Without prior knowledge of the geometric and design data of the employed asymmetrical dual three-phase interior permanent magnet synchronous machine (ADT-IPMSM), this paper proposes effective fundamental and enhanced harmonic models along with parameter identification for the different subspaces and with different neutral point configurations. The cross coupling between the coordinates of the different subspaces is also taken into account. The proposed method is based on simple experimental tests that can be applied to any ADT-IPMSMs. The performed computer simulations coincide to a high extent with experimental validations on a 2.5-kW ADT-IPMSM prototype.

This paper exploits the torque-speed operating limits of a dual three-phase interior permanent magnet synchronous machine (ADT-IPMSM) during post-fault 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: (i) an offline optimization that takes into account simultaneously the voltage and current constraints during post-fault operation and (ii) a simple hardware addition that modifies the neutral points configuration to either isolated (1N) or connected (2N) based on the operating torque and/or speed. Compared to 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.

This article presents the operation of onboard integrated battery chargers tied to a nine-phase EV-drive train, shedding light on the charging performance during the postfault operation, when one or more faulty inverter legs are disconnected. The objective in that case is to ensure balanced grid currents, while maintaining minimum machine losses at zero average torque production. The proposed concept requires a minimalistic change from a control structure perspective to switch between the pre- and postfault cases. Limitations and fault cases are discussed and corroborated with experimental tests on a 1.5-kW prototype.The derived concept is parameter independent and applicable to nine-phase drives, irrespective of the type of rotor used.

This paper presents the pre- and post-fault stator current control structures for symmetrical dual three-phase reluctance synchronous machines (SDT-RSMs) with different neutral-point configurations. The effect of winding chording and rotor saliency on the space harmonic mapping among different subspaces is investigated. This proves on one hand that the control structure in the pre-fault case can be simplified, while on the other hand shows that the derived harmonic mapping in literature is insufficient to ensure high performance operation in the post-fault operation. Moreover, the machine non-linearities are identified, through which the maximum-torque-per-ampere (MTPA) loci are obtained and employed in the pre- and post-fault cases. The theoretical findings are corroborated with finite element simulations and experimental validations on a 3 kW SDT-RSM prototype.