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Electromagnetic wave characteristics of second-order composite frequency-selective surfaces fabricated by e-beam evaporator

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ELECTRONICS LETTERS 2014年第3期50卷 189-190页

作者： Kim, J. Y. Kim, D. S. Woo, D. W. Shin, D. S. Park, W. S. Hwang, W. POSTECH Dept Mech Engn Pohang South Korea POSTECH Dept Elect & Elect Engn Pohang South Korea

A composite frequency-selective surface (FSS) fabricated by using an e-beam evaporator is proposed. This manufacturing process is advantageous in that it can directly achieve an FSS function for real structural surfaces with various skin conformations. A multilayered patch-grid-patch-type FSS consisting of copper layers as capacitive or inductive surfaces and a glass/epoxy prepreg as the substrate is produced. It operates at 9-10 GHz for dual polarisation. This technique can be used to manufacture a stealth technology for communicating in a specific frequency range.

关键词： optimisation transformers transmission lines UHF power amplifiers high-efficiency concurrent dualband power amplifier dualband harmonic wave controlled transformer DBPA second harmonic impedance transmission line optimisation algorithm power added efficiency adjacent channel leakage ratio digital pre-distortion adjustment WCDMA signal input frequency 1 7 GHz frequency 2 6 GHz efficiency 70 percent efficiency 64 percent gain 11 dB frequency 5 MHz

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Review of predictive control methods to improve the input current of an indirect matrix converter

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IET POWER ELECTRONICS 2014年第4期7卷 886-894页

作者： Rivera, Marco Rojas, Christian Wilson, Alan Rodriguez, Jose Espinoza, Jose Baier, Carlos Munoz, Javier Univ Talca Dept Ind Technol Curico Chile Univ Tecn Federico Santa Maria Dept Elect Engn Valparaiso 2390123 Chile Tech Univ Dresden Power Elect Grp D-01062 Dresden Germany Univ Concepcion Dept Elect Engn Concepcion Chile

The experimental implementation and performance analysis of control techniques applied to an indirect matrix converter are presented here, to improve the input current behaviour under resonances and harmonics distortions. The control strategies are based on model predictive control, which uses the commutation state of the converter in the subsequent sampling time, according to an optimisation algorithm given by a simple cost function and the discrete system model. Experimental results with a laboratory prototype are provided in order to validate the different control schemes, and the effects of a distorted source voltage and filter resonance are analysed.

关键词： cost optimal control discrete systems electric current control matrix convertors minimisation predictive control reactive power control filter resonance distorted source voltage discrete system model simple cost function optimisation algorithm subsequent sampling time commutation state model predictive control harmonics distortions input current behaviour indirect matrix converter control techniques

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Comprehensive design methodology of tuned passive filters based on a probabilistic approach

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IET GENERATION TRANSMISSION & DISTRIBUTION 2014年第1期8卷 170-177页

作者： Churio-Barboza, Julio C. Maza-Ortega, Jose Maria Univ Seville Dept Elect Engn Seville 41092 Spain

This study presents a new method for the optimal design of single-tuned harmonic passive filters considering the probabilistic nature of power system magnitudes. For this purpose, the algorithm uses the measurements acquired by a power quality analyser. The Gaussian mixture model has been applied to actual harmonic measurements to obtain a precise statistical representation which is crucial in the proposed design procedure. The optimisation algorithm considers both probabilistic and deterministic variables involving all the harmonic components including the minor or non-characteristic harmonics. Moreover, the objective function of the optimisation algorithm is formulated taken into account all the harmonic terms overpassing other simplified formulations based only on the fundamental component. This study includes a case study with different optimisation scenarios to clearly highlight the benefits of each of the proposed contributions.

关键词： Gaussian processes optimisation passive filters power filters power supply quality power system harmonics comprehensive design methodology probabilistic approach single-tuned harmonic passive filters power system magnitude power quality analyser Gaussian mixture model harmonic measurement statistical representation optimisation algorithm deterministic variable harmonic component

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SuperPUF: Integrating Heterogeneous Physically Unclonable Functions 33

SuperPUF: Integrating Heterogeneous Physically Unclonable Fu...

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33rd IEEE/ACM International Conference on Computer-Aided Design (ICCAD)

作者： Wang, Michael Yates, Andrew Markov, Igor L. Univ Michigan 2260 Hayward St Ann Arbor MI 48109 USA

ISBN: (纸本)9781479962785

Physically Unclonable Functions (PUFs) combat counterfeit ICs by identifying each chip using inherent process variation. PUFs must produce sufficiently many bits, but replicating the same PUF design requires care since process variation and its spatial correlation may change in the next 10 years. Additional challenges arise in system-on-chip and heterogeneous 3D integration of diverse PUFs. Responding to these challenges, we introduce methods for combining PUFs, with provisions for sampling process variation throughout the IC. When multiple sources of entropy are available, our optimization algorithms select sources to maximize joint entropy and minimize physical overhead. Empirical validation uses SPICE simulations for a 45nm technology node.

关键词： entropy integrated circuit design integrated circuit manufacture integrated circuit technology optimisation system-on-chip three-dimensional integrated circuits PUF design replication SPICE simulation chip identification counterfeit IC entropy source heterogeneous 3D integration heterogeneous physically unclonable functions integration inherent process variation optimisation algorithm physical overhead minimization size 45 nm spatial correlation superPUF Clocks Correlation Entropy Integrated circuit modeling Logic gates Robustness system-on-chip entropy Optimization algorithms three-dimensional integrated circuits integrated circuit technology integrated circuit manufacture integrated circuit modelling integrated circuit design Timing devices Logic gates process change

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Assessment of the Cost and Environmental Impact of Demand Side Management on Residential Sector

Assessment of the Cost and Environmental Impact of Demand Si...

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9th International Conference on Ecological Vehicles and Renewable Energies (EVER)

作者： Tsagarakis, G. Thomson, R. C. Collin, A. J. Harrison, G. P. Kiprakis, A. E. Univ Edinburgh Sch Engn Inst Energy Syst Edinburgh Midlothian Scotland

ISBN: (纸本)9781479937875

The paper presents a detailed study of the potential impact on the cost and greenhouse gas emissions (GHG) through low voltage (LV) residential demand-side management (DSM). The proposed optimisation algorithm is used to shift non-critical residential loads, with the wet load category used as a case study, in order to minimise the total daily cost and emissions of GHG due to generation. This study shows that it is possible to reshape the total power demand and reduce the cost and emissions of demand to some extent. It is also shown that further optimisation of the cost leads to an increase in GHG emissions because of their conflicting nature.

关键词： Demand Side Management optimisation algorithm load modelling residential load low voltage

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Transient stability constrained optimal power flow using independent dynamic simulation

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IET GENERATION TRANSMISSION & DISTRIBUTION 2013年第3期7卷 244-253页

作者： Tu, Xiaoping Dessaint, Louis-A. Huy Nguyen-Duc Ecole Technol Super Dept Elect Engn Montreal PQ H1T 2C2 Canada Hanoi Univ Sci & Technol Dept Elect Power Syst Hanoi Vietnam

Transient stability constrained optimal power flow (TSC-OPF) is originally a non-linear optimisation problem with variables and constraints in time domain, which is not easy to deal with directly because of its huge dimension. This study presents an efficient approach to realise TSC-OPF by introducing an independent dynamics simulation algorithm into the optimisation procedure. In the new approach, the simulation algorithm is used to realise the dynamics constraints and to deduce the transient stability constraint, whereas the optimisation algorithm verifies the steady state and the transient stability constraints together. The new TSC-OPF has just one more constraint than that of a conventional OPF and can be solved by a conventional OPF algorithm with small modification. Moreover, the new approach makes it easy to improve the accuracy and efficiency of TSC-OPF, because of its flexibility in choosing machine models and simulation methods, which is important for large power systems. In the study, the proposed approach is tested with two small power systems, where the two-axis machine model and a mixed time step simulation method are used to assess system transient stability with a 1-ms time resolution.

关键词： load flow optimisation power system simulation power system transient stability transient stability constrained optimal power flow independent dynamic simulation TSC-OPF nonlinear optimisation problem time domain independent dynamics simulation algorithm optimisation procedure transient stability constraint optimisation algorithm conventional OPF algorithm machine models power systems two-axis machine model mixed time step simulation method system transient stability

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Minimum cost solution of photovoltaic-diesel-battery hybrid power systems for remote consumers

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SOLAR ENERGY 2013年 96卷 292-299页

作者： Tazvinga, Henerica Xia, Xiaohua Zhang, Jiangfeng Univ Pretoria Ctr New Energy Syst Dept Elect Elect & Comp Engn ZA-0002 Pretoria South Africa

Hybrid systems present a new dimension to the time correlation of intermittent renewable energy sources. The paper considers the daily energy consumption variations for winter and summer weekdays and weekends in order to compare the corresponding fuel costs and evaluate the operational efficiency of the hybrid system for a 24-h period. Previous studies have assumed a fixed load and uniform daily operational cost. A load following diesel dispatch strategy is employed in this work and the fuel costs and energy flows are analysed. The results show that the photovoltaic-diesel-battery model achieves 73% and 77% fuel savings in winter and 80.5% and 82% fuel savings in summer for days considered when compared to the case where the diesel generator satisfies the load on its own. The fuel costs obtained during both winter and summer seasons for weekdays and weekends show substantial variations which should not be neglected if accurate operation costs are to be achieved. The results indicate that the developed model can achieve a more practical estimate of the fuel costs reflecting variations of power consumption behavior patterns for any given system. (C) 2013 Elsevier Ltd. All rights reserved.

关键词： optimisation algorithm Hybrid system Control strategy Economic dispatch Energy efficiency Operation efficiency

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Transmission of JPEG2000 images over frequency-selective channels with unequal power allocation

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IET IMAGE PROCESSING 2013年第1期7卷 33-41页

作者： Shayegannia, Moein Hajshirmohammadi, Atousa Muhaidat, Sami Torki, Mahin Simon Fraser Univ Dept Engn Sci Burnaby BC V5A 1S6 Canada Khalifa Univ Sci Technol & Res Abu Dhabi 127788 U Arab Emirates Simba Technol Inc Vancouver BC V5Z 1E5 Canada

In this study, transmission of JPEG2000 images using an unequal power allocation (UPA) scheme and orthogonal frequency division multiplexing (OFDM) over block-fading frequency-selective channels is presented. A distortion model is provided to evaluate the contribution of each coding pass (CP) in the construction of the received image. The optimisation algorithm exploits the hierarchical structure of the JPEG2000 images and uses the distortion model along with the channel state information for allocating optimal values of power for each CP to minimise the end-to-end distortion. Furthermore, the actual total power consumed for transmission is measured and compared with the total power initially assigned. For the purpose of simulations, the authors set the number of OFDM subcarriers to be 16, the length of the cyclic prefixes equal to the channel memory length and analyse the quality of the received image in a 2-tap and 3-tap frequency-selective channel, with and without our proposed UPA technique in an OFDM system. The results show an improvement of up to 10.5 dB in the decoded image quality when the UPA scheme is used. In addition, our system manages to maintain similar quality for the received image in a multi-tap channel scenario.

关键词： distortion fading channels image coding OFDM modulation JPEG2000 images unequal power allocation UPA orthogonal frequency division multiplexing block fading frequency selective channels distortion model coding pass channel state information cyclic prefixes channel memory length image quality multitap channel scenario optimisation algorithm

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Authenticated voltage control of partitioned power networks with optimal allocation of STATCOM using heuristic algorithm

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IET GENERATION TRANSMISSION & DISTRIBUTION 2013年第9期7卷 1037-1045页

作者： Mehrjerdi, Hasan Ghahremani, Esmaeil Lefebvre, Serge Saad, Maarouf Asber, Dalal Hydro Quebec Res Inst Varennes PQ J3X 1S1 Canada Opal RT Technol Inc Montreal PQ H3K 1G6 Canada Quebec Univ ETS Montreal PQ H3C 1K3 Canada

This study presents a secondary voltage control based on an optimisation algorithm to locate the control buses and regulate the voltage. Control buses are the buses where compensators will be installed on these buses to regulate voltage and avoid voltage violations. Firstly, partitioning algorithm using fuzzy C-means has been implemented on the power network. Partitioning techniques split the power system into regions to avoid the propagation of disturbances between regions by using local controllers. Then, a number of buses are labelled as control buses displaying the critical point for voltage control in each region. The control algorithm is a decentralised controller which tries to eliminate voltage violations in power system resulting from load variations and disturbances. The decentralised controllers are implemented using flexible AC transmission system (FACTS) devices such as static synchronous compensator (STATCOM). The methodology is applied to the IEEE 118-bus network. The results show the performance and ability of the partitioning algorithm and bus control selection to regulate the voltage and avoid propagation of disturbances between regions.

关键词： decentralised control flexible AC transmission systems fuzzy set theory IEEE standards static VAr compensators transmission networks voltage control authenticated voltage control partitioned power networks STATCOM heuristic algorithm optimisation algorithm control buses voltage regulate fuzzy C-means decentralised controller load variations FACTS device IEEE 118-bus network

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State Assignment for Finite State Machine Synthesis

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JOURNAL OF COMPUTERS 2013年第6期8卷 1406-1410页

作者： Yang, Meng Fudan Univ State Key Lab ASIC & Syst Shanghai Peoples R China

This paper proposes simulated annealing based algorithm for the synthesis of a finite state machine to determine the optimal state assignment with less area and power dissipation. The algorithm has two annealing stages. In the first rough annealing stage it tries to search in global scope by the proposed rough search method. In the second focusing annealing stage it tries to search in local scope by using proposed focusing search methods intending changing solution slightly. In both stages, the experience of past solution is utilised by combing the best solution in the past and the current solution. The experiments performed on a large suite of benchmarks have established the fact that the proposed method outperforms the published GA-based algorithms. The results have shown the effectiveness of the proposed method in achieving optimal state assignment for finite state machine.

关键词： state assignment finite state machine optimisation algorithm simulated annealing algorithm

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