Closed transition transfer switch based on multi-mode photovoltaic inverter for preventing power outage

This paper proposes a closed transition transfer switch (CTTS) based on a photovoltaic inverter which is capable of transition between grid-connected and island modes. The proposed system consists of the CTTS, utility grid and photovoltaic inverter connected to each input, respectively, an active load with power factor correction, and a system controller. According to the grid condition, the system controller manages the closed transition between the two inputs and determines the inverter operation mode. The performance was verified by the simulation.