Abstract: In an attempt to deal with the large leakage inductance of fault tolerant permanent magnet machines (FTPMMs), the six-phase ten-pole FTPMM is calculated by finite element method (FEM) of the vector magnetic potential. The components of selfinductance, and especially the distribution of leakage inductance of its windings, are obtained. Simultaneously, a magnetic circuit model of the motor is presented. The analytical formulation of winding self inductance and its portions are predicted by the method of magnetic circuit. The calculation accuracy of this analytical formulation is below 5.6% by verification of FEM. This formulation can be extended to general FTPMMs, so it offers a theoretical reference to original FTPMM design and performanceanalysis. Finally the harmonic leakage of FTPMM is analyzed quantitatively, which provides a foundation for subsequent motor control and heat calculation.

Key words: six-phase ten-pole fault tolerant permanent magnet machine, finite element method, magnetic circuit model, analytical formulation, harmonic leakage