Stability of one-dimensioned spatially interconnected systems

This article is dedicated to the stability of one-dimensioned spatially interconnected systems. More precisely, it focuses on systems which results of the interconnection of a possibly large number of cells (continuous subsystems). This note is restricted to the case where cells are just distributed along a line. The global system can then be seen as a mixed continuous–discrete 2D Roesser system but with implicit discrete dynamics along the space dimension. Recent results on the stability of 2D Roesser models are exploited and adapted to derive a sufficient condition for such a system to be stable. The condition seems to be close to necessity if not necessary. It is tractable since it is expressed in terms of linear matrix inequalities. The novelty clearly lies in the reduction of the conservatism of the proposed analysis.

     

Disaster control coordination for large interconnected systems

A new philosophy for the analysis and design of large electric power interconnections has evolved following the Northeast power failure of November 9, 1965. Most contingencies that can cause wide-spread outages occur too infrequently to be included in the criteria for system design. Nevertheless, systems should be tested for combinations of events that cause system instability and separation so that the consequences of these unlikely occurrences can be evaluated and system designers can provide disaster control procedures to limit the extent and duration of system outages. The design and disaster control procedures should provide successive lines of defense against increasingly severe and unlikely events. Disaster control procedures can be coordinated so that governor action, load shedding, and system separation can be integrated according to time and frequency in such a way that maximum reliability and security will be provided.     

High-gain decentralised control of interconnected dynamical systems

It is shown that the class of controllable and observable interconnected dynamical systems that are amenable to high-gain decentralised control can be characterised in terms of the relatively prime polynomial matrix factors of the transfer-function matrices of the disconnected subsystems. Moreover, this characterisation greatly facilitates the synthesis of high-gain decentralised controllers for such amenable systems.     

Automation developments in the control of interconnected electric utility systems

The rapidly increasing capability of the digital process control computer permits the economic solution of many electric utility system operating problems in a more accurate and timely manner. In this paper, the extension of the application area from the field of economic dispatch of generation to more sophisticated functions of system security is traced. Other related problems in the area of operations planning, operations control, and operations accounting are also reviewed. The requirements of communication systems to provide remote input data to the process computer are discussed, and the close interrelation of business and process computers is recognized. Information display is shown to play a very significant part in providing output to the system operators for further action. Concurrent with the developments in hardware have been significant advances in analytical techniques to encompass the increasing number of problems of system operation. These are reviewed in relation to the two major concerns, system security and system economics. An integrated information and control system may he achieved today for business, engineering, and system operation as a result of significant developments in hardware and in problem solution concepts. The optimum application of these improved equipments and analytical tools requires a total systems viewpoint in relation to both hardware and software.     

Optimal scalar Lyapunov functions for decentralised stabilisation of interconnected systems

The problem of stabilisation of interconnected linear systems is considered by means of scalar Lyapunov functions and aggregation. A sufficient condition is given for an interconnected system to be stabilised using only local state feedback. The aim is to provide the least restrictive condition possible, which is termed `optimal?, by properly choosing the state-variable weighting matrices for each subsystem.     

System-level microwave design projects

The teaching laboratory can be an invaluable component of an undergraduate electromagnetics curriculum. This goal of this article is to illustrate several simple but effective microwave-design laboratory projects, involving both system- and component-level design experiences, based upon radar and wireless communications applications. The projects highlighted include a Doppler radar, a simple synthetic aperture radar (SAR), and wireless links using amplitude and frequency-modulation schemes. Students use modern computer-aided design (CAD) tools, coupled with planar technology     

高频RFID通信系统级仿真

为了揭示RFID系统ISO／IEC标准中高频段通信方式的主要技术及关键参数,采用Simulink对高频RFID通信系统进行建模并在Matlab中进行处理。仿真了高频通信协议中IS0／IEC14443A通信协议,得出ISO／IEC14443A通信协议数据流的主要技术和关键参数。     

T-S fuzzy controllers for nonlinear interconnected systems with multiple time delays

This paper investigates the effectiveness of a passive tuned mass damper (TMD) and fuzzy controller in reducing the structural responses subject to the external force. In general, TMD is good for linear systems. We proposed here an approach of Takagi-Sugeno (T-S) fuzzy controller to deal with the nonlinear system. To overcome the effect of modeling error between nonlinear multiple time-delay systems and T-S fuzzy models, a robustness design of fuzzy control via model-based approach is proposed in this paper. A stability criterion in terms of Lyapunov's direct method is derived to guarantee the stability of nonlinear multiple time-delay interconnected systems. Based on the decentralized control scheme and this criterion, a set of model-based fuzzy controllers is then synthesized via the technique of parallel distributed compensation (PDC) to stabilize the nonlinear multiple time-delay interconnected system and the H/sup /spl infin// control performance is achieved at the same time. Finally, the proposed methodology is illustrated by an example of a nonlinear TMD system.     

Decentralized variable structure control of interconnected multi-input/ multi-output nonlinear systems

For a broad class of interconnected nonlinear systems, this paper develops a complete design methodology for decentralized variable structure control. Specifically, the paper sets forth design schemes for local switching surfaces and the related local switched feedback gains which together force the original nonlinear interconnected system to behave as a reduced order interconnected equivalent system having a desired response such as stability, tracking, or prespecified eigenvalues. Also developed is a numerical algorithm for constructing the switched local feedback gains. A simple nonlinear example illustrates the control strategy.     

A new approach to evaluate two area interconnected power generating systems reliability

This paper presents the developed application of a new approach to evaluate Loss of Load Probability (LOLP) of two area interconnected power systems consisting of different types and sizes of generating units considering independent as well as correlated system demands. This approach uses hourly loads, or any suitable time interval for system demand, for a given period. The Probability Density Function (p.d.f.) of equivalent load is obtained by convolving the p.d.f. of generating unit outages with the p.d.f. of system demands using a new approach. The proposed approach can simulate multistate representation of generating units as well. The LOLP values for each system are obtained from the p.d.f. of equivalent load. This method is applied to two interconnected systems and the results obtained are compared with those obtained using existing methods. It is found that this approach is efficient, exact and easy to apply compared with other methods.     

Characterization of a class of spatially interconnected systems (ladder circuits) using two-dimensional systems theory

Multidimensional Systems and Signal Processing - This paper considers a class of spatially interconnected systems formed by ladder circuits using two-dimensional systems theory. The individual...     

System-level exploration for Pareto-optimal configurations in parameterized system-on-a-chip

In this work, we provide a technique for efficiently exploring the power/performance design space of a parameterized system-on-chip (SOC) architecture to find all Pareto-optimal configurations. These Pareto-optimal configurations will represent the range of power and performance tradeoffs that are obtainable by adjusting parameter values for a fixed application that is mapped on the SOC architecture. Our approach extensively prunes the potentially large configuration space by taking advantage of parameter dependencies. We have successfully applied our technique to explore Pareto-optimal configurations of our SOC architecture for a number of applications.     

System-level power-performance tradeoffs for reconfigurable computing

In this paper, we propose a configuration-aware data-partitioning approach for reconfigurable computing. We show how the reconfiguration overhead impacts the data-partitioning process. Moreover, we explore the system-level power-performance tradeoffs available when implementing streaming embedded applications on fine-grained reconfigurable architectures. For a certain group of streaming applications, we show that an efficient hardware/software partitioning algorithm is required when targeting low power. However, if the application objective is performance, then we propose the use of dynamically reconfigurable architectures. We propose a design methodology that adapts the architecture and algorithms to the application requirements. The methodology has been proven to work on a real research platform based on Xilinx devices. Finally, we have applied our methodology and algorithms to the case study of image sharpening, which is required nowadays in digital cameras and mobile phones.     

SOC技术及系统级低功耗设计

介绍了SOC设计中的IP核可复用技术、软硬件协同设计技术、SOC验证技术、可测性设计技术以及低功耗设计技术。对SOC低功耗设计中的瞬态功耗优化、平均功耗优化以及功耗的物理来源、电容充放电功耗、短路功耗、静电漏电功耗进行了分析。并对典型SOC设计中采取降低芯片和封装电容、降低电源电压,达到降低功耗的技术进行了研究。最后对系统级功耗设计中的电源系统低功耗设计、工作系统低功耗设计进行了探讨。     

System-level performance evaluation of three-dimensional integratedcircuits

In this paper, the wire (interconnect)-length distribution of three-dimensional (3-D) integrated circuits (ICs) is derived using Rent's rule and following the methodology used to estimate two-dimensional (2-D) (wire-length distribution). Two limiting cases of connectivity between logic gates on different device layers are examined by comparing the wire-length distribution and average and total wire-length. System performance metrics such as clock frequency, chip area, etc., are estimated using wire-length distribution, interconnect delay criteria, and simple models representing the cost or complexity for manufacturing 3-D ICs. The technology requirement for interconnects in 3-D integration is also discussed     

电动汽车的系统级EMC设计

在分析整车EMC设计现状的基础上,以大量部件和整车的设计、测试经验为支撑,借鉴学习国外一些车型的先进设计思路,从EMC工程设计角度,提出了一种电动汽车系统级EMC开发方法.该方法成功应用于各研发车型,改变了以往样车难以顺利通过EMC法规的局面,同时保证了系统内EMC.