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Development of sensorless control for permanent magnet synchronous machine (PMSM) successfully finis

Emsiso successfully finished the development of sensorless control for permanent magnet synchronous machine controllers using linear observer to eliminate a need for a rotor position sensor.

This algorithm is optimized for aviation, marine and submarine applications, where due to the harsh environments rotor position sensors are costly and time consuming and are also often presenting a single point of failure in the system.

In addition to standard field oriented control (FOC) with rotor position sensor, linear observer based on phase voltage and current measurements estimates BEMF voltages which are used for electrical angle calculation. Due to accurate phase voltage measurements, power stage can also be smoothly enabled while the motor is already rotating, for correct and robust closing of the loop sophisticated criteria function and sensorless state machine is used which was also developed by Emsiso.

All functionalities becomes convenient especially in applications where starting the motor from standstill is not always possible e.g. serial hybrids, aero-plane and ship propellers.

More info about co-financed project "Degraded mode motor controller" and public tender is available on

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