Control of a 9-Phase PMSM with Stacked Polyphase Bridge Converter including DC Source Impedance

This paper presents a control concept for a drive system consisting of a 9-phase PMSM connected to a stacked polyphase bridge converter (SPBC) under consideration of the DC source impedance (Rb,Lb). When the converter is connected to the DC source with a cable, the cable impedance represents a source impedance that could cause instabilities affecting the total DC link voltage and the module voltage balance. In this paper, a control concept is presented for stabilising the module voltage balance via an appropriate definition of the module reference voltage. The total DC link voltage is not controlled but stability is ensured by sufficiently large DC link capacitors. The complete drive controller concept is validated in a simulation of a 1.5kW drive system.