The VSI topology is possibly the most commonly used
two-level converter in the industry. The AC/AC topology
chosen for analysis is a simple two-level chopper. These two
topologies are equivalent in terms of functionality as in
theory they can both generate an arbitrary sinusoidal AC
output. The DC voltage input of the VSI is V, which is the
same as the amplitude of the input AC supply of the direct
AC/AC converter. This way, the stresses on devices in both
cases is the same. Further, the maximum output voltage that
can be synthesized by both the converters is also the same.
The maximum voltage is achieved at a modulation index of
1for the VSI and at a duty cycle of 100% (top AC switch is
always on) for the direct AC/AC converter.