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This brief proposes an optimization formulation of the control problem for power electronic converters. A benefit of the approach is a systematic method for the control of high-switch-count static converters. In the case of the three-phase, four-leg, two-level inverter, the framework provides a characterization of all the possible solutions that yield a maximal extension of the inverter linearity range. The method makes it possible to recover well-known modulation strategies as well as to discover some new ones having different properties and distinct advantages. The characteristics resulting from different design choices are evaluated in simulations, with consideration being given to the linearity range, total harmonic distortion, and switching losses. Key principles of extension of the proposed method to multilevel, multileg converters are given, as well as motivations for a field-programmable gate array-based hardware implementation enabling real-time pulsewidth modulation control.

International audience; In this paper, a new carrier-based pulse-width modulation (PWM) technique for a voltage source inverter (VSI) is presented. The new modulation law is obtained using a particular configuration of a control allocation technique based on a per-switching-state formulation of the 4-leg 2-level inverter. The resulting modulation law is equivalent to the injection of the opposite of the median reference voltage as a zero-sequence voltage. This particular solution produces a smooth transition from a continuous modulation mode at low modulation depth to a dis-continuous modulation mode at high modulation depth. This hybrid solution makes it possible to focus on the THD for low output voltages and reduce losses for higher voltages.