Power Factor Control

Send me a mail thro this forum's mail box informing your mail ID so that I can send you a detailed write-up on Power Factor.

There are many information available in internet for the power factor. If you search, you will find them. Here are few sites that may help:

http://www.lmphotonics.com/pwrfact.htm

http://www.st.com/stonline/books/pdf/docs/4042.pdf

http://www.allaboutcircuits.com/pdf/AC.pdf (see Chapter 11, Page 347)

http://www.youtube.com/watch?v=7S22cJ_aF9M (Video lecture)

- MS

Power factor is angle between voltage and current wave.power factor is a result of load.In inductive loads current wave lags voltage wave ,where in capacitive loads it is reverse

Many before me have given you links to get educated on what is powerfactor and how it impacts the source feeding the load.

Since you have mentioned that you are from telecom company - I just wanted to emphasis further that - in Telecom the exchange equipments and also transceiver (on Mobile towers) etc all operate on DC input voltages. This is derived from mains supply which is 240 V AC single or three phase depending on total power required. BSNL - oldest telecom company has many exchanges installed for many decades. About 10 to 15 years back - no one had bothered about bad power factor and harmonics. But now it has gained importance (for many reasons - which cannot easily explained in this thread). So all old battery chargers are being replaced with high power factor, low harmonic power supplies. and new ones are necessarily have to be fitted with such high PF supplies. Hence you need to know now more about high PF, low total harmonic distortion (thd) etc.

Hi what do you mean by power factor?

Do you mean reducing your power usage?

Dear guest,

In electrical engineering point of view power factor is ratio of useful power(KW) to power drawn from source(KVA). ie P.F=kw/Kva.Theoretically one will say that all power drawn from net work shall be used as useful power(KW).

However due to inductive type of majority type of electrical loads, reactive power(KVAR) is also drawn from network

.This reactive power (KVAR) does not contribute to useful power.Hence full power drawn from network (KVA) is not converted to useful power(KW).

Hence Power factor can be considered as efficiency of power utilisation.Higher power factor means higher usefulpower-Kw supplied and less reactive power consumed.

Lower Pf means lower useful power -kw supplied and large reactive power consumed.

The theoretical pf is 1.0 ie all power drawn (KVA) is converted to Full Kw.IE 100% EFFICIENCY

In practical case the pf is always less than 1.0 due to reasons stated above.

Trust this clarifies your question

Regards

Hi Guest, this is electrical engineering section. You are wrong person at wrong place.

Power Fator

AC power flow is consists of the three components: Real power (Active power) (P), measured in watts (W); Apparent power (S), measured in volt-amperes (VA); and Reactive power (Q), measured in reactive volt-amperes (VAr).

The Active Power is the power that performs useful work while the Reactive Power is the power that magnetic equipment need to produce magnetic flux, eg. Induction motors.

Together, the two form what is called Apparent Power (MVA).

The ratio of the Real Power flowing to the load to the Apparent Power is what is termed as Power Factor. You should note that its a dimensionless quantity ranging between zero and one.

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. This high current increases the energy lost in the distribution system resulting in wasted energy and potentially higher costs to consumer where there is a low power factor.

Impact

Customers/users can experience a number of negative effects as a result of a low power factor. These include:

1. Increased load to generators, transformers and conductors

2. Increased investments required (Generation, Transmission and Distribution) on the side of the supplier.

3. Increased system losses

4. Reduced system efficiency

5. Reduced system capacity.

Control

Consumers of reactive power can increase their power factor in several ways:

1. Installing capacitor banks which decrease the magnitude of reactive power thereby increasing the power factor.

2. Minimizing the operation of idling or lightly loaded motors

3. Avoiding the operation of equipment above their rated voltage

4. Replacing standard motors as they burn out with more energy efficient motors.

thank u .....very useful knowledge to share