Modelling and simulation of an adaptive differential current protection scheme for a solar PV microgrid

This paper presents modelling and simulation of an adaptive differential current protection scheme for a solar photovoltaic microgrid which is capable of operating in both grid-connected and islanded modes. The microgridtest model comprises three photovoltaic generators, each connected to a load. The entire microgrid is connected to the main utility network through a static switch (SS). The protection system contains differential relays which monitor current parameters at specific points within the microgrid to detect the fault. The settings of the relays are changed through the relay operating algorithm to suit the current mode of operation. The relays are effectively coordinated through a central controller which uses differential current to detect and isolate faults occurring in various zones.