Comparison of duty ratio perturbation & observation and reference voltage perturbation & observation methods applied in MPPT

Aimed to duty radio P&O (Perturbation and Observation) method which is the most widely applied in MPPT (Maximum Power Point Tracking) control for PV (Photovoltaic) generation, steady-state characteristic is analyzed, and the relationship between output power fluctuation of solar cell and disturbance quantity is deduced. On this basis a reference voltage P&O method for maximum power point tracking is proposed and control algorithm is given in this paper. Simulations and experiments prove that MPPT method based on reference voltage P&O is better evidently than that based on duty radio P&O in the field of improving response speed and reducing power fluctuation, and tracking effect is satisfied.