In this paper, a novel controller for parallel-connected online uninterruptible power supplies (UPS) without control interconnections based on the droop method is presented. The control approach consists in drop the f...
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In this paper, a novel controller for parallel-connected online uninterruptible power supplies (UPS) without control interconnections based on the droop method is presented. The control approach consists in drop the frequency of every module when its output power increases, resulting in an unavoidable nominal frequency deviation. Consequently, this method in its original form is only applicable to off-line or line-interactive UPS systems. As opposed to the conventional droop method, the proposed control scheme endows proper transient response, strictly frequency and phase synchronization with the ac mains, and excellent power sharing even for nonlinear loads. Hence, this controller is suitable for paralleled online UPS systems. Experimental results are obtained from two parallel-connected 1-kVA online UPS by using TMS320LF2407A DSP.
We describe the latest additions to SOSTOOLS, a freely available MATLAB toolbox for formulating and solving sum of squares programs. Among the many improvements, there are native polynomial objects, structure-exploiti...
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ISBN:
(纸本)0780383354
We describe the latest additions to SOSTOOLS, a freely available MATLAB toolbox for formulating and solving sum of squares programs. Among the many improvements, there are native polynomial objects, structure-exploiting techniques for sparse and structured polynomials, new customized functions, and support for alternative SDP solvers. We sketch some of the theory behind the new improvements, and illustrate the new commands using control-oriented examples.
The developments and control applications of SOSTOOLS, a free third-party MATLAB toolbox for formulating and solving sum of squares programs was discussed. The technique was based on the sum of squares decomposition f...
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The developments and control applications of SOSTOOLS, a free third-party MATLAB toolbox for formulating and solving sum of squares programs was discussed. The technique was based on the sum of squares decomposition for multivariate polynomials which can be effectively computed using semidefinite programming. The nonlinear stability analysis, parametric robustness analysis, safety verification, and nonlinear controller synthesis was also considered in the control applications. A sparsity structure was used while considering infinitely constrained linear matrix inequalities (LMI).
The purpose of this paper is to develop an analytic way for designing optimal PI-controllers for interval plant family, in the sense that the coefficient intervals of the plant is maximized. It will be shown that the ...
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The paper addresses the problem of robust output feedback controller design with a guaranteed cost and parameter dependent Lyapunov function quadratic stability for linear continuous time polytopic systems. The propos...
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In this paper, we first give a tutorial on the Gröbner bases method. Then it is shown that existing results in multidimensional (nD) feedback control theory using Gröbner bases can be applied to the design o...
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The paper addresses the problem of robust output feedback controller design with a guaranteed cost and quadratic, and parameter dependent Lyapunov function quadratic stability for linear continuous time affine systems...
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The paper addresses the problem of robust output feedback controller design with a guaranteed cost and quadratic, and parameter dependent Lyapunov function quadratic stability for linear continuous time affine systems. The proposed design methods lead to a non-iterative LMI based algorithm. Numerical examples are given to illustrate the design procedure.
The paper addresses the problem of robust output feedback controller design with a guaranteed cost and parameter dependent Lyapunov function quadratic stability for linear continuous time polytopic systems. The propos...
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The paper addresses the problem of robust output feedback controller design with a guaranteed cost and parameter dependent Lyapunov function quadratic stability for linear continuous time polytopic systems. The proposed design methods lead to a non-iterative LMI based algorithm. Numerical example is given to illustrate the design procedure.
This paper considers the stability analysis problem of nD discrete-time systems. It is shown that the problems of stability test and stability margin computation for an nD system described by Roesser model can be reca...
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An innovative watermarking scheme based on progressive transmission with genetic algorithms (GA) is proposed. We implement the watermarking embedding and extraction system in the discrete cosine transform (DCT) domain...
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An innovative watermarking scheme based on progressive transmission with genetic algorithms (GA) is proposed. We implement the watermarking embedding and extraction system in the discrete cosine transform (DCT) domain, and apply the JPEG spectral selection mode for progressive transmission. By employing GA with a proper fitness function into the watermarking system, both the watermark imperceptibility and watermark robustness requirements are considered and optimized. In addition, the embedded watermark can be partly extracted in the receiver side even when the watermarked image is being transmitted. Simulation results show both the robustness and the effectiveness of progressive transmission under different attacking schemes and different bandwidth variations.
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