Hybrid Observer Structure for Sensorless Control of IPMSM Machines

A hybrid angular position sensorless observer structure for interior permanent magnet synchronous motor drives is proposed in this article. To have precise and smooth sensorless control of the IPMSM drive for wide-speed range operation, a hybrid position estimation technique is prepared in collaboration with the high frequency (HF) signal injection method with the electromotive force (EMF) method. While the IPMSM drive operates at a low-speed range, an HF voltage signal is injected, and an angular position observer is designed to estimate rotor position. At medium and high-speed operation of the drive, rotor position information is obtained using the extended EMF-based observer structure in ($\boldsymbol{\alpha}-\boldsymbol{\beta})$ stationary reference frame for the IPMSM drive. Slot harmonics and non-sinusoidal distribution of flux are present in the IPMSM. Observer structures are prepared considering the above problem. The effectiveness of the proposed sensorless control scheme is validated using field-oriented control by simulation analysis and experimental results.