20-10-2010, 04:50 PM
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Voltage Sags and the Response of a Synchronous
Distributed Generator: A Case Study
Edward R. (Randy) Collins, Senior Member, IEEE, and Jian Jiang, Student Member, IEEE
Abstract—
The dynamic behavior of a synchronous distributed
generator connected to a distribution system during fault conditions
is studied. A fault on an actual system was found to have
a sag that was extended after the fault was cleared. It is shown
that the combination of the generator and the load on the system
contributes to the extended sag. The detailed simulation studies
demonstrate that the primary factors are the reactive power drawn
by the load during the fault and recovery along with the reaction
of the generator. The prediction of such behavior requires proper
modeling of the generator, the generator’s controls, and the system
and dynamic load. Operators of such generators need to be aware
of this type of system and load response when synchronous DG is
connected to a distribution network.
Index Terms—Distributed generation (DG), distribution systems,
excitation controls, fault analysis, power quality (PQ),
voltage regulator, voltage sags.
