A Semiconductor Area Based Assessment of AC Motor Drive Converter Topologies

In order to find the optimal converter topology for a given AC motor drive, as defined by its mission profile, suitable assessment criteria have to be applied. A new semiconductor chip area based approach is proposed to compare and assess different motor drive converter topologies. It determines the total semiconductor chip area based on the drive´s operating point and the optimal partitioning of the transistor and diode chip areas. This approach not only provides a distinct figure-of-merit for comparison but also enables the semiconductor costs of different converter topologies to be determined. The chip area based comparison has been successfully used to assess three 3-phase AC-DC-AC converter topologies for a 15 kW (20 HP) motor drive. It is shown that the voltage DC-link back-to-back converter based drive provides the best overall performance in terms of chip area, cost, efficiency, and available nominal torque.