Research on CPSPWM Reconfigurable Control of Cascaded Multilevel Converter

An important performance measure of a device's merit is the reliability of the multilevel converter. The reliability of cascaded multilevel converters can be improved by using fault unit bypass techniques. In this paper, reconfigurable paths of cascaded multilevel converters are analyzed, neutral shift reconfiguration techniques and formulas for calculating parameters are derived, and a carrier phase shift pulse width modulation (CPSPWM) method based on neutral shift is presented. Simulations of the CPSPWM reconfigurable control are carried out in two cases, including the normal case of a three-phase cascaded 11-level converter and the case of a unit failure. The correctness of the control strategy is derived from the simulation results.