Effect of distributed generation on regional voltage stability

In order to minimize the risks of unintentional islanding, IEEE 1547 requires distributed generation (DG) to trip when the severity of a voltage or frequency disturbance exceeds a defined threshold. Where there is a substantial amount of DG within a region, there is a risk that a transmission fault could cause simultaneous tripping of a substantial portion of this DG capacity, thus depriving the system of the support that the DG had been providing. This paper describes an investigation of the impact of DG tripping on the voltage stability of a regional transmission system.