Premium Membership

Get access to premium HV/MV/LV technical articles, electrical guides, studies and much more! Apply 20% OFF Code: EEP09PE
Home / Download Center / Electrical Engineering Books and Technical Guides / Power substation guides / A Guide To Power Factor Correction For The Plant Engineers

Power Factor Correction Capacitors

What do power factor correction capacitors have to do with harmonics? A discussion of power system harmonics is incomplete without discussing the effects of power factor correction capacitors.

A Guide To Power Factor Correction For The Plant Engineers
A Guide To Power Factor Correction For The Plant Engineers

In the power plant containing power factor correction capacitors, harmonic currents and voltages can be magnified considerably due to the interaction of the capacitors with the service transformer.

This is referred to as harmonic resonance or parallel resonance.

For a typical plant containing power factor correction capacitors, the resonant frequency (frequency at which amplification occurs) normally falls in the vicinity of the 5th to the 13th harmonic.

Because nonlinear loads typically inject currents at the 5th, 7th, 11th, and 13th harmonics, a resonant or near-resonant condition will often result if drives and capacitors are installed on the same system, producing the symptoms and problems outlined in the previous section.

NOTE: Capacitors themselves do not cause harmonics, but only aggravate potential harmonic problems .Often, harmonic-related problems do not “show up” until capacitors are applied for power factor correction.

It is a common misconception that the problem of applying capacitors in harmonic environments is limited to problems caused for the capacitor itself – that the capacitor’s lower impedance at higher frequencies causes a current overload into the capacitor and, therefore, must be removed.

Fundamental and 5th harmonic separatly and combined
Fundamental and 5th harmonic separatly and combined

However, the capacitor/harmonics problem must be viewed from a power system standpoint.

The capacitor-induced increase of harmonic voltages and currents on a plant’s system may be causing problems while the capacitor itself remains within its acceptable current rating.

How can harmonics problems be eliminated?

When power factor correction is required in the presence of nonlinear loads, or the amount of harmonic distortion must be reduced to solve power quality problems or avoid penalties, the most reliable, lowest cost solution is often realized with the use of harmonic filters.

Title: Power factor correction – A guide for the plant engineer – EATON
Format: PDF
Size: 2.6 MB
Pages: 24
Download: Right here | Get Download Updates | Get Premium Membership
A guide to power factor correction for the plant engineer
A guide to power factor correction for the plant engineer

Premium Membership

Premium membership gives you an access to specialized technical articles and extra premium content (electrical guides and software).
More Information


  1. Corneille Matala
    Sep 24, 2018

    Knowledge shown.Congratilations

  2. Olufemi Olukoga
    Nov 23, 2014


Leave a Comment

Tell us what you're thinking... we care about your opinion!

Subscribe to Weekly Digest

Get email alert whenever we publish new electrical guides and articles.