Low load flying capacitor balancing method and power converter

Abstract

A control method for controlling a multi-level flying capacitor power converter is disclosed, said power converter being configured to perform a predetermined control function, said function comprising preferably regulating power to a load and / or correcting a power factor, said power converter comprising a plurality of multi-level flying capacitor legs connected together, wherein each multi-level flying capacitor leg comprises at least one flying capacitor, a plurality of controllable switches and an inductor, the control method comprising continuously calculating current components to be injected for controlling the voltages of the flying capacitors over the whole range of leg currents, and controlling the switching of the plurality of controllable switches to obtain leg currents each comprising a respective first current component associated with the predetermined control function and a respective injected current component associated with the respective calculated current component, wherein the injected current components cancel each other out within the power converter. Figure 14