A controlling method for charging photovoltaic generation power obtained by a MPPT control method to series connected ultra-electric double layer capacitors

Abstract

A photovoltaic (PV) generation system which can efficiently acquire the electric energy irrespective of the weather is described. The PV generation system is characterized by two controllers, namely, a maximum power point tracking (MPPT) controller which makes it possible to take the maximum power which solar arrays can generate at any time irrespective of the weather, and a controller which quickly charges the maximum power obtained by the MPPT control to series connected ultraelectric double layer capacitors (ultraEDLCs) while maintaining the electric capacity which solar arrays can generate at that time. The MPPT controller controls the output current of the solar arrays so that the output power converges on the maximum power in the prediction line previously determined based on the linearity between the maximum output power and the optimal current. The MPPT controller is characterized by having the ability to enlarge the controllable range of the output power to lower solar radiation in comparison with the conventional hill-climbing method. The charging controller controls the current and voltage so as to be charged at around the power generated at that time while supervising the maximum voltage and allowable temperature of each series connected EDLC, The combined control method makes it possible to charge with the maximum power generation from solar arrays into ultraEDLCs. Effectiveness of the methods is verified by simulations and experiments.