IEEE Power & Energy Magazine - May/June 2014 - 49

The BPA has installed PMUs at 15 power plants that
account for approximately 70 generators, totaling more than
18,000 MW of generating capacity.

require generator retesting according to Wecc policy. but
the bPa engineers, using the cerTS-developed approach,
were able to calibrate the cgS model to match the actual
responses from several disturbance recordings without taking the generator off-line for retesting. The result is shown
in figure 5(b).

Benefits
as the examples above demonstrate, there are numerous
benefits associated with using PMUs to assist in power plant
model validation. Monitoring power plants using PMUs lets
operators determine whether the simulated response to an
unplanned system disturbance matches the actual response
data captured by the PMU. This knowledge can then be
applied in several ways. first, it can be used to continuously
improve the models of power plants using the calibration
methods described above. any improvement in a power
plant's model improves the overall simulation models of
the power grid and thus the overall reliability of the power
grid. in addition, this information can be used to identify
and troubleshoot malfunctioning equipment, as was demonstrated at grand coulee.
in certain cases, the Wecc will let a generator revalidate its power plant model using synchrophasor data, which
could defer the need for a staged test. for example, at the
hermiston power plant, a natural gas-fired combined-cycle
cogeneration facility in hermiston, Oregon, operated by
calpine corporation, system engineers demonstrated that
the PMU data matched the simulations of the response of
the plant to system disturbances. Since no major equipment
was upgraded, the Wecc deemed the plant's model accurate
and approved the revalidation without the need for staged
testing. according to alan roth, a senior electrical engineer
with calpine corporation, this allowed the validation tests
for both the generator governor and exciter models to be
deferred. This saved at least one full day of testing, allowing
the plant to continue operation without interruption, which
avoided the loss of revenue and costs associated with testing
the plant. even in situations where system tests are deemed
necessary, PMU data can help reduce the time the plant is
required to be off-line for revalidation. in addition to saving
money, this validation method does not require potentially
hazardous tests on generators that could damage older equipment, making it a safer, less invasive option.
The bPa's experience has been that model validation using disturbance recording is often a better, more
may/june 2014

cost-effective, and safer alternative to staged tests. Overall,
this power plant model validation method has the potential
to reduce outages, increase reliability, and save money.

Future Work
as PMU-based model validation capabilities continue to
improve, the bPa is sharing its success with industry. The bPa,
through the Wecc, has engaged other organizations in connection with the research, and many entities are now seeking to use
this technology to improve their power plant models. currently,
the bPa is in contact with Salt river Project, Southern california edison, and Pacific gas and electric, with the goal being to
expand the work across the Western interconnection.
in 2010, the bPa initiated an effort to expand PMU network coverage to wind power plants. The bPa has experienced a rapid growth of wind generation, from 250 MW in
2005 to 5,000 MW today. This growth has increased the
need to consider the effects of wind power plants on the
power grid. new PMUs will provide vital data needed for
wind power plant dynamic performance assessment and
model validation. The bPa is partnering with the electric
Power research institute, national renewable energy laboratory, and Utility variable generation integration group in
wind generation model validation efforts.
The american recovery and reinvestment act of 2009
funded nearly a dozen synchrophasor projects totaling over
US$200 million, including wide-scale deployment of PMUs.
for example, the DOe awarded the Wecc US$53.9 million
in funding for the Western interconnection Synchrophasor
Program (WiSP). (See http://www.smartgrid.gov/recovery_act/overview/smart_grid_investment_grant_program,
under electric Transmission, for other projects.) The funding
matches dollars committed by nine partners in the western
United States to extend and deploy synchrophasor technologies within their electrical systems. The bPa is the largest
contributor of these nine cost-sharing participants. The total
funding for WiSP is US$107.8 million. Ten additional participants are installing PMUs and system infrastructure outside
of the DOe grant funding to help achieve full observability
of the Western interconnection. One of WiSP's deliverables
is to use synchrophasor data to improve and verify the accuracy of generator models. These projects, when completed,
will supplement and reinforce the achievements and value of
the work done by the bPa and the DOe.
as the project continues to succeed and scale up, new
technical challenges have emerged for the DOe-cerTS
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Table of Contents for the Digital Edition of IEEE Power & Energy Magazine - May/June 2014