Sensorless Control for IPMSM Based on Adaptive Super-Twisting Sliding-Mode Observer and Improved Phase-Locked Loop

Shuo Chen,Xiang Wu,Xiao Zhang,Xianchao Chen,Guojun Tan

doi:10.3390/en12071225

Abstract

In traditional sensorless control of the interior permanent magnet synchronous motors(IPMSMs) for medium and high speed domains, a control strategy based on a sliding-mode observer(SMO) and phase-locked loop (PLL) is widely applied. A new strategy for IPMSM sensorless controlbased on an adaptive super-twisting sliding-mode observer and improved phase-locked loop isproposed in this paper. A super-twisting sliding-mode observer (STO) can eliminate the chatteringproblem without low-pass filters (LPFs), which is an effective method to obtain the estimated backelectromotive forces (EMFs). However, the constant sliding-mode gains in STO may causeinstability in the high speed domain and chattering in the low speed domain. The speed-relatedadaptive gains are proposed to achieve the accurate estimation of the observer in wide speed rangeand the corresponding stability is proved. When the speed of IPMSM is reversed, the traditionalPLL will lose its accuracy, resulting in a position estimation error of 180°. The improved PLL basedon a simple strategy for signal reconstruction of back EMF is proposed to ensure that the motor canrealize the direction switching of speed stably. The proposed strategy is verified by experimentaltesting with a 60-kW IPMSM sensorless drive.

Highlights

Interior permanent magnet synchronous motors (IPMSMs) have been extensively utilized in the fields of electromechanical drives, electric vehicles, and numerical control servo systems due to their robustness, high efficiency, high power density, and compactness [1,2,3,4]
The control diagram of proposed sensorless control strategy for interior permanent magnet synchronous motors (IPMSMs) based on adaptive STO
Is is utilized to to obtain thethe estimated back electromotive forces and thethe speed-related adaptive gains are proposed to achieve the accurate estimation of the observer in wide speed-related adaptive gains are proposed to achieve the accurate estimation of the observer in wide speed range

Summary

Introduction

Interior permanent magnet synchronous motors (IPMSMs) have been extensively utilized in the fields of electromechanical drives, electric vehicles, and numerical control servo systems due to their robustness, high efficiency, high power density, and compactness [1,2,3,4]. The first one is called signal injection methods [7,8,9] This method is based on the salient pole effect of the motor, which is mainly used in zero and low speed domains. The second one is called back EMF based methods [10,11,12,13,14,15,16,17,18,19], which utilizes the estimated back EMF signals to obtain the position information of the motor. Back EMF based methods and signal injection methods are usually combined to achieve sensorless control for a whole speed range [12,13,14]. Back EMF based methods primarily includes the model adaptive method (MRAS) [16], Energies 2019, 12, 1225; doi:10.3390/en12071225 www.mdpi.com/journal/energies

Methods

Results

Conclusion