Extending the operating range in Diode-Clamped Multilevel inverters with Active Front Ends

A new modulation scheme, optimized for achieving a correct dc-link capacitor voltages balance in Diode-Clamped Multilevel inverters with Active Front End (AFE), beyond the limits found in the past, is presented. A detailed explanation of the new technique and how the optimization is achieved are presented. The results are completely general, analytically obtained and each result is verified using energetic considerations: the voltage variation of all capacitors due to the inverter must correspond to the energy drawn by the load and must be supplied by the AFE. The main results are shown and several simulation results in particular working conditions are presented in order to verify the general analytical computations.