Analysis and Tests of the Sensorless Rotor Position Detection of Ringed-Pole Permanent-Magnet Motor

Abstract

To the aim of creating a high-frequency (HF) anisotropy in a surface-mounted PM machine conductive rings are placed around each pole such rings modify the d-axis HF impedance of the machine. A novel strategy is adopted to evaluate the HF signal injection response of such a ringed-pole electrical machine. The self-sensing capability of the machine is evaluated by means of a small-signal model of the machine in the d−q reference frame and finite-element simulations. The impact of the rings on the HF signals achieved in the analysis is validated by the comparison with experimental results.Index Terms-AC motor drives, finite-element (FE) simulations, high-frequency (HF) saliency, permanent-magnet (PM) machines, sensorless drives.

A test bench for hybrid propulsion train research and development

“…As already proved by similar electromagnetic structure in an inner SPM motors [9], this configuration ex hibits a high frequency (hi) anisotropy that can be detected by conventional hf signal injection sensorless techniques for rotor position measurement [10], [11]. Induced hf currents in rotor cage are very low; therefore additional losses are negligible as well as hf parasitic torque [12].…”

Design and Evaluation of a Short-Circuit Rotor-Ring for Enhanced Self-Sensing Capability in a Slotless PM Motor

“…However, high-dynamic control of slotless PM motors requires significantly improved position estimation capability. Another way to enhance magnetic anisotropy in slotted SPM motors is to utilize a rotor winding [27]- [30], enabling an asymmetric high-frequency signal response. The method not only improves anisotropy but also the sensitivity to saturation and d and q-axis cross-coupling [28], [31] at the expense of additional rotor losses [32].…”

Self‐commissioning of flux linkage curves of synchronous reluctance machines in quasi‐standstill condition

“…The interest in taking into account undesired effects while estimating magnetic models is also a target of self‐commissioning methods for position‐sensorless estimation techniques, especially for those based on high‐frequency signal injection. Many examples are reported in the literature [18–22]. While concluding that magnetic models are frequency dependent, the reported solutions do not discuss the core losses phenomena at lower frequencies.…”