Novel Rotor Design of Wound Field Synchronous Motor for Torque Ripple Reduction in ISG System

  • Choong Sung Lee
  • Myung Hwan Yoon
  • Jung Pyo Hong
  • Young Kyoun KimEmail author


This paper describes a method to reduce the torque ripple for the Wound Field Synchronous Motor, which does not use a permanent magnet. When a WFSM is used in an Integrated Starter Generator system, it must have a higher power density than other automotive motors in order to satisfy the size constraints and required power. An increase in the power density creates a magnetic flux saturation in the rotor, and this soon becomes the cause of an increase in the torque ripple of motor. An increase in the torque ripple can degrade the Noise Vibration Harshness characteristics of automotive by creating vibration and noise in the engine start-up mode, in which the maximum torque is generated in an ISG system. This paper proposes a method of reducing the torque ripple via a design that uses a flux barrier model in the WFSM’s rotor. The Response Surface Method is used to optimize the flux barrier model, and Finite Element Method is used to to verify the torque ripple reduction.

Key Words

ISG WFSM Flux barrier Torque ripple Response surface method Finite element method 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Cai, W. (2004). Comparison and review of electric machines for integrated starter alternator applications. Proc. IEEE Int. Conf. Industrial Application Systems, Seattle, Washington, USA.Google Scholar
  2. Hayashi, S., Morikawa, M. and Murasaki, M. (2003). Tasks and provisions for motor generator designing. Denso Technical Review, 81, 115–119.Google Scholar
  3. Hendershot, J. R. and Miller, T. J. E. (2010). Design of Brushless Permanent Magnet Machine. 2nd edn. Motor Design Books LLC. Florida, USA.Google Scholar
  4. Hong, J. P. (2013). Trends of wound field synchronous motor development. Auto Journal, Korean Society of Automotive Engineers, 3510, 31–37.Google Scholar
  5. Jo, Y. S., Kim, Y. K. and Hong, J. P. (2001). Advanced design approach to the high temperature superconducting magnet. Cryogenics, 411, 27–33.CrossRefGoogle Scholar
  6. Jung, J. W., Lee, B. W., Kim, D. J. and Hong, J. P. (2012). Mechanical stress reduction of rotor core of interior permanent magnet synchronous motor. IEEE Trans. Magnetics, 482, 911–914.CrossRefGoogle Scholar
  7. Kato, T., Akatsu, K. and Lorenz, R. D. (2015). Design methodology for variable leakage flux IPM for automobile traction drives. IEEE Trans. Industry Applications, 515, 3812–3820.CrossRefGoogle Scholar
  8. Kelly, J., Scanes, P. and Bloore, P. (2014). Specification and design of a switched reluctance 48 V belt integrated starter generator for mild hybrid passenger car applications. SAE Paper No. 2014-01-1890.Google Scholar
  9. Lee, C. S., Kim, J. H. and Hong, J. P. (2015). Core loss effects on electrical steel sheet of wound rotor synchronous motor for integrated starter generator. J. Magnetics, 20,2, 148–154.CrossRefGoogle Scholar
  10. Li, J. T., Jabbar, M. A. and Gao, X. K. (2004). Design optimization for cogging torque minimization using response surface methodology. IEEE Trans. Magnetics, 402, 1176–1179.CrossRefGoogle Scholar
  11. Murata, Y. and Morimoto, S. (2001). Design and Control of IPMSM. Ohm Press. Tokyo, Japan.Google Scholar
  12. Rick, A. and Sisk, B. (2015). A simulation based analysis of 12 V and 48 V microhybrid systems across vehicle segements and drive cycles. SAE Paper No. 2015-01-1151.Google Scholar
  13. Shimizu, H., Okubo, T. and Abe, M. (2013). Development of an integrated electrified powertrain for a newly developed electric vehicle. SAE Paper No. 2013-01-1759.Google Scholar
  14. Umeda, A. and Mastumura, S. (2002). Development of a higher performance alternator. Denso Technical Review, 71, 56–62.Google Scholar

Copyright information

© KSAE 2019

Authors and Affiliations

  • Choong Sung Lee
    • 1
    • 2
  • Myung Hwan Yoon
    • 2
  • Jung Pyo Hong
    • 2
  • Young Kyoun Kim
    • 3
    Email author
  1. 1.Central R&D CenterSeongnam-si, GyeonggiKorea
  2. 2.Automotive EngineeringHanyang UniversitySeoulKorea
  3. 3.Electrical EngineeringOsan UniversityGyeonggiKorea

Personalised recommendations