Design, simulation and implementation of a buck-boost converter using pic 18f4550 microcontroller

This thesis describes the design, simulation and implementation of a buck-boost converter using PIC18F4550 microcontroller. Two stages of DC to DC converters are used for producing positive regulated output voltage. A PIC 18F4550 microcontroller is used to control these two stages. The first stage of DC to DC converter is buck converter while second stage of DC to DC converter is boost converter. The buck converter (first stage) is made as a source of the boost converter (second stage). The PIC 18F4550 microcontroller is programmed such as the buck converter operates in buck mode when the output voltage needs to be less than the input voltage while the boost converter is made in OFF state. When the output voltage needs to be greater than the input voltage, the PIC 18F4550 microcontroller is programmed such as the boost converter operates in boost mode while the buck converter is made in ON state. The overall converter is simulated using computer simulation program . A prototype of a buck-boost converter operates at a frequency 20 kHz with input voltage range (15-20) V and output voltage range (3-30) V is successfully implemented.