Scenario - Downtime & Product Quality issues
David is the engineer in
charge of stamping operations
at Peak Auto Plant #1.
Two weeks ago, the plant’s
electrical supervisor found
significant harmonics problems
within the plant.
And
last week, the amount of
downtime at the plant and
product-quality issues had
become so bad they had
come to the attention of
David’s boss.
Fuses and
breakers were blowing,
and machine controls were
giving false readings – far out
of normal ranges.
David
needed to understand the
plant’s harmonics problem
better so he could find a
way to fix the problems and
improve overall quality.
Identifying the Harmonic Distortion Problems
David contacted an engineering service
company to take a closer look at Peak Auto
Plant’s harmonics problems. The service
company’s power quality (PQ) energy
adviser began by reviewing the plant’s
electrical single-line drawings to identify:
- Variable-speed drives and switchgear
installed
- Electronically controlled equipment
present
- The level of harmonic content that
might exist.
The adviser told David that certain orders
of harmonics (harmonic distortion), created from non-linear loads,
can cause serious equipment and system
problems.
For example, adjustable-speed drives, UPS systems, motor
(soft) starters
and other electronically controlled
equipment such as CNC devices and
programmable logic controllers, are
sensitive to power amplifications – in
current, voltage and frequency – from
harmonics on the factory floor.
That’s why
tripping breakers and blown fuses, as well
as false controller data, had shut down part
of the stamping operation twice last week.
Unless the plant developed a plan to
manage their harmonic-rich power system to eliminate their harmonic
distortions, interruptions in production would continue, producing:
- More quality problems
- Higher
scrap rates
- Additional time and money
for restarts
- Shorter life spans for Peak’s electronically controlled equipment.
SOLUTION:
Installing an Active harmonic filter from Staco Energy
Products
COLLECTING THE DATA The energy adviser continued evaluating
Peak’s
harmonic distortion problems by installing temporary instrumentation
inside the plant. The data collected would be reviewed and used for
computer modeling and simulations if necessary, so that the best solution
could be designed.
Engineers often design power network models and run “what if” scenarios
to size a tuned system’s harmonic filter properly, and prevent negative
effects on the equipment at the plant. But, by using an active
harmonic filter, such modeling is not necessary, and generally extensive
on-site analysis and monitoring is not required, helping to save evaluation
costs.
The adviser determined that some
of the plant’s new stamping equipment was contributing to a high
concentration of harmonics – 50 percent – in the 480 VAC power
distribution system. A significant portion of the adverse harmonics
had to be removed so Peak could reach an acceptable level of harmonic
content as suggested by IEEE 519 guidelines.
HARMONIC FILTERING SOLUTION. The adviser recommended
an active harmonic filter from Staco
Energy Products. This solution would resolve Peak Auto Plant’s
particular problems with 5th, 7th, 11th and several higher order harmonic
orders. Active harmonic filters mitigate a broad range of multiple
harmonic orders – up to the 51st order.
Because this system would
be tailored for Peak’s individual requirements, it would be very
effective in removing the harmonic distortions from the plant’s
electrical system. Because power factor correction was
not required for the stamping operation, capacitors were not incorporated
into the solution.
RESULTS. Once
installed, the StacoSine active harmonic filter reduced the targeted
harmonics to acceptable levels. The solution gave David maximum uptime
and allowed him to meet the quality standards for finished products.
Staco Energy’s
active harmonic filter is a fast-response, power-electronics based
device that injects and cancels harmonic currents using IGBTs (Insulated
Gate Bipolar Transistors). The filter is sized for the corrected harmonic
current, and units can be added over time as the company expands.
Contact Us
Staco Energy has off-the-shelf and custom harmonic filtering solutions.
