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DISTRIBUTED GENERATION ISSUES
•Technical Issues
•Non-Technical Issues
Technical Issues
•DG Size
•The greater the DG size, the higher the
fault duty capacity
•Location and type of fault
•Contribution of DG to fault on the feeder
reduces expected current for substation
relays. They must be able to see faults at
the end of the circuit.
Technical Issues (continued)
•Configuration of interconnection
transformer
•Ungrounded windings greatly affect relay
performance during grounded faults
•If primary winding is delta and a phaseto-ground fault occurs on the grid, the
current relays of the DG will not be as
sensitive to it. DG voltage relays on the
primary side must see rise in voltage.
Technical Issues (continued)
•Lowest expected feeder load compared
to maximum generator output
•DG is preferred not to back feed
substation bus under minimal circuit
loading
•At all times of year, power must not be
pushed back to substation transformer
(generator could feed transmission fault)
Technical Issues (continued)
•Voltage issues near DG site
•Voltage on feeder must not be outside of
allowable range due to presence of DG
•Undesired voltage regulation on circuit
must not result during low circuit loading
Non-Technical Issues
•Customer’s system configuration and
operation with DG
•Understanding prints and scheme
involved
•Need generator data to model DG
•Increasing volume of DG applications