Black-Box Behavioral Modeling of Voltage and Frequency Response Characteristic for Islanded Microgrid

The voltage and frequency response model of microgrid is significant for its application in the design of secondary voltage frequency controller and system stability analysis. However, most models developed for this aspect are complex in structure due to the difficult mechanism modeling process and are only suitable for offline identification. To solve these problems, this paper proposes a black-box modeling method to identify the voltage and frequency response model of microgrid online. Firstly, the microgrid system is set as a two-input, two-output black-box system and can be modeled only by data sampled at the input and output ports. Therefore, the simplicity of modeling steps can be guaranteed. Meanwhile, the recursive damped least squares method is used to realize the online model identification of the microgrid system, so that the model parameters can be adjusted with the change of the microgrid operating structure, which makes the model more adaptable. The paper analyzes the black-box modeling process of the microgrid system in detail, and the microgrid platform, including 100 kW rated power inverters, is employed to validate the analysis and experimental results.

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Keysight 3458A Frequency Response Model Identification

2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) ◽

10.1109/cpem.2018.8500944 ◽

2018 ◽

Cited By ~ 1

Author(s):

Rado Lapuh ◽

Rok Lapuh

Keyword(s):

Frequency Response ◽

Model Identification ◽

Response Model

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Amplitude Frequency Response Analysis and Synthesis of Unfactored Transfer Functions

Journal of Basic Engineering ◽

10.1115/1.3653106 ◽

1964 ◽

Vol 86 (1) ◽

pp. 32-36 ◽

Cited By ~ 4

Author(s):

J. S. Ausman

Keyword(s):

Frequency Response ◽

Transfer Functions ◽

Response Characteristic ◽

System Stability ◽

System Response ◽

Response Analysis ◽

Frequency Response Analysis ◽

Response Curves ◽

Analysis And Synthesis ◽

Amplitude Versus

A graphical method provides, without templates and without factoring, a means for rapidly estimating log-amplitude versus log-frequency response curves from transfer functions in their unfactored polynomial form. The technique can also be used to design or synthesize transfer functions which will produce a specified frequency response characteristic. Included is a graphical stability criterion for third and fourth-order systems which provides a quick check on system stability during the course of design or of analysis of the system response.

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Improved frequency response model identification method for processes with initial cyclic-steady-state

AIChE Journal ◽

10.1002/aic.12550 ◽

2011 ◽

Vol 57 (12) ◽

pp. 3429-3435 ◽

Cited By ~ 8

Author(s):

Yu Jin Cheon ◽

Su Whan Sung ◽

Jietae Lee ◽

Cheol Ho Je ◽

In-Beum Lee

Keyword(s):

Steady State ◽

Frequency Response ◽

Model Identification ◽

Response Model ◽

Identification Method

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Constructing and model-fitting receiver operator characteristics using continuous data.

10.31234/osf.io/qdgjc ◽

2018 ◽

Author(s):

Josephine Ann Urquhart ◽

Akira O'Connor

Keyword(s):

Signal Detection ◽

Least Squares Method ◽

Model Fitting ◽

Simulated Data ◽

Continuous Variable ◽

Continuous Data ◽

Model Parameters ◽

Operating Characteristics ◽

Unequal Variance ◽

Discrete Discrimination

Receiver operating characteristics (ROCs) are plots which provide a visual summary of a classifier’s decision response accuracy at varying discrimination thresholds. Typical practice, particularly within psychological studies, involves plotting an ROC from a limited number of discrete thresholds before fitting signal detection parameters to the plot. We propose that additional insight into decision-making could be gained through increasing ROC resolution, using trial-by-trial measurements derived from a continuous variable, in place of discrete discrimination thresholds. Such continuous ROCs are not yet routinely used in behavioural research, which we attribute to issues of practicality (i.e. the difficulty of applying standard ROC model-fitting methodologies to continuous data). Consequently, the purpose of the current article is to provide a documented method of fitting signal detection parameters to continuous ROCs. This method reliably produces model fits equivalent to the unequal variance least squares method of model-fitting (Yonelinas et al., 1998), irrespective of the number of data points used in ROC construction. We present the suggested method in three main stages: I) building continuous ROCs, II) model-fitting to continuous ROCs and III) extracting model parameters from continuous ROCs. Throughout the article, procedures are demonstrated in Microsoft Excel, using an example continuous variable: reaction time, taken from a single-item recognition memory. Supplementary MATLAB code used for automating our procedures is also presented in Appendix B, with a validation of the procedure using simulated data shown in Appendix C.

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Iterative feedback control based on frequency response model for a six-degree-of-freedom micro-vibration platform

Journal of Vibration and Control ◽

10.1177/1077546321997310 ◽

2021 ◽

pp. 107754632199731

Author(s):

He Zhu ◽

Shuai He ◽

Zhenbang Xu ◽

XiaoMing Wang ◽

Chao Qin ◽

...

Keyword(s):

Feedback Control ◽

Frequency Response ◽

Control Strategy ◽

Degree Of Freedom ◽

Small Displacement ◽

Response Model ◽

Parameter Uncertainties ◽

Micro Vibration ◽

Six Degree Of Freedom ◽

Iterative Feedback

In this article, a six-degree-of-freedom (6-DOF) micro-vibration platform (6-MVP) based on the Gough–Stewart configuration is designed to reproduce the 6-DOF micro-vibration that occurs at the installation surfaces of sensitive space-based instruments such as large space optical loads and laser communications equipment. The platform’s dynamic model is simplified because of the small displacement characteristics of micro-vibrations. By considering the multifrequency line spectrum characteristics of micro-vibrations and the parameter uncertainties, an iterative feedback control strategy based on a frequency response model is designed, and the effectiveness of the proposed control strategy is verified by performing integrated simulations. Finally, micro-vibration experiments are performed with a 10 kg load on the platform. The results of these micro-vibration experiments show that after several iterations, the amplitude control errors are less than 3% and the phase control errors are less than 1°. The control strategy presented in this article offers the advantages of a simple algorithm and high precision and it can also be used to control other similar micro-vibration platforms.

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Determination of synchronous generator nonlinear model parameters based on power rejection tests using a gradient optimization algorithm

Bulletin of the Polish Academy of Sciences Technical Sciences ◽

10.1515/bpasts-2017-0053 ◽

2017 ◽

Vol 65 (4) ◽

pp. 479-488 ◽

Cited By ~ 4

Author(s):

A. Boboń ◽

A. Nocoń ◽

S. Paszek ◽

P. Pruski

Keyword(s):

Parameter Estimation ◽

Objective Function ◽

Optimization Algorithm ◽

Least Squares Method ◽

Synchronous Generator ◽

Operating Conditions ◽

Model Parameters ◽

State Variables ◽

Starting Point ◽

Gradient Optimization

AbstractThe paper presents a method for determining electromagnetic parameters of different synchronous generator models based on dynamic waveforms measured at power rejection. Such a test can be performed safely under normal operating conditions of a generator working in a power plant. A generator model was investigated, expressed by reactances and time constants of steady, transient, and subtransient state in the d and q axes, as well as the circuit models (type (3,3) and (2,2)) expressed by resistances and inductances of stator, excitation, and equivalent rotor damping circuits windings. All these models approximately take into account the influence of magnetic core saturation. The least squares method was used for parameter estimation. There was minimized the objective function defined as the mean square error between the measured waveforms and the waveforms calculated based on the mathematical models. A method of determining the initial values of those state variables which also depend on the searched parameters is presented. To minimize the objective function, a gradient optimization algorithm finding local minima for a selected starting point was used. To get closer to the global minimum, calculations were repeated many times, taking into account the inequality constraints for the searched parameters. The paper presents the parameter estimation results and a comparison of the waveforms measured and calculated based on the final parameters for 200 MW and 50 MW turbogenerators.

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Simulation and Simulation Software Development of the Braking Process of a Subway Train

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.556-562.294 ◽

2014 ◽

Vol 556-562 ◽

pp. 294-301 ◽

Cited By ~ 1

Author(s):

Long Han ◽

Chun Tian ◽

Yan Wang ◽

Meng Ling Wu ◽

Zhuo Jun Luo

Keyword(s):

Computational Effort ◽

Simulation Software ◽

System Model ◽

Brake System ◽

Railway Vehicle ◽

Model Parameters ◽

Modeling Process ◽

Time Simulation ◽

Subway Train ◽

Braking Process

This paper deals with the problem of braking process modeling. A subway train braking process simulation software is built, which composes of a GUI and a underlying model. The underlying model consists of a train model and a brake system model. The train model is simplified and built by assembling subcomponent element models of a railway vehicle. The brake system model is simplified and built based on experimental data in order to reduce computational effort. The GUI of the software can be use to input model parameters, display simulation results, and store simulation data. As a result of the simplifications of the modeling process, the developed software can perform real time simulation.

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Motion Model of Two-Wheel Differential Drive Mobile Robot under Variable Load

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.668-669.352 ◽

2014 ◽

Vol 668-669 ◽

pp. 352-356 ◽

Cited By ~ 1

Author(s):

Zhi Hu Ruan ◽

Niu Wang ◽

Bing Xin Ran

Keyword(s):

Mobile Robot ◽

State Space Model ◽

Response Characteristic ◽

Model Parameters ◽

Variable Load ◽

Motion Model ◽

Actual System ◽

Wheel Load ◽

Differential Drive ◽

Entire Vehicle

Based on kinematics characteristic of two-wheeled differential drive mobile robot (WMR) and response characteristic of fact motor drive system, this paper presents the analysis method of the equivalent rotation inertia, and the entire vehicle load is assigned to each wheel, and then the wheel load is converted into the corresponding equivalent rotation inertia of the motor shaft of each wheel, and motion model of WMR are obtained for combining with quasi-equivalent (QE) state space model of double-loop direct current motor systems under variable load and kinematics model of WMR under the load changes. By using speed response data of the actual system and combining with genetic algorithm to accurately identify the model parameters. Finally, through experiments results of the WMR motion model and the second order model respectively comparing with the actual system which demonstrates the effectiveness of the proposing method and model.

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