Abstract
The growth in distributed energy resources has the
potential to reduce system stresses caused by transmission grid
congestion by supplying power and voltage regulation closer to
load centers. However, the additional voltage regulation provided
by these resources can mask the onset of voltage collapse. Local
voltage support flattens the slope in the upper region of the
power-voltage nose curve. Coordinating voltage-regulation
behavior with the droop-control scheme in distributed resources
improves the observation of voltage collapse margins.
Incorporating distributed resource models in the continuation
power flow analysis, allows the exploration of the power transfer
gains by the application of distributed resources. The analysis
provides insight to the impact of droop control on the behavior of
the power-voltage curve and voltage collapse. The analysis is
applied to a fixed speed induction generator wind farm with
separate reactive compensation and the interconnection to the
local power system. Results reveal that coordinating the droop
control strategy allows the distributed resource to significantly
increase the voltage collapse margin without hiding the threat of
voltage stability problems.
