This paper presents a simple and general direct modulation strategy that
enables to copy directly modulated waveforms onto output voltages of a
multilevel three-phase Diode Clamped Inverter (DCI). A general modelling of
this converter is presented. A space vector scheme is developed without using Park transforms. Based on this algorithm, the location of the reference voltage vector is determined
and the voltage vectors for the modulation are deduced. Simultaneously,
their durations are calculated. The proposed algorithm is general and can be
directly applied to a (n+1) levels inverter independently on its topology
(Diode Clamped Inverter, Neutral Point Clamped, Flying Capacitor Inverter...). To verify this algorithm, both control algorithms of a 5-level
DCI and a 11-level DCI are considered and simulation results are given.