Voltage balance modeling in single-leg flying capacitor multicell converters employing a balance booster circuit

This paper provides a mathematical model for voltage natural balancing process in single-leg flying capacitor multicell converters by taking into account the balance booster circuit effect. The analysis leads to state-space model of the converter. This analytic model of the flying capacitor multicell converters can be utilized to investigate the start-up and steady states of flying capacitor voltages. To provide verification, numeric results pertaining to a single-leg capacitorclamped multicell converter's analytic model are presented in different cases and compared against simulation results. Moreover experimental results taken from a laboratory prototype are also presented. An excellent match between experimental and numeric results confirms the validity of the proposed analytic model for the single-leg flying capacitor multicell converters.