What is power factor?

Power factor is the relationship between working (active) power and total power consumed (apparent power). Essentially, power factor is a measurement of how effectively electrical power is being used. The higher the power factor, the more effectively electrical power is being used. A distribution system's operating power is composed of two parts: Active (working) power and reactive (non-working magnetizing) power. The ACTIVE power performs the useful work - the REACTIVE power does not. It's only function is to develop magnetic fields required by inductive devices.

Why improve low power factor?

Low power factor means poor electrical efficiency. The lower the power factor, the higher the apparent power drawn from the distribution network.
When low power factor is not corrected, the utility must provide the nonworking reactive power in addition to the working active power. This results in the use of larger generators, transformers, bus bars, wires, and other distribution system devices that otherwise would not be necessary.
As the utility's capital expenditures and operating costs are going to be higher, they are going to pass these higher expenses to industrial users in the form of power factor penalties and higher utility bills.

 

 

ABB's Power Factor Correction Capacitors Solve the Problem

Solve low power factor problems by adding power factor correction capacitors to your electrical network. As illustrated below, power factor correction capacitors work as reactive current generators "providing" needed reactive power (kvar) to the power supply. By supplying their own source of reactive power, the industrial user frees the utility from having to supply it; therefore, the total amount of apparent power (kVA) supplied by the utility will be less. Power factor correction capacitors reduce the total current drawn from the distribution system and subsequently increase system capacity.

Who can benefit?

Many industrial and commercial applications can benefit from improving power factor levels. These include: manufacturers, hospitals, shopping malls, office building & institutions, pulp & paper mills, saw mills, textile mills, printing plants, Dlastic manufacturers. etc.

How much can be saved?

In the following example, if power factor correction is applied to the electrical network, increasing power factor to 90%, the potential annual savings on utility bills would be $4,322.23, or an average of $360 per month, a savings of up to 15%!

what is the role of reactive power in power generation?why we have maintain it.

 Electrical machines work on the principle of conversion of
electromagnetic energy.A part of input energy is consumed 
for creating and maintaining the magneticfield.This part of
the input energy cannot be converted into active energy and
is returned to the electrical network on removal of the
magnetic field. This power is known as “reactive” power Q.
The Q Power flows back and forth, causing 90º Out of phase
shift between the current and voltage waveform.This
Reactive Power has one half of the Power In the positive
area and the other half in the negative area.
Unlike true power, reactive power is not useful power
because it is stored in the circuit itself.
This power is stored by
1)Inductors,
Because they expand and collapse their magnetic
fields in an attempt to keep current constant,
2) Capacitors, Because they charge and discharge in an
attempt to keep voltage constant.