Fault evaluation and performance of an IEEE Bus 30 power distribution network with distributed generation (DG)

Due to the penetration of Renewable energy to the power system which is inevitable, the power system will experience a drastic change, not only in its performance but also on the protective settings of relays. Thus, characterization of faults is necessary to determine the settings of the protective devices. In this paper, Fault Characterization studies are used to determine the performance and the fault values of all of the busses of the power system but with the impact of Distributed generation (DG). An IEEE Bus 30 system is a good selection of power system test case since it can be easily penetrated by a DG and can be connected as a mesh network. System performance during steady state and transient state is analyzed using the ETAP 6.0 software. A thorough investigation is needed so that the researchers can analyze the effect of DG's in the protection scheme of the relay settings, circuit breaker selection and protective device coordination. The simulation of results indicates that penetration of DG's in the network affects the fault current nevertheless where the fault occurs. But the fault current contribution depends on the location of the fault point to the penetrated DG in the system. Based from the graph of the DG contribution for different fault locations, the DG contributes the most fault current when the fault occurs connected at their respective busses. When the fault occurs at bus 29, DG 11 has the least contribution since it is far away from the fault point. In the summary of fault percentages, the researchers may say that the worst case of fault current occurs at Case 17 where Gen 2, Gen5 and Gen 13 are removed in the system.