A.7
K Factor
K–Factor is a weighting of the harmonic load currents according to their
effects on transformer heating, as derived from ANSI/IEEE C57.110. A
K–Factor of 1.0 indicates a linear load (no harmonics). The higher the
K–Factor, the greater the harmonic heating effects. It is calculated based
on the following equation:
(A.1)
KF actor
=
(
V
1
×
1)
2
+
· · ·
+ (
V
50
×
50)
2
V
2
1
+
· · ·
+
V
2
50
where each component is multiplied by the harmonic number
(
e.g.
1
,
2
,
· · ·
,
50), called a weighting factor.
Harmonic load currents significantly affect power distribution system
design. Harmonics create additional losses through the skin effect at high
frequencies and through higher RMS load currents. By specifying K-Rated
transformers and using other techniques, power distribution systems and
customer equipment should have lower failure rate.
Harmonic Summary data returned from the 933A can be a strong indicator
of what harmonics are being returned to the distribution system location
by users with nonlinear loads. Harmonic content is potentially damaging
both to the power company and the user. Without adequate protection,
equipment will experience early failure and reduced overall efficiency.
A.8
KYZ (Pulse Metering)
KYZ Pulse Metering is a method of measuring energy usage by mechanical
contact closures and openings at the meter. Each opening and each closure
are separately counted as one energy unit, which unit is normally assigned
by the utility provider. KYZ pulse metering is normally counted at the
end of a line connected to the meter.
A.9
Kp Register Scale Factors
Kp register scale factors are used to scale the weighting of pulses in KYZ
pulse metering. For more information on scale factors, see Section 7.5.3.
160
