Research on a Novel PMSM with Tooth-Tip Span Angle Modulation Configuration for Aircraft Spool-Integrated Generator Application

As aircraft progressively transition toward more-electric architectures, the requirements for power generation systems in terms of power density and reliability are becoming more stringent. Conventional electric machines, such as Permanent Magnet Synchronous Machines (PMSMs) or Switched Reluctance Machines (SRMs), struggle to simultaneously fulfill all these requirements. To address these limitations, this paper proposes a novel PMSM with Tooth-tip Span Angle Modulation Configuration (TSAM-PMSM). The incorporation of inter-phase fault-tolerant teeth significantly reduces mutual inductance. Furthermore, by introducing air gaps between adjacent fault-tolerant teeth to form a modular stator, inter-phase magnetic isolation is further enhanced. Aligned with design characteristics of high-speed aerospace electric machines, both 4-pole and 8-pole TSAM-PMSM configurations are proposed. A high-power-density design methodology integrating stator tooth-tip offset and distribution factor optimization is presented, with experimental validation of its power density enhancement efficacy. An analytical method based on slot inductance is established for short-circuit current evaluation. The impacts of critical stator structural parameters on electromagnetic performance and reliability are examined. Finite Element Analysis (FEA) results demonstrate that the asymmetric stator teeth configuration provides measurable improvements in both power density and reliability compared to conventional symmetric designs.