A Coupled Circuit and Field Analysis of a Stand-Alone Permanent-Magnet Synchronous Generator with Inset Rotor

  • Chan T. F. (Department of Electrical Engineering, The Kong Polytechnic University) ;
  • Yan Lie-Tong (Department of Electrical Engineering, Tsinghua University) ;
  • Lai L. L. (The Energy Systems Group, School of Engineering, City University)
  • Published : 2005.09.01


By using a coupled circuit, time-stepping, two-dimensional finite element method (2-D FEM), the performance of a stand-alone permanent-magnet synchronous generator (PMSG) with inset rotor can be computed without involving the classical two-axis model. The effects of interpolar air gap length and armature resistance on the load characteristics are investigated. It is shown that the interpolar flux density, and hence the amount of voltage compensation, is affected by magnetic saturation. Validity of the coupled circuit and field analysis is confirmed by experiments on a prototype generator. The machine exhibits an approximately level load characteristic when it is supplying an isolated unity-power-factor load.


  1. B. J. Chalmers, 'Performance of interior type permanent-magnet alternator,' IEE Proceedings - Electrical Power Applications, vol. 141, no. 4, pp. 186-190, July 1994 https://doi.org/10.1049/ip-epa:19941207
  2. T. F. Chan, Lie-Tong Yan, and L. L. Lai, 'Performance of a three-phase a.c. generator with inset NdFeB permanent-magnet rotor,' IEEE Transactions on Energy Conversion, vol. 19, no. 1, March 2004, pp. 88-94 https://doi.org/10.1109/TEC.2003.821861
  3. S. L. Ho and H. L. Li, 'Dynamic modeling of permanent magnet synchronous machines using direct-coupled time stepping finite element method,' IEEE International Electric Machines and Drives Conference (IEMDC '99), Seattle, Washington, USA, May 9-12, 1999, pp.113-115
  4. Pi-Zhang Chen, Lie-Tong Yan and Ruo-Ping Yao. Theory and Computation of Electromagnetic Fields in Electrical Machines. Beijing: Science Press, 1986
  5. S. J. Salon. Finite Element Analysis of Electric Machines. Boston: Kluwer Academic Publishers, 1995