Analytically Closed Calculation of the Conduction and Switching Losses of Three-Phase AC-AC Sparse Matrix Converters

TLDR: In this article, a novel concept for the analytical calculation of the current stresses on the power semiconductors of the Sparse Matrix Converter Topologies (SMC, VSMC, and USMC) is proposed.

Abstract: For three-phase AC-AC power conversion a conventional matrix converter (CMC) or a DC side connection of a current DC link rectifier and a voltage DC link inverter comprising no energy storage components in the DC link could be employed. The combination of DC converters does show a lower number of turn-off power semiconductors and, therefore, has been denoted as Sparse Matrix Converter (SMC) or Very Sparse Matrix Converter (VSMC). A limitation of the phase displacement of the current and voltage fundamentals at the input and at the output to ±π/6 does allow a further reduction of the system complexity, the respective circuit topology has been introduced as Ultra Sparse Matrix Converter (USMC) in the literature. In this paper a novel concept for the analytical calculation of the current stresses on the power semiconductors of the Sparse Matrix Converter Topologies (SMC, VSMC, and USMC) is proposed. Furthermore, the switching losses of the output stage which shows identical structure for the SMC, VSMC and USMC are calculated analytically based on an experimentally determined dependency of the switching loss energy on the switching voltage and current. As a comparison to a digital simulation shows, the analytical results do show a very good accuracy in a wide modulation range and for widely varying load current phase angle and widely varying ratio of output and mains frequency and therefore do provide an excellent basis for the dimensioning of the SMC, VSMC or USMC and/or for the determination of the rated output power and efficiency which could be achieved by employing given power transistors and diodes.