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Dynamic Power Filter & Capacitor

Compensator for Isolated Self-excitedInduction Generator driven by a Wind

Turbine 

Dr. A.M. Sharaf & Subramanian Kanthi.

University of New Brunswick, Canada.

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Contents

Harmonics & Reactive Compensation.

Concept of Dynamic Power Filter & Capacitor

Compensator (DPFCC).

DPFCC for SEIG Driven by a Wind Turbine.

Dynamic PID Controller for DPFCC.

Dynamic Simulation Models. Matlab/ Simulink Simulation Results.

Conclusion.

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 Power Quality

 Definition :  “Power  quality problem is any power problem

manifested in voltage, current, or frequency deviation thatresults in failure or misoperation of customer equipment”.

Power quality can be simply defined as shown in theinteraction diagram: 

Electrical Grid

Utility

Nonlinear Loads

Consumers

Voltage

Quality CurrentQuality

Power 

Quality

•Voltage Sags

•Voltage Swells

•Transients, Glitches

•Inrush current

•Flickering •Harmonics

•Waveform Distortion

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Harmonics and Reactive Compensation

P.F for sinusoidal waveforms (Linear Load- Sinusoidal):

Displacement Power Factor :

Solutions are Shunt capacitors.

Real Power Factor for non-sinusoidal waveforms (NonlinearLoads):

True Power Factor :

Solutions are not just shunt capacitors as well as reduction of Harmonics. For Nonlinear Loads,

(THD )i can be as high as 50% - 75%.

1cos 

2

1.

1 i

PF DPF  

THD

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Concept of Dynamic Power Filter.

Frequency Response of the Tuned-Arm Filter with Fixed

Filter parameters R, L, C and Varying Duty Cycle αD 

Magnitude and Angle of YF (jw)

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DPFCC for SEIG driven by a

Wind Turbine.

WECS- Wind Energy- SEIG scheme Dynamic Compensator Topology

Windvelocity

PL , QL 

Loadswitching

OFF state

ON

State

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DPFCC for SEIG driven by a

Wind Turbine.

Dynamic VARS compensation for any load/speedchanges/excursions.

Harmonic power Filter combined to reduce fastvoltage transients or quasi-dynamic harmonicsencountered during Load switching.

Max. Wind Utilization by stabilizing VAR generator

capacitor-extra switched (Leading power factorcurrent).

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DPFCC for SEIG driven by a

Wind Turbine.

Equivalent Circuit of SEIG when

Switch is OFF.

Equivalent Circuit of SEIG when

Switch is ON.

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DPFCC for SEIG driven by a

Wind Turbine.

Tri-Loop Dynamic PID Tri-Loop Controller (Ig, Vg , speed Loops)(Developed by Dr.Sharaf)

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Dynamic Simulation Models.

3.~23,~2

p.u1Vp.u,3.0Q,p.u3.0P

.QQ , .

g000

0

0

0

0

 

 

 

 

 

 

 

 

   

   

g

g

g

g

V 

V 

V 

V PP

Nonlinear Load Model

velocity.turbinewindtheisw ratio;speedtiptheis 

efficient;-coconversionpowertheisC 

blades;rotortheof radiustheisR 

blades;by thesweptareatheisA

);kg/m(1.25airof densityspecifictheiswhere

.....2

1..

.2

1

w

p

2

32

 

  

     

w pw

W w V C  Aw

V  ARC T  p

Wind Turbine Model

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Matlab/ Simulink Simulation Results.

Time (t =0.1s) Wind excursion applied + 20%

Time (t=0.3 s) Wind excursion removed – 20%

Time (t=0.2 s) Load excursion applied +20 %

Time (t=0.4 s) Load excursion removed -20%.

Control signals (Vc) to the PWM generator. PWM output signals (alpha d) for

GTO/bridge IGBT.

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Matlab/ Simulink Simulation Results.

Without Dynamic Compensator With Dynamic Compensator

Generator Voltage (Vg) with wind and Load variations

1.0 p u 1.0 p u

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Matlab/ Simulink Simulation Results.

Without Dynamic Compensator With Dynamic Compensator

Generator Power (Pg) with wind and Load variations

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Matlab/ Simulink Simulation Results.

Dynamic waveforms of RMS of Vg, Ig, Vg vs. Ig 

Without DPFCC With DPFCC

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Matlab/ Simulink Simulation Results.

Reactive Power at Generator Bus (Q g)

Without DPFCC With DPFCC

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Matlab/ Simulink Simulation Results.

Without DPFCC With DPFCC

Generator Current (ig) with wind and Load variations

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Matlab/ Simulink Simulation Results.

Without DPFCC With DPFCC

RMS of Generator Voltage (Vg) Vs Generator Current (Ig)

Vs Generator Power (Pg)

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Conclusions

Voltage stabilization (Vg) in the Generator Bus and

minimum impact of electrical load excursions as well

as wind gusting conditions.

Stabilization of Generator Power (Pg) Output. The Tri-loop Dynamic PID controller is validated as

an effective controller ensuring voltage stability and

avoidance of conditions of loss of excitation.

Reduction of Capacitor Switching Transients and

Harmonics.