PQ, Reliability and DG

DISTRIBUTED GENERATION (DG) CAN improve a utility's ability to serve peak load on a feeder, thus allowing the deferral of capital investments on a feeder. A common case where DG is effective and economical occurs when it helps to supply load during contingencies until the utility can build additional delivery capacity. Figure 1 shows an example with the DG located near the end of the feeder. In this location, DG can provide voltage support and reduce currents in the conductors near the substation [!}. Depending on the voltage and current constraints, the DG may even provide a larger increase in feeder capacity than the DG power rating. On the other hand, DG located near the substation might augment the capacity of the substation transformer or transmission system, but it does nothing to increase capacity on the feeder.