Dan Noël, Motor Drive Expert

In the mid 1980's, Dan worked for the Aerospace Division of Thomson-Lucas, where he rose up to the challenges of the company's riskiest project at the time

& Leadership


DC Power






Dan's biggest project at Thomson-Lucas was to develop prototypes of 100 kVA GTO-based PWM inverter for reluctance motors with evaporation cooling system for the revolutionary highly flexible public transportation vehicle of the Aramis project:

  • the inverter was enclosed in airtight container and bathed in a fluorocarbon liquid; the heated liquid boiled and its steam condensed on a water-cooled heat exchanger
  • Dan, although new to the industry, surprised experts with his mastery of thermodynamics and came up with unexpectedly minuscule heatsinks and heat exchanger
  • Dan amazed company insiders with his understanding of the specifics of traction applications
  • Dan preached, based on his extensive traction experience and against prevailing wisdom, that the proposed system was complex, risky and expensive; as a skunk project, he put together the outline of an alternate design based on induction motors, Darlington modules and air cooling that promised to cut costs at least in half; he provided company with the files and verbal explanations on his last day of work there
  • Dan was overruled as he warned of subtle but debilitating risks at project inception; after Dan left company, at least one of them yielded field failures that contributed to project cancellation
  • Dan stayed on top of manufacturing, factory and field tests of first protos

Dan also made the case to introduce Japanese Darlington modules instead of European and American hockey-puck transistors for new designs.

Dan designed several PWM and square-wave inverters in the 100 kVA range for military, aviation and marine applications of variable speed permanent magnet and induction drives; most technically challenging was a torpedo drive, where Dan determined that space could be gained by using a 2-phase motor.

Dan also provided decisive boosts to other projects and other companies, among others:

  • tracing in a few hours a frustrating drive failure to the common-mode limitation of an optocoupler
  • stabilizing a robotic motion control loop by introducing a non-linear function in it
  • finding in a few days a 3 phase PWM optimization that had eluded experts for months
  • taming an induction motor drive by an IC intended to drive permanent magnet synchronous motors