Power Factor in Electrical Energy Management
A. Bhatia, B.E.
'power factor measurement' and 'power factor correction' are well known to electrical
engineers, the real importance of 'power factor' is not always recognized -particularly
in terms of reducing electrical energy cost.
This 4-hour course looks briefly at what is a very large subject and highlights a systematic approach to the measurement, correction and control of power factor with the objective of cutting energy costs.
This course is
aimed at students, electrical & control engineers, energy auditors, operational
& maintenance engineers, contractors and system designers who are responsible
for design and operation of the system.
This course includes
a multiple-choice quiz at the end, which is designed to enhance the understanding
of the course materials.
At the conclusion of this course, the student will:
Power factor is
little understood, but is a very important characteristic of an alternating
current system. Power factor is the percentage of electricity that is being
used to do useful work. It is expressed as a ratio. For example, a power factor
of 0.72 would mean only 72% of your power was being used to do useful work.
Perfect power factor is 1.0, (unity); meaning 100% of the power is being used
for useful work. Power factor correction, then, is the method(s) used to fix
the problems that cause power to be wasted. Energy is saved, and penalties levied
by power companies are reduced or eliminated.
With increasing electrical charges, and the need to save energy it is paramount importance to both industrial and commercial users of electricity to ensure that their installations operate at maximum efficiency. To achieve this it is essential to have a high power factor throughout the system.
The the course content is in a PDF file Power Factor in Electrical Energy Management. You need to open or download this document to study this course.
This course has
attempted to indicate just how power factor can have a significant financial
influence on the running of your facility and also upon its overall efficiency.
Without the correct 'Power factor Correction' costly energy is wasted and has the greatest effect on those who use most energy and an adverse effect on our environment.
To overcome this problem, and at the same time ensure that the electrical system is not overloaded with wattles current (as this excess current is termed), power factor correction is applied to circuits which include induction motors as a means of reducing the inductive component of the current and thereby reduce the losses in the supply. The utility companies often provide incentives or reduce terms to consumers whose power factor is high and impose penalties for those with low power factor. Utility deregulation is changing metering techniques, which now measures KVAR instead of watts. The new meters are more accurately measuring true power factor and penalties are being assessed for insufficient levels. The cost of poor power quality may be much greater than simply the penalties involved.
In the past it has been generally assumed that only utility company derived benefits from power factor correction. In today's high cost energy market, the user receives benefits in form of increase system capacity, reduced distribution losses, gain in voltage, improved efficiency and high productivity.
It is absolutely essential for industries and commercial establishments to adopt a systematic approach to power factor measurement, correction and control consisting of 4 elements:
3) Correct and
Using a portable digital power factor meter, it is comparatively easy to carry out a power factor survey of any industrial plant. Using the data obtained from this survey, a comprehensive power factor correction plan can be worked out. Based on this plan, automatic power factor correction and control equipment like PLC based auto power factor regulator can be installed. With the cost of energy rising at a fairly alarming rate power factor is not something, which can be dismissed lightly.
The addition of power factor correction equipment is a simple, durable and cost effective method of for reducing wasted resources. It is common to recover the initial cost of equipment and installation within two years.
The power factor correction devices such as capacitors are the additional investment required to derive benefits for maximizing efficiency of the electrical network, increase productivity and eliminating penalties. Although the cost of power factor correction is not significant, engineers might need to perform cost-benefit analysis to check the payback period before taking an appropriate decision. A 2-hour generic reading titled "Six Ways to Perform Economic Evaluation of Projects" is a recommended reading.
Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.