Brief introduction to active power filters

1. Emre DURNA

2.  Definition of POWER QUALITY
 Definition of Harmonic Components
 Elimination of Current Harmonics
 Passive Filters
 Active Power Filters
 Voltage Sourced Active Power Filters
 Current Sourced Active Power Filters
 Active Power Filter vs Passive Filter
 Active Filter Application of TUBİTAK UZAY
 Summary
 References

3.  Power quality is the set of limits of
electrical properties that allows electrical
systems to function in their intended manner
without significant loss of performance or
life
 Reliable Mains:
 Magnitude (Rated Voltage)
 Frequency (50 Hz)
 Sustainability
 Stability

4.  Allof the signals can be represented as the
summation of sinusoidal signals of various
frequencies.

5. + + =
5th 7th Resultant
Fundemental Harmonic Harmonic Signal
Component Component

6.  In Power Systems, harmonics appear on the
current signals.
 Motor Drives, Soft Starters, UPS
 Power Electronic Converters
 Industrial Loads, Single Phase Loads
 AC to DC Converters (Rectifiers)
are typical harmonic current sources.
 Current Harmonics,which reduces the
power quality, are harmful for vulnerable
loads. It distorts mains voltage.
 Electronic Devices
 Motors
 Illumination Systems

7.  Vulnerable loads should be isolated from the
harmonic sources.
 Power System transmission lines and
transformers are over-loaded.
 Electromagnetic noises in systems.
 So, current harmonics should be eliminated
 CURRENT HARMONICS ELIMINATION SYSTEMS
 PASSIVE FILTERS
 ACTIVE POWER FILTERS

8.  Pasive
Filters are composed of passive circuit
elements such as resistor,capacitor and
inductor
 ForPassive Filters, the aim is to adjust the
resonance frequency of the filter to desired
harmonic elimination.

10.  Active Power Filters are simply power
electronic converters, specifically designed
to inject harmonic currents to the system.
 Active Power Filter Capabilities;
 Eliminating Voltage and Current Harmonics
 Reactive Power Compensation
 Regulating Terminal Voltage
 Compensating the Voltage flickering

12.  Voltage sourced active filters creates AC
voltage at its output terminal.
 Voltage sourced active filters use capacitor
(voltage sink) for DC Link.
 The output filter should be an inductor.
LF
Cdc

13. S1 S3 S5
Lf
Vdc
Cf
S4 S6 S2
Voltage Sourced Active Power Filter Topology

14.  Current sourced active filters creates AC
current at its output terminal.
 Current sourced active filters use inductor
(current sink) for DC Link.
 The output filter should be a shunt capacitor.
CF
Ldc

15. S1 S3 S5
Lf
Ldc
Cf
S4 S6 S2
Current Sourced Active Power Filter Topology

16.  Passive Filters
 Cheap, Easy design,Reliable,High Efficiency
BUT
 Resonance Problems, Tuning for fixed frequency
 Fixed Reactive Power Compensation, Large Size
 Active Filters
 No resonance problems, Can eliminate any
harmonics (no tuning), Voltage regulation,
Reactive Power Compensation,Reliable Operation
BUT
 Expensive, Complex control systems

17.  DENIZLI-2
TM Active Power Filter
(NATIONAL POWER QUALITY PROJECT)
 Specifically designed for 5th Harmonic Filtering
 5 MVA
 Current sourced converter based shunt active
filter

19. Power Stage Panels Control Panels

20.  Definition of POWER QUALITY
 Definition of Harmonic Components
 Elimination of Current Harmonics
 Passive Filters
 Active Power Filters
 Voltage Sourced Active Power Filters
 Current Sourced Active Power Filters
 Active Power Filter vs Passive Filter
 Active Filter Application of TUBİTAK UZAY

21.  Wikipedia.
Power Quality
en.wikipedia.org/wiki/Power_quality
 Denizli
2-TM Training Documents. TÜBİTAK
UZAY, Power Electronics Group.
A Current Sourced Converter based Active
Power Filter for mitigation of harmonics at
the interface of distribution and transmission
systems. Terciyanlı,A.; Avcı,T ; Ermiş, M. ;
Çadırcı, I.