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Dran-View 6 User Guide

Where:

b=1 if you wish the sign of the expression ωt ±δ to be the same for the normalized

expansion as it was in the UN normalized expansion (i.e., if the un normalized

expansion used sin(ωt ±δ) and the normalized expansion used sin (ωt ±δ

Normalized

then b=1). Otherwise, b=(-1). For example, in Dran-View the expansion is changed

from cos(ωt -δ) to cos (ωt +δ

Normalized

), here b=(-1).

is the nth harmonic phase angle. δ

on the right side of the equation is the phase

angle generated from the Un-Normalized Transform. The left side is the phase

angle transformed to its normalized perspective. δ

is expressed as a positive

number modulo 360.

φ is the Un-Normalized fundamental phase angle of the selected channel. If you

selected “Normalize To the Fnd” φ is the un normalized phase angle of the

currently displayed channel. If you select “Normalize to the Fnd of:” then φ is the

unnormalized phase angle of the selected voltage channel.

n is the harmonic number

The expression used to normalize a sine expansion is what one would intuitively

expect to see. We wish to “subtract out” the fundamental phase angle, therefore it is

logical to subtract nφ degrees from each harmonic phase offset. The harmonic

number “n” is required because one degree of shift along the fundamental is equal

to n degrees of shift along the nth harmonic. Note that the normalization equation

for cosine expansions is just the negation of the expression for sine expansions.

This unfortunate bit of confusion is caused by the fact that in the process of

normalizing the cosine expansion, the form of the expansion is changed from cos

(ωt -δ) to cos (ωt +δ). The change of the minus sign to a plus sign requires the

negation of the normalization result. Note that if we are normalizing the channel

from which we get φ the phase of the normalized fundamental will always be zero.

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Dranetz Guide Guía de usuario Pagina 213