Unjo presents motor control lecture

Unjo R&D engineer Björn Alving gave a presentation providing both an overview and some advanced in-depth topics on motor control for synchronous motors at the annual Kraftforum meeting 30th of August 2018 in Gothenburg.

Kraftforum is a regional electronic engineering network of companies, engineers and schools with the vision to become a world-class knowledge arena through active networking, education and joint research.

The goal is to provide higher electrical and electronic competence levels, thereby providing companies to develop and launch more advanced products and services in a faster way.


Unjo contributed to Kraftforum’s mission of increasing technological interest and industry-oriented education in cooperation with the region’s schools.

The lecture from Unjo focused on the synchronous motor, the motor constants and motor control basics such as field oriented controls and trajectory shaping to guarantee smooth movements.

Other topics were various options for brake energy handling including dumping the brake energy into the motor windings.

The topics that generated most interest were;

  • HFI (high frequency injection) based sensorless control to determine the angular position of the rotor, which is possible even from standstill by applying test currents along and perpendicular to the rotor magnet.
  • Field weakening, a technique that lowers the phase voltage making it possible to run the motor faster than the back-emf otherwise would allow.

For more information;