The new FLC-variable incremental conductance MPPT with direct control method using Cuk converter

Maximum power point tracking (MPPT) is a necessary function for all photovoltaic (PV) systems. The classical incremental conductance (IncCond) maximum power point tracking (MPPT) with direct control is widely applied in many papers. The IncCond algorithm is prone to failure during high changes in the irradiance. This paper deals with a new algorithm based on variable step size to eliminate all drawbacks of the classical IncCond algorithm with direct control. We use fuzzy logic controller to adjust the duty cycle change, therefore, the reach of MPP is quick and accurate simultaneously during the dynamic and steady state conditions compared to conventional IncCond MPPT with direct control method, a controlled Cuk dc-dc converter was used and connected to a SunTech STP085B in order to verify the results. We used Matlab Simulink for simulation, the results clearly indicate the improvement of the proposed method.