In this paper, an improved version of differential evolution (DE) algorithm which incorporates wavelet-based mutation strategy called differential evolution with wavelet mutation (DEWM) is proposed for the design of d...
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In this paper, an improved version of differential evolution (DE) algorithm which incorporates wavelet-based mutation strategy called differential evolution with wavelet mutation (DEWM) is proposed for the design of digital infinite impulse response (IIR) filters. Unlike fixed value of scaling factor in standard DE, the proposed optimisation technique DEWM adopts iteration dependent scaling factor governed by the wavelet function during the mutation process. This modification in the mutation process not only ensures the faster searching in the multidimensional search space but also the solution produced is very close to the global optimal solution. The effectiveness of this algorithm is justified with a comparative study of some well established algorithms, namely, real coded genetic algorithm (RGA), conventional particle swarm optimisation (PSO) and standard DE with a superior DEWM-based outcome for the designed 8th order IIR low pass (LP), high pass (HP), band pass (BP) and band stop (BS) filters. Simulation results affirm that the proposed DEWM algorithm outperforms its counterparts not only in terms of quality output, i.e., sharpness at cut-off, pass band ripple and stop band attenuation but also in convergence speed with assured stability.
This paper presents a global heuristic search optimization technique, which is a hybridized version of the Gravitational Search Algorithm (GSA) and Wavelet Mutation (WM) strategy. Thus, the Gravitational Search Algori...
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This paper presents a global heuristic search optimization technique, which is a hybridized version of the Gravitational Search Algorithm (GSA) and Wavelet Mutation (WM) strategy. Thus, the Gravitational Search Algorithm with Wavelet Mutation (GSAWM) was adopted for the design of an 8th-order infinite impulse response (IIR) filter. GSA is based on the interaction of masses situated in a small isolated world guided by the approximation of Newtonian's laws of gravity and motion. Each mass is represented by four parameters, namely, position, active, passive and inertia mass. The position of the heaviest mass gives the near optimal solution. For better exploitation in multidimensional search spaces, the WM strategy is applied to randomly selected particles that enhance the capability of GSA for finding better near optimal solutions. An extensive simulation study of low-pass (LP), high-pass (HP), band-pass (BP) and band-stop (BS) IIR filters unleashes the potential of GSAWM in achieving better cut-off frequency sharpness, smaller pass band and stop band ripples, smaller transition width and higher stop band attenuation with assured stability. (C) 2014 King Saud University. Production and hosting by Elsevier B.V. All rights reserved.
This paper presents the design of a stable and efficient z-source voltage regulator using small signal analysis. Z-source ac-ac converter operates in buck-boost mode without any additional circuit. Controlling the sho...
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ISBN:
(纸本)9781479974559
This paper presents the design of a stable and efficient z-source voltage regulator using small signal analysis. Z-source ac-ac converter operates in buck-boost mode without any additional circuit. Controlling the shoot-through duty ratio, maintain the desired output voltage level. Proposed voltage regulator is replaced by traditional voltage regulator with additional features. Control transfer functions obtained using small signal analysis given a precise idea about stability of the system. Closed loop control system of z-source ac-ac converter with PID controller provides a steady state output voltage during voltage sag and surge. The proposed system is demonstrated with MATLAB simulation results.
Distributed secondary controllers in dc microgrid are used for low voltage regulation and proportional current sharing among the source converters. These controllers depend on the calculation of global average of the ...
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ISBN:
(纸本)9781728142180
Distributed secondary controllers in dc microgrid are used for low voltage regulation and proportional current sharing among the source converters. These controllers depend on the calculation of global average of the source voltages and ideal value of the current that each source must share. These values are usually calculated using an all-to-all communication network which is not easily scalable. In this paper, ideal current sharing based controller is extended for reduced communication network. For each converter, the presented method involves a consensus-based ideal current estimator and average voltage estimator. The error between these estimates with respect to the current/voltage of the converter is used to modify its droop characteristic. In literature, it is shown that similar performance can be achieved even in the presence of a reduced communication network by using higher values of weights on communication links. As the information communicated among the sources is discrete, higher values of weights may lead to unstable operation. In this paper, an upper bound is determined on the range of weight. Roots loci plots are used to show the effect of variation in weights of communication links in a given communication graph on small signal stability of the system. The efficacy of consensus based controller is validated using detailed simulation studies in Matlab/Simulink.
This paper presents the design of a stable and efficient z-source voltage regulator using small signal analysis. Z-source ac-ac converter operates in buck-boost mode without any additional circuit. Controlling the sho...
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ISBN:
(纸本)9781479974566
This paper presents the design of a stable and efficient z-source voltage regulator using small signal analysis. Z-source ac-ac converter operates in buck-boost mode without any additional circuit. Controlling the shoot-through duty ratio, maintain the desired output voltage level. Proposed voltage regulator is replaced by traditional voltage regulator with additional features. Control transfer functions obtained using small signal analysis given a precise idea about stability of the system. Closed loop control system of z-source ac-ac converter with PID controller provides a steady state output voltage during voltage sag and surge. The proposed system is demonstrated with MATLAB simulation results.
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