The rapid growth of solar photovoltaic (PV) systems has increased the demand for efficient medium-voltage (MV) grid-connected inverters. Multilevel inverters, particularly Cascaded H-Bridge (CHB) topologies, are widely used in the 7.2–13.8 kV range due to their modularity, high power capability, and isolated input operation, which is essential in PV applications. To provide this isolation, a dual active bridge (DAB) converter is often employed, but its dual full- bridge structure raises cost and complexity. To address this, an integrated three-phase dual active bridge (I3DAB) is proposed by NCPRE researchers. Using a three-phase DAB input stage and three isolated full-bridge outputs, the I3DAB reduces component count, enables MPPT, and ensures galvanic isolation while interfacing directly with CHB inverters.

Furthermore, a Fourier series–based harmonic modelling approach is introduced for the I3DAB, providing a simplified yet accurate representation of its voltage, current, and power characteristics across various operating conditions. This contribution enables efficient design and control of I3DAB-CHB systems, advancing their application in MV PV grid-connected systems. This work was presented in IEEE Energy Conversion Congress & Expo (ECCE) Asia 2025 at Bengaluru, India. This work was done by NCPRE student Jenson Joseph under the guidance of Prof. B. G. Fernandes.