Control of a single phase inverter with multiple modulation strategies based on plant inversion

This work proposes a control linearization technique for a single phase 3 level-flying capacitor multi-level (FCML) inverter with multiple modulation strategies along the line period, based on the plant inversion. Multiple modulation strategies are used along the line cycle so that the overall size and efficiency of the converter are optimized. This benefit from the point of view of the energy processing generates a design challenge for the control. The proposed technique allows decoupling the control of the input current and the output current, which simplifies the control of the output voltage and the storage capacitor voltage in two ways: first, the control of both variables is independent and second, the controller parameters will be independent on the modulation strategy due to the plant inversion. These advantages are critical for the successful control of this highly non-linear time-varying system.