It is the cosine of the phase angle between the applied voltage and resulting current of the circuit

1. Power Factor
and its
Importance
• Introduction ( KW, KVAR, KVA)
• Definition – Power factor
• Power factor correction
• Importance of Power factor

2. Introduction ( KW, KVAR, KVA)
 To understand power factor, we’ll first start with
the definition of some basic terms:
 KW is Working Power (also called Actual Power or
Active Power or Real Power). It is the power that
actually powers the equipment and performs
useful work.
 KVAR is Reactive Power. It is the power that
magnetic equipment (transformer, motor and
relay) needs to produce the magnetizing flux.
 KVA is Apparent Power. It is the “vectorial
summation” of KVAR and KW.

3. Definition - 1
 It is the cosine of the
phase angle
between the applied
voltage and resulting
current of the circuit

4. Definition - 2
 It is defined as the ratio of
resistance of the circuit to
the impedance of the circuit.
 For a purely resistive AC
circuit, R=Z and the power
factor = 1.

5. Definition – 3
 Power Factor (P.F.) is
the ratio of Active
Power to Apparent
Power.
 P.F. = KW / KVA
 P.F. = KW / KW +
KVAR

6. What Causes Low 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.
 What causes a large KVAR in a system? The answer is…inductive loads.
 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 your distribution system.
 This increase in reactive and apparent power results in a larger angle θ
(measured between KW and KVA). As θ increases, cosine θ (or power factor)
decreases.

7. Why Should I Improve My Power
Factor?
 Some of the benefits of improving our power
factor include:
1. Lower utility fees
2. Increased system capacity and reduced
system losses in your electrical system
3. Increased voltage level in your electrical
system and cooler, more efficient motors

8. Power Factor Correction (1)
 We have seen that sources of Reactive Power
(inductive loads) decrease power factor.
 Similarly, consumers of Reactive Power increase
power factor.
 Thus, it comes as no surprise that one way to
increase power factor is to add capacitors to the
system. This--and other ways of increasing power
factor--are listed in the next slides:

9. Power Factor Correction (2)
1. Installing capacitors (KVAR Generators)
 Installing capacitors decreases the magnitude of
reactive power (KVAR or foam), thus increasing your
power factor. Here is how it works (Figure 5)…
Reactive power (KVARS), caused by inductive loads,
always acts at a 90-degree angle to working power
(KW).
 Inductance and capacitance react 180 degrees to
each other. Capacitors store KVARS and release
energy opposing the reactive energy caused by the
inductor.
 The presence of both a capacitor and inductor in the
same circuit results in the continuous alternating
transfer of energy between the two.
 Thus, when the circuit is balanced, all the energy
released by the inductor is absorbed by the capacitor.

10. Power Factor Correction (3)
2. Minimizing operation of idling or lightly loaded motors.
 We already talked about the fact that low power factor is caused
by the presence of induction motors. But, more specifically, low
power factor is caused by running induction motors lightly
loaded.
3. Avoiding operation of equipment above its rated voltage.
4. Replacing standard motors as they burn out with energy-
efficient motors.
 Even with energy-efficient motors, power factor is significantly
affected by variations in load. A motor must be operated near its
rated load in order to realize the benefits of a high power factor
design.

11. Importance of Power Factor
 A power factor of one or "unity power factor" is the
goal of any electric utility company since if the
power factor is less than one, they have to supply
more current to the user for a given amount of
power use. In so doing, they incur more line
losses.
 They also must have larger capacity equipment in
place than would be otherwise necessary.
 As a result, an industrial facility will be charged a
penalty if its power factor is much different from 1.

12. Importance of Power Factor
 Industrial facilities tend to have a "lagging power
factor", where the current lags the voltage (like
an inductor). This is primarily the result of having a
lot of electric induction motors - the windings of
motors act as inductors as seen by the power
supply.
 Capacitors have the opposite effect and can
compensate for the inductive motor windings.
Some industrial sites will have large banks of
capacitors strictly for the purpose of correcting the
power factor back toward one to save on utility
company charges.

13. Prepared by :-
 Name – Priyansh J. Thakar
 ID. No. – 16BECEG082
 Branch – Computer
 Batch – CE2 : A