A new stabilizer design technique for multimachine power systems

A simple and systematic procedure for decentralized stabilizer design for multimachine systems is presented in this paper. The procedure first selects the most effective location of a stabilizer according to a machine stability index. The parameters of the stabilizer are then determined by a decentralized feedback control scheme. This process is carried out for one stabilizer at a time. The resultant overall improvement of the system stability, measured by a system stability index, is used to decide how many stabilizers are required for the system. The proposed technique is illustrated by a test system. Both eigenvalue analysis and nonlinear simulation are performed to investigate the effectiveness of the technique.     

A microprocessor design project in an introductory VLSI course

An introductory very large scale integration (VLSI) design course has been taught at the University of Michigan (USA) since 1980. In 1990, it was redesigned around a simple 8-bit microprocessor project in the format described in this paper; in 1996, the project was updated to a 16 bit reduced instruction set computer (RISC) processor. The authors describe the course philosophy, content, and the baseline architecture from which class projects begin. The key features of the course are: close coordination of lectures and project activity; prompt and regular feedback on design work; and a schedule which spreads the workload over the full term. In this course, students learn VLSI fundamentals and good design methodology that will be important throughout their careers     

A model reduction technique suitable for optimal controller design in high-order power systems

One of the most difficult problems facing today's power system/control engineers is to find a relatively simple model for a complex physical process in order to apply powerful analysis and design techniques. This paper introduces an existing model reduction technique for high-order systems such as a modern large power plant and improves it by suggesting a new procedure for selecting the state variables of the reduced-order model. It applies this reduction technique to an example consisting of a turbogenerator feeding an infinite bus through a series capacitor compensated transmission line; the turbogenerator is equipped with a shunt reactor at the high voltage side of the step-up transformer in order to damp torsional oscillations. By using this new selection procedure within the model reduction technique a reduced-order model is derived and then used to design the shunt reactor's controller based upon optimal output feedback techniques. Computed transient response results of the full-order system are finally used to validate the reduction technique.     

网络式微机保护装置通信模块设计

提出一种以DSP和196单片机为核心的网络式微机保护装置，并着重介绍其通信网络方案的设计，给出部分硬件框图和软件流程。     

微机保护带负荷检查方法

详细介绍了WXH_11型、WXH_15型微机保护的带负荷检查方法 ,对实际工作有一定的借鉴意义。     

微机保护带负荷检查方法

详细介绍了WXH-11型、WXH-15型微机保护的带负荷检查方法,对实际工作有一定的借鉴意义.     

Power system stabilizer design based on the pole assignment technique for SIMO systems

A new power system stabilizer (PSS) design method for single-machine infinite-bus systems is developed. This design method not only assigns the poles corresponding to the electro-mechanical oscillation modes in the system, but also locates other system poles in suitable places in the s-plane. The design procedure is used first to translate a PSS design problem to an equivalent constant output feedback controller design problem for a single-input multi-output (SIMO) system. Then, a new algorithm developed in this paper is applied to design a constant output feedback controller to achieve the desired closed-loop system pole locations. Finally, the controller gains are transferred back to the parameters in the PSS. The extension of the method to multi-machine power systems is also illustrated.     

Robust excitation control design using sliding-mode technique for multimachine power systems

An output feedback controller is proposed to enhance the transient stability of nonlinear multimachine power systems considered as a classical model with flux decay dynamics. Combining high-order sliding-mode techniques with a robust high-order sliding-mode differentiator, a robust decentralized controller is obtained. Numerical results are presented to illustrate the performance of the proposed control scheme and its robustness properties.     

Differential evolution based technique for reliability design of meshed electrical distribution systems

This paper describes a methodology for allocating repair times and failure rates to segments of a meshed distribution system using differential evolution (DE) technique. A cost function based on Duane’s reliability growth testing model has been proposed. Constraints on basic reliability indices i.e. failure rate, average interruption duration and average interruption duration per year have been accounted. The algorithm has been implemented on a meshed distribution system and results have been compared with those obtained using particle swarm optimization (PSO) and co-ordinated aggregation based PSO (CAPSO).     

一种嵌入式微处理器cache存储体系结构设计

本文介绍了一种基于32位整数单元的片上cache存储体系结构设计的方案.作为SOC平台的核心部件,本设计中所有模块均自行设计,采用自顶向下的设计方法,应用Verilog HDL硬件描述语言进行设计,总线接口符合AMBATM总线规范(Rev 2.0).为了对设计功能的有效性进行验证,还设计了一个基于AMBATM总线协议的通用SOC的系统虚拟验证平台,利用该平台对相关模型进行了调试和仿真.仿真结果表明,设计达到预期的功能要求.     

A set‐based model‐free reinforcement learning design technique for nonlinear systems

In this study, we propose an extremum‐seeking approach for the approximation of optimal control problems for a class of unknown nonlinear dynamical systems. The technique combines a phasor extremum‐seeking controller with a reinforcement learning strategy. The learning approach is used to estimate the value function of an optimal control problem of interest. The phasor extremum‐seeking controller implements the approximate optimal controller. The approach is shown to provide reasonable approximations of optimal control problems without the need for a parameterization of the nonlinear system's dynamics. A simulation example is provided to demonstrate the effectiveness of the technique.     

A role model for electromagnetic systems design

The authors discuss the antenna test range at the US Naval Ocean Systems Center, which provides solutions to some formidable electromagnetics problems on ships. They describe the measurement approach; the pattern range, a 160 ft diameter ground plane constructed of prestressed concrete covered with a very thin coating of lead; the impedance range, which has a subterranean instrument room that houses the measurement equipment and personnel during the test; and the time-domain measurement range. The authors then examine computer modelling of antennas and analysis of the EMC (electromagnetic compatibility) problem. The modelling approach as presented is not limited to ships; it can work for power lines, buildings, and even mountains     

GT100系列微机型发电机变压器保护装置的设计

论述了MGT1 0 0系列微机型发电机变压器保护装置设计开发所依据的电力系统主设备保护动作情况的统计数据和动作原因分析、设计中所依据的高可靠性为主的总体设计原则和分布式单元结构、嵌入式控制器技术、分层式软件功能、实时操作系统等新技术的使用和软硬件设计要点。介绍了所采用的四段式比例差动、自动跟踪式定子 1 0 0 %接地保护和乒乓式转子接地保护等主要保护原理的特点 ,发电机、变压器后备保护的“N + 1”、“N + 2”配置方法和组屏设计方法 ,以及该系列装置在华能明台电厂等厂站的运行情况。证明达到了可靠性     

MGT100系列微机型发电机变压器保护装置的设计

论述了MGT100系列微机型发电机变压器保护装置设计开发所依据的电力系统主设备保护动作情况的统计数据和动作原因分析、设计中所依据的高可靠性为主的总体设计原则和分布式单元结构、嵌入式控制器技术、分层式软件功能、实时操作系统等新技术的使用和软硬件设计要点.介绍了所采用的四段式比例差动、自动跟踪式定子100%接地保护和乒乓式转子接地保护等主要保护原理的特点,发电机、变压器后备保护的"N+1"、"N+2"配置方法和组屏设计方法,以及该系列装置在华能明台电厂等厂站的运行情况.证明达到了可靠性高、保护配置齐全、组屏灵活、调试简单、使用方便的设计要求.     

MGT100系列微机型发电机变压器保护装置的设计

论述了ＭＧＴ１００系列微机型发电机变压器保护装置设计开发所依据的电力系统主设备保护动作情况的统计数据和动作原因分析、设计所依据的高性的主要的总体设计原理和分布式单元结构、嵌入式控制器自动跟踪式定子１００％接地保护和乒乓等新技术的使用和软硬件设计要点,介绍了所采用的四段式比例差动、自动跟踪式定子１００％接地保护和乒乓式转子接地保护等主要保护原理的特点,发电机、变压器后备保护的“Ｎ＋１”、“Ｎ＋２”配     

A probabilistic method for the design of power grounding systems

An improved multivariable, probabilistic method for the safety analysis of power grounding systems is presented. The application of this method is demonstrated in four examples. The first three examples illustrate the practical evaluation of one new and two existing substation grounding grids when the substation is connected to an overhead distribution system. The fourth example ascertains the relative impact of a difference between the S curve of IEC Publication 479 and Dalziel's equation for the allowable body current used in ANSI/IEEE Std 80-1986 on the validity of an exposure model based on the requirements of Std 80. In this example, the statistical data on ground faults have been taken from actual system records. Further possible refinements of the exposure model are discussed     

A computer-aided teaching package for microprocessor systemseducation

A computer-aided teaching (CAT) package for use in a microprocessor systems course is described. It uses the Z80 CPU as the basis for describing how an eight-bit CPU functions internally and as the master of a microcomputer system. The package, which consists of an assembler and a graphics simulator, aids as a powerful teaching tool that enables the student to learn about the internal architecture of a microprocessor as applied to the Z80 CPU and its instruction set with a step-by-step graphics animation of the instruction execution and timing. The package allows the user to execute a program step by step and to test the operation of the internal registers, buses, and memory contents at every clock edge. It also simulates read/write cycles from/to memory and input-output devices. Finally, it allows the user to write and debug problems at the assembly language or machine code level. The package is menu driven, interactive, flexible, and user-friendly     

A tight clock synchronization technique for multiprocessor systems

In this paper we present a tight clock synchronization scheme for large-scale multiprocessor systems. the proposed scheme consists of two symmetric loops for transmission of the master clock signals and a skew cancellation circuit (SCC) for each node to be synchronized to the master clock. Each clocking signal generated by the master clock source is replicated into two identical copies and the twin signals are transmitted on two symmetric loops in opposite directions. to cancel the time skew between them caused by the transmission network, the time difference between the two clocks' arrival times at any node is first measured and stored in each node. Then each of the leading signals received from the loop in a node is issued to its functional units after the signal is delayed by half the measured phase difference. It is shown that the system clock skew can be made independent of the delay of the transmission lines by the proposed scheme at a low hardware cost. To explore the feasibility of the proposed scheme, the SCC is designed with a combination of programmable delay element arrays and a phase detector. the floor-plan of the SCC is implemented by the MAGIC VLSI lay-out tool based on MOSIS CMOS 2 μm technology and extensively simulated.     

基于SPI接口的凌阳单片机键盘设计

介绍了一种通过凌阳单片机SPCE061A的SPI接口进行键盘扩展的设计方案.该方案采用具有SPI接口的周立功智能显示驱动芯片ZLG7289进行键盘管理,其外围电路设计简单,使用方便,管理按键多.这种键盘设计占用I/O口资源少,应用广泛.文中给出了系统硬件电路设计图、软件流程图以及仿真结果.     

A design method for continuous deadbeat control systems

Deadbeat control of discrete‐time systems has attracted particular interest because it ensures setting the deviation response to zero within finite time and affords fast responsiveness. By using controllers which include a delay element, however, the deadbeat characteristics can be realized in the continuous‐time domain, and such a tracking system has been obtained. In this paper, we propose a new design method of continuous deadbeat control systems without using delay elements. Our new controller is composed of a digital deadbeat compensator using state feedback and a series smoothing filter. Illustrative numerical examples are presented. The method proposed here is very simple compared with other methods and it seems to be useful for practical applications. © 1999 Scripta Technica, Electr Eng Jpn, 127(2): 42–48, 1999