Analysis and Modulation of Nine-Switch Split Source Inverter (9S-SSI)

Abstract

The nine-switch (9S) topology is an interesting alternative to the traditional three-phase backto-back converter because it allows the reduction of active semiconductors count. On the other hand, some applications have input dc voltages lower than that minimum required for the synthesis of ac voltages and an additional dc-dc stage is required. Furthermore, the Split-Source Inverter (SSI) aggregates the boost and inversion stage in a single power processing unit, eliminating multiple converters. This paper proposes the Nine-Switch Split-Source Inverter (9S-SSI) that joins the characteristisc of dual three-phase power ports with the dc voltage boost stage. In addition, a PWM strategy is proposed where the SV and scalar approaches are presented. Both approaches are correlated, however the first one allows the direct choice of switching vectors while Manuscript received 05/13/2020; first revision 09/13/2020; accepted for publication 10/15/2020, by recommendation of Editor Demercil de Souza Oliveira Jr. http://dx.doi.org/10.18618/REP.2020.4.0030 the second has the advantage of ease of implementation. Futhermore, the loss analysis and the dimentioning of power devices are presented. Simulation and experimental results are presented to demonstrate the good performance of the proposed topology and modulation strategy.