Hioki PW3360-20, Instruction Manual

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Appendix4 Terminology
Active power Power that is consumed doing work.
Active power
demand value
The average active power used during a set period of interval time (usu-
ally 30 minutes).
Apparent power
The (vector) power obtained by combining active power and reactive
power. As its name suggests, apparent power expresses the “visible"
power and comprises the product of the voltage and current RMS values.
Harmonics
A phenomenon caused by distortions in the voltage and current wave-
forms that affect many devices with power supplies using semiconductor
control devices. In the analysis of non-sine waves, the term refers to one
RMS value among the components with harmonic frequencies.
LAN
LAN is the abbreviation of Local Area Network. The LAN was developed
as a network for transferring data through a PC within a local area, such
as an office, factory, or school.
This device comes equipped with the LAN adapter Ethernet 10/100Base-
T.Use a twisted-pair cable to connect this device to the hub (central com-
puter) of your LAN. The maximum length of the cable connecting the ter-
minal and the hub is 100 m. Communications using TCP/IP as the LAN
interface protocol are supported.
Power factor (PF/
DPF)
Power factor is the ratio of effective power to apparent power. The larger
the absolute value of the power factor, the greater the proportion of effec-
tive power, which provides the power that is consumed, and the greater
the efficiency. The maximum absolute value is 1. Conversely, the smaller
the absolute value of the power factor, the greater the proportion of reac-
tive power, which is not consumed, and the lower the efficiency. The mini-
mum absolute value is 0.
A positive value (LAG) indicates that the current phase is lagging the volt-
age. Inductive loads (such as motors) are characterized by lagging phase.
A negative value (LEAD) indicates that the current phase is leading the
voltage. Capacitive loads (such as capacitors) are characterized by lead-
ing phase. Sign is reversed harmonic phase angle, and the phase differ-
ence.
The power factor (PF) is calculated using rms values that include har-
monic components. Larger harmonic current components cause the
power factor to deteriorate. By contrast, since the displacement power fac-
tor (DPF) calculates the ratio of effective power to apparent power from
the fundamental voltage and fundamental current, no voltage or current
harmonic component is included. This is the same measurement method
used by reactive power meters installed at commercial-scale utility cus-
tomers' facilities.
Displacement power factor, or DPF, is typically used by the electric power
system, although power factor, or PF, is sometimes used to measure
equipment in order to evaluate efficiency.
When a lagging phase caused by a large inductive load such as a motor
results in a low displacement power factor, there are corrective measures
that can be taken to improve the power factor, for example by adding a
phase advance capacitor to the power system. Displacement power factor
(DPF) measurements can be taken under such circumstances to verify the
improvement made by the phase advance capacitor.
Power factor
demand value
The power factor calculated using the active power demand value (con-
sumption) and the reactive power demand value (lag) for the set interval
time (usually 30 minutes).
PF dem
=
(
P
dem
+
)
2
+(Qdem_LAG)
2
P dem+