Abstract:
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The connection of Distributed Generation (DG) units
to existing networks may give rise to harmful effects on the
network and the DG units itself. Therefore, due to increasing
penetration of DG units, it is important to consider these effects
in order to avoid some of harmful events. Ferroresonance is one
of these destructive phenomena. Over voltages due to this
phenomena can damage devices which are connected to the
network. In DG systems, due to the use of capacitor banks which
are used for VAR compensation, grid connection filters, etc.
ferroresonance may appear. Also, special operations like
islanding, may lead these systems to ferroresonance. In
traditional systems ferroresonance normally appear after there is
an unbalance in the system. Nevertheless, for networks with
significant penetration of DG units, the situation that gives rise to
ferroresonance may be different from traditional systems and
they can happen without any unbalancing occurrence. In this
paper a distribution system integrating wind (WT) and
photovoltaic (PV) power systems has been evaluated in order to
analyze the performance of ferroresonance in such systems.
Finally, the most appropriate techniques to prevent its
appearance, and the associated over voltages, have been studied
and implemented using PSCAD/EMTDC. |