Voltage inverters - Implementation

The problem of AC voltage generation from structures operating in switching mode was addressed in a general way (notion of time control and level control) in the article "Structures. Principles. Applications". In this "Implementation" section, we provide a few details on the various modulation techniques used in inverter control, their characteristics and the broad outlines of their implementation.

The main aim of these techniques, as applied to inverters, is to obtain alternating voltage waves of adjustable amplitude and fundamental frequency, by eliminating or pushing back as far as possible the parasitic harmonic components resulting from switching. In the final analysis, their use corresponds to a principle of active filtering via the control system, with active filtering usually combined with passive filtering, a subject we'll address in the next paragraph.

Regardless of the AC waveform required (usually sinusoidal), the control strategy must first take into account two steady-state constraints: minimization of parasitic harmonic components, and optimum use of the inverter power stage (sizing) to generate useful harmonic components.

The other aspect that needs to be considered is how these techniques will fit into the control and regulation loops that are mandatory in all inverter applications. It is therefore important to address the question of their dynamic potential.