Observability Analysis and Improved Zero‐Speed Position Observer Design of Synchronous Motor with Experimental Results

Abstract

This paper deals with the permanent magnet synchronous motor (PMSM) observability analysis for sensorless control design. The problem of loss of observability at low frequency range is always recognized in experimental settings. Nevertheless, there are no sufficient theoretical observability analyses for the PMSM. In the literature, only the sufficient observability condition has been presented. Therefore, the current work is aimed especially towords the necessary observability condition analysis. Furthermore, improved zero-speed observation is presented here for a surface PMSM (SPMSM) to overcome position observability problems at zero-speed which is an unobservable state point. The proposed observer based on higher order sliding mode (HOSM) is designed in order to ensure robustness against disturbances and to avoid the chattering phenomenon which is inherent in standard first order sliding modes. The stability and finite time convergence of the developed observer are studied and discussed. Experimental results are carried out to illustrate the effectiveness and robustness of the proposed observer. d dt P J L L i i f J T J [ sin( ) cos( ) ] 2 1 v v l J T J ω −

Nonlinear observer for the PM synchronous motor

“…Remark 2: The rotor position can be estimated by integrating the rotor speed with the knowledge of the initial rotor position [6].…”

“…Numerous observer strategies are developed to estimate the states and the parameters of PMSM, such as adaptive observer [1], [2], sliding mode observer [3], [4], [5], [6] and Extended Kalman filter [7], [8], [9], [10]. Recently in [11], [12] an adaptive interconnected observer has been proposed.…”

Sensorless control of permanent magnet synchronous motor based on fixed‐time terminal sliding mode observer

“…Sensorless techniques for PMSMs are broadly classified into three types: motion electromotive force (EMF), inductance, and flux linkage [9]. Currently, model-based approaches are generally recognized as effective methods for the sensorless PMSM control strategy, especially during the medium-and high-speed ranges [10][11][12][13]. Several model-based approaches have recently been explored, such as the sliding mode observer (SMO) [14][15][16][17][18][19], the model-referenced adaptive system [20], and the extended Kalman filter [21], among others.…”

Differential Mode Modeling of PMSM for High Frequencies and Harmonic Pulses Calculation

“…These inverters have switching frequencies in the range of 1-20 kHz for power levels over 500 kW. The existence of these switching frequencies together with their short pulse rise time (0.1-2 μs), result in deteriorations of sensitive control algorithms such as observability analysis [2]. Additionally, it results in over-voltage at motor terminals in the existence of connected cables [3][4][5][6].…”