Re: Harmonics in electrical systems (back to basics)

Home Electrical Engineering Forum General Discussion Harmonics in electrical systems (back to basics) Re: Harmonics in electrical systems (back to basics)

Spir Georges GHALI


Refer to the Topic of Mr. Mill, I would like to mention the following points:

– The number of Harmonic is called “ Order ” ( Harmonic order 3 is the Third Harmonic “ 150 Hz ).

– The “ Soft Starter ” generates the Harmonics only in the starting & stopping steps, and as those steps are transient ( a few seconds ), so, in normal running no Harmonics are generated, and it’s considered that the “ Soft Starter ” are not Harmonics generator.

– The Elevator generates harmonics only if it’s controlled by VSD.


By the way, I want to mention that :

– “ IEC 61000-2-2  &  2-4 ” defined the maximum accepted level percentages of Voltage Harmonics in the LV Networks, either for Distribution Networks, or for privet networks connected to the utilities networks.

– “ IEC 61000-3-2  &  3-12 ” defined the maximum percentages of Current Harmonics that can be generated by electronic equipment, and even the maximum value of “ THD-I ”.