A Novel Inductor Based Balancing Circuit for Diode Clamped Converters

Abstract

The paper proposes a new balancing circuit for multilevel diode clamped converters (DCC) aimed to keep the DC-Link voltages balanced, regardless of the converter operating condition. The proposed architecture, which is based on the same topology of a DCC leg, is connected to an external inductor and is driven by a specialized modulation technique acting on the instantaneous DC-Link differential voltages. The balancing circuit, presented in both its complete and simplified topology, is discussed with reference to a generic number of levels and is validated through numerical simulations.