Analytical Phase Shift Control for Asymmetric Two-Input Boost Converters to Minimize Output Capacitor Current

Interleaved boost converters (IBCs) are widely used in voltage step-up applications due to their high-power density and current ripple reduction. For some applications such as hybrid renewable energy systems, multistring photovoltaic (PV) systems, and solar-charged electric vehicles, the IBC may be connected to different inputs, such as different PV panels with different shading conditions, creating an asymmetric input IBC. For asymmetric IBCs, the standard phase shift angle of 360 divided by the number of phases does not minimize output capacitor current and voltage ripple. While prior approaches have suggested complex optimization search algorithms to solve this problem, this article is the first to propose an analytical phase shift calculation method for a two-input asymmetrical IBC that lowers output capacitor root mean square (rms) current. The proposed method is simple and fast, with low computational requirements, and allows for real-time phase shift adjustments with minimal control system overhead. Extensive simulation and experimental results demonstrate that the proposed analytical method effectively reduces rms current by up to 67.2, validating its performance across a wide range of voltage and current operating conditions.