Conversores estáticos utilizando estruturas de dois e três-níveis.

Abstract

The reduction in complexity and cost of the static converters may be achieved through the use of topologies with few devices. Therefore, it is proposed in this paper the study of topologies of converters using arms of two and three-levels (NPC - Neutral Point Clamped) in its composition (hybrid topologies). For DC/AC power conversion, four configurations present in the literature will be studied. To AC/DC/AC conversion with three-wire loads, two conventional topologies and five proposals. For DC/AC conversion using four-wire loads, two conventional topologies and four proposals. For each presented topology, the following points were studied: modeling setup, PWM strategies, control strategy. Comparative studies have been conducted between the proposed and conventional topologies, evaluating their performance, through the parameters: voltage harmonic distortions, current harmonic distortions, switches losses and voltage bus. From the analysis it is shown that the proposed topologies have better results than conventional two-level converters (for three legs topologies, the 222 had a total voltage harmonic distortion of 0.78% and hybrid topologies 322 and 323, with 0.67% and 0.46%, respectively). Some proposed topologies exhibited performance equivalent to that observed in the conventional three-level converters (the efficiency of five legs proposed topology 22322 was equal to conventional topology 33333, 0.94, using a reduced number of components). Simulation results and experimental support the analyzes.