Enhanced Control of Photovoltaic Voltage Regarding Mixed Conduction Modes of Power Interfaces

The photovoltaic power output is characterized by a nonlinear and time-variant behaviour that changes significantly with the operating condition and environmental variables, e.g., solar irradiance and temperature. The switching operation of power interfaces is also nonlinear, time-variant, and load-dependence, inevitably experiencing both the continuous and discontinuous conduction modes (CCM/DCM) to accommodate the power variation. These lead to a difficult control problem and compromise the performance of maximum power point tracking (MPPT). This paper provides a comprehensive analysis of the system dynamics and proposes a universal but simple control law to support consistently stable, fast, and robust control operations.