Non‐isolated single‐phase inverter based on an autotransformer for low‐power applications

Abstract

AbstractThis work presents a non‐isolated single‐phase voltage‐source inverter (VSI) topology using an autotransformer to provide an alternating current (AC) output voltage whose maximum peak value can be up to twice that obtained with the conventional half‐bridge and full‐bridge inverters. Prominent advantages include a simple structure with low component count, as well as the fact that both switches are connected to a same reference node, as there is no need for isolated driver circuitry. As a possible drawback, the maximum voltage across the switches is equal to twice the input voltage, but it is still reasonable to state that the topology is adequate for low‐power, low‐input‐voltage applications. A thorough qualitative and quantitative analysis is presented, from which it is possible to derive a consistent design procedure. An experimental prototype with a rated power of 100 W, switching frequency of 20 kHz, direct current (DC) input voltage of 35 V, and rms output voltage of 37 V is developed to validate the theoretical assumptions.