Print this page Power Factor in Electrical Energy Management
A. Bhatia, B.E.
Course Outline
Although terms
'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.
Learning Objective
At the conclusion of this course, the student will:
- Be able to understand the importance of power factor improvement;
- Be knowledgeable about the selection aspects of power factor capacitors; and
- Be able to
conceptualize, judge and select the right system.
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.
Course Content
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.
Course
Summary
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:
1) Survey
2) Plan
3) Correct and
4) Control
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.
Related Reading
Economic Evaluation
of Projects
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.
Quiz
Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.
DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDHonline.com or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered professional engineer. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.
