Desenvolvimento de uma fonte de tensão regulada para a alimentação de equipamentos eletrônicos a partir de painéis solares fotovoltaicos

Abstract

The present report describes the design and implementation of a regulated voltage source from solar photovoltaic panels, with 5 V output direct current (DC) - same voltage level of the USB ports of personal computers - to power electronic equipments, such as mobile phones, tablets, mp3 players, external hard drives, etc. In addition to the knowledge in power electronics, analog electronics and digital control concepts should be employed in the development of this regulated voltage source. The developed control system must sample periodically sample the values of the current sensor (for protection purpose) and the voltage sensor (variable to be controlled). A step-down DC-DC Buck converter is used to implemente the source. Additionally, am isolated DC-DC Flyback converter are used to source the ancillary circuits (gate-driver and instrumentation circuits). With the implementation of an appropriate control logic, the Buck converter provides the value of 5 V voltage in a USB connector, allowing a broad compatibility with electronic equipments. The control of Buck converter is accomplished with the aid of a microcontroller Arduino Mega 2560, in which it is implemented a proportional-integral control technique (PI) in order to ensure that there is no steady state error in the source voltage value. Beyond the range of practical applications, this project has an environmental appeal due to make use of a renewable source of energy.