General-Purpose High-Speed Position-Sensorless Control of Switched Reluctance Motors Using Single-Phase Adaptive Observer

The article proposes a general-purpose full-position estimation strategy for switched reluctance motors (SRMs) in high-speed operation using a single-phase adaptive observer (SPAO). The proposed approach does not need prestored flux linkage characteristics of SRMs for the full range position estimation, thereby avoiding offline magnetic parameter measurement. The SPAO has excellent adaptive bandpass characteristics, which can effectively suppress flux bias and harmonics from the real-time single-phase stator flux; therefore, the nonlinear SRM flux linkage can be decomposed into a pair of position orthogonally sine-cosine signal that is independent of motor parameters. Then, the speed and position of the SRM can be estimated from the orthogonal signals through the single-phase phase-locked loop (PLL). In particular, the position estimation offset caused by the discontinuous SRM conduction is obtained by the Fourier analysis in PLL. The control strategy is verified on the three-phase 12/8 SRM experimental setup. The findings demonstrate that, despite the flux linkage characteristics being unknown, the proposed method can estimate the rotor position using a single-phase observer; furthermore, the proposed high-speed sensorless control strategy is not only straightforward and efficient, but it also exhibits universality for SRMs with varying specifications and parameters.