A New Electrode Regulator System Identification of Arc Furnace Based on Time-Variant Nonlinear-Linear-Nonlinear Model

2016 ◽  
Vol 2 (1) ◽  
pp. 32
Author(s):  
Jinfeng Wang ◽  
Shoulin Yin ◽  
Xueying Wang
Keyword(s):  
Nonlinear Model ◽  
Model System ◽  
Time Varying ◽  
Arc Furnace ◽  
Identification Process ◽  
System Parameters ◽  
Online Identification ◽  
Arc Characteristics ◽  
Controlling System ◽  
The Mind

<p>In this paper, we express arc furnace electrode regulator system as a time-variant nonlinear-linear-nonlinear model. On this basis, we propose an online identification method based on nonlinear-linear-nonlinear model system. This new scheme solves the problem of model variation and prediction precision decline causing by time-varying of arc characteristic. In order to dispose the difficulty of parameters separation in the online identification process, this new method adopts the mind of update the parameters of linear parts and nonlinear parts respectively. It realizes the parameters separation of system effectively. Simulation results show that this method can track the changes of arc characteristics effectively. That it achieves the aim of real-time monitoring and controlling system parameters.</p>

scholarly journals Model system parameters influence the sodium hypochlorite susceptibility of endodontic biofilms

2021 ◽  
Author(s):  
R.C.D. Swimberghe ◽  
A. Crabbé ◽  
R.J.G. De Moor ◽  
T. Coenye ◽  
M.A. Meire
Keyword(s):  
Sodium Hypochlorite ◽  
Model System ◽  
System Parameters

Dynamics of a Continuous System With Clearance and Motion Limiting Stops

1999 ◽  
Author(s):  
P. Metallidis ◽  
S. Natsiavas
Keyword(s):  
Piecewise Linear ◽  
Research Work ◽  
Continuous System ◽  
Continuous Model ◽  
Equation Of Motion ◽  
Model System ◽  
Periodic Motions ◽  
System Parameters ◽  
Rigid Rods ◽  
The Stability

Abstract The present study generalises previous research work on the dynamics of discrete oscillators with piecewise linear characteristics and investigates the response of a continuous model system with clearance and motion-limiting constraints. More specifically, in the first part of this work, an analysis is presented for determining exact periodic response of a periodically excited deformable rod, whose motion is constrained by a flexible obstacle. This methodology is based on the exact solution form obtained within response intervals where the system parameters remain constant and its behavior is governed by a linear equation of motion. The unknowns of the problem are subsequently determined by imposing an appropriate set of periodicity and matching conditions. The analytical part is complemented by a suitable method for determining the stability properties of the located periodic motions. In the second part of the study, the analysis is applied to several cases in order to investigate the effect of the system parameters on its dynamics. Special emphasis is placed on comparing these results with results obtained for similar but rigid rods. Finally, direct integration of the equation of motion in selected areas reveals the existence of motions, which are more complicated than the periodic motions determined analytically.

Confirmation of a Nonlinear Model Predictive Control Strategy Applied to a Permanent Magnet Linear Generator for Wave-Energy Conversion

2014 ◽  
Author(s):  
Nathan Tom
Keyword(s):  
Predictive Control ◽  
Nonlinear Model ◽  
Power Output ◽  
Electrical Power ◽  
Equation Of Motion ◽  
Nonlinear Model Predictive Control ◽  
Floating Body ◽  
Time Varying ◽  
Irregular Wave ◽  
Electrical Power Output

This paper begins with a brief review of the time-domain equation of motion for a generic floating body. The equation of motion of the floating body was modified to account for the influence of a power-take-off unit (PTO) to predict the hydrodynamic and electromechanical performance of the coupled system. As the damping coefficient is considered the dominant contribution to the PTO reaction force, the optimum non time-varying damping values were first presented for all frequencies, recovering the well-known impedance-matching principle at the coupled resonance frequency. In an effort to further maximize power absorption in both regular and irregular wave environments, nonlinear model predictive control (NMPC) was applied to the model-scale point absorber developed at UC Berkeley. The proposed NMPC strategy requires a PTO unit that could be turned on and off instantaneously, leading, interestingly to electrical sequences where the generator would be inactive for up to 60% of the wave period. In order to validate the effectiveness of this NMPC strategy, an in-house designed permanent magnet linear generator (PMLG) was chosen as the PTO. The time-varying performance of the PMLG was first characterized by dry-bench tests, using mechanical relays to control the electromagnetic conversion process. Following this, the physical set-up was transferred to the wave tank. The on/off sequencing of the PMLG was tested under regular and irregular wave excitation to validate NMPC simulations using control inputs obtained from running the control algorithm offline. Experimental results indicate that successful implementation was achieved and the absorbed power using NMPC was up to 50% greater than the passive system, which utilized no controller. However, after considering the PMLG mechanical-to-electrical conversion efficiency the useful electrical power output was not consistently maximized. To improve output power, a mathematical relation between the efficiency and damping magnitude of the PMLG was inserted in the system model to maximize the electrical power output through continued use of NMPC. Of significance, results from these latter simulations provided a damping time series that was active over a larger portion of the wave period and required the actuation of the applied electrical load connected to the PMLG, rather than a simple on/off type control.

Nonlinear Model Predictive Control Strategy for Limit Management of Aero-Engines

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Xian Du ◽  
Yan-Hua Ma ◽  
Xi-Ming Sun
Keyword(s):  
Predictive Control ◽  
Nonlinear Model ◽  
Penalty Function ◽  
Control Strategy ◽  
Nonlinear Model Predictive Control ◽  
Time Varying ◽  
Input Output ◽  
Computational Burden ◽  
Prediction Horizon ◽  
Aero Engines

Abstract A Min-Max structure combined with several linear limit controllers are utilized for conventional aero-engines safety control, which is complex and conservative, therefore a new nonlinear model predictive control strategy is proposed that owns the ability to manage time-varying input/output limits during acceleration/deceleration transient states of aero-engines. Penalty function items are constructed according to the characteristics of input/output limits, and are incorporated in the cost function of online receding horizon optimization for limit management of aero-engines. Considering the large computational burden of nonlinear component-level aero-engine model directly used as prediction model, a piecewise linear model is built to describe the steady-state and dynamic properties of aero-engines and its design process is explained in detail. Further, computational efforts are investigated as control horizon, prediction horizon are varied in the improved nonlinear predictive controller. Particularly, when penalty function items are activated, control performance and computational burden are examined, thus providing guidelines for key parameters tuning. Simulations show two clear results. One is that computational efforts become larger for bigger control horizon or prediction horizon, but it depends more on control horizon than prediction horizon. The other is that the proposed method can handle time-varying input/output limits effectively without resulting in a great increase of computational burden.

scholarly journals Windowed Least Square Algorithm Based PMSM Parameters Estimation

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Song Wang
Keyword(s):  
Embedded System ◽  
Window Size ◽  
Parameters Estimation ◽  
Least Square ◽  
Time Varying ◽  
Recursive Least Square ◽  
Permanent Magnet Synchronous Motors ◽  
Practical Applications ◽  
Controlling System ◽  
System Resource

Stator resistance and inductances ind-axis andq-axis of permanent magnet synchronous motors (PMSMs) are important parameters. Acquiring these accurate parameters is usually the fundamental part in driving and controlling system design, to guarantee the performance of driver and controller. In this paper, we adopt a novel windowed least algorithm (WLS) to estimate the parameters with fixed value or the parameter with time varying characteristic. The simulation results indicate that the WLS algorithm has a better performance in fixed parameters estimation and parameters with time varying characteristic identification than the recursive least square (RLS) and extended Kalman filter (EKF). It is suitable for engineering realization in embedded system due to its rapidity, less system resource possession, less computation, and flexibility to adjust the window size according to the practical applications.

Application of a Hilbert Transform-Based Algorithm for Parameter Estimation of a Nonlinear Ocean System Roll Model

1997 ◽  
Vol 119 (4) ◽  
pp. 239-243 ◽  
Author(s):  
O. Gottlieb ◽  
M. Feldman
Keyword(s):  
Parameter Estimation ◽  
Nonlinear Model ◽  
Hilbert Transform ◽  
Random Noise ◽  
Nonlinear Damping ◽  
Model System ◽  
Field Calibration ◽  
Calibration Test ◽  
Fishing Boat ◽  
Backbone Curves

We combine an averaging procedure with a Hilbert transform-based algorithm for parameter estimation of a nonlinear ocean system roll model. System backbone curves obtained from data are compared to those obtained analytically and are found to be accurate. Sensitivity of the results is tested by introducing random noise to a nonlinear model describing roll response of a small fishing boat. An example field calibration test of a small semisubmersible exhibiting nonlinear damping is also considered.

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