This document defines power quality and current harmonics. It discusses passive filters and active power filters, including voltage sourced and current sourced active power filters. Active power filters are compared to passive filters, noting active filters' advantages in eliminating any harmonics without tuning, but their higher cost and complexity. The document concludes by describing the Denizli-2 active power filter application in Turkey, which uses a current sourced converter design to filter 5th harmonics at a 5 MVA installation.

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.