In commercial buildings and industries, engineers are confused as to why transformers overheat, while supplying average loads.
Neutral conductors overheat from excessive loads, while the circuit is balanced. Circuit breakers tripping for no apparent reason. Yet all standard checks confirm everything is normal and ok.
What then is the cause? – HARMONICS.
Harmonics
What are they?
Harmonic frequencies are integral multiples of the fundamental supply frequency resulting in current and voltage distortions.
These harmonic frequencies are of different orders and could be odd or even number harmonics.
Why are they so prevalent these days?
With the increasing use of modern electronics. The miniaturization of electronic components as a result of technological strides and the drive for industrial optimization for efficiency prevalent today
Harmonic pollution is now on the rise because of the large number of personal computers in use, adjustable speed drives and other equipment that draws current in a non-linear (short pulses) manner. Instead of the normal sine waveforms.
While these equipment enhance efficiency, it injects harmonics onto the load current.
The types of equipment that normally generate current harmonics are;
- Switch mode power supplies (SMPS)
- Electronic fluorescent ballasts…..
- variable speed drives
- UPS units etc
While Harmonic voltages are caused by;
- Voltage distortions
- Induction motors
- Zero-crossing noise
As the quantity of installed electronics and energy efficient equipment rise, harmonic pollution will continue to be on the increase.
This is risk to businesses and has to be managed.
With appropriate investment in good design and best practices, the right electrical equipment and good maintenance culture will mitigate the effects of harmonics.
We shall discuss more on harmonic pollution, what to do in the harmonic rich environment, the mitigation equipment, technique and technologies in our subsequent post.
However help is available at FullSpectrum Energy www.fullspectrumenergyng.com
Contact us
Victor Oyedu, FNSE, FNIEEE, CPQ.
Power Quality and Energy Management Specialist.
Publisher at Afrienergyonline.com &
CEO, FullSpectrum Energy Solutions Limited, Nigeria.
