Comparative Evaluation of the Boost-Buck-Inverter and the Boost-Voltage-Source-Inverter

A modular three-phase Boost-Buck dc/ac Inverter (BBI) is presented. The BBI has the advantages of voltage step-up/step-down capability, high-quality/low-harmonic output voltage/current waveform and high efficiency. Extensive comparative evaluations are made between the BBI and the conventional two-level voltage source inverter with a boost dc/dc stage (B-VSI). It is shown that, compared to the B-VSI topology, the BBI topology has (a) much lower THD of the output current, (b) much lower CM voltage and CM current, (c) much lower switch device voltage stress and losses and (d) much lower rms current ripple in the de link capacitor.