부산대학교 도서관

Variable speed drives (VSDs) for electric motors are a foundational component of global electrification, with electric motors consuming 45% of global electricity. Conventional three-phase buck–boost inverter topologies have substantial low-frequency current stresses in the buck–boost inductor, driving size, losses, and cost in VSD systems. In this letter, we propose a novel circuit topology for phase-modular three-phase buck–boost inverter systems based on the four-switch noninverting buck–boost concept, which we call the return path inductor Y-inverter (RPI-YI). By relocating the buck–boost inductors from the forward current path to the return path, the RPI-YI concept reduces the inductor rms and peak current stresses by up to $90 \%$ compared to a conventional topology, resulting in a potential magnetics volume reduction of $80 \%$. The RPI-YI concept, therefore, supports more compact, efficient realizations of modular buck–boost VSD systems.