Inverter-based versus synchronous-based distributed generation; fault current limitation and protection issues

The contribution of distributed generation (DG) to network fault levels depends heavily on the technology employed. In the case of directly connected rotating machines the fault behavior is well established; with synchronous generators contributing higher fault levels than the corresponding induction generators. The contribution of inverter-based distributed generation (IBDG) is the lowest due the capability of this technology to exhibit non over-load characteristics. However the behavior of this generation technology under fault conditions is determined by the employed control methods. In this paper, an investigation of the effect of the DG type on the fault current is investigated. Simulations for case studies have been conducted using Matlab/Simulink.