Using smart meter data to improve the performance of overcurrent protective devices in distribution systems with DG

Several researchers have presented methods to preserve the selectivity of overcurrent protection in radial distribution systems (RDS) with distributed generation (DG), but due to inherent changes in system configuration, protective device sensitivity is sacrificed. This paper presents two approaches to utilize smart meter measurements in adapting overcurrent protective device settings in two different protection schemes for RDS with DG. The first approach is planning based, and uses prior year demand information available via smart metering, to determine seasonal overcurrent pickup settings for the substation relay. These settings are used to improve the tripping times of the substation relay for a protection scheme that reverts the DS to a radial topology. The second approach uses smart meters to provide prior day demand information to estimate the peak demand for two 12-hour periods. These peak demands are used to operationally determine the appropriate pickup settings for the substation relay in a zonal protection scheme. Simulations are performed in EMTP™/PSCAD® and the results show that the developed techniques improve the sensitivity of the substation relay in both protection schemes.