Impact of Distributed Generation on the IEEE 34 Node Radial Test Feeder with Overcurrent Protection

The use of distributed generation (DG) in power systems has many possible benefits, but also presents many challenges. Notable among these challenges is the effect DG can have on overcurrent protection. This paper contains results pertinent to the addition of DG to the IEEE 34 node test feeder. After an overcurrent protection scheme was implemented for the benchmark system, DG of various sizes was added at specific locations. The impact of these generators was evaluated in terms of steady state normal and short circuit currents as well as protection coordination. In the studies performed so far, generally DG did not adversely affect protection selectivity and coordination for penetration levels of 20% of the original feeder load, but there were some problematic situations. The overcurrent protection must be modified so that the circuit remains correctly protected for specific DG cases.