Design of a two-stage on-grid single-phase photovoltaic microinverter

This paper presents the design of a non-isolated two-stage on-grid microinverter that conditions the power of a 200 W photovoltaic (PV) module and injects it into a single-phase utility grid with 127 V/60 Hz. The microinverter's first stage is a quadratic boost, whose purpose is to provide maximum power point tracking (MPPT) and high gain. The DC-AC stage consists of a full bridge inverter, which is responsible for DC link voltage regulation and control of the current injected into the grid. The microinverter also includes a PLL, in order to provide unit power factor, and an anti-islanding algorithm. The theoretical results acquired through Simulink/Matlab simulations proved the efficiency of the proposed topology for a microinverter, which fulfilled the stablished design requirements.