Product: Power Factor & Harmonics: StacoSine: Harmonics

1. Power Quality Products and
Applications: Harmonics

2. Harmonics is a term used to
explain currents and voltages that
have multiplied in an AC electrical
power network
Harmonic producing areas include
ferromagnetics (transformers,
motors), arcing equipment
(welders, arc furnaces), and
rectifiers (UPS, adjustable speed
drives)
Harmonic
Basics

3. Power electronic devices
used in numerous equipment
Loads are non-linear, with an
erratically shaped sine-wave
60hz fundamental becomes
amplified when harmonics
present
5th order harmonic
represents 300hz
Harmonic
Basics

4. Harmonic spectrum may include
various harmonic orders, each with its
own values for current and voltage
IEEE 519 Guide for Harmonics,
references different types of harmonics
and methods for mitigation
Industrial applications typically involve
odd order harmonics, 5th, 7th, 11th,
13th
Zero sequence harmonics affect the
neutral
Harmonic
Basics

5. Adjustable speed drives and systems, electric arc furnaces, welding equipment,
transformers and generators, UPS and storage systems, medical/dental
equipment, lighting controls/dimmers, computers, copiers, scanners
Common Causes

6. Overheating of conductors, bus bar, switchgear, circuit breaker
nuisance tripping/arcing, meters/instruments not accurate, AC
motor reverse torque, transformers overheating/insulation
breakdown, capacitors overload/blown fuse, reduced equipment life,
early failure
Effects

7. Capacitors do not create harmonics
Concern for resonance – currents amplified, voltage
distortion, potential damage to capacitors
Reactors help to “de-tune” to below a certain order,
balancing the capacitive requirement
Harmonics
and PFC

8. Harmonics
Application
Review
Facility walk-through – installed equipment, systems and processes
Review plant electrical documents
Note plans for new equipment, expansion
Analyze 6-12 months of electric bills
Review past electrical system studies, may require a PQ survey, energy
audit

9. Harmonics
Application
Review
Note equipment most vulnerable to harmonics
Any critical loads and process requiring “premium power”, outage
concerns?
Review downtime, scrap, maintenance, equipment replacement costs, loss
of production, profits
Isolated solution, long term PQ strategy

10. Water treatment, glass making, steel processing, packaging, data
centers, printing/publishing, paper processing, plastics,
chemicals, automotive, to name few
Where Harmonics Exist

11. Harmonics can create nuisance problems (rebooting a PC, restarting
equipment) to serious concerns (product quality issues), through
catastrophic events (production halted)…….monies lost
Economic
Considerations

12. New and replacement
equipment/controls and devices
typically are electronic, which may
exacerbate a border-line harmonic
condition, immediately creating a
new set of problems, which ultimately
affect business…….monies lost
Partial “fixes”, lack to review total PQ
situation……..monies lost
Harmonic
Basics

13. Keep a record of problems and associated costs
Actions taken to review and “fix” problem(s), associated costs
Potential need to monitor (collect data) on facility loads, to help with evaluation
Discuss problem with a “solutions driven” equipment manufacturer
Suggestions

14. IEEE519-1992
Current Distortion Limits for General Distribution Systems (120V
through 69000V)
SCR=IS/IL
Harmonic Percentage
H<11 11-16 17-22 23-24 34<h THD
<20 4.0 2.0 1.5 0.6 0.3 5.0
20-50 7.0 3.5 2.5 1.0 0.5 8.0
50-100 10.0 4.5 4.0 1.5 0.7 12.0
100-
1000
12.0 5.5 5.0 2.0 1.0 15.0
>1000 15.0 7.0 6.0 2.5 1.4 20.0

15. EN61000-3-4
Admissible Current for Entire Installation
Harmonic
Number
n
Admissible
Harmonic Current
In/Iact (%)
Harmonic
Number
n
Admissible
Harmonic Current
In/Iact (%)
3 19 21 <0.6
5 9.5 23 0.9
7 6.5 25 0.8
9 3.8 27 <0.6
11 3.1 29 0.7
13 2.0 31 0.7
15 0.7 <33 <0.6
17 1.2
19 1.1 Even <4/n or <0.6

16. Conventional
Methods to Solve
Harmonics
Poly-phase Rectifier and Phase-
shift Transformer
Adding transformers,
thyristors and controller… etc.
Regardless of Mains Power I
mpedance and Frequency
Must be built-in before
equipment delivery

17. Conventional
Methods to Solve
Harmonics
Passive Power Filter
Made of Capacitors and
Inductors
Very Sensitive to Mains
Power Impedance and
Frequency
Can be Built-In at
Any Time

18. Best Method to
Solve Harmonics
Active Power Filter
Uses Solid State Power
Converters
Independent of Mains
Power Impedance and
Frequency
Can be Built-In Any Time

19. Operation Principle of
StacoSine
Phase 1: Measure the harmonic current from the load
Ih waveform
Ie
Ih
IS

20. Operation Principle of
StacoSine
Phase 2: Inject harmonic current in opposite phase to the load
Ie waveform
Ie
Ih
IS

21. CONTACT US
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