Analogue versus digital solution for motor control

Abstract: Saab has an analogue solution which is used to drive small motors in aircrafts. The motor is a brushless DC-motor and uses a resolver and hall sensors to control it. As sensorless control is something that has been expanding and attracting more interest over the last decade, Saab is considering the possibility of using a digital sensorless system depending on its performance on the control compared to their analogue system. There is little documentation of performance for a digital sensorless solution compared to an analogue solution. Therefore the question to be answered in this research is: How is the performance of the digital solution compared to the existing analogue solution? It was answered by finding a complete sensorless system on the market and then compare its performance to a digital system with sensors that resembles the analogue solution. Performance wise, InstaSPIN does not perform as well as EPOS2 which represent the sensorless system respective the system with sensors. InstaSPIN needs a startup sequence, can not run at the same low velocities, has a longer rise time, settling time and greater ripple. An examination of the software should be done before using the disadvantages that was found as a reason for not considering a sensorless system. Especially the startup sequence in the software should be examined as it is InstaSPINs greatest weakness compared to EPOS2.