Automobile and Aerospace, Available technologies, Clean Technologies, Energy, Engineering, Green transportation


70% reduction in torque ripple and an improved power capability for a wider range of the speed

Challenge market of electric vehicle permanent magnet synchronous motor/drive 

  • Permanent magnet synchronous motors (PMSMs) with rare-earth magnets are widely utilized
  • Application of low coercively magnets provides the ability of magnetization and demagnetization of the rotor magnets that improves the efficiency of the machine in the high speed region
  • Variable flux machine (VFM) can work with high efficiency for a wider range of speed while conventional rare-earth PMSM suffers from lower efficiency at high speed
  • 30% loss reduction for the urban driving cycle of an electric vehicle (EV) using a variable flux motor/drive
  • Characterization of the torque-speed envelope is an important step in the design of PMSMs, specifically for the field weakening mode of operation
  • VFM has the capability of operating at different MLs
  • Need of a new design of VFM with conventional saliency to enhance its power and torque capabilities in the field weakening region

The new design of optimized radially magnetized variable flux motor / drive

  • Novel design of AlNiCo-based radially magnetized variable flux machine
  • Positioning interior magnets to keep the fully magnetized condition at no-load and be able to get demagnetized and re-magnetized
  • 6 pole design of rotor with radially magnetized interior magnet to provide the positive reluctance torque in the field weakening region
  • An analytical method using the finite element results and ted q model of the PMSM is to develop the torque-speed and power-speed characteristics
  • Prototype available
  • Technology developed by Prof. Pragasen Pillay, Amirmasoud Takbash and Maged Ibrahim at Concordia University

Competitive advantages

  • 70% reduction in torque ripple
  • Maximizing power and torque capabilities at wide range of the speed
  • Reducing the dependency on rare-earth elements
  • Operating at high temperatures (without demagnetization)
  • Low cost (don’t need rare-earth magnets)

Interesting market applications 

  • Industrial motors operating at variable speeds, high power density and high efficiency
  • Motors for home appliances
  • Automotive applications for electric and hybrid electric vehicles

Business opportunity

  • Technology available for licensing
  • Provisional patent application filed


If you are interested by this technology, please contact :
Duc LeVan, Director Business Development, (514) 840-1226, Ext. 3003


Concordia University

Main inventors

Pragasen Pillay & Tamanwè Payarou

Photo of Prof. Pillay, he is a professor in the department of Electrical and Computer Engineering, Concordia University

Pragasen Pillay
Professor and NSERC/Hydro-Québec Senior Industrial Research Chair

Prof. Pillay is a professor in Electrical and Computer Engineering Department. His research interests are in Modeling, Analysis, Design and Control of Electrical Machines, Electric Motor Drive Systems, Traction Motors for Electric and Hybrid Electric Vehicles, Renewable Energy including Wind, Biomass and Solar Energy, Energy Storage, Energy Efficiency and Conservation, Sustainability issues in Power and Energy Engineering.


Amirmasoud Takbash 

Amirmasoud Takbash received the bachelor’s degree in electrical engineering from the Iran University of Science and Technology, Tehran, Iran, in 2008, and the master’s degree in electrical engineering from the University of Tehran, Tehran, in 2011. He is currently pursuing the Ph.D. degree in electrical engineering with Concordia University.,His current research interests include electrical machine design, modeling and characterization, and core loss estimation.

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