scholarly journals Position Estimation and Compensation Based on a Two-Step Extended Sliding-Mode Observer for a MSFESS

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2467 ◽  
Author(s):  
Shusheng Li ◽  
Yongling Fu ◽  
Ping Liu
Keyword(s):  
Sliding Mode ◽  
Estimation Error ◽  
Angular Position ◽  
Position Estimation ◽  
Sliding Mode Observer ◽  
Measurement Noise ◽  
Estimation Accuracy ◽  
Second Step ◽  
Optimization Strategy ◽  
Unknown Disturbances

This paper aims to deal with the problem of rotor position estimation and compensation for a magnetically suspended flywheel energy storage system under the consideration of measurement noise and unknown disturbances. First, the flywheel system working principle and description are analyzed and, based on this, the mathematical model as well as the coordinates transformation are introduced. For the purpose of the state estimation, a two-step extended sliding-mode observer is considered to obtain the estimates of the rotor angular position. In this control strategy, a traditional sliding-mode observer is adopted as a first-step original state estimator. After that, the relationship between the angular position and the estimation error is established and a second-step observer is designed to obtain the estimation of the error. The estimated error is then used to compensate the real values of the rotor angular position generated by the first-step observer. To reject the influences of the measurement noise and unknown disturbances, the H∞ optimization strategy is considered to determine the second-step observer structure. Finally, experimental results are presented to demonstrate the effectiveness of the proposed method. It is demonstrated that the proposed two-step observer method has a better estimation accuracy and control performance.

A new reaching law for sliding mode observer of controllable excitation linear synchronous motor

2021 ◽  
pp. 014233122110320
Author(s):  
Xiaolei Shi ◽  
Yipeng Lan ◽  
Yunpeng Sun ◽  
Cheng Lei
Keyword(s):  
Sliding Mode ◽  
Dynamic Performance ◽  
Angular Position ◽  
Lyapunov Stability Theory ◽  
Synchronous Motor ◽  
Position Estimation ◽  
Sliding Mode Observer ◽  
Sigmoid Function ◽  
Reaching Law ◽  
Linear Synchronous Motor

This paper presents a sliding mode observer (SMO) with new reaching law (NRL) for observing the real-time linear speed of a controllable excitation linear synchronous motor (CELSM). For the purpose of balancing the dilemma between the rapidity requirement of dynamic performance and the chattering reduction on sliding mode surface, the proposed SMO with NRL optimizes the reaching way of the conventional constant rate reaching law (CRRL) to the sliding mode surface by connecting the reaching process with system states and the sliding mode surface. The NRL is based on sigmoid function and power function, with proper options of exponential term and power term, the NRL is capable of eliminating the effect of chattering on accuracy of the angular position estimation and speed estimation. Compared with conventional CRRL, the SMO with NRL achieves suppressing the chattering phenomenon and tracking the transient process rapidly and accurately. The stability analysis is given to prove the convergence of the SMO through the Lyapunov stability theory. Simulation and experimental results show the effectiveness of the proposed NRL method.

State of Charge Estimation of Power Lithium-Ion Battery Based on Sliding Mode Observer

2013 ◽  
Vol 805-806 ◽  
pp. 1692-1699 ◽  
Author(s):  
Tie Zhou Wu ◽  
Ming Yue Wang ◽  
Qin Xiao
Keyword(s):  
Sliding Mode ◽  
Estimation Error ◽  
Lithium Ion ◽  
Value Theory ◽  
The State ◽  
Sliding Mode Observer ◽  
State Of Charge ◽  
Estimation Accuracy ◽  
Design Parameters ◽  
State Of Charge Estimation

The study of the application of the sliding mode observer method that estimates the state of charge. Based on the state space model of battery established on the model of improved EMF equivalent circuit, a sliding mode state observer is designed to help improve the jitter problem. Considering the nonlinear terms in the model for the analysis of the stability of the observer and the characteristics of the industry under its derivative, and using Lagrange mean value theory to guarantee the convergence conditions of the observer, the design parameters of the observer can thus be determined .Then, this thesis compares the simulation of this method under Matlab environment with the extended Kalman filter method. The results show that the method has higher estimation accuracy in the case of the same battery modeling errors. Therefore, the SOC estimation of the sliding mode observer can effectively reduce the state of charge estimation error introduced by the model error.

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

Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1225 ◽  
Author(s):  
Shuo Chen ◽  
Xiao Zhang ◽  
Xiang Wu ◽  
Guojun Tan ◽  
Xianchao Chen
Keyword(s):  
High Speed ◽  
Sliding Mode ◽  
Sensorless Control ◽  
Estimation Error ◽  
Signal Reconstruction ◽  
Phase Locked Loop ◽  
Position Estimation ◽  
Sliding Mode Observer ◽  
Accurate Estimation ◽  
Simple Strategy

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.

scholarly journals Estimation and Fault Diagnosis of Lithium-Ion Batteries: A Fractional-Order System Approach

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Shulan Kong ◽  
Mehrdad Saif ◽  
Guozeng Cui
Keyword(s):  
Fault Diagnosis ◽  
Fault Detection ◽  
Fractional Order ◽  
Sliding Mode ◽  
Estimation Error ◽  
Lithium Ion ◽  
Fault Isolation ◽  
Sliding Mode Observer ◽  
Fault Detection And Isolation ◽  
Order System

This study investigates estimation and fault diagnosis of fractional-order Lithium-ion battery system. Two simple and common types of observers are designed to address the design of fault diagnosis and estimation for the fractional-order systems. Fractional-order Luenberger observers are employed to generate residuals which are then used to investigate the feasibility of model based fault detection and isolation. Once a fault is detected and isolated, a fractional-order sliding mode observer is constructed to provide an estimate of the isolated fault. The paper presents some theoretical results for designing stable observers and fault estimators. In particular, the notion of stability in the sense of Mittag-Leffler is first introduced to discuss the state estimation error dynamics. Overall, the design of the Luenberger observer as well as the sliding mode observer can accomplish fault detection, fault isolation, and estimation. The effectiveness of the proposed strategy on a three-cell battery string system is demonstrated.

scholarly journals An Improved Super-Twisting High-Order Sliding Mode Observer for Sensorless Control of Permanent Magnet Synchronous Motor

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6047
Author(s):  
Yujiao Zhao ◽  
Haisheng Yu ◽  
Shixian Wang
Keyword(s):  
Permanent Magnet ◽  
High Performance ◽  
Sliding Mode ◽  
Sensorless Control ◽  
Permanent Magnet Synchronous Motor ◽  
High Order ◽  
Sliding Mode Observer ◽  
Estimation Accuracy ◽  
Permanent Magnet Synchronous Motors ◽  
Rotor Position

This article presents an improved super-twisting high-order sliding mode observer for permanent magnet synchronous motors to achieve high-performance sensorless control. The proposed observer is able to simultaneously estimate rotor position and speed, as well as track parameter disturbances online. Then, according to the back-EMF model, the sensorless observer is further constructed to improve the estimation effect. The estimated rotor position and speed are used to replace the actual values detected by the sensor, and the estimated parameter disturbances are considered as feedback values to compensate the command voltage. In this way, not only is the estimation accuracy improved, but the robustness against uncertainties is also enhanced. Simulation and experimental results show that the proposed observer can effectively track the rotor position and speed and obtain good dynamic and steady-state performance.

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