Projeto de um inversor de tensão meia-ponte como kit didático para o ensino de eletrônica de potência

Abstract

This work provides an introduction to teaching methods in engineering, demonstrating that laboratory (experimental) classes are effective in teaching, as they allow students to apply, understand and retain the knowledge obtained in theoretical classes. This way, it presents the design and manufacturing of a low-cost, low-power, single-phase voltage source inverter in half-bridge topology, for a teaching bench that can be used in the experimental classes of Power Electronics. The kit also includes a printed circuit board (PCB) for the microcontroller that implements the inverter modulation, a gate-driver circuit and an auxiliary power supply. Using this kit, some experiments were proposed for the students. These experiments consist of ini tially analysing the kit, where each item of the PCBs is described and illustrated. The second experiment validates the application of the bootstrap technique to drive an inverter arm with a floating reference. Experiments three and four consist of connecting the inverter in open loop and checking its behavior before and after the LC filter. The kit was designed to allow variation of the amplitude and frequency modulation indices, as well as offering different combinations of resistors. For this reason, in the fifth experiment we suggest comparing the output results due to the attenuation caused by the LC filter when varying the frequency modulation index, as well as applying a reference step in amplitude modulation.