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IEEE-Power-and-Energy-Society General Meeting (PESGM)

作者： Zeng, Fanhong Zhang, Junbo Huang, Siwei Guangdong Power Grid Corp Guangdong Power Supply Co Guangzhou Peoples R China South China Univ Technol Sch Elect Power Guangzhou Peoples R China

ISBN: (纸本)9781665405072

In this paper, we identify the transfer function model relating the active power to the bus frequency using recursive weighted least square ( RWLS) algorithm with ambient signals measured by the phasor measurement units (PMUs). Then, the inertia at different hierarchies, Le. individual generator, area and the whole system, are estimated from unit step responses of the identified models. Compared to the conventional methods using transient signals, the proposed method can estimate the power system inertia under normal operating conditions as well as provide the tracking trajectory of inertia in real-time. The effectiveness of the proposed method is validated in the IEEE 39-bus system.

关键词： Power system inertia ambient signals transfer function model swing equation step response

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Regional precipitation trends since 1500 CE reconstructed from calcite sublayers of a varved Mediterranean lake record (Central Pyrenees)

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SCIENCE OF THE TOTAL ENVIRONMENT 2022年 826卷 153773-153773页

作者： Vegas-Vilarrubia, Teresa Pablo Corella, Juan Sigro, Javier Rull, Valenti Dorado-Linan, Isabel Valero-Garces, Blas Gutierrez-Merino, Emilia Univ Barcelona Dept Evolutionary Biol Ecol & Environm Sci Av Diagonal 643 Barcelona 08028 Spain CIEMAT Environm Dept Av Complutense 40 Madrid 28040 Spain Univ Rovira & Virgili Ctr Climate Change Dept Geog Tarragona Spain CSIC Bot Inst Barcelona Passeig Migdia S-N Barcelona 08038 Spain Politecn Univ Madrid Dept Syst & Nat Resources ETSI Montes Madrid Spain CSIC Inst Pirenaico Ecol Avda Montanana 1005 Zaragoza 50059 Spain

The Mediterranean region is expected to be highly impacted by global warming, although the uncertainty of future scenarios, particularly about precipitation patterns remains quite large. To better predict shifts in its current climate system and to test models, more regional climate records are needed spanning longer than the instrumental period. Here we provide a high-resolution reconstruction of autumn precipitation for the Central Pyrenees since 1500 CE based on annual calcite sublayer widths from Montcortes Lake (Central southern Pyrenees) varved sediments. The 500-yr calcite data series was detrended and calibrated with instrumental climate records by applying correlations and cross-correlations to regional precipitation anomalies. Highest relationships were obtained between a composite calcite series and autumn precipitation anomalies for the complete calibration period (1900-2002) and for the two halves of the full period. Applied statistical tests were significant, evidencing that the climatic signal could be reconstructed. The reconstructed precipitation anomalies show interdecadal shifts, and rainfall decrease within the coldest period of the LIA and during the second half of the 20th century, probably associated to current Global Warming. Neither increasing nor decreasing linear trends or periods of extreme precipitation events were identified. Our results are coherent with other palaeohydrological reconstructions for northern Iberian Peninsula. Correlations between the predicted autumn precipitation and the main teleconnections -NAO, ENSO and WEMO- were weak, although a potential relationship with the Atlantic Multidecadal Oscillation (AMO) pattern is suggested. The obtained reconstruction provides the first estimations of regional autumn precipitation shifts in the Central Pyrenees and is one of the few reconstructions that cover annual-to-century scale climate variability of precipitation in the Mediterranean region from the end of the Litte Ice Age (L

关键词： Authigenic varves Autumn precipitation Climate warming Little Ice Age transfer function model Water resources

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Time series analysis of covariance based on linear transfer function models

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STATISTICAL INFERENCE FOR STOCHASTIC PROCESSES 2019年第1期22卷 1-16页

作者： Azimmohseni, M. Khalafi, M. Kordkatuli, M. Golestan Univ Dept Stat Fac Sci POB 155 Gorgan Golestan Iran

In this article, a time series analysis of covariance model is introduced when covariates time series have lead-lag relationship with response time series. Parameter estimation and hypothesis testing for this model are made in spectral domain. We provide an instruction for our approach using a real Hydrological time series data set.

关键词： Discrete Fourier transform Frequency response function Prewhitening Spectral representation transfer function model

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Impact of Wide-Area Oscillation Damping Control using Measurement-Driven Approach on System Separation - Saudi Grid Case Study

Impact of Wide-Area Oscillation Damping Control using Measur...

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IEEE/PES Transmission and Distribution Conference and Exposition (T and D)

作者： Altarjami, Ibrahim Zhu, Lin Lu, Dongbin Deng, Xianda Liu, Yilu Farantatos, Evangelos Ramasubramanian, Deepak Patel, Mahendra Ijaz, Muhammad Al-Mubarak, Ahmed H. Bashraheel, Salem O. Univ Tennessee Dept Elect Engn & Comp Sci Knoxville TN 37996 USA Oak Ridge Natl Lab Oak Ridge TN USA Elect Power Res Inst Palo Alto CA USA Saudi Elect Co Riyadh Saudi Arabia

ISBN: (纸本)9781728145471

In any interconnected power grid, low-frequency oscillations is a major problem that can limit the power transfer capability and deteriorate power system security due to potential low-damped or even undamped oscillations. Synchronized measurements provided by PMUs enable the design and development of wide-area oscillation damping controllers (WADC) based on measurement-driven model to overcome the limitations of traditional controllers. This work focuses on the impact of a WADC based on a measurement-driven approach on system separation for the Saudi Electricity Company (SEC) grid. A grid model is provided by SEC for this study. Modal analysis is performed to identify the oscillation mode of interest for which the controller is designed. Damping the dominant oscillation mode helps slightly to improve transient stability of the system. Considering bus frequency at different locations in SEC's system as the candidate observation signals, the optimal observation signal is chosen for the WADC by using the FFT method. The system transfer function model is constructed by utilizing probing measurements. Then, the WADC parameters are calculated based on the identified model. The performance of the designed WADC is tested under different contingencies.

关键词： Low frequency oscillation System identification transfer function model Wide-area damping controller (WADC) System Separation Transient stability

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Simplified transfer function approach for modeling frequency dependency of damping characteristics of rubber bushings

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PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART D-JOURNAL OF AUTOMOBILE ENGINEERING 2019年第10期233卷 2518-2531页

作者： Aydemir, Eren Sendur, Polat Ford Otomot Sanayi AS Istanbul Turkey Ozyegin Univ Mech Engn Dept TR-34794 Istanbul Cekmekoy Turkey

Physical systems that consist of parts and vibration isolators such as rubber bushings are usually modeled in multibody simulations, where parts are represented as rigid bodies with their mass and inertia properties and rubber bushings are modeled with Voigt models to represent their stiffness and damping characteristics. Employment of Voigt models in multi-degree-of-freedom systems, however, may result in lower accuracy due to limitations in representing frequency-dependent dynamic characteristics of vibration isolators. To overcome this challenge, in this study, we develop and present a simplified frequency-dependent transfer function model by generating their frequency-dependent complex stiffness and damping from vehicle-level measurements. The damping characteristics of rubber bushings as a function of frequency is represented by a second-order transfer function. Three parameters of the transfer function are determined by solving an optimization problem to minimize the integral of absolute error between the measurement and simplified model's predictions. Sequential Quadratic Programming, a gradient descent-based algorithm, is selected as the optimization algorithm for this purpose. The proposed methodology is demonstrated on a heavy commercial truck. Truck cabin is represented as a rigid body connected to four rubber bushings, which are modeled to show the frequency dependency of the damping as a simple transfer function. Simulation results are well correlated with the measurements obtained from prototype vehicle tests on various road profiles showing capability improvement over Voigt modeling approach due to a more representative damping characteristic of rubber bushings as a function of frequency. Integration of the proposed method into multibody simulation software is also demonstrated with cosimulation between *** and MATLAB software.

关键词： Multibody dynamics rubber bushings frequency-dependent stiffness damping characterization cabin suspension design transfer function model

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Fuzzy predictive functional control of a class of non-linear systems

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IET CONTROL THEORY AND APPLICATIONS 2019年第14期13卷 2281-2288页

作者： Wang, Bin Yang, Lan Wu, Fengjiao Chen, Diyi Northwest A&F Univ Dept Elect Engn Yangling 712100 Shaanxi Peoples R China Northwest A&F Univ Minist Educ Key Lab Agr Soil & Water Engn Arid & Semiarid Are Yangling 712100 Shaanxi Peoples R China Xi An Jiao Tong Univ Dept Elect Engn Xian 710049 Shaanxi Peoples R China

This study investigates a fuzzy predictive functional control scheme of a class of non-linear systems. According to the Takagi-Sugeno fuzzy model, a fuzzy prediction model of the presented non-linear system is given. Also, the fuzzy prediction model is transformed into the transfer function model. Then, a novel fuzzy predictive functional control scheme is proposed for a class of non-linear systems by combining the multi-variable centralised control and predictive functional control. The rigorous theoretical derivation is presented to ensure the stabilisation of the non-linear systems. Two representative cases, including the three-dimensional brushless DC motor and the 4D Chen system, are implemented to confirm the validity and superiority compared with an existing pure fuzzy control method.

关键词： nonlinear control systems predictive control control system synthesis fuzzy control brushless DC motors DC motors transfer functions nonlinear system Takagi-Sugeno fuzzy model fuzzy prediction model transfer function model novel fuzzy predictive functional control scheme existing pure fuzzy control method

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Mathematical modeling of a pressurizer in a pressurized water reactor for control design

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APPLIED MATHEMATICAL modelLING 2019年 65卷 187-206页

作者： Wang, Pengfei He, Jianjun Wei, Xinyu Zhao, Fuyu Xi An Jiao Tong Univ Shaanxi Key Lab Adv Nucl Energy & Technol Xian 710049 Shaanxi Peoples R China Xi An Jiao Tong Univ Shaanxi Engn Res Ctr Adv Nucl Energy Xian 710049 Shaanxi Peoples R China

A pressurizer is a key equipment to ensure the safe operation of a pressurized water reactor by maintaining the reactor coolant system pressure within allowed tolerances. In this paper, a nonequilibrium three-region pressurizer model for the pressurized water reactor was developed first base on the basic conservation laws of mass and energy for the steam and water in the pressurizer. Then the nonlinear model was linearized to introduce the transfer function models of the pressurizer during insurge and outsurge transients for the controller design of a small pressurized water reactor pressurizer. Based on the developed transfer function models, the closed-loop pressurizer pressure and water level control systems including conventional proportional-integral-derivative controllers were designed employing the control strategy that uses a spray valve and two electric heaters for pressure control and regulates the charging flow rate with the letdown flow rate keeping constant for water level control. Finally, a simulation platform for the small pressurized water reactor pressurizer was developed in MATLAB/Simulink with implementation of the proposed nonlinear and nonequilibrium three-region pressurizer model, a widely-used nonlinear and nonequilibrium three-region pressurizer model and the designed pressure and water level controllers. Two typical load change transients, including the 100% to 90% of full power step load decrease and load rejection from 100% to 25% of full power, were simulated based on the platform. Dynamic responses of the pressure and water level obtained using the two nonlinear pressurizer models were analyzed, and the controller performances were assessed. The analysis and assessment results have shown satisfactory control performance and good robustness of the designed controllers regardless of the pressurizer simulation model adopted, demonstrating the feasibility, effectiveness and accuracy of the developed nonlinear and transfer function models of

关键词： Pressurized water reactor Pressurizer transfer function model Controller design Dynamic simulation

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An electromechanical model of an electro-responsive liquid droplet actuator for microsystems: modeling and verification

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SENSORS AND ACTUATORS A-PHYSICAL 2019年 285卷 338-347页

作者： Mulla, Tausif Choi, Seung-Bok Inha Univ Dept Mech Engn Smart Struct & Syst Lab Incheon 22212 South Korea

Dielectric liquids are used to actuate microfluidic devices. Droplet movement is achieved by applying a voltage across the electrodes beneath the dielectric substrate material. To understand the dynamics of these systems, an electromechanical model of a dielectric liquid movement between two parallel plate electrodes is presented herein. The system was modeled using lumped parameter approach using an equivalent capacitance circuit. This model was used to calculate the net electrostatic force acting on the liquid droplet and to predict the response of the liquid under the step input voltage. This model could be generalized to estimate the response of the any dielectric liquids in microfluidic devices of known geometry. Further, it could be used to design any model-based controller to accurately control actuating liquid for displacement or force control applications. The experiments were conducted with the water droplet as a dielectric liquid to validate the theoretical model and to analyze its dynamic characteristics under applied DC voltage. We experimentally investigated the effect of applied voltage, gap between the parallel electrodes, relative permittivity of dielectric fluid, and thickness of substrate material on the response of the water droplet. (C) 2018 Elsevier B.V. All rights reserved.

关键词： Electro-responsive actuator Lumped parameter model Water-droplet actuation Dynamic characteristics transfer function model

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Parameter Identification of Single-Phase Inverter Based on Improved Moth Flame Optimization Algorithm

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ELECTRIC POWER COMPONENTS AND SYSTEMS 2019年第4-5期47卷 456-469页

作者： Wu, Zhongqiang Shen, Dandan Shang, Mengyao Qi, Songqi Yanshan Univ Key Lab Ind Comp Control Engn Hebei Prov Qinhuangdao Hebei Peoples R China

By identifying the parameters of electronic circuit, parametric fault diagnosis of power electronic circuits can be realized. Many intelligent optimization algorithms are used to identify the parameters of electronic circuit, but most of them have the defects of slow convergence rate and easy to fall into local minimum. Moth flame optimization algorithm is a novel swarm intelligence bionic algorithm based on the intelligence behavior of moth positioning, which also has the above drawbacks. In order to improve the performance of algorithm, when updating the moth position, moth firstly moves in a straight line to the optimal position, then Levy flight is added. The improved algorithm improves the global optimization ability and accelerates the convergence speed. The improved moth flame optimization algorithm is applied for the parameter identification of single-phase inverter. The identification result is compared with the results of the other optimization techniques. The effectiveness and superiority of the improved algorithm are verified.

关键词： parameter identification fault diagnosis optimization algorithm single-phase inverter transfer function model moth flame optimization algorithm particle swarm optimization genetic algorithm Fast Fourier transform Levy flight

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Stability conditions and robustness analysis of a general MMSE run-to-run controller

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IISE TRANSACTIONS 2019年第11期51卷 1279-1287页

作者： Tseng, Sheng-Tsaing Tsung, Fugee Wu, Jo-Hua Natl Tsing Hua Univ Inst Stat Hsinchu Taiwan Hong Kong Univ Sci & Technol Dept Ind Engn & Logist Management Kowloon Hong Kong Peoples R China

Run-to-run (R2R) control plays a vital role in monitoring or adjusting the manufacturing process of integrated circuits. In this article we propose a generalized quasi-MMSE controller for a process whose Input-Output (I-O) model follows a general transfer function (TF) model with ARIMA disturbance and analytically derive the long-term stability conditions and their limiting distribution. Furthermore, we use a comprehensive simulation study to compare the control performances among several potential controllers when the process I-O model follows a TF model of order (2, 2, 0) with ARIMA disturbance of order (2, 1, 2). The results demonstrate that using improper controllers may seriously affect the control performance in terms of the long-term stability conditions and the short-term total mean squared error. are available for this article. Go to this article's online edition of IIE Transactions for Appendices.

关键词： Run-to-run control dynamic system quasi-MMSE controller process disturbance transfer function model

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