Performance comparison of inverter and drive configurations with open-end and star-connected windings

Electrical drives with open-end winding configurations offer certain advantages over drives with star-connected windings such as higher dc-link voltage utilization and lower inverter losses. However, there are a couple of drawbacks like circulating currents, diminishing the performance of the drive. This paper compares the performance of inverter and drive configurations with star-connected windings and open-end windings regarding efficiency, THD and torque ripple over the entire operation range of the drive. The most widely used B6C topology is compared to the H-bridge topology for open-end winding machines using different modulation schemes. Inverter losses as well as losses due to switching harmonics are taken into account. The comparison is carried out for an interior permanent magnet synchronous machine (IPMSM) with a nominal power of 60kW.