How to improve energy efficiency in motor applications?
In buildings
In industrial processes
Or for machine applications?
Electric motors are among
the major electrical energy consumers
in today’s world,
with more than 90% share
for electro-intensive industries.
Motor cost and maintenance is only 5%
of its total cost of ownership.
The major part is the electrical energy consumption.
With such a predominance of energy consumption,
energy losses have a substantial economic impact!
Improving motor efficiency is the first step
towards energy saving.
Especially for low power motors,
the vast majority in number and consumption.
Consecutively,
motor related standards have continuously
pushed for higher efficiency.
But do not think about efficiency of the motor only.
Because in some cases,
higher motor efficiency class may not be
the single answer to energy saving during operation.
Better think about the efficiency of the entire motor application,
considering the electric motor
and the driven equipment in its regular operation.
For motor applications that move fluids
and need flow reduction below the rated flow level,
such as fans and centrifugal pumps,
you can go much further in energy saving
and save up to 30% energy consumption.
Maximize your energy saving
with Motor application efficiency,
not only motor efficiency.
Now, let’s check it out!
Let’s start by comparing the methods.
Flow variation can be achieved with two different methods:
The first method, presented on the left,
is to use a flow control system
and keep the motor running at rated speed.
In this case,
losses will increase with the amplitude
of the flow variation.
The second method,
presented on the right,
is to use variable speed drive
to vary the speed of the motor and therefore, the flow.
The energy efficiency
is optimum with minimum losses.
With variable speed,
energy approximates an optimum consumption,
proportional to the flow.
On the contrary,
at constant speed, the motor application
overconsumes energy at lower flow.
Energy consumption depends on both
the flow and the flow variation method.
To detect potential energy saving
and justify a closer look, remember:
The higher the flow variation is,
the higher the benefit of variable speed will be.
Let’s have a look on the main data
to consider in a comparison.
Electro-mechanical characteristics of the motor
and the application are the basics.
They will determine the magnitude
of energy consumption and set the potential
for efficiency improvement.
Process characteristics are required to account
for typical working conditions over the year.
This will create the reference for the comparison.
Investment and operation costs allow to go from
the energy domain to the economic domain.
Environmental and pollution information
will support the sustainability approach.
Finally,
come the comparison and the decision-making.
The indicators that support your decision-making are:
The saving per year,
which can be expressed in energy and financial values.
The payback period,
that justifies the variable speed drive investment.
And the corresponding pollution reduction.
As you have seen,
energy saving needs a close look and specific analysis.
This is where
EcoStructure Motor Management Design Web-App
can be your best support.
It is simple to use.
It has a dedicated function for energy saving.
Data filling is easy
with synthetic motor application characteristics.
It is fast.
It supports your decision-making, displaying the main indicators:
The energy and cost saved per year,
The payback period,
And the corresponding pollution.
You can back-up and distribute your analysis
with an automatic and detailed report.
Let’s keep in mind:
When dealing with energy saving,
consider the motor application efficiency.
Do not limit it to motor efficiency only.
With centrifugal type applications,
the higher the flow variation is,
the higher the benefit of a variable speed drive will be.
By using EcoStructure Motor Management Design Web-App,
you can drive a complete energy analysis, in no-time.
To continue on this subject,
start experimenting with EcoStructure Motor Management Design Web-App
or discover Schneider Electric motor management
through the dedicated web pages.