Higher-Order Sliding Mode Observer for Speed and Position Estimation in PMSM

Suneel K Kommuri,Yeng C Soh,M Defoort,Kalyana C Veluvolu

doi:10.1155/2014/589109

Abstract

This paper presents a speed and position estimation method for the permanent magnet synchronous motor (PMSM) based on higher-order sliding mode (HOSM) observer. The back electromotive forces (EMFs) in the PMSM are treated as unknown inputs and are estimated with the HOSM observer without the need of low-pass filter and phase compensation modules. With the estimation of back EMFs, an accurate estimation of speed and rotor position can be obtained. Further, the proposed method completely eliminates chattering. Experimental results with a 26 W three-phase PMSM demonstrate the effectiveness of the proposed method.

Highlights

The permanent magnet synchronous motor (PMSM) has high efficiency, high torque to inertia ratio, and high power density, and it is popular for high performance motion control applications
The motor used in the experimental setup is a TBL-i model TS4632N2050E510 3-phase PMSM
The PMSM is powered by a Fairchild FSB50325S smart power module which includes 6 fast-recovery MOSFET (FRFET) inverters and 3 half-bridge high voltage integrated circuits (HVICs)

Summary

Introduction

The permanent magnet synchronous motor (PMSM) has high efficiency, high torque to inertia ratio, and high power density, and it is popular for high performance motion control applications. Several methods are available for rotor position and/or speed estimation in a sensorless PMSM drive [2, 6]. The speed estimation based on ISM current control requires an additional low-pass filter, which introduces the delay, and which in turn reduces the system’s phase margin and can cause instability. The motivation of this work is to provide the HOSM observer with the properties of finite time convergence and low chattering effect compared to the classical equivalent control obtained with a traditional firstorder SMO that requires a low-pass filter [3]. The observer enables the estimation of the rotor position and speed of the PMSM in real time while reducing the well-known chattering phenomenon. A; ‖A‖ denotes the 2-norm √λmax(ATA) of A. λmin(A) represents its minimum singular value

PMSM Modeling and Problem Statement

High Order Sliding Mode Observer

Experimental Results

Conclusion