Sensorless Control of Wound Rotor Synchronous Motors Based on Rotor High-Frequency Signal Injection

High-frequency (HF) signal injection-based has been widely investigated for sensorless position/speed control of permanent magnet synchronous machines (PMSMs). In PMSMs, the HF signal must be injected in the stator windings and an asymmetric (salient) rotor is required. The extension of HF injection-based sensorless methods with wound-rotor synchronous motors is studied in this article. The fact that rotor terminals are accessible opens interesting possibilities, as avoids the dependency on rotor asymmetries.