Torque estimation in permanent magnet synchronous machines and synchronous reluctance machines is required in many applications. Torque produced by a permanent magnet synchronous machine depends on the permanent magnets’ flux and d q -axes inductances, whereas torque in synchronous reluctance machines depends on the d q -axes inductances. Consequently, precise knowledge of these parameters is required for proper torque estimation. The use of high frequency signal both for permanent magnets’ flux and d q -axes inductances estimation has been recently shown to be a viable option. This paper reviews the physical principles, implementation and performance of high-frequency signal injection based torque estimation for permanent magnet synchronous machines and synchronous reluctance machines.
Review of Research on Sensorless Control of Permanent Magnet Synchronous Machines Based on Fluctuating High-Frequency Carrier Signal Injection