POWER April 2016 - 52

OPERATIONS & MAINTENANCE
7. Fine tuning. Getting a Francis runner ready for installation requires a lot of skill and attention
to detail. Voith has been doing that type of work for a long time. Courtesy: Voith Hydro
practice, using exercises, case studies, simulations,
and visits to factories and laboratories.
The company also stresses the importance
of reading the operations and maintenance
manuals and following the original equipment
manufacturer's recommendations.
Changing with the Times
Orwick said that modernization programs
could be driven by a wide variety of factors,
including relicensing requirements, changes
in plant usage, environmental mitigation efforts,
a desire to increase capacity, and reliability
or availability concerns. While each
owner has its own threshold for pursuing
upgrades, he said most are driven by costto-benefit
ratios, that is, either reducing the
cost of operation or increasing the benefits of
generation.
" We have historically found that the allRoberts
added that, although mechanical
governors can provide excellent frequency
control when properly maintained, in many
cases the importance of the governor isn't
well understood by the utilities themselves.
Without adequate training for plant staff,
maintenance will suffer, eventually resulting
in governor problems, such as difficulty synchronizing,
hunting, and excessive governor
oil pump runtime.
" One of the leading reasons we see companies
upgrade to digital governors is simply
a lack of in-house understanding of how to
support their original equipment, " Roberts
said.
However, mechanics can be taught how to
perform all types of governor maintenance
tasks, including major overhauls. American
Governor offers such training at its facility
in Amherst, Wis. Governor schools and focus
classes include a combination of classroom
and hands-on sessions (Figure 5) to give
technicians the knowledge and skills that
they need. American Governor also offers
onsite training, covering plant-specific governor
equipment.
Roberts suggested that all plants should
have a governor training strategy and a
preventive maintenance plan. With proper
training, in-house staff can usually complete
routine maintenance jobs without any
trouble.
Big Jobs Could Require Help
When it comes time for major work, such
as a five-year overhaul, some facilities have
the staff to do the job, but others may want
to hire a contractor. For example, American
52
Governor has teams that do less-routine
work regularly. For them, showing up onsite
with a full parts kit, doing a top-to-bottom
governor disassembly and inspection, replacing
worn components along the way,
and recalibrating the reassembled governor
is just another day on the job. That is most
likely not the case for in-house workers,
who might only do such work a few times
during their entire career.
Frequent technology changes and the loss
of know-how-as experienced engineers
and technicians reach retirement age-also
calls for action. Rodney Orwick, president of
Voith Hydro's HyService division, suggested
that the loss of experienced employees is one
of the biggest challenges facing owners. He
said that many times when the Voith HyService
team is called to disassemble a unit,
plant personnel tell them that no one working
at the facility has ever seen the machine
disassembled (Figure 6). Frequently, the staff
doesn't know the process, and often they
don't know where the original equipment
handling fixtures are located, or if they even
exist.
Voith claims to have installed a quarter of
the world's 40,000 hydropower units (Figure
7), which it feels is a big advantage. The
company says that having the experience-
and the original drawings-gives it a leg up
on the competition. But if a company wants
to go it alone, Voith can help them prepare.
Voith offers training programs tailored to
fit customer needs too. The company has expert
instructors with solid experience that are
available worldwide. Orwick said the company's
methodology alternates theory and
www.powermag.com
in costs and payback periods of hydro modernization
and life extension are quite often
competitive with other options for owners to
add capacity/energy, such as gas-fired generation, "
Orwick said.
Both Orwick and Roberts pointed to
functionality as another driving factor for
upgrades. Roberts said there are just certain
things that are quite a bit harder to do with
a mechanical governor than with a digital
system.
" Mechanical governors can't really be reprogrammed, "
Roberts said. " With a digital
governor, it's a blank slate. You can do anything.
You can have remote operation. You
can have diagnostics. You can send alarms
back and say 'this specific thing failed.' You
can change the operation. "
And while Roberts admitted that obsolescence
used to be a significant problem for
digital governors, he said that is not really
the case anymore.
" One of the biggest advances in governor
technology over the last 10 to 20 years has
not been in functionality but in the type of
equipment that's been used, " said Roberts.
In the old " black box " days of digital
governors, if a chip failed, the entire system
might have required replacement. But now,
American Governor uses all off-the-shelf,
nonproprietary components in its digital systems.
If something fails, any local industrial
electrical supplier is likely to carry the replacement
part that is needed.
" You're seeing equipment lifecycles of
30 to 40 years already, with commitments
from the manufacturers to support them for
another 20 years, " Roberts said. " So you're
starting to see obsolescence periods that are
getting closer to what the mechanical governors
were. " ■
-Aaron Larson is a POWER associate
editor.
POWER | April 2016

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POWER April 2016

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