### IMPORTANCE OF POWER FACTOR IN AN ELECTRICAL SYSYTEM

To know the importance of power
factor in an electrical system, first of all we should have the knowledge of
some basic terms which are used in an electrical system i.e actual power,
reactive power etc.. In an electrical system the power flow has two components,
one flow from source to load and able to perform the work at load known as KW
or actual power, and the other one is the reactive power which cannot perform
any work and it is generated due to the delay between voltage and current known
as phase angle. There are one another term is apparent power which are the sum
of actual power & reactive power, It is denoted as KVAR. So that we can say
that

Apparent Power = Actual Power +
Reactive Power

Total KVA = KW + KVAR

Power factor = KW / KVA = KW /
(KW+KVAR)

In an ideal system KVAR would be very small and
KW and KVA would be almost equal, so we are trying to design an electrical
system with power factor 1 than only we are able to get the maximum output from
a system. This phenomenon can also be shown as power triangle as below:

Where Cos Ɵ is
power factor angle i.e. Cos Ɵ = KW/KVA

**Reasons of Lower Power Factor:**

Since
power factor is defined as the ratio of KW to KVA, we see that low power factor
results when KW is small in relation to KVA. Now the question arises what
causes a large KVAR in a system? The answer is…inductive loads.

Inductive
loads (which are sources of Reactive Power) include:

Transformers

Induction motors

Induction generators (wind mill generators)

High intensity discharge (HID) lighting

These
inductive loads constitute a major portion of the power consumed in industrial
complexes. Reactive power (KVAR) required by inductive loads increases the
amount of apparent power (KVA) in our distribution system. This increase in
reactive and apparent power results in a larger angle θ (measured between KW
and KVA). Recall that, as θ increases, cosine θ (or power factor) decreases. So,
inductive loads (with large KVAR) result in low power factor.

So
there are several reasons due to which, we have to improve our system power
factor, some of the benefits are as below:

**1) Lower Utility Charges**

**:**

**a. Reducing Peak KW billing demand**

Inductive
loads require reactive power, which caused low power factor. This increase in
required reactive power (KVAR) causes an increase in required apparent power
(KVA), which is what the utility is supplying. So, a facility’s low power
factor causes the utility to have to increase its generation and transmission
capacity in order to handle this extra demand. By raising power factor, we use
less KVAR. This results in less KW, which will help in savings of the utility.

**b. Eliminating the power factor penalty**

Utilities
usually charge customers an additional fee when their power factor is less. Thus,
we can avoid this additional fee by increasing our power factor. Now a day’s
utilities start the billing in KVAH instead of KWH, this is another reason due
to which controlling of power factor is essential.

**2) Increased System Capacity and Reduced System Losses in our Electrical System**

By
adding capacitors (KVAR generators) to the system, the power factor is improved
and the KW capacity of the system is increased.

For
example, a 1,000 KVA transformer with an 80% power factor provides 800 KW (600
KVAR) of power to the main bus.

1000
KVA = (800 KW)2 + ( ? KVAR)2

KVAR
= 600

By
increasing the power factor to 90%, more KW can be supplied for the same amount
of KVA.

1000
KVA = (900 KW)2 + ( ? KVAR)2

KVAR
= 436

The
KW capacity of the system increases to 900 KW and the utility supplies only 436
KVAR. Uncorrected power factor causes power system losses in our distribution
system. By improving our power factor, these losses can be reduced. With the
current rise in the cost of energy, increased efficiency is very desirable, and
with lower system losses, we are also able to add additional load to your system.

In case any enquiry feel free to contact us at: info@saielectricals.com

In case any enquiry feel free to contact us at: info@saielectricals.com

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