In addition to the decentralized nature of the proposed coordination scheme, it provides three important features: 1) a maximized flexible asymmetrical voltage Support that does not affect the active current injection of individual units at the time of the Support, 2) maximum Support point tracking of each unit considering current, voltage, and power constraints, and 3) guided dynamic movement of the Support points for each unit. The proposed scheme is examined in a practical test system, adapted from Hydro One medium-voltage distribution system in Ontario, Canada. Test results demonstrate the promising performance of the proposed control scheme.
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asymmetrical ride through and Grid Support in converter interfaced dg units under unbalanced conditions
IEEE Transactions on Industrial Electronics, 2019Co-Authors: Masoud M. Shabestary, Yasser Abdel-rady I. MohamedAbstract:Increasing penetration level of distributed generation (DG) units necessitates their participation in Supporting power system stability and providing ancillary services. This paper highlights the necessity of Supporting the connection voltage by these units under short-term unbalanced voltage sags. To address this, a new regulation scheme, named asymmetrical ride-through (ART), is proposed in this paper. The proposed scheme enforces DG units to properly regulate the voltage within the dynamic limits for three important voltage parameters: positive sequence, negative sequence, and phase voltage magnitude. The main advantages of applying the ART scheme are avoiding unnecessary outages due to temporary unbalanced faults and enhancing the Grid stability. As the second contribution, an advanced dynamic voltage Support method is also proposed to accurately address the specifications determined in the ART scheme. The successful results of the ART regulation scheme and the proposed dynamic voltage Support method are verified using simulation and experimental test cases.
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Dynamic Analysis and Improved LVRT Performance of Multiple DG Units Equipped With Grid-Support Functions Under Unbalanced Faults and Weak Grid Conditions
IEEE Transactions on Power Electronics, 2018Co-Authors: Shahed Mortazavian, Yasser Abdel-rady I. MohamedAbstract:Due to the increased integration of multiple distributed generation (DG) units into the distribution network, riding through short-term faults and Supporting the host Grid have been requested by the new Grid codes in many countries. However, the literature lacks the detailed dynamic analysis and control coordination of multiple Grid-connected converter-based DG units, equipped with advanced controllers in the synchronous reference frame. To fill this gap, this paper initially presents a detailed small-signal modeling framework for typical medium-voltage multi-bus power distribution systems with multiple DG units equipped with Grid-Support functions to operate under the unbalanced conditions. This model encompasses the positive and negative sequences of the current and voltage and is developed for three stages of the fault (i.e., before, during, and after the fault) to cover a wide range of system operating points. In addition, to precisely study the interactions among DG units, four different control modes in DG units are considered to study the system dynamics under low-voltage and unbalanced conditions and at different Grid strengths. Using the proposed detailed state-space models and based on the small-signal stability analyses, different control parameters are redesigned using the eigenvalue analysis on the complete multi-DG system. As a second contribution, sensitivity analyses are performed to study the effects of different system parameters, such as line characteristics, loading levels, and unbalanced fault characteristics, on the stability of the multi-DG system under unbalanced faults. Comparative simulation and experimental results are also reported to show the accuracy and effectiveness of the theoretical analyses.
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an analytical method to obtain maximum allowable Grid Support by using Grid connected converters
IEEE Transactions on Sustainable Energy, 2016Co-Authors: Masoud M. Shabestary, Yasser Abdel-rady I. MohamedAbstract:Recently, Supporting the Grid voltage and proper operation of the Grid-connected converters (GCCs) under a wide range of Grid voltage conditions have become major requirements. An analytical study is very useful for evaluating the Supporting capability of the available control strategies in GCCs. This paper analytically studies, then modifies the Supporting capability of three existing strategies. The contribution of this paper is two-fold: first, analytical expressions of instantaneous active/reactive powers oscillation and maximum phase currents are formulated and used to conduct several comparisons among different strategies. Second, based on the obtained formulas for the maximum phase currents, maximum allowable Support (MAS) control schemes are proposed under unbalanced voltage conditions. The MAS control schemes have two important objectives: obtaining maximum active or reactive power delivery and simultaneously respecting the maximum phase currents under the unbalanced condition. The proposed equations can further estimate the maximum depth of the faulted voltage where each strategy is still able to satisfy the voltage Support requirements imposed by the Grid codes. The proposed expressions can also help all techniques to provide their maximum voltage or frequency Support under the pre-set maximum phase current limitations. Different selected simulation and experimental tests are carried out for comparing the strategies, and validating the effectiveness of the proposed MAS equations.
Thomas Räther - One of the best experts on this subject based on the ideXlab platform.
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Grid Support with Wind Turbines: The Case of the 2019 Blackout in Flensburg
Energies, 2021Co-Authors: Arne Gloe, Clemens Jauch, Thomas RätherAbstract:The work presented in this paper aims to show how modern wind turbines can help to control the frequency in a small Grid which suffers from large power imbalances. It is shown for an exemplary situation, which occurred in Flensburg’s distribution Grid in 2019: a major blackout, which occurred after almost two hours in islanding operation, affecting almost the entire distribution Grid, which supplies approximately 55,000 households and businesses. For the analysis, a wind turbine model and a Grid Support controller developed at the Wind Energy Technology Institute are combined with real measurements from the day of the blackout to generate a fictional yet realistic case study for such an islanding situation. For this case study, it is assumed that wind turbines with Grid Support functionalities are connected to the medium voltage distribution Grid of the city. It is shown to what extent wind turbines can help to operate the Grid by providing Grid frequency Support in two ways: By supplying synthetic inertia only, where the wind turbines can help to limit the rate of change of frequency in the islanded Grid directly after losing the connection to the central European Grid. In combination with the primary frequency control capabilities of the wind turbines (WTs), the disconnection of one gen set in the local power station might have been avoided. Furthermore, wind turbines with primary frequency control capabilities could have restored the Grid frequency to 50 Hz shortly after the islanding situation even if the aforementioned gen-set was lost. This would have allowed connecting a backup medium voltage line to the central European Grid and thereby avoiding the blackout.
Anca Daniela Hanse - One of the best experts on this subject based on the ideXlab platform.
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multi pole permanent magnet synchronous generator wind turbines Grid Support capability in uninterrupted operation during Grid faults
Iet Renewable Power Generation, 2009Co-Authors: Anca Daniela Hanse, Gabriele MichalkeAbstract:Emphasis in this paper is on the fault ride-through and Grid Support capabilities of multi-pole permanent magnet synchronous generator (PMSG) wind turbines with a full-scale frequency converter. These wind turbines are announced to be very attractive, especially for large offshore wind farms. A control strategy is presented, which enhances the fault ride-through and voltage Support capability of such wind turbines during Grid faults. Its design has special focus on power converters' protection and voltage control aspects. The performance of the presented control strategy is assessed and discussed by means of simulations with the use of a transmission power system generic model developed and delivered by the Danish Transmission System Operator Energinet.dk. The simulation results show how a PMSG wind farm equipped with an additional voltage control can help a nearby active stall wind farm to ride through a Grid fault, without implementation of any additional ride-through control strategy in the active stall wind farm.
