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(1) a.K Factor :

K-factor is a weighting of the harmonic load currents according to theireffects on transformer heating, as

derived from ANS ! """ #$%.11&. A K-factor of 1.& indicates a linear load (no

harmonics). 'he higher theK-factor, the greater the harmonic heating effects.hen a non-linear load is su lied from a transformer, it is sometimes

necessar* to derate the transformerca acit* to avoid overheating and su+se uent insulation failure. 'he reason

for this is that the increased edd* currents caused +* the harmonics increasetransformer losses and thus generate additional heat. Also, the S loadcurrent could +e much higher than the /0A rating of the load would indicate.

ence, a transformer rated for the e2 ected load will have insufficientca acit*. 'he K-Factor is used +* transformer manufacturers and their customersto ad3ust the load rating as a function of the harmonic currents caused +* the

load(s).4enerall*, onl* su+station transformer manufacturers s ecif* K-factor loadde-rating for their roducts. So, for K-factors higher than 1, the ma2imumtransformer load is de-rated.

Some manufacturers, who roduce +oth transformers and roducts li/emotors or +allasts, are sensitive to measuring K-factor since the* /now that

oor K-factors of +allasts and motors will de-rate the ma2imum loadtheir transformers can carr*. From the customer5s view oint, K-factor must

+e esta+lished in order to calculate the si6e of the transformer that is needed.n other words, if a com an* with man* offices were to install oor ualit*

electronic +allasts having a oor K-factor, a larger transformer would +e

needed than is a arent from the overall ower consum tion calculation

(7) a.

h* large 8- hase induction mortors need s ecial starting arrangements 9

99

(8) a.

oad curve : load curve is a gra h of variation of electrical load vs time.

load curve gives an idea how electrical load is consumed during a certaineriod. "lectrical load consum tion varies in different times during a da* and

the amount of electrical load re uired +* various consumers also var*. A loadcurve can give us an sufficient idea on how overall electrical load re uirement isvaried when certain geogra hical area is considered or it also can give us theinformation on load consum tion variation of a selected consumer. 'hus load

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curve rovide a convenient wa* of deciding the ma2imum load that must +egenerated.

+. ).

+ase load : minimum load that has to +e generated in order to meet

the consumer demands.ea/ load : ma2imum load that is re uired during certain eriods of

time. 'his varies var* much from the +ase load.

ii)

;ea/ load of an electrical area is met using ea/ load ower stations. 'heseare ower stations that o erate onl* when ea/ load is needed. est of thetimes the* remain inactive.