Stacked Polyphase Bridges Converter having Common-Duty-Ratio Control with Gate Signal Delay

Stacked polyphase bridges (SPB) combined with multiphase induction machine (M-IM) is a great fit for transformerless medium-voltage (MV) motor-drive. Amongst controls for SPB, common-duty-ratio (CDR) reduces control complexity by eliminating need for local controllers. However, CDR control suffers from inability to overcome effects of non-symmetrical machine parameters on input dc-link voltage balancing (IVB) and output current sharing (OCS), confirmed through experimental results. Closed-loop gate signal delay CDR control is proposed for superior results in terms of IVB and OCS. Analysis corroborated with simulations, confirms success of proposed method.