Simple voltage balancing method to protect series-connected devices experimentally verified in a 5L-MPC converter

Abstract

This paper presents a solution for the voltage balance problem of the series-connected devices that can be applied to multilevel converters in which the series-connected devices need to block twice their switched voltage. The solution is based on two ideas, the control of the switching commands to achieve proper switching losses balance and the use of additional circuitry to achieve proper voltage balance during their blocking state. The proposed strategy is experimentally validated into a 5-level multipoint clamped full-scale converter. However, it can be used in any other converter topology in which the devices need to block twice their switched voltage.