This case study examines the installation of active harmonic filters (AHF) at a manufacturing plant in Andhra Pradesh to mitigate harmonics and improve power factor. Before the AHF solution, the plant exceeded IEEE harmonic limits and experienced excess kVAh billing of over 600 units per day due to distortion power from non-linear loads. After installing AHFs, harmonic levels were reduced below limits, kVAh billing decreased to 150 units per day, and equipment failures were reduced, saving the plant over 9 lakhs rupees annually in energy costs. The solution improved power quality and reduced losses in the distribution system.

1. Energy Saving & Machine Uptime
Through Harmonic Mitigation
CASE STUDY
ACE ENABLERS LLP
CHENNAI

2. Case - Overview
• The case is about PF and Harmonic mitigation solution done at a FMCG
manufacturing company. Plant is situated in the State of Andhra Pradesh
• APGENCO, power utility, charges energy on KVAH billing at ₹.6.32 per unit
• There is no incentive for PF >0.95
• Plant consumed nearly 15000 units/month kVAh more than kWh value
• Client also had frequent failures of PCBs & other tripping
• Transformer and Busbar humming was evident
• Power-Harmonic audit, analysis and recommendation was carried out and
Active Harmonic Filters (AHF) installation and commissioning was done
• This case study captures the effect of pre and post AHF installation while
PF and DPF are close to unity
• A confirmatory audit done with direct measurement of distortion power,
also establishes the new 3 dimensional power triangle discussed under
IEEE: 1459/2010

3. Power & Harmonic Data at Transformer & DG Incomer

4. Transformer & Reactive Power Compensation in the
Plant

5. IEEE 519/1992 Limits at the PCC
Current Distortion for <69 KV general system
Voltage Distortion for <69 KV general System

6. Full Day Recording of Harmonics & Energy Data
Before AHF Solution
Average
Current
Harmonic close
to 20%

7. Full Day Recording of Harmonics & Energy Data
Before AHF Solution
kVAh minus kWh = 610 Units/
day……. ……….15250 units/
month

8. The Solution Architecture

9. Plant Layout with AHF Solution

10. Power Triangle
• .
In the diagram, P is the active power, Q is
the reactive power (in this case positive), S
is the complex power and the length of S is
the apparent power. Reactive power does
not do any work, so it is represented as the
imaginary axis of the vector diagram.
Active power does do work, so it is the real
axis

11. Power Triangle – Analogy To Beer
For easier understanding, the
difference is shown with beer.
Reactive power is like the foam on
top of a glass of beer, where the
liquid in the glass represents active
power. The foam takes space in the
glass and, therefore, reduces the
beer containing capacity. By
comparison, the reactive power
reduces the electricity transport
capacity of a power transmission
line

12. The New Power Triangle is 3 Dimensional
Nowadays the typical power triangle doesn’t
fit any more because other parameters like
the distortion or harmonic reactive power
have to be considered due to more and
more non-linear loads (inverter, electronic
ballast unit, etc...)

13. IEEE Standard 1459-2010
• Definitions for the Measurement of Electric Power Quantities
Under Sinusoidal, Non-sinusoidal, Balanced, or Unbalanced
Conditions

14. Full Day Recording of Harmonics & Energy Data
after AHF Solution
Average
Current
Harmonic
reduced to
<4%

15. Full Day Recording of Harmonics & Energy Data
after AHF Solution
kVAh minus kWh = 150
Units/day…….
………3750 units/ month

16. Case Study – Summary
• This plant had installed detuned-APFC of 2 nos 1500 KVAR with 7%
detuned reactors, as the first line of defense
• Harmonic analysis report showed 6.4% THD-U and 19.4% THD-I at the
PCC level, exceeding the IEEE: 519/1992 limits.
• kVAh showed >600 units/day, against kWh due to distortion power
• Unit also reported frequent failure of PCBs and PLCs
• AHF for a total of 1440 A were installed at different DB and main panels.
THD-I reduced to <5% and THD-U reduced to < 2% at the PCC level
• PCB failures and other interruptions reduced to less than 20% from
previous level, as THD-I reduced to less than 8% at machines level
• KVAH reduced to around 485 units/ day or 145440 units /annum
• Direct saving in energy cost is ₹ 9.20 Lakhs per annum @ ₹6.32 tariff
• Indirect savings through reduction in PCB failures, machine tripping and
reduction in I²R losses in the distribution system have also been observed

17. Confirmatory Recording Done on 29.09.2016 for 30 Minutes
with all AHF Switched Off
kVAh minus kWh = 655.2 –
642.1 = 13.1 units.
13.1 *2*24*25*12
=188640 units/annum

18. Confirmatory Recoding Done on 29.09.2016 for 30 Minutes
with all AHF Switched ON
kVAh minus kWh = 626.7 –
623.7 = 3.0 units.
3.0 *2*24*25
*12 =43200 units/annum.
77% reduction in energy
loss

19. Case Study- Summary - Conclusion
• Confirmatory survey at the plant was done on 29.09.2016.
• The Power-Harmonic Analyser was configured to record directly the
Distortion reactive power D, apart from apparent (kVA), Active (kW) &
Reactive (kVARh)
• Industries under kVAh billing must adopt techniques to improve
PF and also mitigate Harmonics
Non-linear loads
cause harmonics
and increase
distortion power.
Hence the kVAh
increases to cause
revenue loss

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