MFC BASED DOUBLY FED INDUCTION

GENERATOR IN WIND ENERGY CONVERSION SYSTEM

DONE BY GUIDED BY

S.NAGARAJAN (950313411010) S.THANGARAJME-POWER SYSTEM ENGINEERING ASST.PROFESSOR, DEPARTMENT OF EEE

nagarajan.ijce@gmail.com

PROJECT WORK (PHASE -II)

8807501375

OUTLINE:Abstract IntroductionExisting systemProposed systemLiterature reviewSimulationOutput resultConclusionFuture scopeReference

Abstract:

Wind energy generator.MFC controller .Avoid an external reactive power

compensator.Extracting maximum of power .

Objective:

Extract maximum power using Magnitude and frequency control(MFC) and control reactive power flow.

Introduction:

Key role of renewable energy.Wind energy power extraction .Induction generator used in wind

energy system.Wind energy generation method

Fixed speedVariable speed

Condt…..Fixed speed system - small scale

application.Variable speed system - large

scale application.Drive train system.Feature of DFIG system.

Existing system:

Dynamic slip control technique Variable resistor employed. FACTS controller needed. Suitable only limited variation of wind

speed. Drawback -external reactive power

compensator

Field oriented control technique Stator winding directly connected to grid. Field winding are controlled. Complexity to control field winding.

Proposed system:

Magnitude and frequency control technique

Rotor side to be controlled. Two feedback loop. Reactive power compensation.

Advantages: maintain constant voltage and frequency. Reduce the complexity of controller. Improve the reliablity.

All Simulink -MATLAB environment .

Literature review:

Y. Lei, A. Mullane, and G. Lightbody, “Modeling of the wind turbine with a doubly fed induction generator for grid integration studies,” IEEE Trans. Energy Convers., vol. 21, no. 1, pp. 257–264, Mar. 2006.

This paper highlights the induction generator efficiency as a basic factor.

The loading parameters have to be controlled . Blade pitch control, control and protective

schemes considered.steady state performance of the induction

generator is investigated.Disadvantages:

1.Power quality issues. 2.problem in reactive power control.

Cont….

• L. Xu and P. Cartwright, “Direct active and reactive power control of DFIG for wind energy generation,” IEEE Trans. Energy Convers., vol. 21, no. 3, pp. 750–758, Sep. 2006

This paper presents direct active and reactive power control.

Done by selecting appropriate voltage vectors on the rotor side.

It found that the initial rotor flux has no impact on the changes of the stator active and reactive power.

Disadvantages: 1).accurate power ratting of machine

needed. 2).suitable only grid integrated system.

Cont…

M. Orabi, T. Ahmed, and M. Nakaoka, “Efficient performances of induction generator for wind energy utilization,” in Proc. 30th Annu. Conf.IEEE Ind. Elect. Soc., Nov. 2004, pp. 838–843

This paper develops a simple DFIG wind turbine model in which the power converter is simulated as a controlled voltage source, regulating the rotor current to meet the command of real and reactive power production.

This model has the form of traditional generator model and hence is easy to integrate into the power system simulation tool .

Disadvantages: 1).Machine ratting is high. 2).converter cost high. 3).Facts controller needed.

Cont…

N. W. Miller, W. W. Price, and J. J. Sanchez-Gasca, “Comparative simulation of Dynamic modeling of DFIG based wind turbine-generators,” GE Power Systems Energy Consulting, Gen. Elect. Int., Inc., Schenectady, NY, USA, Oct. 2003.

This paper mainly focused on 1).wind turbine system. 2).pitch angle control. 3).Drive train model. Disadvantages: 1).issues in grid integration. 2).Does not meet out real time

requirments.

Power extracted from wind:Pwind = 1/2 * ρ * A * V 3

ρ =Density of airA =swept area of bladeV =velocity of windPwind = power extracted from wind

P=0.5*0.4*2.1519*10*10*10*1.24 P=533w

DFIG:

MFC controller diagram:

BLOCK PARAMETER:

PARAMETER VALUE

Nominal wind speed 10 m/s

No of wind blade 1

Power factor 0.9

Grid voltage 120 kv

Grid frequency 60 Hz

Rotor resistance 0.171 p.u

Dc link capacitance 1 mf

System inertia 5 sec

Rotor resistance 0.171 pu

simulation for mfc control system:

Simulation for Wind turbine model:

Simulation for pulse generation circuit:

Stator output voltage:

Stator output current:

Real and reactive power flow:

Output Torque:

DC LINK VOLTAGE:

Rotor speed output:

Result:Stator RMS output voltage 0.868 p.u

Maximum extracted power(practical)Maximum extracted power(theoritical)

0.776 p.u0.533 p.u

Maximum attained rotor speed 0.85 p.u

Dc link voltage 0.78p.u

THD 0.28 p.u

Conclusion:

Control technique of DFIG have been analysed.

Maximum rotor speed is attained.Maximum stator voltage is

obtained.

Future scope:

Matrix converters may consider.Direct torque control and direct

power control.Wind speed sensorless control

strategie.

Reference:

M. Orabi, T. Ahmed, and M. Nakaoka, “Efficient performances of induction generator for wind energy utilization,” in Proc. 30th Annu. Conf.

IEEE Ind. Elect. Soc., Nov. 2004, pp. 838–843 L. Xu and P. Cartwright, “Direct active and

reactive power control of DFIG for wind energy generation,” IEEE Trans. Energy Convers., vol. 21, no. 3, pp. 750–758, Sep. 2006

Y. Lei, A. Mullane, and G. Lightbody, “Modeling of the wind turbine with a doubly fed induction generator for grid integration studies,” IEEE Trans. Energy Convers., vol. 21, no. 1, pp. 257–264, Mar. 2006.

CONT…

Yu Zou, Malik E. Elbuluk, “ Simulation Comparisons and Implementation of Induction Generator Wind Power Systems”, IEEE transactions on industry applications, vol. 49, NO. 3, MAY/JUNE 2013.

S. Heier, “ Grid Integration of Wind Energy Conversion Systems. Hoboken”, NJ, USA: Wiley, 2006.

H. Sun, Y. Ren, and H. Li, “DFIG wind power generation based on backto- back PWM converter,” in Proc. IEEE Int. Conf. Mechatron. Autom., Aug. 2009, pp. 2276–2280.

M. Stiebler “ Wind Energy Systems for Electric Power Generation ” Berlin, Germany: Springer-Verlag, 2008.