Fault Level Studies in a Low Voltage Distribution Network in the Presence of Small Scale Distributed Generations– Case Study for Mauritius

The robustness of a power system is determined by its stability during dynamic system behaviour as well as during fault conditions. Protective schemes are devised to ascertain that the power system remains stable during fault conditions by disconnecting the unhealthy part. One main input for the protective schemes is the fault level along the network. Advanced numerical models are used to calculate the fault levels for the traditional power system characterized by unidirectional current flow. With the popularization of Distributed Generations (DG), more of such units are being connected to the network. They disrupt the traditional model of power flow and alter the fault level in the system. Being sources of energy, they inherently contribute to feeding a fault condition resulting in more intense fault conditions which may become hazardous. This study deals with demonstrating how the fault level is affected by the introduction of Small Scale Distributed Generations (SSDG). An actual residential area in Mauritius is modelled in DIgSILENT Power Factory ^® using actual site parameters. This model is fed with recorded consumption data as well as photovoltaic and wind generation recorded patterns. The results obtained can be directly applied by any utility having similar residential area and increasing presence of SSDG.