Martina Schäfer, Noara Kebir, Daniel Philipp (editors) - TU Berlin

PROCEEDINGS Conference MPDES 2011
Study Case and Simulation Results
The New England 9-Bus IEEE Network is shown in
figure 3. We overload this network with a 24 MW load in
second 5 of the time simulation and can see its impact on
the network frequency in figure 4. The frequency value
decreases to 49.78 Hz, then the power plant governor
systems act automatically to bring back the frequency
value to its nominal value, but finally the frequency
receives 49.94 Hz because of the governor’s droop
adjustment, and remains in this value which is in the
defined limit.
The frequency behavior of the system can be seen in
figure 5, where the secondary frequency control system
comes 100 seconds after the simulation begins, in action.
As can be seen, while using the AGC system as a
secondary frequency control, the frequency value
increases up to 49.96 Hz and is still less than the nominal
value. The influence of applying the ADC system in
addition to the AGC system at the same time (100 seconds
after the simulation run) and controlling the participating
removable loads on the market is observable in figure 6.
In the end this hybrid method is able to bring back the
frequency value to its nominal value. The simulation
results in this paper show that the ADC system is capable
of complete secondary frequency control in power
systems next to the AGC system with minimal costs due
to Smart Grid capabilities.
Conclusion
Through a Smart Grid, regional electric power companies
are able to identify the consumption of their costumers
and consumers at any time, enabling optimal generation
Figure 3: New England 9-Bus IEEE Network
and distribution, and employment of available resources
and increased efficiency.
The proposed system in this paper (ADC) uses Smart
Grid capabilities along with the AGC system to increase
the power capacity of the secondary frequency control
system. It also has an important influence on providing
more competitive electricity market for frequency control
and decreasing its relative costs. In addition it reduces the
system reserves while maintaining system reliability and
security. Furthermore, this method leads to reduced
pollution while removing loads instead of increasing
power generation for the secondary frequency control.
On the other hand it is clear that the operation, optimal
control and stability maintenance of a Micro Grid requires
more reserve capacities comparing the power network due
to their limited production capacity. Definitely would
these reserves be very expensive and also would cause
pollution and greenhouse gas emissions. Thus the system
presented in this paper (ADC) could be particularly useful
and efficient in raising the reliability of the operation of
Micro Grids. Moreover it's easily operable using Smart
Grid capabilities without incurring additional cost.
Therefore, the application of this new approach to
secondary frequency control is highly recommended.
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