Hall-Effect Sensors as Multipurpose Devices to Control, Monitor and Diagnose AC Permanent Magnet Synchronous Machines

The increasing use of permanent magnet synchronous machines is motivating the research on lower cost and higher reliability techniques for control, diagnostics and condition monitoring. Control of PMSMs typically involves current and position sensors while diagnostics tasks usually rely on vibration, flux measurements, current monitoring etc. Hall-effect sensors have shown to be a low cost, robust and reliable option for position/speed feedback (to control the machine), online monitoring and detection of failures through the leakage flux measurement using simple processing algorithms. This paper summarizes the available techniques for motion control, monitoring and diagnosis of permanent magnet synchronous machines using Hall-effect sensors and proposes a processing method to allow simultaneous operation of all these techniques. The output of the proposed system are estimations of the rotor position, electromagnetic torque, permanent magnet magnetization state, permanent magnet temperature and degree of eccentricity.