Variable switching frequency operation of DCM flyback micro-inverter

Since the dedicated micro-inverters operate individual photovoltaic (PV) modules at its maximum power point, the micro-inverter topology exhibits better performance than the central and string topologies against partial shading. Among the micro-inverter topologies, discontinuous conduction mode (DCM) flyback micro-inverter is the most attractive one due to its simplest structure, easy control and potentially low cost. However it suffers from low input voltage range and high conduction loss. In this paper, a variable switching frequency control method is proposed which allows extending the input voltage range considerably. Additionally, the proposed method can decrease the total losses by 24.82% according to the simulation results.