Field programmable gate array-based control method for a pulse density modulated microinverter operating in island mode

This study proposes a new control method for a pulse-density modulated microinverter and its implementation within a field programmable gate array circuit. The structure and operating principle of the studied microinverter demand implementation of a pulse-density modulation-based control method with two independent control loops. The first one ensures a constant input current from the source while the second one provides a sinusoidal voltage at the converter's output. At the same time the implemented control method ensures zero-current switching of the utilised power transistors in decoupling and output stages which allows operation at high switching frequency. The performance of the proposed control method for a microinverter operating in island mode was experimentally verified in steady-state operation, as well as during load transients.