Optimised SEnsorless Control systems for rare-earth brushless Traction motORs SECTOR

The aim of this DTI sponsored project is to realise a power dense direct-drive, in-hub brushless traction system to a specification in terms of torque, mass, volume, range and cost.

Internal view of prototype 300W external rotor motor

Initial consortium partners:

  • Axeon Power
  • EMD Drive Systems
  • Magnet Applications Group
  • NXP
  • PERA
  • Powakaddy
  • The University of Sheffield

Direct-drive traction motors are becoming increasingly popular for all-electric vehicles over traditional geared motor solutions, due to their ability to provide torque over a wide operating range without the need of a mechanical gearbox, thereby mitigating issues concerning mechanical wear, and lubrication.

The in-hub design of the SECTOR motor utilises a fixed axle internal stator with rotating external rotor forming the wheel hub, allowing direct fitment of the tyre. In many cases, the drive electronics can be mounted within the confines of the stator, providing a fully integrated wheel solution.

Final product development is aimed towards sensorless control of a brushless AC motor.

Three target markets have been specified as electric mobility vehicles, battery powered floor cleaners/polishers and motorised golf-trolleys.

Prototype 300W external rotor, brushless DC traction motor for electric mobility vehicle