Modeling and Control of a Cascaded Doubly Fed Induction Generator Dedicated to Isolated Grids

In this paper, the control of a stand-alone doubly fed induction generator (DFIG)-based wind power conversion system with unbalanced and nonlinear loads is investigated. Under these load conditions, the quality of stator voltage and current waveforms of the DFIG is strongly affected due to the negative and distorted components, reducing the performance of other normal loads connected to the DFIG. To tackle this problem, the control strategy is comprehensively developed in both rotor-side converter (RSC) and load-side converter (LSC) of the DFIG. The LSC is used as an active power filter to compensate for unbalanced and distorted stator currents whereas the RSC is developed to fully eliminate unbalanced and harmonic voltages at the point of common coupling. The proposed compensation method is based on current controllers in either the RSC or the LSC, which employ a proportional integral plus a resonant controller. These current controllers are controlled in the positive synchronous reference frame so that the rotor current and stator current are directly regulated without decomposing sequential components. Analytical issues on how to eliminate unbalanced and distorted components in the stator voltage and current are also described in this paper. To verify the effectiveness of the proposed control strategy, experimental results with 2.2-kW DFIG topology are presented and discussed in the paper.

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“…To accurately control the reference rotor current in (21), a block diagram of the closed-loop current controller is developed in Fig. 8.…”

Section: ) Reference Rotor Current Generation Strategymentioning

confidence: 99%

Performance Enhancement of Stand-Alone DFIG Systems With Control of Rotor and Load Side Converters Using Resonant Controllers

Phan

Lee

2012

IEEE Trans. on Ind. Applicat.

129

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“…Here, a design procedure similar to that used for a system with sliding-mode controllers is adopted, and it can be summarized in two main steps: 1) to define a sliding surface to control the motion of the reduced order system (6) and 2) to select a control law that assures stability even under uncertainties and grid disturbances.…”

Section: Robust Controller: Design and Stabilitymentioning

confidence: 99%

“…T HE DOUBLY fed induction generator (DFIG) is one of the most frequently deployed large grid-connected wind turbines (WTs; > 1 MVA) [1]- [6]. When compared with the full-scale power converter WT concept, the DFIG offers some advantages, such as reduced inverter and output filter costs due to low rotor-and grid-side power conversion ratings (25%-30%).…”

Section: Introductionmentioning

confidence: 99%

Robust Controller for DFIGs of Grid-Connected Wind Turbines

Costa

Pinheiro

Degner

et al. 2011

IEEE Trans. Ind. Electron.

156

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This paper proposes a new robust controller in a stationary reference frame for doubly fed induction generators (DFIGs) of grid-connected wind turbines. Initially, a DFIG dynamic model is derived from the voltage and flux equations in αβ coordinates, where uncertainties and disturbances intrinsic to the system are accounted for as perturbation terms are added to the nominal model. Then, a controller design procedure that guarantees the DFIG stability under uncertainties and disturbances at the grid side is presented in detail. It is demonstrated that a very fast dynamic behavior can be obtained with the proposed controller, which improves the transient response of the grid-connected DFIG, particularly under conditions of unbalanced voltage dips resulting from asymmetrical network faults. In order to conform with the fault ride-through capability requirements, this paper proposes a new reference strategy, which is divided into normal and fault operation modes. Experimental results are given to support the theoretical analysis and to illustrate the performance of the grid-connected DFIG with the proposed controller.

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“…The stator windings of the Power machine M2 are directly connected to the grid, whereas the stator of the Control machine M1 is fed at variable frequency via a bidirectional double-sided PWM power converter. The two rotors are electrically and mechanically coupled, leading to a complete brushless solution [3].…”

Section: Introductionmentioning

confidence: 99%

New voltage sensorless approach for maximum constant power tracking of WECS based on a cascaded DFIG

Achkar

Mbayed

Salloum

et al. 2014

IECON 2014 - 40th Annual Conference of the IEEE Industrial Electronics Society

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The paper proposes a new control strategy of a grid connected variable speed wind turbine (WT), based on a cascaded doubly fed induction generator (CDFIG). The generating plant is carried to extract the maximum power relative to the predicted mean wind speed, thus eliminating the power fluctuations associated to high frequencies component. Moreover the system attempts to adjust the power factor of the generated power according to grid code requirements. This can be achieved by means of a bidirectional back to back PWM converter. A virtual flux oriented vector control is applied for the decoupled regulation of active and reactive powers, leading to grid voltage sensorless operation. The suggested method ensures high efficiency and enhances the energy quality by feeding constant power into the grid, regardless wind fluctuations.

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Modeling and Control of a Cascaded Doubly Fed Induction Generator Dedicated to Isolated Grids

Cited by 48 publications

References 14 publications

Performance Enhancement of Stand-Alone DFIG Systems With Control of Rotor and Load Side Converters Using Resonant Controllers

Performance Enhancement of Stand-Alone DFIG Systems With Control of Rotor and Load Side Converters Using Resonant Controllers

Robust Controller for DFIGs of Grid-Connected Wind Turbines

New voltage sensorless approach for maximum constant power tracking of WECS based on a cascaded DFIG

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