An Adaptive Balancing Modulation for Multilevel Diode Clamped Converters without Common Mode Voltage Injection

In this paper, a new multi-modulating single-carrier based pulse-width modulation technique is proposed for the output control and the voltage balancing of a multilevel Diode Clamped Converter (DCC). The used approach does not rely on the injection of a common mode reference voltage. Instead, the voltages equalization is achieved by a proper control of the switching devices duty-cycles. Although the conceived balancing technique leads to a general increase of both the average switching frequency and the output voltage harmonic content, it can be applied regardless of the number of levels and of the converter operating conditions, contrarily to most of the other available software techniques.