Postfault Full Torque–Speed Exploitation of Dual Three-Phase IPMSM Drives

This paper exploits the torque-speed operating limits of a dual three-phase interior permanent magnet synchronous machine (ADT-IPMSM) during postfault operation for different neutral configurations. To achieve the maximum permissible torque-speed limits, the study proposes software and hardware modifications to the latest fault-tolerant techniques using: an offline optimization that takes into account simultaneously the voltage and current constraints during postfault operation and a simple hardware addition that modifies the neutral points configuration to either isolatede (1N) or connected (2N) based on the operating torque and/or speed. Compared to the literature, the proposed study considers the field-weakening operation, extending the permissible achievable speeds. A 2.5-kW ADT-IPMSM prototype validates the theoretical findings.