Design Issues and Estimation Errors Analysis of Back-EMF-Based Position and Speed Observer for SPM Synchronous Motors

Abstract

A back-electromotive force-based sensorless technique for surface-mounted permanent magnet synchronous motor drives is considered in this paper. The model of the observer is developed in the Laplace domain and represents an original approach with respect to state-of-art proposals, normally employing a state-space representation. This allows a more intuitive but equivalent design of the observer's gains, based on the standard frequency response, as compared with eigenvalues analysis. Moreover steady-state errors are obtained from a theoretical point-of-view, including the effects of the most common nonidealities affecting the drive system and parameters sensitivity. Full simulation and experimental characterization of the sensorless drive is provided with reference to a general purpose industrial drive, i.e., both in transient and steady-state and in the most meaningful speed/torque operating conditions

Impact of iron losses and parameter errors on back-EMF based sensorless control of PMSM

“…This leads to the conclusion that the iron losses are properly considered by the proposed model (2).…”

“…The error occurs by reason the iron losses are not considered in the model based dynamic feed forward control which is based on model (1). In the following the impact of iron losses on the position estimation error is analyzed usiing model (2). The calculation of the error signal is performed the same way as in the previous subsection: account:…”

“…Stateof-the-art methods use machine model based observers which provide an estimate of the (electric) rotor position needed for field oriented control. The impact of parameter errors on position estimation accuracy is an important issue [1], [2], [3]. However, the impact of iron losses was not taken into consideration for back-EMF based sensorless control of PMSM so far.…”

Design of a globally stable position estimator for surface permanent‐magnet synchronous motors

“…Much research on the model-based position estimation of surface permanent-magnet synchronous motors (SPMSMs) has been conducted until now [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Model-based estimation algorithms can be classified into two categories, i.e.…”

“…On the other hand, many observer-based estimators use the stator model and the stator current error feedback to estimate the back EMF, which is, in turn, used to calculate the position and speed [6,7,10,11]. However, these methods are derived based, again, on a steady-state assumption of the back EMF.…”