In these presentation ,we have discussed about power factor, disadvantages of low power factor and how to improve it. Also, capacitor bank and how to install capacitor bank are discussed.

1. Capacitor Bank
and
Improvement
of power factor

2. Instructor
Rethwan Faiz
Assistant Professor
AIUB

3. Hello! Every One
American International University-
Bangladesh (AIUB)
Group Members-
1.Shahriar Niloy. 14-26876-2
2.Kabir,Md.Ahshan 14-26903-2
3.Nurnobe ,Md. 14-26845-2
4.Hossain,Mohammad Ismail 14-27342-2
5.Shahabuddin,khan Istiak 13-24372-2

4. Contents:
•Capacitor Bank
•Power factor
•Causes of low power factor
•Disadvantages of low power factor
•The Need for Power factor correction
•Methods for improving Pf
•Advantages of power factor correction
•How capacitor Bank install in the plant
•Reference

5. What is Capacitor Bank?
A capacitor bank is a group of several capacitors
of the same rating that are connected in series or
parallel with each other to store electrical energy .
The resulting bank is then used to counteract or
correct a power factor lag or phase shift in an
alternating current (AC) power supply.

6. What is the reason for using it?
Capacitor banks are generally used in
substations. Since most of the household
and industrial appliances are either
resistive(eg. incandescent light, heater,
etc.) or inductive(e.g. refrigerator, air-
conditioner, motor, etc). The capacitive
load of the capacitor bank will help to
adjust the power factor as close to 1 as
possible, in which case the voltage and
current are in phase and deliver maximum
usable power to the load.

7. Power Factor:
 The power factor is the ratio of the real
power that is used to do work and the apparent
power that is supplied to the circuit.
 The power factor can get values in the range
from 0 to 1.
 When all the power is reactive power with no real
power (usually inductive load) - the power factor
is 0.
 When all the power is real power with no reactive
power (resistive load) - the power factor is 1.

8. The power factor can be expressed in
two ways:
■Power factor (pf) = Useful power (kW)
divided by the total power (kVA),or
■Power factor (pf) = The cosine of the
angle between useful power and total
power= cos ø.

9. Cause of low power factor:
Low power factor results when KW is small
in relation to KVA.
What causes a large KVAR in a system?
Inductive Loads
•Transformer
•Induction motors
•Induction generators (Wind mill
generators)
•High intensity discharge (HID) lighting

10. Disadvantages of low power factor:
•The increase in reactive power increases
the current flowing through the network
•Large copper losses
•Large KVA rating and size of electrical
equipment
•Greater conductor size and cost
•Poor voltage regulation and large voltage
drop
•Low efficiency
•Reduced handling capacity of the system

11. What can I do to improve power factor?
You can improve power factor by adding power factor
correction capacitors to your plant distribution system.

12. 95% power factor provides maximum benefit
Theoretically, capacitors could provide 100% of needed reactive
power. In practical usage, however, power factor correction to
approximately 95% provides maximum benefit.
Other methods of improving PF :
Synchronous Condenser
Phase Advancer

13. ■To reduce losses in the distribution system
■Reduction of electricity bills
■Extra kVA available from the existing supply
■Reduction of I2R losses in transformers and
distribution equipment
■Reduction of voltage drop in long cables.
■Extended equipment life – Reduced
electrical burden on cables
■and electrical components.
How much can I save by installing
power capacitors?

14. Where should I install capacitors in my plant
distribution system?
At Load-
Because capacitors act as kVAR generators, the most efficient
place
to install them is directly at the motor, where kVAR is consumed.
Three options exist for installing capacitors at the motor.

15. Want big impact?
Use big image.

16. At the service feeder-
When correcting entire plant loads, capacitor banks can be
installed
at the service entrance, if load conditions and transformer size
permit. If the amount of correction is too large, some capacitors
can
be installed at individual motors or branch circuits.
When capacitors are connected to the bus, feeder, motor control
center, or switchboard, a disconnect and overcurrent protection
must be provided.

17. References-
i. https://en.wikipedia.org/wiki/Traffic_light
ii. http://circuitdigest.com/electronic-circuits/four-
way-traffic-light-circuit
iii. https://www.youtube.com/watch?v=_XtsEVTro
gc&feature=youtu.be
iv. http://www.powershow.com/view/1f2279-
MTA5Y/Traffic_Signs_powerpoint_ppt_presentati
on

19. What about maintenance?
Capacitors have no moving parts to wear out and
require very little maintenance.Check fuses on a
regular basis. If high voltages,harmonics,switching
surges, or vibration exists, fuses should be checked
more frequently.

20. References-
i. International Journal of Emerging Technology
and Advanced Engineering Website:
www.ijetae.com (ISSN 2250-2459, ISO
9001:2008 Certified Journal, Volume 4, Issue
8, August 2014)
ii. http://www.eaton.com/electrical.
iii. http://www.electrical4u.com/capacitor-bank-
reactive-power-compensation/