Ace enablers energy saving machine uptime-harmonic mitigation

Energy Saving & Machine Uptime Through Harmonic Mitigation

CASE STUDY

ACE ENABLERS LLP

CHENNAI

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

Power & Harmonic Data at Transformer & DG Incomer

Transformer & Reactive Power Compensation in the Plant

IEEE 519/1992 Limits at the PCC

Current Distortion for <69 KV general system

Voltage Distortion for <69 KV general System

Full Day Recording of Harmonics & Energy Data Before AHF Solution

Average Current

Harmonic close to 20%

Full Day Recording of Harmonics & Energy Data Before AHF Solution

kVAh minus kWh = 610 Units/ day……. ……….15250 units/

month

The Solution Architecture

Plant Layout with AHF Solution

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

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

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...)

IEEE Standard 1459-2010

• Definitions for the Measurement of Electric Power Quantities Under Sinusoidal, Non-sinusoidal, Balanced, or Unbalanced Conditions

Full Day Recording of Harmonics & Energy Data after AHF Solution

Average Current

Harmonic reduced to

<4%

Full Day Recording of Harmonics & Energy Data after AHF Solution

kVAh minus kWh = 150 Units/day……. ………3750 units/ month

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

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

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

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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ACE ENABLERS LLP