The Grid Interfaced PV-Driven Dual Port Solar System With Improved Depth of Power Extraction Under Solar Irradiance Disparity

This work introduces a dual solar port voltage-sharing grid-following inverter configuration with reduced operating DC bus potentials. The proposed configuration enhances energy extraction in medium and high-power applications by adeptly managing the solar irradiance disparities between input ports. Under disparities, an efficient solar power extraction method is proposed, utilizing a cascaded dual inverter configuration paired with a DC/DC converter to integrate the solar ports with the grid. In this configuration, the DC/DC converter works with the dual inverter for efficient energy extraction by maintaining the total DC bus voltage. However, the individual DC bus voltages vary according to the available solar power at each port. The designed control loop effectively handles the voltage asymmetry while maintaining the total DC bus voltage constant for seamless power injection to the grid. The voltage asymmetry across the individual inverters enhances the dual configuration's phase voltage levels, which helps improve the quality of the grid-injected current. Conversely, the voltage disparity influences the common mode voltages, but the magnitudes are under acceptable limits due to reduced operating DC bus potentials. The efficacy of the proposed configuration, along with its control methodology for handling solar irradiance disparity, is validated experimentally.