Direct Torque Control of DFIG Driven by Wind Turbine System Connected to the Grid

ABSTRACT:

This paper described a Direct Torque Control (DTC) applied to a Doubly Fed Induction Generator (DFIG) driven by a Wind Turbine (WT) connected to the grid. This control strategy based on the regulation of the flux and the torque, the currents and voltages are used to estimate the torque and the flux and compare those magnitudes to the reference values, the obtained results will be converted to digital form by hysteresis comparators. The commutation table will use those values and the sector number to choose the voltage vector. The aim of this study is to treat three modes that can drive WT-DFIG system utilizing Maximum Power Point Tracking (MPPT) technique. Computer simulation has carried out under MATALB/Simulink environment and the obtained results demonstrate the effectiveness of the proposed control.

 KEYWORDS:

1.      Direct Torque Control

2.      Doubly Fed Induction Generator

3.      Wind Turbine

4.      Wind Energy

5.      Maximum Power Point Tracking

 SOFTWARE: MATLAB/SIMULINK

 BLOCK DIAGRAM:

Fig.1. DTC Control applied to DFIG connected to the grid.

EXPECTED SIMULATION RESULTS:

Fig.2. Wind speed.

Fig.3. Cp (λ) Characteristic.

Fig.4. Mechanical speed (generator speed).

Fig.5. Waveform of Slip.

Fig.6. Electromagnetic Torque.

Fig.7. Rotor and Reference flux.

Fig.8. The rotor flux.

Fig.9. Wave form of Rotor flux φ_rα and φ_rβ.

Fig.10. Rotor Current Ir(abc)

Fig.11. Rotor Reactive Power

Fig.12. Stator Current Is(abc)

Fig.13. Stator Power

 

Fig.14. Rotor Power

Fig.15. The FFT analysis of phase (a) stator current (Synchronous mode).

CONCLUSION:

A study of Direct Torque Control strategy applied to Doubly Fed Induction Generator used for Wind Turbine Conversation system has been presented in this paper. As known, the wind has a random movement imposing indiscriminate speed for the turbine, therefore driving DFIG in different modes (sub-synchronous, synchronous and super synchronous modes), those modes have been treated in this work. The obtained results show clearly satisfactory performances, they showed a good dynamic of the torque and the flux, low THD in synchronous mode and constant stator frequency, while keeping a better precision of control, as well as the efficiency of the control strategy leading to better performances.

REFERENCES:

 

[1] C. J. Nobles, E. F. Schisterman, Sandie Ha, Keewan Kim, and all, “Ambient air pollution and semen quality,” Environmental Research. 163, 2018, pp. 228-236.

[2] B. Sawetsakulanond, V. Kinnares, “Design, analysis, and construction of a small scale self-excited induction generator for wind energy application,” Energy Journal. 2010, pp. 4975–4985.

[3] A. Tapia, G. Tapia, J.X. Ostolaza, J.R. Saenz, “Modeling and control of a wind turbine driven doubly fed induction generator,” IEEE Trans. Energy Convers. 2003, pp. 194–204.

[4] “GWEC’s Global Wind Report - Annual Market Update,” the Global Wind Energy Council, 2017. Available: http://www.gwec.net.

[5] “Renewables 2017 global status report 2017,” Ren21, 2017.

DTC of DFIG included in a Wind Turbine Connected to the Grid

ABSTRACT:

This article presents a contribution of the application of direct torque control, for the control of the powers of a double power induction generator (DFIG), used in a constant speed wind energy conversion system. This type of control based on two hysteresis band controllers of torque and flux. The simulation results showed that it is possible to control the rotor powers with this method.

 KEYWORDS:

1.      DFIG

2.      DTC

3.      WIND TURBINE

4.      GRID

 SOFTWARE: MATLAB/SIMULINK

 BLOCK DIAGRAM:

Fig.1. Block diagram of DTC.

 EXPECTED SIMULATION RESULTS:

Fig.2. The rotor flux sector location.

Fig.3. evolution of rotor flux estimated components.

Fig.4. Waveform of the alpha/beta rotor flux (Wb).

Fig.5. The rotor flux  (Wb).

Fig.6. Waveform of the alpha/beta rotor currents

Fig.7. Waveform of the rotor currents and voltages.

CONCLUSION:

This paper presents the simulation of the direct torque control for a doubly fed induction generator connected to the grid. The results obtained confirm the theoretical studies of this commande, and show the effectiveness of the proposed control strategy.

REFERENCES:

[1] A. Kadri , H. Marzougui , K. Omrani , F. Bacha, “DTC of Doubly Fed Induction Generator for Wind Power System based on Rotor Flux Estimation,” International Confernece on Control Engineering Information Technology. Tunisia, vol. 34, pp. 33-38, December 2017.

[2] Y. Sahri, S.Tamalouzt, S. L. Belaid, “Direct Torque Control of DFIG Driven by Wind Turbine System Connected to the Grid,” International Conference on Wind Energy and Applications in Algeria. Algeria, pp. 88-93, November 2018.

[3] N. El Ouanjli1 , A. Derouich , A. El Ghzizal , M. Taoussi , Y. El Mourabit, “Direct torque control of doubly fed induction motor using three-level NPC inverter,” Protection and Control of Modern Power Systems 4. October 2019

[4] G.Naveen, P.K.S.Sarvesh, B.Rama Krishna, “DTC Control Strategy for Doubly Fed Induction Machine,” International Journal of Engineering and Advanced Technology. India, vol. 3, pp. 92-95, October 2013.

[5] A. Bakouri, H. Mahmoudi, A. Abbou, “Intelligent Control for Doubly Fed Induction Generator Connected to the Electrical Network,” International Journal of Power Electronics and Drive System. Indonesia, vol. 7, pp. 688-700, September 2016.