Passivity-based control of a single-phase H-bridge multilevel active rectifier

This paper proposes a passivity-based controller for a H-bridge multilevel rectifier feeding a number of DC buses. The balance of the DC voltages under different operating conditions and a satisfactory dynamic behaviour at load step changes are guaranteed through the independent control of each H-bridge multilevel switching function. Thus a new modulation strategy is proposed to obtain a multilevel voltage waveform on the basis of the knowledge of the desired switching function of each converter. Many test results are reported to verify both the passivity-based control and the new multilevel modulation strategy.