Sensorless Control of Permanent Magnet Machine Drives for Aerospace Applications

A real-time, sensorless, zero speed position sensing algorithm for permanent magnet machines is presented. The strategy is applicable to any brushless permanent magnet machine that exhibits magnetic saliency. It is computationally simple and fast and can be used with machines that exhibit distorted saliencies. A Finite Element model confirms the form of the magnetic saliency and provides a design tool enabling suitability for sensorless control to be included as a key consideration in the development of bespoke machines. This offers advantages in terms of improving the accuracy and robustness of any saliency based sensorless scheme. Finally, experimental results show that the position measurement scheme exhibits excellent agreement with results obtained using a resolver. The robustness of the technique makes it ideally suited to aerospace applications.