Authors

Abstract

Recently, there has been great interest in the integration of distributed
generation units at the distribution level. This requires new analysis tools for
understanding system performance. Installing Distribution Generation (DG) in
the distribution level has positive impacts on the system voltage profile as well on
the substation’ s capacity. However the extent of such benefits depends greatly of
the DG size and location.
In this work, investigation of adding diesel units regarded as distributed
generators at the distribution voltage levels were done. These investigations dealt
with the impact of the units addition on the Iraqi grid power flow and short circuit
levels . This work is done by using PSS/E program (Power System Simulation for
Engineering), A sample from substations (with fuel and space availability ) of the
Baghdad area were considered for the diesel units addition, in order to find
recommendations for the voltage level to connect these units to it.
The extension in mind was to develop a quick rule of thumb in order to decide
where to add the DG units. This of course with no regard to the unit size as it is
limited by the Short Circuit Level (SCL) and economic considerations. IEEEstandard
systems were considered here with the development of Matlab routines
for the simulation and calculations required.
A novel quick criterion as where to add the distributed generation to minimize
loss was proved. This state’s “add the units at the lowest short circuit level bus,
i.e., at the bus of highest Thevenin impedance”.

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