EPE Association: EPE-PEMC 2004 - Topic 13-1: Wind energy systems

EPE-PEMC 2004 - Topic 13-1: Wind energy systems
You are here: EPE Documents > 04 - EPE-PEMC Conference Proceedings > EPE-PEMC 2004 - Conference > EPE-PEMC 2004 - Topic 13: RENEWABLE, WASTE ENERGY SYSTEMS > EPE-PEMC 2004 - Topic 13-1: Wind energy systems

   [return to parent folder]

   A New Topology For High Powered Wind Energy Converters
By B. Rabelo, W. Hofmann, M. Tilscher, A. Basteck [View]
[Download]

Abstract: The wind energy penetration level on the electrical system is increasing in considerable rates nowadays. This concerns the power supply and transmission companies because of the regulation of the interconnected network. Power reserve to guarantee the stability of this new system configuration would increasethe energy costs considerably. A new topology for a windenergy converter using a constant speed driven synchronous generator, where the power electronics between its terminals and the mains is not needed, is proposed. A variable speed planetary gear with a hydrodynamic torque control keeps the generator shaft velocity constant. An induced voltage controller on the excitation circuit fulfil the further electrical requirements on wind power plants.

   Analytical Generator Model For Fault Simulation Of Wind Turbines
By Sigrid M. Bolik [View]
[Download]

Abstract: Wind turbine modelling became an important part in the study of control, design and production of wind turbines. Thereby doubly-fed induction machine modelling as a part of variable speed wind turbines plays an important role. Therefore this paper is dealing with an introduction of a detailed analytical three-phase induction machine model. The model uses only a minimum set of parameters. The simulation accuracy is dramatically improved by including the saturation of main and leakage inductances. In the end of the paper experimental measurements at an 850 kW test bench for model validation are included and a simulation of a three-phase short circuit on a variable speed wind turbine with doubly fed generator is shown.

   Control System Of Variable Speed Autonomous Doubly Fed Induction Generator
By Grzegorz Iwanski, Wlodzimierz Koczara [View]
[Download]

Abstract: In the following paper the autonomous power generation system includes a doubly fed induction generator is described. A simplified topology of the power electronics converter, connected to the rotor, is applied. Subsynchronous range of speed is main region of operation but small, negative, close to rated slip, is also possible. An external source is used for an initial excitation of the generator and then a converter connecting rotor and stator is used to control stator voltage. The space vector theory is used for the control algorithm. The stator voltage vector components in x and y axes in the rotating reference frame are responsible properly for the stator voltage amplitude and frequency. In this way the stator voltage frequency and amplitude are speed independent. A PSIM software is applied for regulators quick designing and tuning. A laboratory system including 1.5kW slip-ring machine is build and tested. As a controller the floating point processor Sharc™ with a programmable unit ALTERA™/FPGA support was used. Results of the simulation tests and oscillograms from the laboratory setup are presented in the paper.

   Estimation Of Potential Wind Energy Curtailment For Wind Power Plants In Power Systems With Bottleneck Problems
By J. Matevosyan, L. Soeder [View]
[Download]

Abstract: Wind power plant is planned transmission capacity should not be increased at any cost; an optimal trade-off should be made between grid reinforcement and other measures, e.g. wind energy curtailments. Method presented in this paper allows us to estimate the amounts of possible wind energy curtailments at different levels of wind power penetration in areas with limited transmission capacity. The costs for wind energy curtailments can then be estimated and compared to the costs of grid reinforcement. The developed method is applied in the case study.

   Grid Connected Or Islanded Operation Of Variable Speed Wind Generators Associated With Flywheel Energy Storage Systems
By L. Leclercq, A. Davigny, A. Ansel, B. Robyns [View]
[Download]

Abstract: In this paper, the possibility of a generating system, which associates a variable speed wind turbine and a flywheel energy storage system, to participate to the ancillary services is investigated. The interconnection of three of them connected to a power grid is considered. A solution is proposed to allow the wind generator based generating systems to work as voltage sources with the help of a frequency droop. It is shown that the power generated by these systems can be controlled by fixing the power set point when they are connected to the grid, and that, in case of islanding, they can share the global load of the isolated network.

   Impedance Spectroscopy On Fuel Cells-Some General Considerations
By Birger Fricke, Dirk Linzen, Abderrezak Hammouche, Stephan Buller, Dirk Uwe Sauer, Rik W. De Doncker [View]
[Download]

Abstract: Impedance Spectroscopy On Fuel Cells-Some General Considerations

   Influence Of Independent Producers Power Plants On Reactive Power Balance At Load Centres In Latvia
By Sandis Jermuts, Janis Rozenkrons [View]
[Download]

Abstract: The paper describes the comparison of three modes of relations between an independent producer (20 MW Wind Park) and the state power system regarding provision of reactive power balance on 20 kV busbar. The modes differ in levels of reactive power compensation and control in WPP. Calculations of energy losses in the cables of the Wind Park and in the power system transformers caused by the transfer of reactive power were made. The paper gives recommendations both for the Wind Park and for power system regarding the reactive power compensation and/or transfer.

   Modeling Method Of Wind Speed Turbulence For Wind Energy Conversion Simulator
By Idriss Boumahraz(fr), Cristian Nichita(fr), Brayima Dakyo(fr), Emil Ceanga(ro) [View]
[Download]

Abstract: In order to improve the performances of Real Time Wind Energy Conversion Simulators (RTWECS), the internal wind speed models must reproduce, as faithful as possible, the real conditions of the wind speed regime. The main purpose of our approach is to contribute to the development of a simulation tool for the estimation of the wind resource and its variability. The paper deals with a modelling method of the wind speed short–term component. The proposed methodology is adapted to a specific structure of a Real Time Wind Energy Conversion Simulator (RTWECS) and is developed to study isolated wind power systems.

   Modeling Of Isolated Wind Diesel System With A Maximum Wind Power Transfer Control Structure
By Mostafa El Mokadem(fr), Cristian Nichita(fr), Brayima Dakyo(fr), Wlodzimierz Koczara(pl) [View]
[Download]

Abstract: In this paper we proposed a control connection structure for a hybrid wind diesel system required to provide a maximum power under stochastic wind for a resistive variable load. The wind turbines connection in small grid systems using diesel generators could decrease the diesel contribution of the system energy production or save fuel, if the wind resources are very available. The structure, implemented in Matlab-Simulink environment, is aimed to ensure the power conditioning for a variable load adapting the two power units and the storage energy device with a maximum utilization of wind resources.

   New Voltage Source Converter Topology For Hvdc Grid Connection Of Offshore Wind Farms
By Meier Stephan, Norrga Staffan, Nee Hans-Peter [View]
[Download]

Abstract: Large offshore wind farms are recently emerging as promising alternative power sources. Long distances between offshore generation and onshore distribution grid demand new solutions for their connection to the AC network. HVDC systems based on voltage source converters (VSC) are a promising alternative to conventional AC transmission above a certain cable length. This paper presents a new VSC transmission topology for HVDC grid connection of offshore wind farms.

   On The Transient Stability Of Large Wind Farms
By V. Knyazkin, M. Ghandhari, C. Canizares [View]
[Download]

Abstract: This paper presents an analytical method for the assessment for the transient stability domain estimates of large wind farms. A detailed derivation of a reduced-order mathematical model of the wind farm is presented and analyzed. The model reduction commences with the treatment of a well-known fifth order model of the asynchronous generator and utilizes the integral manifold theory to arrive at the model described by a set of three differential equations. The obtained reduced-order model is essentially treated as a linear system with a structured, vector valued vanishing perturbation, which sets the analytical framework for the analytical explorations presented in this paper. In particular, the Lyapunov second method is applied to analyze the dynamic properties of the wind farm. Four well-known techniques for Lyapunov function construction are considered in the context of a simple power system consisting of a single asynchronous generator. It is shown analytically that certain techniques fail to yield valid Lyapunov functions. A methodology for constructing a quadratic Lyapunov function is presented and discussed. Nonlinear simulations are used to demonstrate the theoretical finding reported in the paper and gain further insights into the dynamic properties of wind farms.

   Simulation Of Doubly Fed Induction Generator Wind Turbine With An Active Crowbar
By J. K. Niiranen [View]
[Download]

Abstract: A detailed simulation program has been developed in order to stimulate voltage dip ride through of a doubly fed induction generator with an active crowbar. The frequency converters are controlled by a direct torque control strategy. As an example a 1.8 MVA doubly fed induction generator is simulated and compared with the measurements made in the full scale laboratory test equipment.

   Simulation Of The Dynamic Behaviour Of Non-Sine Emf Pm Synchronous Machine Based Stand Alone Wind Energy Converter
By Sambatra Eric Jean Roy, Barakat Georges, Dakyo Brayima [View]
[Download]

Abstract: This paper deals with the simulation of the dynamic behaviour of non-sine electromotive force (emf) PM synchronous generator based stand alone wind energy converter. First, the model of each component constituting the path of the conversion is established. The PM synchronous generator is modelised in considering a trapezoidal emf waveform. Then, based on simulation results, the dynamic behaviour of the main stages of the conversion chain, in particular the PM synchronous generator, face to the variations of the wind speed and of the electrical load are observed and analyzed. The obtained results show the advatanges of this type of PM synchronous generator in the case of coupling it to a diode rectifier.

EPE-PEMC 2004 - Topic 13-1: Wind energy systems
You are here: EPE Documents > 04 - EPE-PEMC Conference Proceedings > EPE-PEMC 2004 - Conference > EPE-PEMC 2004 - Topic 13: RENEWABLE, WASTE ENERGY SYSTEMS > EPE-PEMC 2004 - Topic 13-1: Wind energy systems
	[return to parent folder]

	A New Topology For High Powered Wind Energy Converters By B. Rabelo, W. Hofmann, M. Tilscher, A. Basteck	[View] [Download]
Abstract: The wind energy penetration level on the electrical system is increasing in considerable rates nowadays. This concerns the power supply and transmission companies because of the regulation of the interconnected network. Power reserve to guarantee the stability of this new system configuration would increasethe energy costs considerably. A new topology for a windenergy converter using a constant speed driven synchronous generator, where the power electronics between its terminals and the mains is not needed, is proposed. A variable speed planetary gear with a hydrodynamic torque control keeps the generator shaft velocity constant. An induced voltage controller on the excitation circuit fulfil the further electrical requirements on wind power plants.

	Analytical Generator Model For Fault Simulation Of Wind Turbines By Sigrid M. Bolik	[View] [Download]
Abstract: Wind turbine modelling became an important part in the study of control, design and production of wind turbines. Thereby doubly-fed induction machine modelling as a part of variable speed wind turbines plays an important role. Therefore this paper is dealing with an introduction of a detailed analytical three-phase induction machine model. The model uses only a minimum set of parameters. The simulation accuracy is dramatically improved by including the saturation of main and leakage inductances. In the end of the paper experimental measurements at an 850 kW test bench for model validation are included and a simulation of a three-phase short circuit on a variable speed wind turbine with doubly fed generator is shown.

	Control System Of Variable Speed Autonomous Doubly Fed Induction Generator By Grzegorz Iwanski, Wlodzimierz Koczara	[View] [Download]
Abstract: In the following paper the autonomous power generation system includes a doubly fed induction generator is described. A simplified topology of the power electronics converter, connected to the rotor, is applied. Subsynchronous range of speed is main region of operation but small, negative, close to rated slip, is also possible. An external source is used for an initial excitation of the generator and then a converter connecting rotor and stator is used to control stator voltage. The space vector theory is used for the control algorithm. The stator voltage vector components in x and y axes in the rotating reference frame are responsible properly for the stator voltage amplitude and frequency. In this way the stator voltage frequency and amplitude are speed independent. A PSIM software is applied for regulators quick designing and tuning. A laboratory system including 1.5kW slip-ring machine is build and tested. As a controller the floating point processor Sharc™ with a programmable unit ALTERA™/FPGA support was used. Results of the simulation tests and oscillograms from the laboratory setup are presented in the paper.

	Estimation Of Potential Wind Energy Curtailment For Wind Power Plants In Power Systems With Bottleneck Problems By J. Matevosyan, L. Soeder	[View] [Download]
Abstract: Wind power plant is planned transmission capacity should not be increased at any cost; an optimal trade-off should be made between grid reinforcement and other measures, e.g. wind energy curtailments. Method presented in this paper allows us to estimate the amounts of possible wind energy curtailments at different levels of wind power penetration in areas with limited transmission capacity. The costs for wind energy curtailments can then be estimated and compared to the costs of grid reinforcement. The developed method is applied in the case study.

	Grid Connected Or Islanded Operation Of Variable Speed Wind Generators Associated With Flywheel Energy Storage Systems By L. Leclercq, A. Davigny, A. Ansel, B. Robyns	[View] [Download]
Abstract: In this paper, the possibility of a generating system, which associates a variable speed wind turbine and a flywheel energy storage system, to participate to the ancillary services is investigated. The interconnection of three of them connected to a power grid is considered. A solution is proposed to allow the wind generator based generating systems to work as voltage sources with the help of a frequency droop. It is shown that the power generated by these systems can be controlled by fixing the power set point when they are connected to the grid, and that, in case of islanding, they can share the global load of the isolated network.

	Impedance Spectroscopy On Fuel Cells-Some General Considerations By Birger Fricke, Dirk Linzen, Abderrezak Hammouche, Stephan Buller, Dirk Uwe Sauer, Rik W. De Doncker	[View] [Download]
Abstract: Impedance Spectroscopy On Fuel Cells-Some General Considerations

	Influence Of Independent Producers Power Plants On Reactive Power Balance At Load Centres In Latvia By Sandis Jermuts, Janis Rozenkrons	[View] [Download]
Abstract: The paper describes the comparison of three modes of relations between an independent producer (20 MW Wind Park) and the state power system regarding provision of reactive power balance on 20 kV busbar. The modes differ in levels of reactive power compensation and control in WPP. Calculations of energy losses in the cables of the Wind Park and in the power system transformers caused by the transfer of reactive power were made. The paper gives recommendations both for the Wind Park and for power system regarding the reactive power compensation and/or transfer.

	Modeling Method Of Wind Speed Turbulence For Wind Energy Conversion Simulator By Idriss Boumahraz(fr), Cristian Nichita(fr), Brayima Dakyo(fr), Emil Ceanga(ro)	[View] [Download]
Abstract: In order to improve the performances of Real Time Wind Energy Conversion Simulators (RTWECS), the internal wind speed models must reproduce, as faithful as possible, the real conditions of the wind speed regime. The main purpose of our approach is to contribute to the development of a simulation tool for the estimation of the wind resource and its variability. The paper deals with a modelling method of the wind speed short–term component. The proposed methodology is adapted to a specific structure of a Real Time Wind Energy Conversion Simulator (RTWECS) and is developed to study isolated wind power systems.

	Modeling Of Isolated Wind Diesel System With A Maximum Wind Power Transfer Control Structure By Mostafa El Mokadem(fr), Cristian Nichita(fr), Brayima Dakyo(fr), Wlodzimierz Koczara(pl)	[View] [Download]
Abstract: In this paper we proposed a control connection structure for a hybrid wind diesel system required to provide a maximum power under stochastic wind for a resistive variable load. The wind turbines connection in small grid systems using diesel generators could decrease the diesel contribution of the system energy production or save fuel, if the wind resources are very available. The structure, implemented in Matlab-Simulink environment, is aimed to ensure the power conditioning for a variable load adapting the two power units and the storage energy device with a maximum utilization of wind resources.

	New Voltage Source Converter Topology For Hvdc Grid Connection Of Offshore Wind Farms By Meier Stephan, Norrga Staffan, Nee Hans-Peter	[View] [Download]
Abstract: Large offshore wind farms are recently emerging as promising alternative power sources. Long distances between offshore generation and onshore distribution grid demand new solutions for their connection to the AC network. HVDC systems based on voltage source converters (VSC) are a promising alternative to conventional AC transmission above a certain cable length. This paper presents a new VSC transmission topology for HVDC grid connection of offshore wind farms.

	On The Transient Stability Of Large Wind Farms By V. Knyazkin, M. Ghandhari, C. Canizares	[View] [Download]
Abstract: This paper presents an analytical method for the assessment for the transient stability domain estimates of large wind farms. A detailed derivation of a reduced-order mathematical model of the wind farm is presented and analyzed. The model reduction commences with the treatment of a well-known fifth order model of the asynchronous generator and utilizes the integral manifold theory to arrive at the model described by a set of three differential equations. The obtained reduced-order model is essentially treated as a linear system with a structured, vector valued vanishing perturbation, which sets the analytical framework for the analytical explorations presented in this paper. In particular, the Lyapunov second method is applied to analyze the dynamic properties of the wind farm. Four well-known techniques for Lyapunov function construction are considered in the context of a simple power system consisting of a single asynchronous generator. It is shown analytically that certain techniques fail to yield valid Lyapunov functions. A methodology for constructing a quadratic Lyapunov function is presented and discussed. Nonlinear simulations are used to demonstrate the theoretical finding reported in the paper and gain further insights into the dynamic properties of wind farms.

	Simulation Of Doubly Fed Induction Generator Wind Turbine With An Active Crowbar By J. K. Niiranen	[View] [Download]
Abstract: A detailed simulation program has been developed in order to stimulate voltage dip ride through of a doubly fed induction generator with an active crowbar. The frequency converters are controlled by a direct torque control strategy. As an example a 1.8 MVA doubly fed induction generator is simulated and compared with the measurements made in the full scale laboratory test equipment.

	Simulation Of The Dynamic Behaviour Of Non-Sine Emf Pm Synchronous Machine Based Stand Alone Wind Energy Converter By Sambatra Eric Jean Roy, Barakat Georges, Dakyo Brayima	[View] [Download]
Abstract: This paper deals with the simulation of the dynamic behaviour of non-sine electromotive force (emf) PM synchronous generator based stand alone wind energy converter. First, the model of each component constituting the path of the conversion is established. The PM synchronous generator is modelised in considering a trapezoidal emf waveform. Then, based on simulation results, the dynamic behaviour of the main stages of the conversion chain, in particular the PM synchronous generator, face to the variations of the wind speed and of the electrical load are observed and analyzed. The obtained results show the advatanges of this type of PM synchronous generator in the case of coupling it to a diode rectifier.