Analytic Modeling and Integral Control of Heterogeneous Thermostatically Controlled Load Populations

2014 ◽  
Author(s):  
Azad Ghaffari ◽  
Scott Moura ◽  
Miroslav Krstić
Keyword(s):  
Power Control ◽  
Output Feedback ◽  
Electricity Consumption ◽  
Output Feedback Control ◽  
Stability Margin ◽  
Control Technique ◽  
Seasonal Temperature ◽  
Integral Control ◽  
Modeling And Control ◽  
The Stability

Thermostatically controlled loads (TCLs) account for approximately 50% of U.S. electricity consumption. Various techniques have been developed to model TCL populations. A High-fidelity analytical model of heterogeneous TCL populations facilitates the aggregate synthesis of power control in power networks. Such a model assists the utility manager to increase the stability margin of the network. The model, also, assists the customer to schedule his/her tasks in order to reduce his/her energy cost. We present a deterministic hybrid partial differential equation (PDE) model which accounts for heterogeneous populations of TCLs, and facilitates analysis of common scenarios like cold load pick up, cycling, and daily and/or seasonal temperature changes to estimate the aggregate performance of the system. The proposed technique is flexible in terms of parameter selection and ease of changing the set-point temperature and deadband width all over the TCL units. We provide guidelines to maintain the numerical stability of the discretized model during computer simulations. Moreover, the proposed model is a close fit to design output feedback algorithms for power control purposes. Our integral output feedback control, designed using the comparison principle, guarantees fast and efficient power tracking for various real-world scenarios. We present simulation results to verify the effectiveness of the proposed modeling and control technique.

Modeling, Control, and Stability Analysis of Heterogeneous Thermostatically Controlled Load Populations Using Partial Differential Equations

2015 ◽  
Vol 137 (10) ◽  
Author(s):  
Azad Ghaffari ◽  
Scott Moura ◽  
Miroslav Krstić
Keyword(s):  
Power Control ◽  
Electricity Consumption ◽  
State Feedback Control ◽  
Seasonal Temperature ◽  
Partial Differential ◽  
Modeling And Control ◽  
Proposed Model ◽  
The Stability ◽  
Utility Managers ◽  
And Control

Thermostatically controlled loads (TCLs) account for more than one-third of the U.S. electricity consumption. Various techniques have been used to model TCL populations. A high-fidelity analytical model of heterogeneous TCL (HrTCL) populations is of special interest for both utility managers and customers (that facilitates the aggregate synthesis of power control in power networks). We present a deterministic hybrid partial differential equation (PDE) model which accounts for HrTCL populations and facilitates analysis of common scenarios like cold load pick up, cycling, and daily and/or seasonal temperature changes to estimate the aggregate performance of the system. The proposed technique is flexible in terms of parameter selection and ease of changing the set-point temperature and deadband width all over the TCL units. We investigate the stability of the proposed model along with presenting guidelines to maintain the numerical stability of the discretized model during computer simulations. Moreover, the proposed model is a close fit to design feedback algorithms for power control purposes. Hence, we present output- and state-feedback control algorithms, designed using the comparison principle and Lyapunov analysis, respectively. We conduct various simulations to verify the effectiveness of the proposed modeling and control techniques.

scholarly journals Decentralized Adaptive Tracking of Interconnected Nonlinear Systems by Corrupted Output Feedback

Mathematics ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 1340
Author(s):  
Dong Min Jeong ◽  
Sung Jin Yoo
Keyword(s):  
Nonlinear Systems ◽  
Output Feedback ◽  
Output Feedback Control ◽  
Feedback Stabilization ◽  
Control Technique ◽  
Control Input ◽  
Measurement Sensitivity ◽  
Control Scheme ◽  
Interconnected Nonlinear Systems ◽  
Output Information

A decentralized adaptive resilient output-feedback stabilization strategy is presented for a class of uncertain interconnected nonlinear systems with unknown time-varying measurement sensitivities. In the concerned problem, the main difficulty is to achieve the decentralization of interconnected output nonlinearities unmatched to the control input by using only local output information corrupted by measurement sensitivity, namely the exact output information cannot be used to design the decentralized output-feedback control scheme. Thus, a decentralized output-feedback stabilizer design using only the corrupted output of each subsystem is developed where the adaptive control technique is employed to compensate for the effects of unknown measurement sensitivities. The stability of the resulting decentralized control scheme is analyzed based on the Lyapunov stability theorem.

Energy-based output feedback control of the underactuated 2DTORA system with saturated inputs

2020 ◽  
Vol 42 (14) ◽  
pp. 2822-2829
Author(s):  
Kexin Xu ◽  
Xianqing Wu ◽  
Miao Ma ◽  
Yibo Zhang
Keyword(s):  
Feedback Control ◽  
Lyapunov Function ◽  
Output Feedback ◽  
Control Method ◽  
Actuator Saturation ◽  
Output Feedback Control ◽  
Lyapunov Theory ◽  
Velocity Signal ◽  
Feedback Control Method ◽  
The Stability

In this paper, we consider the control issues of the two-dimensional translational oscillator with rotational actuator (2DTORA) system, which has two translational carts and one rotational rotor. An output feedback controller for the 2DTORA system is proposed, which can prevent the unwinding behaviour. In addition, the velocity signal unavailability and actuator saturation are taken into account, simultaneously. In particular, the dynamics of the 2DTORA system are given first. On the basis of the passivity and control objectives of the 2DTORA system, an elaborate Lyapunov function is constructed. Then, based on the introduced Lyapunov function, a novel output feedback control method is proposed straightforwardly for the 2DTORA system. Lyapunov theory and LaSalle’s invariance principle are utilized to analyse the stability of the closed-loop system and the convergence of the states. Finally, simulation results are provided to illustrate the excellent control performance of the proposed controller in comparison with the existing method.

Guaranteed Cost Output Feedback Control of Fuzzy Systems via LMI Approach

2010 ◽  
Vol 14 (6) ◽  
pp. 567-573 ◽  
Author(s):  
Shusaku Nishikawa ◽  
◽  
Jun Yoneyama
Keyword(s):  
Feedback Control ◽  
Output Feedback ◽  
Fuzzy System ◽  
Design Method ◽  
Fuzzy Model ◽  
Output Feedback Control ◽  
Control Design ◽  
Tuning Parameter ◽  
Guaranteed Cost ◽  
The Stability

This paper is concerned with the stability with guaranteed cost for a fuzzy system with immeasurable premise variables via output feedback. It is well known that Takagi-Sugeno fuzzy model describes a wide class of nonlinear systems especially when its premise variables include immeasurable functions. However, when it comes to output feedback control design of such a fuzzy system, a conventional Parallel Distributed Compensator (PDC) is not feasible because the PDC shares the same immeasurable premise variables as those of a fuzzy system. In this paper, we introduce an output feedback controller with the estimate of the premise variables of an original fuzzy system. We then formulate the stabilization problem with guaranteed cost for a fuzzy system with immeasurable premise variables. Our control design method is based on a set of strict LMI conditions. No tuning parameter is necessary a priori to solve them. The stability with guaranteed cost takes care of not only stabilization but also control performance. Our proposed method attempts to minimize the upper bound of the performance index, which results in the satisfactory trajectories of the system. Finally, numerical examples are given to illustrate our control design method.

scholarly journals Comparative Study of Control Strategies for Stabilization and Performance Improvement of DC Microgrids with a CPL Connected

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2663
Author(s):  
Isaías V. de Bessa ◽  
Renan L. P. de Medeiros ◽  
Iury Bessa ◽  
Florindo A. C. Ayres Junior ◽  
Alessandra R. de Menezes ◽  
...  
Keyword(s):  
Control Strategies ◽  
Output Feedback Control ◽  
Stability Margin ◽  
Performance Indices ◽  
Dc Microgrid ◽  
Stability Margins ◽  
Dc Microgrids ◽  
Constant Power Loads ◽  
And Performance ◽  
The Stability

The DC microgrid system is composed by converters that operate like feeders and loads. Among these loads, we highlight the constant power loads (CPLs) that may cause instability in the microgrid, observed in the form of undesired oscillations due to its negative impedance behavior. Therefore, this work proposes to use performance indices and stability margins to evaluate state and output feedback control strategies for stabilization of DC microgrids. In particular, it is proposed to evaluate the stability margin of the proposed methodologies by means of the impedance relations in the microgrid based on the Middlebrook criterion. Our simulations and tests showed the relation between the performance and stability degradation and the microgrid impedances variation.

scholarly journals Output Feedback Control for Couple-Group Consensus of Multiagent Systems

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Huanyu Zhao ◽  
Hongbiao Zhou ◽  
Zhongyi Tang
Keyword(s):  
Feedback Control ◽  
Multiagent Systems ◽  
Discrete Time ◽  
Output Feedback ◽  
Sufficient Conditions ◽  
Output Feedback Control ◽  
Group Consensus ◽  
System Transformation ◽  
Discrete Time Case ◽  
The Stability

This paper deals with the couple-group consensus problem for multiagent systems via output feedback control. Both continuous- and discrete-time cases are considered. The consensus problems are converted into the stability problem of the error systems by the system transformation. We obtain two necessary and sufficient conditions of couple-group consensus in different forms for each case. Two different algorithms are used to design the control gains for continuous- and discrete-time case, respectively. Finally, simulation examples are given to show the effectiveness of the proposed results.

scholarly journals Performance analysis and enhancement of direct power control of DFIG based wind system

2021 ◽  
Vol 12 (2) ◽  
pp. 1034
Author(s):  
Mohamed Amine Beniss ◽  
Hassan El Moussaoui ◽  
Tijani Lamhamdi ◽  
Hassane El Markhi
Keyword(s):  
Power Control ◽  
Wind Turbine ◽  
Reactive Power ◽  
Control Technique ◽  
Direct Power ◽  
Direct Power Control ◽  
Modeling And Control ◽  
Point Tracking ◽  
Wind Turbine System ◽  
Power Point

<span lang="EN-US">The paper proposes a complete modeling and control technique of variable speed wind turbine system (WTS) based on the doubly fed induction generator (DFIG). Two levels back-to-back converter is used to ensure the energy transfer between the DFIG rotor and the grid. The wind turbine to operate efficiently, a maximum power point tracking (MPPT) algorithm is implemented. Then, direct power control (DPC) strategy has been combined with the MPPT technique in order to guarantee the selection of the appropriate rotor voltage vectors and to minimize the active and reactive power errors. Finally, the simulation is performed by using MATLAB/simulink platform basing on 7.5KW DFIG wind generation system, and the results prove the effectiveness of our proposed control technique.</span>

Modified Sky-Hook Control of a Semi-Active Suspension System Using H∞ Robust Control Theory

2009 ◽  
Author(s):  
Mohammad Saber Fallah ◽  
Rama Bhat ◽  
Wen-Fang Xie
Keyword(s):  
Feedback Control ◽  
Output Feedback ◽  
Controller Design ◽  
Kinematic Model ◽  
Three Dimensional ◽  
Output Feedback Control ◽  
Suspension System ◽  
Linear Matrix ◽  
Control Force ◽  
The Stability

The main focus of the present paper is on the design of a modified sky-hook control of a semi-active Macpherson suspension system by means of H∞ Output Feedback Control (OFC) theory. To this end, a new dynamic model, incorporating the kinematics of the suspension system, is used for the controller design. The combination of a Linear Matrix Inequality (LMI) solver and Genetic Algorithm (GA) is adopted to regulate the static output feedback control gain so that the stability conditions are fulfilled and control objectives are achieved. Meanwhile, a three-dimensional kinematic model of the system is incorporated to investigate the influence of the control force variation on the steering, handling and stability of the vehicle. A geometric relation of the vehicle roll center is employed to study one more extra aspect of the comfort and stability of the vehicle. The results show that the proposed controller improves the kinematic and dynamic performances of the suspension well compared with those of the passive system. Moreover, it is concluded that a superior stability of the vehicle during the cornering can be achieved by adjusting the height of the vehicle roll center passively so that the stability of the vehicle is improved while the forward motion specifications can be modified by an appropriate suspension control design.

Stability of nonlinear output‐feedback control system

Kybernetes ◽  
2004 ◽  
Vol 33 (2) ◽  
pp. 347-354 ◽  
Author(s):  
Guangxing Tan ◽  
Jian Pan
Keyword(s):  
Control System ◽  
Feedback Control ◽  
Asymptotic Stability ◽  
Nonlinear Control ◽  
Output Feedback ◽  
Sufficient Conditions ◽  
Liapunov Function ◽  
Output Feedback Control ◽  
Feedback Control System ◽  
The Stability

This paper studies the stability properties of a class of nonlinear output‐feedback control system. By using a control transform and constructing Liapunov function, the sufficient conditions of the asymptotic stability for the nonlinear control system are presented. The result in this paper includes some existing results.

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