High-Frequency Isolated Three-phase Grid-Tied PV Converter Based a New Boost Inverter Topology

This paper proposes a new topology of PV grid-tie applications. The full system consists of two-stages, high-frequency boost inverter cascaded by rectifier–inverter system. In the first stage, a new single-stage high-frequency boost inverter is designed to boost and convert the DC output voltage of the PV array to a high-frequency single-phase square waveform in addition to realizing maximum power point tracking (MPPT). The proposed topology enables high-frequency transformer to be used for providing galvanic isolation between the two-stages. The second stage is rectifier-inverter system that links the first stage to three-phase grid connected. Many advantages of the 5kW three phase grid connected proposed system are provided such as boosting the inverter output voltage level, MPPT, galvanic isolation, high reliability, small size, and light weight. In addition, a grid side controller is used to inject a sinusoidal current into the grid at unity power factor. The proposed topology has been verified analytically by using PSIM software.