New logic-form-equation based active voltage control for four-level flying capacitor multicell (FCM) converter

摘要

This paper presents a new active capacitor voltage balancing method for flying capacitor multicell (FCM) converter which is implemented using logic-form equations. The proposed active capacitor voltage balancing technique, measures output current and FC voltages to generate switching states to produce the required output voltage level as well as balance FC voltages at their reference values. Output voltage of the FCM converter with the proposed active voltage balancing method can be modulated with any kind of the pulse-width-modulation method such as phase-shifted-carrier PWM (PSC-PWM) or level-shifted-carrier PWM (LSC-PWM). Advantage of the proposed active voltage balancing method is its simplicity without any complex computation burden. Simulation results of a three-cell four-level FCM converter are presented to verify performance of the proposed active capacitor voltage balancing method.