| 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 ±ð/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. |
