Mtech IEEE Conference Presentation

05/01/2023 TAP ENERGY 2015,Paper ID-270‑ 1

Control of Doubly Fed Induction Generator connected to Variable Speed

Wind Turbine

IEEE International Conference on Technological Advancements in Power and Energy-2015.

Paper ID-270

Authors: Presented By1. Anjana Jain B.Janardhan Reddy Asst Professor, ASE, Bangalore 2. B.Janardhan Reddy TAP ENERGY-2015 PG student, ASE, Bangalore


Overview:• Objective• Introduction• Block Diagram• Proposed Control Algorithm• Simulation Results• Conclusion• References


Objective• Derived the closed loop control scheme of DFIG.• To maintain the terminal voltage and frequency constant.• To maintain the slip power as negative in super synchronous mode of

operation and as positive in sub synchronous mode of operation. By using bidirectional back-to-back SPWM converters connected to rotor terminals.


Introduction• Wind Energy is a source of renewable power.• Wind turbines harvest this kinetic energy and convert it into usable

power.• In earlier period the technology used in WECS was based on SCIG

running at constant speed, directly connected to the grid.so wind power is not utilized completely. • Presently the technology moves towards the variable speed WECS and

hence influencing the system dynamics.• But unbalances in wind energy are highly impacting the energy

conversion.• Doubly fed induction generators (DFIG) are commonly used in wind

turbines to generate large amounts of electric power.


Wind turbine:• The maximum power extractable from the wind turbine is defined as = = =Parameters of Wind turbineRadius = 1mPitch angle for small wind turbines.Wind velocity=15m/s for super synchronous mode and 5m/s for sub synchronous mode of operation.


Block diagram:

For Pm=Ps+PrPs=sPrsupersynchronous speed operation Pm=(1+s)Pr, s=-ve

For Pm=Ps+Pr Ps=-sPrsubsynchronous speed operation Pm=(1-s)Pr, s=+ve

Fig:1 Structure of DFIG wind generation system


Characteristics of DFIG:

Fig:2 Torque,current & slip characteristics of DFIG


Stator side converter control scheme:

Fig:3 Stator side converter control

TAP ENERGY 2015,Paper ID-270‑ 9

Proposed control algorithm for Rotor side converter:

05/01/2023

Fig:4 Proposed control algorithm for rotor side converter


Simulation circuit:

Fig:5 Simulation circuit


Rotor speed Electromagnetic Torque

Mechanical Torque Stator active power

SIMULATION RESULTS


Stator reactive power Stator Voltages

Stator Currents DC Link Voltage


Rotor active power Rotor reactive power

Rotor Voltages Rotor Currents


Grid Voltages Grid Currents

Grid Synchronization THD for o/p Voltage Waveform


TABULATION FOR VARIOUS SPEED:

Speed in wr

(rad/sec)

Mechanical Power in Watts(W)

Slip (s) Stator Electrical Power in Watts(W)

Rotor Electrical Power in Watts(W)

DC link voltage

162.3 Pm=(1+s)Pr=Tm*wr=162.3*22=

3570.6 W

S=-0.03 Ps=Pm-Pr =s*Pr=Te*ws=157*-22

=-3454 W

Pr=-36.5W

Vdc=452.5V

158.5 Pm=158.5*6.9 =1093.65W

S=-0.009 Ps=157*-6.5=-1020.5W

Pr=-8.5W Vdc=452.5V

156.5 Pm=(1-s)Pr 156.5*1.7=266.05W

S=0.0031 Ps=-s*Pr=157*-1.4=-219.8W

Pr=2.3W Vdc=452.5V

154.3 Pm=154.3*1.5=232.5W

S=0.012 Ps=157*-1.2=-188.4W Pr=5.2W Vdc=452.5V

In steady state at fixed speed for a loss less generator is Tm=Te

Table 1: Tabulation for various speeds


Machine parameters:

• Type: Slip Ring Induction Motor Stator Resistance = 4.781 Power = 5HP=5*746=3.7KW Rotor Resistance = 3.91 Stator winding Stator Inductance = 0.0248 Voltage : 415 V Rotor Inductance = 0.0248 Current : 7.5 A Mutual Inductance = 0.459 Rotor winding Moment of Inertia = 0.205 Voltage : 200 V Friction Factor = Current : 11 A Pole Pairs = 2


Conclusion:• The complexity of the rotor-side converter control is reduced by

applying the proposed rotor control algorithm.• Improvements in the grid-synchronization technique can be achieved

by applying the control technique using fuzzy logic to obtain negligible oscillations in the various system parameters.


References:[1] R. Pena, J. C. Clare and G. M. Asher, “Doubly-Fed Induction Generator using back-to-back PWM converters and its application to Variable-speed wind energy generation” IEEE Proceedings on Electrical Power Applications, Vol.143, No.3, pp. 231-241, May 1996.

[2] R. Pena, J. C. Clare and G. M. Asher, “Doubly-Fed Induction Generator using back-to-back PWM converters supplying an isolated load from a Variable-speed wind turbine” IEEE Proceedings on Electrical Power Applications, Vol.143, No.5, pp. 380-387, Sep 1996.

[3] A.Jayalaxmi and Yerra Sreenivasa Rao “Direct Torque Control of Doubly Fed Induction Generator based wind turbine under Voltage Dips” International Journal of Advances of Engineering & Technology, may 2012.

[4] Gilsung Byeon*, In Kwon Park** and Gilsoo Jang, “Modelling and Control of a Doubly-Fed Induction Generator (DFIG) Wind Power Generation System for Real-time Simulations.

[5] S. Muller, M. Deicke, and R. W. De Doncker, “Doubly-Fed Induction Generator Systems for Wind Turbines,” IEEE Ind. Appl.Mag., Vol.8,n0. 3,pp. 26-33, May/Jun. 2002.

[6] R. Pena, J. C. Clare and G. M. Asher, “Doubly-Fed Induction Generator using back-to-back PWM converters and its application to Variable-speed wind energy generation” IEEE Proceedings on Electrical Power Applications, Vol.143, No.3, pp. 231-241 May 1996.

[7] Srinath Vanukuru & Sateesh Sukhavasi “Active and reactive power control of a Doubly Fed Induction Generator driven by a Wind Turbine.

[8] Rishabh Dev Shukla & Ramesh Kumar Tripathi “A novel Voltage and Frequency controller for standalone DFIG based Wind Energy Conversion system.

[9] Iwanski G, Koczara W. “Sensorless direct voltage control method for standalone slip-ring induction generator.” In:Proceedings of 11 th EPE, Dresden, Germany, CD-ROM; 2005.

[10] Bhim Singh, Fellow, IEEE, & N. K. Swami Naidu, “Direct Power Control of single VSC based DFIG without rotor position sensor”, IEEE transaction on industry applications, vol. 50, no. 6, November/December 2014.


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