6
2.2 Effectiveness of Energy Saving Device ESD
The effectiveness of the ESD is related to how this device can improve power factor and stabilize the input power on different load usage. The relationship of power
factor and how it can be corrected and the assessment method for power factor correction will describes in the following sections.
2.2.1 Power Factor
In an electric power system, a load with low power factor draws more current than a load with a high power factor, for the same amount of useful power transferred. Linear
loads with low power factor can be corrected with a passive network of capacitors or inductors. Power factor
P F
is the ratio between real power
P
and apparent power
S
[12]. Power factor is a power in an alternating current
AC
electrical circuit of the electrical appliances. By measure the power factor, the efficiency of electrical power can
be known [7].
2.1 Therefore,
2.2 and
2.3
where,
V
is voltage volts,
I
is current amperes and is angle between apparent power
and real power. The real power
P
with the unit in kilowatts kW is electrical energy that consumed and not stored in a magnetic field. Meanwhile, the apparent power
S
with the unit is kilowatt amperes kVA which is the total of reactive power and real power [12].
There are disadvantages when a house or company have low power factor. The low power factor may make the current have same value of active power, then the power usage
increases. The higher current causes power loss and reduced the life of the insulation [5]. Other than that, low power factor can reduce the effective capacity of the electrical supply
7 and make the electricity costs consumption becomes expensive [7]. Besides the
disadvantages, there are advantages of power factor when it became higher, the advantages described in the following section.
By improving the power factor, the user can get advantages of it. The advantages of higher power factor are improving voltage level, reduced line losses; reduce electrical
system capacity [5]. In addition, the effective capacity will increase due to higher power factor [7]
The power factor can be corrected or improved by adding the capacitive or inductive loads. In other words, power factor can be corrected by adding the capacitor and
inductor [10], it is called as power factor correction and have been describes in the following section.
2.2.2 Power Factor Correction
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