1 / 2

Measures of Power Quality (1)

Measures of Power Quality (1). Displacement Power Factor (Displacement Factor)  = Cosine of phase shift between fundamental component of line current and the associated phase voltage (ie I A and V AN )

nhi
Télécharger la présentation

Measures of Power Quality (1)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Measures of Power Quality (1) • Displacement Power Factor (Displacement Factor) •  = Cosine of phase shift between fundamental component of line current and the associated phase voltage (ie IA and VAN) • Accounts for proportion of fundamental current that does something useful.  = 1 is good,  = 0.5 is bad (50% of fundamental current does nothing useful) • Distortion Factor •  = RMS fundamental current/total RMS current • Accounts for the proportion of RMS current that is due to harmonics.  = 1 is good (pure sinewave).  = 0.5 is bad (50% of RMS current is due to the harmonics) • Power Factor • pf = power delivered/total RMS volts * total RMS amps • Tells us what proportion of the total apparent power (VA) represents useful power delivered to the load (Watts) • pf=1 is good, pf = 0.5 is bad (have to supply 1000VA to get 500W for example)

  2. Measures of Power Quality (2) • Relationship between quantities • Assume voltage is undistorted compared to current – normally reasonable for a decent power system • Then total RMS voltage = fundamental RMS voltage Power factor = Displacement factor * Distortion factor Note if the current is undistorted then  = 1 and Power factor = Displacement factor = Cosine of phase shift (as given in 1st year notes)

More Related