In this paper three different converter topologiesare compared concerning their usability for permanent magnet integral motors. In the analysis special attention is payed to the efficiency ofeach converter topology, since the volume of the converter is highly dependent on the cooling requirements. Aspects of power factor correction of the line currents are also included in this paper. Only two of the three converter topologies fulfill the EMC standards. The line-side switch-mode rectifier and the Vienna rectifier. Both have a satisfactory efficiency but the line-side switch-mode rectifier provides also a regenerative braking possibility.