Design of Flat Two-stage Hybrid Resonant Isolated Micro-inverter

With the rapid development of the photovoltaic industry, microinverters have gradually become the preferred choice for photovoltaic products due to their relatively small power and flexible adjustment. This paper proposes a two-stage hybrid resonant microinverter structure based on planar magnetic components, featuring a flattened design with a maximum thickness of 18mm. The front stage of the microinverter is a hybrid resonant DC-DC converter, which can accommodate a wide range of input voltage from 15V to 60V. The second stage employs a full-bridge inverter structure (H4) that utilizes PR control. The prototype operates at a switching frequency of 113kHz, enabling a full-load power output of 450W within an input voltage range of 25V to 35V. The rated output voltage is 220.96Vac (50.04Hz), and its THD is only 0.8%.