The Experts below are selected from a list of 18525 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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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.
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modelling and control of variable speed multi pole permanent magnet Synchronous Generator wind turbine
Wind Energy, 2008Co-Authors: Anca Daniela Hansen, Gabriele MichalkeAbstract:Emphasis of this article is on variable-speed pitch-controlled wind turbines with multi-pole permanent magnet Synchronous Generator (PMSG) and on their extremely soft drive-train shafts. A model and a control strategy for a full back-to-back converter wind turbine with multi-pole PMSG are described. The model comprises submodels of the aerodynamic rotor, the drive-train by a two-mass model, the permanent magnet Generator and the full-scale converter system. The control strategy, which embraces both the wind turbine control itself and the control of the full-scale converter, has tasks to control independently the active and reactive powers, to assist the power system and to ensure a stable normal operation of the wind turbine itself. A multi-pole PMSG connected to the grid through a full-scale converter has no inherent damping, and therefore, such configuration can become practically unstable, if no damping by means of external measures is applied. In this work, the frequency converter is designed to damp actively the drive-train oscillations, thus ensuring stable operation. The dynamic performance of the presented model and control strategy is assessed and emphasized in normal operation conditions by means of simulations in the power system simulation tool DIgSILENT. Copyright © 2008 John Wiley & Sons, Ltd.
Toshifumi Ise - One of the best experts on this subject based on the ideXlab platform.
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enhanced virtual Synchronous Generator control for parallel inverters in microgrids
IEEE Transactions on Smart Grid, 2017Co-Authors: Jia Liu, Yushi Miura, Hassa Evrani, Toshifumi IseAbstract:Virtual Synchronous Generator (VSG) control is a promising communication-less control method in a microgrid for its inertia support feature. However, active power oscillation and improper transient active power sharing are observed when basic VSG control is applied. Moreover, the problem of reactive power sharing error, inherited from conventional droop control, should also be addressed to obtain desirable stable state performance. In this paper, an enhanced VSG control is proposed, with which oscillation damping and proper transient active power sharing are achieved by adjusting the virtual stator reactance based on state-space analyses. Furthermore, communication-less accurate reactive power sharing is achieved based on inversed voltage droop control feature ( V–Q droop control) and common ac bus voltage estimation. Simulation and experimental results verify the improvement introduced by the proposed enhanced VSG control strategy.
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comparison of dynamic characteristics between virtual Synchronous Generator and droop control in inverter based distributed Generators
IEEE Transactions on Power Electronics, 2016Co-Authors: Jia Liu, Yushi Miura, Toshifumi IseAbstract:In recent researches on inverter-based distributed Generators, disadvantages of traditional grid-connected current control, such as no grid-forming ability and lack of inertia, have been pointed out. As a result, novel control methods like droop control and virtual Synchronous Generator (VSG) have been proposed. In both methods, droop characteristics are used to control active and reactive power, and the only difference between them is that VSG has virtual inertia with the emulation of swing equation, whereas droop control has no inertia. In this paper, dynamic characteristics of both control methods are studied, in both stand-alone mode and Synchronous-Generator-connected mode, to understand the differences caused by swing equation. Small-signal models are built to compare transient responses of frequency during a small loading transition, and state-space models are built to analyze oscillation of output active power. Effects of delays in both controls are also studied, and an inertial droop control method is proposed based on the comparison. The results are verified by simulations and experiments. It is suggested that VSG control and proposed inertial droop control inherits the advantages of droop control, and in addition, provides inertia support for the system.
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Power system stabilization using virtual Synchronous Generator with alternating moment of inertia
IEEE Journal of Emerging and Selected Topics in Power Electronics, 2015Co-Authors: Jaber Alipoor, Yushi Miura, Toshifumi IseAbstract:The virtual Synchronous Generator (VSG) is a control scheme applied to the inverter of a distributed generating unit to support power system stability by imitating the behavior of a Synchronous machine. The VSG design of our research incorporates the swing equation of a Synchronous machine to express a virtual inertia property. Unlike a real Synchronous machine, the parameters of the swing equation of the VSG can be controlled in real time to enhance the fast response of the virtual machine in tracking the steady-state frequency. Based on this concept, the VSG with alternating moment of inertia is elaborated in this paper. The damping effect of the alternating inertia scheme is investigated by transient energy analysis. In addition, the performance of the proposed inertia control in stability of nearby machines in power system is addressed. The idea is supported by simulation and experimental results, which indicates remarkable performance in the fast damping of oscillations.
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dynamic characteristics and stability comparisons between virtual Synchronous Generator and droop control in inverter based distributed Generators
Power Electronics Conference (IPEC-Hiroshima 2014 - ECCE-ASIA) 2014 International, 2014Co-Authors: Jia Liu, Yushi Miura, Toshifumi IseAbstract:Recent years, to replace current source control methods, voltage source control methods such as virtual Synchronous Generator (VSG) and droop control have been proposed for grid-connected and/or stand-alone inverters. Both methods imitate the behaviors of Synchronous Generator. With the presence of swing equation, VSG has a virtual inertia, while droop control does not, and the rest of the two control methods are nearly the same. In this paper, the difference brought by the swing equation is studied. Small signal models for both control methods are built to compare the dynamic response during a small loading transition, and state space models are built to analyze the stability of both control methods. The results are verified by simulation in PSCAD/EMTDC.
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Oscillation damping of a distributed Generator using a virtual Synchronous Generator
IEEE Transactions on Power Delivery, 2014Co-Authors: Toshinobu Shintai, Yushi Miura, Toshifumi IseAbstract:These days, distributed Generators (DGs), such as photovoltaic, wind turbine, and gas cogeneration systems have attracted more attention than in the past. DGs are often connected to a grid by power inverters. The inverters used in DGs are generally controlled by a phase-locked loop (PLL) in order to be synchronized with the grid. In a stability point of view, the power system will be significantly affected if the capacity of inverter-based DGs becomes larger and larger. The concept of the virtual Synchronous Generator (VSG), which is used to control inverters to behave like a real Synchronous Generator, can be considered as a solution. The VSG can produce virtual inertia from energy storage during a short operation time, and the active power can be produced by a VSG similar to a Synchronous Generator. In this paper, an oscillation damping approach is developed for a DG using the VSG. The method is confirmed analytically, and verified through computer simulations. Finally, some laboratory experiments are conducted using 10-kW inverters and a transmission-line simulator.
Anca Daniela Hansen - 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 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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modelling and control of variable speed multi pole permanent magnet Synchronous Generator wind turbine
Wind Energy, 2008Co-Authors: Anca Daniela Hansen, Gabriele MichalkeAbstract:Emphasis of this article is on variable-speed pitch-controlled wind turbines with multi-pole permanent magnet Synchronous Generator (PMSG) and on their extremely soft drive-train shafts. A model and a control strategy for a full back-to-back converter wind turbine with multi-pole PMSG are described. The model comprises submodels of the aerodynamic rotor, the drive-train by a two-mass model, the permanent magnet Generator and the full-scale converter system. The control strategy, which embraces both the wind turbine control itself and the control of the full-scale converter, has tasks to control independently the active and reactive powers, to assist the power system and to ensure a stable normal operation of the wind turbine itself. A multi-pole PMSG connected to the grid through a full-scale converter has no inherent damping, and therefore, such configuration can become practically unstable, if no damping by means of external measures is applied. In this work, the frequency converter is designed to damp actively the drive-train oscillations, thus ensuring stable operation. The dynamic performance of the presented model and control strategy is assessed and emphasized in normal operation conditions by means of simulations in the power system simulation tool DIgSILENT. Copyright © 2008 John Wiley & Sons, Ltd.
Laren M. Tolbert - One of the best experts on this subject based on the ideXlab platform.
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virtual Synchronous Generator control of full converter wind turbines with short term energy storage
IEEE Transactions on Industrial Electronics, 2017Co-Authors: Liu Yang, Fei Fred Wang, Laren M. TolbertAbstract:One way to incorporate the increasing amount of wind penetration is to control wind turbines to emulate the behavior of conventional Synchronous Generators. However, the energy balance is the main issue for the wind turbines to be truly dispatchable by the power system operator such as the Generators. This paper presents a comprehensive virtual Generator control method for the full converter wind turbine, with a minute-level energy storage in the dc link as the energy buffer. The voltage closed-loop virtual Synchronous Generator control of the wind turbine allows it to work under both grid-connected and stand-alone condition. Power balance of the wind turbine system is achieved by controlling the rotor speed of the turbine according to the loading condition. With the proposed control, the wind turbine system can enhance the dynamic response, and can be dispatched and regulated by the system operator. The sizing design of the short term energy storage is also discussed in this paper. Experimental results are presented to demonstrate the feasibility and effectiveness of the proposed control method.
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three phase power converter based real time Synchronous Generator emulation
IEEE Transactions on Power Electronics, 2017Co-Authors: Liu Yang, Laren M. Tolbert, Jingxin Wang, Fei Fred Wang, Xiaohu Zhang, Jing Wang, Kevin TomsovicAbstract:This paper develops a Synchronous Generator emulator by using a three-phase voltage source converter for transmission level power system testing. Different interface algorithms are compared, and the voltage type ideal transformer model is selected considering accuracy and stability. At the same time, closed-loop voltage control with current feed-forward is proposed to decrease the emulation error. The emulation is then verified through two different ways. First, the output waveforms of the emulator in experiments are compared with the simulation under the same condition. Second, a transfer function perturbation-based error model is obtained and redefined as the relative error for the amplitude and phase between the emulated and the target system over the frequency range of interest. The major cause of the error is investigated through a quantitative analysis of the error with varying parameters.
Liu Yang - One of the best experts on this subject based on the ideXlab platform.
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virtual Synchronous Generator control of full converter wind turbines with short term energy storage
IEEE Transactions on Industrial Electronics, 2017Co-Authors: Liu Yang, Fei Fred Wang, Laren M. TolbertAbstract:One way to incorporate the increasing amount of wind penetration is to control wind turbines to emulate the behavior of conventional Synchronous Generators. However, the energy balance is the main issue for the wind turbines to be truly dispatchable by the power system operator such as the Generators. This paper presents a comprehensive virtual Generator control method for the full converter wind turbine, with a minute-level energy storage in the dc link as the energy buffer. The voltage closed-loop virtual Synchronous Generator control of the wind turbine allows it to work under both grid-connected and stand-alone condition. Power balance of the wind turbine system is achieved by controlling the rotor speed of the turbine according to the loading condition. With the proposed control, the wind turbine system can enhance the dynamic response, and can be dispatched and regulated by the system operator. The sizing design of the short term energy storage is also discussed in this paper. Experimental results are presented to demonstrate the feasibility and effectiveness of the proposed control method.
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three phase power converter based real time Synchronous Generator emulation
IEEE Transactions on Power Electronics, 2017Co-Authors: Liu Yang, Laren M. Tolbert, Jingxin Wang, Fei Fred Wang, Xiaohu Zhang, Jing Wang, Kevin TomsovicAbstract:This paper develops a Synchronous Generator emulator by using a three-phase voltage source converter for transmission level power system testing. Different interface algorithms are compared, and the voltage type ideal transformer model is selected considering accuracy and stability. At the same time, closed-loop voltage control with current feed-forward is proposed to decrease the emulation error. The emulation is then verified through two different ways. First, the output waveforms of the emulator in experiments are compared with the simulation under the same condition. Second, a transfer function perturbation-based error model is obtained and redefined as the relative error for the amplitude and phase between the emulated and the target system over the frequency range of interest. The major cause of the error is investigated through a quantitative analysis of the error with varying parameters.
