大规模复杂配电网三相不平衡潮流并行计算方法

以牛顿拉夫逊法为基础,建立了复杂配电网中的三相配电线路、负荷、变压器和调压器等的数学模型,提出了复杂配电网三相不平衡潮流的并行计算方法,以提高大规模复杂配电网潮流计算的性能。考虑配电网的馈线数和节点数,设计了同构模式下多核(2、4)处理器的任务分配,对比负载均衡、并行加速比。通过IEEE 123节点标准馈线、某电网1000节点馈线及IEEE 123、37、34和13标准馈线拆装重组而成的数十条馈线等的仿真,对所提并行潮流计算方法的计算速度、收敛性和加速比进行测试和比较分析。仿真结果表明,所提并行计算算法能充分利用计算机的多核资源、显著提高了计算效率。     

Parallel computing for less

High speed networks and improved microprocessor performances are making workstations an appealing prospect for parallel computing. With just commodity hardware and software, networked workstations can offer parallel processing at a relatively low cost. Parallel computing can be implemented in two ways. The networked workstations can be set up as a processor bank with dedicated processors providing computing cycles. Or, it can consist of a dynamically varying set of machines that perform long running computations during idle periods. In the latter case, the hardware cost is essentially zero since many organizations already have extensive workstation networks. For some applications, networked workstations can approach or exceed supercomputer performance. However, these loosely coupled multiprocessors will by no means replace the more tightly coupled designs. Supercomputer lower latencies (time elapsed between issuing a memory request and receiving the corresponding data from memory) and higher bandwidths are more efficient for applications with stringent synchronization and communication requirements. But, advances in networking technology and processor performance are expanding the applications that can be executed efficiently on networked workstations     

A study based on the factorization-tree approach for parallel solution of power network equations

Advance in the development of distribution computer architecture, parallel processing systems have the potential to become useful for power system applications by simultaneously solving the independent functions of a given task. A power system is separated into as many subnetworks, referred to as a bordered block diagonal form (BBDF) matrix, as the processors of a parallel computer. Balance loading on all processors is essential to ensure the success of any parallel approach. In this study, a novel method involving the factorization tree approach on the basis of calculating the maximum number of fill-in and the degree of every node as the cutest block nodes is proposed. Using the proposed approach, the number of nodes in each subnetwork is more uniform and the computation time is saved. Simulation results of the IEEE test systems and the Taiwan Power Company 288-bus system are presented to verify the feasibility of the proposed approach and its capability to implement parallel computing for load flow analysis.     

SIMD processors-expanding its horizons by emulating others

Parallel processing has established itself as the key enabling technology for the future of high performance computing. A parallel machine can be abstracted as a collection of processing elements (PEs) connected using some form of communication network. Parallel machines have been built along two major architectural formats: multiple-instruction streams multiple-data streams (MIMD) machines and single-instruction stream multiple-data streams (SIMD) machines. The hardware differences and general programming models for SIMD and MIMD processors have led many to believe each can solve only limited types of problems. SIMD machines, for instance, are often used in applications such as image processing. In that application, the same set of operations are performed on many different pieces of data. MIMD machines are commonly used when the control flow needs vary in correspondence with differences in data, such as parallel simulation     

An embedding debugging architecture for SOCs

Multiple cores embedded debugging architecture for system on chip design (SOC) is presented. It presents an asymmetrical functional test problem. To analyze the problem and optimize performance in multicore operation, debug tools with interfaces are exercised for several cores. HyperJTAG (joint test action group) interface reduces the IO pin interfaces required for debugging several cores. To overcome the wiring problem in hyperJTAG, wire routing and debugging synchronization is proposed. Hyper debug action nodes at each core initiate global or local control actions that synchronously reset the cores. To provide a virtual connection between the processor core in the SoC and its corresponding probe control, MED (multicore embedded debugging) software tool is proposed. This allows a contiguous analysis flow from the system level simulation models of SoC systems through FPGA and emulation prototyping and finally it debug the silicon hardware.     

多核处理器在智能间隔装置中的应用探讨

在智能间隔装置中提高系统的主频,装置的发热与成本会急剧地增加,但性能并不会成倍地提高。阐述了在智能间隔装置中使用多核处理器其硬件及软件上的优越性。通过一个应用实例,分析了多核装置的内核引导顺序及引导方式,解析了内核间内存分配模式,剖析了多核的中断处理方式、多核操作的软件可靠性和数据安全性,并详细说明了智能间隔装置中内核间任务分解的方式。相对于单核处理器而言,在智能间隔设备中使用多核处理器,通过合理的任务分解和中断向量的分配,会极大地提高系统的运算速度,但系统的发热及功耗相对增加很少,可以大大提高设备的性能     

On distributed computing for on-line power system applications

This paper reviews the state-of-the-art of distributed computing (also called coarse-grained parallel computing) technology, which has rapidly evolved over the last two decades, with emphasis on the trend towards standardization that has occurred in the last few years. The review is focused on on-line power system applications, and excludes fine-grained parallel applications and planning applications. The applications are divided into two categories. The first category consists of applications where the motivation for distributed processing stems from geographical distribution. The second category is the rest of the on-line applications where the parallelism stems from the easily decomposable abstract (mathematical) model of the problem as opposed to being ‘physically based’. Some of the issues in such distributed computing are illustrated using the example of security-constrained optimal power flows. The paper concludes with some projections on the use of this technology in energy management systems (EMS) in the near future.     

Technical reports-a new cable phenomenon

A hitherto unknown phenomenon was discovered while developing a novel type of medium-voltage cable. In an attempt to increase the operation voltage of plastic-insulated belted-type cables, breakdown tests were performed on cables using sandwich insulation, i.e. a dielectric-air-dielectric composite. It was found that if a nonwoven porous tape was applied to the cores, so that the interstices between the cores were partly filled with fibrous material, the breakdown voltage was significantly raised over the desired level corresponding to 30 years at 10 kV. Several tests, both at full reel lengths, of longer duration are reported that confirm this phenomenon. The phenomenon can be used for designing improved multicore medium-voltage cable and leads to novel conceptions of the behavior of internal discharges, especially in large cavities     

基于Beowulf集群的大规模电力系统牛顿法潮流求解的并行GMRES方法

大规模电力系统牛顿法潮流计算中,修正方程组的系数矩阵具有高维、稀疏、非对称的特点,结合该特点,提出基于预条件GMRES的并行牛顿法潮流计算方法.其中,对块Jacobi预条件子矩阵而言,根据处理器数确定其分块数,依此设计出高效的准对角并行预条件子矩阵;通过对Jacobi矩阵更新过程的矢量化处理,结合并行稀疏矩阵向量运算技...     

基于实时数字仿真器的模块化多电平换流器的建模

模块化多电平换流器（modular multilevel convener,MMC）主电路的搭建和仿真可以在实时数据仿真器（real time digital simulator,RTDS）的小步长环境下完成,由于目前的RTDS处理器计算容量不足以进行多达200电平的MMC仿真,为了尽可能在现有处理器运算情况下进行更大...     

Current rating of multicore cables

An algorithm to calculate the current-carrying capability of multicore cables is presented. The method takes into account the presence of air gaps and metallic conductors in the cable bundle. Under an assumption of a uniform loss density, analytical expressions, which take into account conduction inside the bundle and convection and radiation outside it, are developed. The method is illustrated with a numerical example of a telecommunication cable with 96 stranded cores. Experimental results are also reported for the same cable.     

云计算综述及电力应用展望

云计算是当前较为流行的信息新技术之一,技术发展快,已由概念阶段步入到应用实践阶段,全球公用事业用户对云计算的使用也呈快速增长趋势。本文以近几年国内外核心期刊文献为主要依据,针对虚拟化、并行计算、分布式等云计算相关技术,总结了当前技术的研究概况,分析了未来技术的发展趋势。在此基础上,结合智能电网、“三集五大”等业务的发展,对电力企业云计算的应用需求进行了全面梳理与展望,为电力企业云计算的发展与应用提供指导和参考。     

Multicore Photonic Crystal Fiber Lasers for High Power/Energy Applications

In this paper, the authors discuss the modal and lasing properties of multicore photonic crystal fiber lasers in the context of high power/energy production from fiber cores with very large mode area. Supermode selection methods like Talbot imaging or far-field aperturing are tested using 6-, 7-, and 18-core fibers. It is shown that in-phase mode selection is achieved efficiently by using either method. The fibers have been tested in continuous-wave (CW) and Q-switched laser operation. The mode field area is as large as 4240 mum² for one of the fibers, providing up to 2 mJ of pulse energy in Q-switched operations with 30 ns pulse duration.     

不对称三相P—Q分解法潮流的并行计算

本文利用解耦－补偿法模型，通过对三序间弱耦合的补偿，实现了三序间的解耦求解；构筑了不对称三相潮流的同步并行算法，实现了并行计算，并对计算结果进行了分析。     

面向宽频振荡抑制的宽频相量测量装置

快速实时测量宽频相量对于宽频振荡抑制有着重要意义。然而,已有宽频相量测量装置主要面向监测类应用,响应速度慢。研制了一种面向宽频振荡抑制的宽频相量测量装置。该装置采用加窗插值离散傅里叶变换算法,实现多模式宽频相量测量;采用较短时间窗缩短算法的动态响应时间;通过2个数字信号处理器并行计算分别完成基波和谐波/间谐波相量测量。通过性能测试发现,所研制的宽频相量测量装置响应速度快、准确度高,能满足宽频振荡抑制等应用对相关性能的要求。     

High-order volterra series analysis using parallel computing

This paper addresses the determination of high-order Volterra transfer functions of non-linear multiport networks containing multidimensional non-linear elements. A new method is developed for utilizing parallel computing which is very efficient for approximately 10–20 processors. The utilization of each processor may be as high as 80%–95%. The developed program is very flexible as it is ANSI C++ compatible and may run on both single- and multiprocessor computers. Using about eight processors it is possible to analyse rather complicated non-linear circuits up to ninth order in a few hours. © 1997 by John Wiley & Sons, Ltd.     

Concurrent boundary element computation

A major limitation of the boundary element method (BEM) for the solution of electrical potential problems is the long computational time required. However, a large portion of the calculations involved can be viewed as being parallel in nature and can therefore be computed concurrently. This paper makes an effort to increase the efficiency of the BEM process using transputer-based multiprocessor computing techniques. The algorithms developed may equally well be applied to any multiprocessor system. The application selected to demonstrate the technique is the solution of an electrostatic problem governed by a two-dimensional Laplace equation. A parallel algorithm for problem setup and field extraction using BEM is designed and implemented on a transputer array. Special attention is directed to the utilization of the parallel processors to achieve maximum efficiency. The analysis in this work concentrates on the communication strategies for passing data between processors as well as a consideration of the workload attributed to each processor. The parallel algorithms were implemented using 3L Parallel Fortran; however, the choice of topology for the overall BEM implementation was limited by the fact that certain parts of the algorithm could only utilize a pipeline configuration of processors. Comprehensive results for the parallel BEM algorithm are given and they are encouraging, indicating that parallel processing has much to offer when applied to the boundary element method.     

电力系统静态安全最优潮流并行计算方法

针对大规模预防性安全约束最优潮流计算耗时长的问题,提出2种基于单机多处理器平台的粗粒度并行计算方法以提高求解效率。依据多预想故障计算过程相互独立的特点合理分解计算任务,平衡各核心负载,降低通信损耗,并利用MATLAB并行工具箱编写具有高并行度的程序代码,充分利用多核资源。得到的优化调度方案可使电网运行同时满足正常状态和N-1故障状态约束,使电力系统具备承受一定程度故障干扰的能力。3个系统的多预想故障设置方案的测试结果表明,所提算法在保证精确性和收敛性的基础上,加速效果明显,易扩展至多机集群架构。     

高性能CMOS全加器设计

全加器是数字信号处理器、微处理器中的重要单元,它不仅能完成加法,还能参与减法、乘法、除法等运算,所以,提高全加器性能具有重要意义.本文分析了两种普通全加器,运用布尔代数对全加器和函数、进位函数进行全面处理,提取了和函数、进位函数优化函数式.根据最优化函数式,设计了高性能CMOS管级全加器单元电路.这种CMOS全加器电路与常用CMOS全加器电路相比,电路结构简单、芯片面积小、电路传输延迟时间小、运算速度快.     

Mix-and-match high performance computing

Scientific researchers who perform large numerical simulations often put great demands on the processing power of even the fastest computers. High performance computers (HPCs), such as massively parallel processors, supercomputers, and graphical workstations, each have unique characteristics that make them well suited for a particular aspect of a large computer simulation. Often, however, no one individual HPC has the ideal combination of raw computing power, memory capacity, and graphics capability to best address all aspects of a large simulation. We show an example of how mix-and-match computing was used to perform a large-scale 3D numerical simulation, one that models the convection of magma in the earth's interior, using a set of specialized high performance computers