多单元耦合的能量双向无线馈动系统分析及控制策略

双向无线电能传输技术是无线电能传输领域的一个重要研究方向。文中研究了含有(k+1)个能量传输单元的双向无线电能传输系统,通过建立(k+1)个传输单元的能量馈动模型,提出一种灵活控制系统功率流动方向以及有功出力(或功率分配)的方法。该方法利用各回路单元双向变换器出口电压幅值以及相角之间的关系,降低了系统能流方向和功率分配的控制难度。以3回路能量传输单元的双向无线电能传输系统为例,给出了功率流动方向控制和有功出力控制的约束关系,并进行仿真与实验研究,结果验证了理论分析的正确性与可行性。

考虑气热能延迟特性的综合能源系统内能流自分配策略

针对沿海工业园区及靠岸船舶供电负荷惯性薄弱、需求量波动大、响应性较差等问题,提出一种考虑气热能延迟特性的综合能源系统(Integrated energy system,IES)日前-日内调度策略,实现多能流的解耦与分配。在工业负荷出现波动时,日内调度根据每个时刻预测负荷和日前预测负荷的差值,考虑能流多种转化途径,以优先保持电负荷平衡的情况下最大限度地满足冷热负荷平衡为调度原则,建立能流分配的判断指标,对日前计划进行修正。策略中计及了气热能转换设备出力的延迟特性,在延迟时间内补充了能量损失。通过算例仿真分析,验证了所提复合调度策略能够利用各类能流的耦合互补关系,平抑冷热电负荷波动,减小调度误差,提高综合能源系统的能量利用效率和经济效益。

基于H∞鲁棒控制的船用混合储能双向DC-DC变换系统设计

双向DC-DC变换系统是为实现船舶混合储能中不同类型储能元件间匹配控制和能量管理必要的执行机构。针对传统DC-DC控制策略的混合储能系统存在较大程度的参数摄动和负载干扰的问题,引入H∞鲁棒控制策略,从而弥补传统控制策略的缺陷;运用Matlab/Simulink软件搭建船用混合储能双向DC-DC变换系统仿真模型,开展有功负荷突增突卸和系统响应特性试验。结果表明:采用该策略能有效提升混合储能系统平抑冲击负荷的动态性能,充分发挥混合储能系统内储能元件各自的优势,延长系统使用寿命。

DCFl-Checker： Checking Kernel Dynamic Control Flow Integrity with Performance Monitoring Counter

It is a challenge to verify integrity of dynamic control flows due to their dynamic and volatile nature. To meet the challenge, existing solutions usually implant an ＂attachment＂ in each control transfer. However, the attachment introduces additional cost except performance penalty. For example, the attachment must be unique or restrictedly modified. In this paper, we propose a novel approach to detect integrity of dynamic control flows by counting executed branch instructions without involving any attachment. Our solution is based on the following observation. If a control flow is compromised, the number of executed branch instructions will be abnormally increased. The cause is that intruders usually hijack control flows for malicious execution which absolutely introduces additional branch instructions. Inspired by the above observation, in this paper, we devise a novel system named DCFI- Checker, which detect integrity corruption of dynamic control flows with the support of Performance Monitoring Counter （PMC）. We have developed a proof-of-concept prototype system of DCFI-Checker on Linux fedora 5. Our experiments with existing kemel rootkits and buffer overflow attack show that DCFI- Checker is effective to detect compromised dynamic control transfer, and performance evaluations indicate that performance penaltyinduced by DCFI-Checker is acceptable.

Active control of structural vibration by piezoelectric stack actuators

This paper presents a general analytical model of flexible isolation system for application to the installation of high-speed machines and lightweight structures. Piezoelectric stack actuators are employed in the model to achieve vibration control of flexible structures, and dynamic characteristics are also investigated. Mobility technique is used to derive the governing equations of the system. The power flow transmitted into the foundation is solved and considered as a cost function to achieve optimal control of vibration isolation. Some numerical simulations revealed that the analytical model is effective as piezoelectric stack actuators can achieve substantial vibration attenuation by selecting proper value of the input voltage.

Application of Fuzzy Discrete Event System in Air Conditioning Energy-saving

Air conditioning (AC) system is the one with asynchronous and uncertain nature. In this paper, the fuzzy discrete event system (FDES) is introduced to the research of AC energy-saving control. A fuzzy automaton modeling is given for AC energy-saving control and effectiveness optimization is made. To facilitate the implement of the control and energy saving, priorities have been assigned to the major control steps based on logical reasoning. Forward-looking tree modeling based on FDES has been simplified to help further optimization, and a simple and concrete example has been put forward illustrating energy-saving control in AC system.

ANN Based Performance Analysis of UPFC in Power Flow Control

The Unified Power Flow Controller （UPFC） is one of the most versatile Flexible AC Transmission Systems （FACTS） devices that has unique capability of independently controlling the real and reactive power flows, in addition to regulate the system bus voltage. This paper presents performance analysis of Unified Power Flow Controller based on two axis theory. Based on this analysis, a new Artificial Neural Network （ANN） based controller has been proposed to improve the system performance. The controller rules are structured depending upon the relationship between series inserted voltage and the desired changes in real/reactive power flow in the power system. The effects of different controllers along with parameters of series transformer and transmission line have been investigated through developed control block model in SIMULINK tool box of MATLAB. The effectiveness of the proposed scheme is demonstrated by case studies.

Left Ventricle Failure and Blood Flow Estimation for Centrifugal Blood Pumps

This paper shows the blood flow control （FwC） performance to adjust rotational speed of an ICBP （implantable centrifugal blood pump） in order to provide an adequate flow to left ventricle in different patient conditions. ICBP is a totally implantable LVAD （left ventricular assist device） with ceramic bearings developed for long term circulatory assistance. FwC uses PI （proportional-integral） control to adjust rotational speed in order to provide blood flow. FwC does not use sensor for feedback, as there is an estimation system to provide blood flow measurement. Control strategy has being studied in a HCS （hybrid cardiovascular simulator） as a tool that allows the physical connection of ICBP during evaluation. In addition, HCS allows changes of some cardiovascular parameters in order to simulate specific heart disease： ejection fraction （10-25%） and heart rate （50-110 bpm）. FwC was able to adjust blood flow with steady error less than 2%. Results demonstrated that FwC is adequate to LVAD control irL different left ventricle failure conditions.

Anglo-American Special Relations： Atomic Diplomacy and the Canadian Dimension, 1942-1948

In recent years, we have entered a period of increasing impact of world affairs on national politics and international security. Notwithstanding, the present debate on national security and nuclear proliferation, Anglo-American ＂special relations＂ continue to be a subject of vigorous discussion influenced by the impact of new international emergencies as unstable countries acquire nuclear power and refuse ＂to reign＂ in their nuclear programmes （The Globe and Mail, 12 January 2012）. Along these lines the 71st anniversary of the Anglo-American Manhattan Project presents a unique opportunity to reappraise the Anglo-American wartime collaboration （or lack of） in atomic energy developments that resulted in the tragedy of nuclear weapons escalation. The Quebec Agreements of 1943-1944 were crafted to address the controlled flow of scientific information. But did this mean a trend toward more effective collaboration or toward greater American control of the atomic project？ This study explores the subject of nuclear politics from an unique vantage point of Anglo-Canadian and American-Canadian atomic diplomacy. In doing so, it will show that both the American and British atomic policy makers violated the Quebec Agreements. It seeks to demonstrate that （1） in the tangle of competition replacing cooperation, Canada was more important to the American atomic monopolists than the Anglo-AmcTican partnership, （2） the US-Canada Trade and Defence Agreements contributed to United States retaining exclusive control of the ＂absolute weapon＂, and that （3） their post-war nuclear energy agenda delayed Britain＇s atomic venture and isolated Britain from full participation in Arctic research. In practical terms, the emerging atomic policy in Washington boiled down to maintaining the American edge, come what may, and reducing British prestige in the post-war world. The article concludes by raising the question： did the United States, Britain, and Canada really work for atomic control？

Systematic Logic Controller Design as Sequential Function Chart Starting from Informal Specifications

Today＇s automation industry is driven by the need for an increased productivity, higher flexibility, and higher individuality, and characterized by tailor-made and more complex control solutions. In the processing industry, logic controller design is often a manual, experience-based, and thus an error-prone procedure. Typically, the specifications are given by a set of informal requirements and a technical flowchart and both are used to be directly translated into the control code. This paper proposes a method in which the control program is constructed as a sequential function chart （SFC） by transforming the requirements via clearly defined intermediate formats. For the purpose of analysis, the resulting SFC can be translated algorithmically into timed automata. A rigorous verification can be used to determine whether all specifications are satisfied if a formal model of the plant is available which is then composed with the automata model of the logic controller （LC）.

Experimental analysis on adjusting performance of vapor-liquid two-phase flow controller

The vapor-liquid self-adjusting controller is an innovative automatic regulating valve.In order to ensure adjusted objects run safely and economically,the controller automatically adjusts the liquid flux to keep liquid level at a required level according to physical properties of vapor-liquid two-phase fluid.The adjusting mechanics,the controller’s performance and influencing factors of its stability have been analyzed in this paper.The theoretical analysis and successful applications have demonstrated this controller can keep the liquid level steady with good performance.The actual application in industry has shown that the controller can satisfactorily meet the requirement of industrial production and has wide application areas.

Numerical Simulation of Aspect Ratio Effect on Turbulent Annular Flows

The control of energy in various industrial applications passes by the comprehension of the phenomena of transfers especially in complex flows. The structure of the turbulent flow in the cavities in rotation depends on several parameters like the Reynolds number of rotation Ra and the aspect ratio of the cavity. The purpose of this work is to simulate numerically the effect of the aspect ratio on the level of turbulence in the annular steady flow with an incompressible fluid for three different configurations. In the first, the interior cylinder is fixed and the external is moving. The second configuration is the reverse. The third is the contra-rotating cylinders. For all these configurations, we varied the aspect ratio from 0.5 to 2.5. The numerical tool is based on a statistical model in a point using the closing of the second order of the transport equations of the Reynolds stresses （Reynolds Stress Model： RSM）. The results of our numerical simulation show that this geometrical parameter can be an interesting factor to increase the level of turbulence that is often required in several industrial applications where the economy and the control of energy are always required.

The Сoncept of Lava Flow Controlled Use as a Source of Energy and Materials

Our civilization is facing an urgent need to include innovative, large-scale sources of energy and raw materials into its technological cycles. One potential source is magma, which now still inspires awe with its unpredictable power of volcanic eruptions. We propose a method of remote control of lava flow which is based on a special design of a pipe which is lowered into the crater of a volcano. The magma is raised with the help of a well-known method for raising liquids, the airlift. This article includes a detailed description of the structure of the disperser that we shall use to introduce gas into the magma, explains the possible ways to manage the flow of magma, and describes the results that can be achieved. There is potential for the establishment of a whole new industry that will produce cheap electricity, hydrogen, rare metals, fertilizers and innovative construction materials.

Finite Set-Model Predictive Current Control of Three-Phase Voltage Source Inverter for RES （Renewable Energy Systems） Applications

This paper focuses on a combination of three-phase VSI （voltage source inverter） with a predictive current control to provide an optimized system for three-phase inverters that control the load current. A FS-MPC （finite set-model predictive control） strategy for a three-phase VSI for RES （renewable energy systems） applications is implemented. The renewable energy systems model is used in this paper to investigate the system performance when power is supplied to resistive-inductive load. With three different cases, the evaluation of the system is done. Firstly, the robustness of control strategy under variable DC-Link is done in terms of the THD （total harmonic distortion）. Secondly, with one prediction step, the system performance is tested using different sampling time, and lastly, the dynamic response of the system with step change in the amplitude of the reference is investigated. The simulations and result analyses are carried out using Matlab/Simulink to test the effectiveness and robustness of FS-MPC for two-level VSI with AC filter for resistive-inductive load supplied by a renewable energy system.

Dysfunctional Audit Behaviour： The Effects of Employee Performance, Turnover Intentions and Locus of Control

Dy Ov sfunctional audit behaviour （DAB） and staff turnover are associated with decreased audit quality （Public ersight Board, 2000）. This study develops and tests a theoretical model that turnover intentions and locus of control as antecedents of attitudes toward DAB survey results from 225 auditors support the theoretical model identifies employee performance, Using a path analysis technique,

Recent Development in Data Processing and Control Research on the HL-2A ＆ HL-2M Tokamak

In 2006, except the basic improvement on HL-2A tokamak control system, data acquisition and processing system, a series of research activities have been developed in computer and control division. They include the construction of the high performance computer （HPC） system, the plasma configuration real-time reconstruction with EFIT code, the immigration of plasma simulation codes, the improvement of the poloidal field control system with circulating current, the design of the new data acquiring device with higher anti-disturbing power, the new software on soft X-ray spectrum measurement providing the multi-channel Te evolution, the upgrade to the HL-2A data storage system and experimental net. On the other hand, according to the arrangement of HL-2A modification project, a series of designs such as new plasma configuration, poloidal field coils distribution and plasma shape and position control system are on the processing.

Modern Control and Diagnostic System of Traction Vehicle with Hybrid Drive System

In paper it introduced a review of modem traction vehicle drive system with induction motor drive system （PMSM with single or dual rotor drive system） or BLDC motor with different configuration of magnetic circuits. For particular part of drive system proposed a quasi intelligent control system version smart control enables multi criteria predictive control of vehicle work. In the paper presented also a selected diagnostic procedure, enables monitoring exploitation parameters, and prediction of probable failure state. For different vehicle work state realized a simulation models and crash test of exploitations failure models.

Drag reduction via turbulent boundary layer flow control

Turbulent boundary layer control(TBLC) for skin-friction drag reduction is a relatively new technology made possible through the advances in computational-simulation capabilities,which have improved the understanding of the flow structures of turbulence.Advances in micro-electronic technology have enabled the fabrication of active device systems able to manipulating these structures.The combination of simulation,understanding and micro-actuation technologies offers new opportunities to significantly decrease drag,and by doing so,to increase fuel efficiency of future aircraft.The literature review that follows shows that the application of active control turbulent skin-friction drag reduction is considered of prime importance by industry,even though it is still at a low technology readiness level(TRL).This review presents the state of the art of different technologies oriented to the active and passive control for turbulent skin-friction drag reduction and contributes to the improvement of these technologies.

A survey on fabrication,control,and hydrodynamic function of biomimetic robotic fish

Understanding and replicating the locomotion principles offish are fundamental in the development of artificial fishlike robotic systems,termed robotic fish.This paper has two objectives:(1) to review biological clues on biomechanics and hydrodynamic flow control offish swimming and(2) to summarize design and control methods for efficient and stable swimming in robotic fishes.Our review of state-of-the-art research and future-oriented new directions indicates that fish-inspired biology and engineering interact in mutually beneficial ways.This strong interaction offers an important insight into the design and control of novel fish-inspired robots that addresses the challenge of environmental uncertainty and competing objectives;in addition,it also facilitates refinement of biological knowledge and robotic strategies for effective and efficient swimming.

Numerical Study of Improving Aerodynamic Performance of Low Solidity LPT Cascade through Increasing Trailing Edge Thickness

This paper presents a new idea to reduce the solidity of low-pressure turbine(LPT) blade cascades,while remain the structural integrity of LPT blade.Aerodynamic performance of a low solidity LPT cascade was improved by increasing blade trailing edge thickness(TET).The solidity of the LPT cascade blade can be reduced by about12.5% through increasing the TET of the blade without a significant drop in energy efficiency.For the low solidity LPT cascade,increasing the TET can decrease energy loss by 23.30% and increase the flow turning angle by1.86% for Reynolds number(Re) of 25,000 and freestream turbulence intensities(FSTT) of 2.35%.The flow control mechanism governing behavior around the trailing edge of an LPT cascade is also presented.The results show that appropriate TET is important for the optimal design of high-lift load LPT blade cascades.