Power system of DC/DC applications: Case of cooking

Abstract

In this paper, we present the structure, the sizing and the experimentation of a power system that allows to feed, through solar batteries, the DC (direct current) equipment with photovoltaic renewable energies (Cookers, distillers, refrigerators, drying, …). The proposed system is based on the use of a multi-branch Boost type DC/DC converter, controlled by a Microcontroller, which generates PWM signals of frequency 20 kHz and variable α duty cycle. The electrical energy, produced by the photovoltaic panels (600 W), is stored in the solar batteries (24 V, 520 Ah) and then transferred to the application through the proposed DC/DC converter. The experimentation of the proposed system to supply a solar cooker (Box Oven) of 500–600 W, heated by thermal resistances, shows efficiencies of the DC/DC converter of 86 %, heating temperature of the thermal resistance and water that reach 640 °C and 99 °C after 20 s and 25 min, energy supplied by the batteries and that of heating are respectively of the order of 491 Wh and 421 Wh (That is to say 3.93 % and 3.37 % of the total energy supplied by the battery).The comparison of all the results obtained with those simulated and the economic analysis of the use of renewable energies stored in the batteries, show the good functioning and the validity of the power system, proposed in this work.