A converter circuit is specified for at least one phase (R, Y, B), which
converter circuit has a first switching group system which is provided
for each phase (R, Y, B) and has a first main switching group which is
formed by a power semiconductor switch and by a capacitor which is
connected to the power semiconductor switch, and which first switching
group system has at least one intermediate switching group which is
formed by two series-connected power semiconductor switches which can be
driven and by a capacitor, with the or one intermediate switching group
being connected to the first main switching group. Furthermore, the first
switching group system has a second main switching group which is formed
by a power semiconductor switch, with the or an intermediate switching
group being connected to the second main switching group. For simplicity
and in order to improve the reliability of the converter circuit, the
power semiconductor switch in the first main switching group and the
power semiconductor switch in the second main switching group are each
formed by only one passive electronic component which cannot be driven
and has a unidirectional current-flow direction. In order to increase the
capability to store electrical energy when there are a plurality of
phases (R, Y, B), the first switching group systems in the phases (R, Y,
B) are connected in parallel with one another.