基于xPC目标的输电线路微气象数据实时采集系统

介绍了一种输电线路微气象数据实时采集系统,此系统是基于Matlab/Simulink下xPC目标搭建的硬软件结合的实时仿真平台。它利用微气象传感器、信号调理板、数据采集卡和双PC机,通过以太网实现数据实时采集与可视化显示,同时利用数据进行Simulink下的输电线路相关理论计算,为模型算法的开发与数据的监测提供较为便捷的途径。通过实验,该采集环境在基于实验室的输电线路工况模拟中具有一定的实用性。     

Supervisory fault‐tolerant control with mutual performance optimization

The problem of active fault‐tolerant control with reconfiguration mechanism for uncertain linear systems with external disturbances is addressed applying the supervisory control approach. A key feature of the proposed approach is establishment of a set of conditions providing mutual performance in the sense of taking into account the interaction of the fault detection, isolation, and accommodation subsystems in order to achieve global fault‐tolerance performance with guaranteed global stability. The efficiency of the approach is demonstrated in an example of computer simulation for a flight system benchmark. Copyright © 2012 John Wiley & Sons, Ltd.     

基于RBF神经网络的光伏动态重组系统

光伏系统的模块重组对于改善系统的P-V特性有非常重要的作用。提出了一种在部分阴影遮蔽情况下基于人工神经网络算法的光伏模块重组方案。这个方案中,光伏模块分为固定部分和自由部分,并通过开关矩阵来连接。然后测量的每个自由模块以及每行固定模块的短路电流值,测量值通过人工神经网络算法得到的结果决定开关矩阵的连接方式。仿真实验显示所提出的方案的参数测量实时简易、重组策略高效,能有效地改善部分阴影状态下的光伏阵列的功率输出。最重要是所提出的控制策略能应用于较大规模光伏系统结构重组。     

基于核主元分析与模糊神经网络的汽轮发电机振动故障诊断方法

针对现有汽轮发电机振动故障诊断运算量大、时间长的问题,本文提出基于核主元分析与模糊神经网络的汽轮发电机振动故障诊断方法。首先采用核主元分析并经矩阵变换和降维来提取故障的主要特征值,其次将提取(降维后)的数据作为Takagi-Sugeno模糊神经网络输入数据,最后在Matlab中建立Takagi-Sugeno型自适应模糊神经网络进行训练测试。该方法用较少的数据代表原数据的最大信息量,并且仿真与标准的模糊神经网络、BP神经网络进行性能对比,最后仿真结果表明该方法的有效性,并且具有诊断速度快、收敛迅速和故障诊断效率高等特点。     

A distribution automation laboratory for undergraduate and graduateeducation

This paper outlines a five-year work of developing a distribution automation laboratory for undergraduate and graduate education at the Electrical Engineering Department of National Taiwan University. A scaled-down three phase distribution system model with a data acquisition system connected to a personal computer is built to facilitate physical experiments and real-time measurements. Remote control of the switches in the distribution system is made possible through the function of 8255 output ports and solid-state relays. Digital simulation programs are also written in order for the students to understand the basic concepts before they actually perform experiments. Three important applications in distribution automation, fault location identification, feeder reconfiguration, and feeder reactive power/voltage control using capacitor switching, are described     

If approximating nonlinear areas, then consider fuzzy systems

The fuzzy system is a knowledge-based system consisting of linguistic if-then rules. This article will focus on the Takagi-Sugeno (TS) type models. A novel approach of INFUMO has been applied in fault detection. The INFUMO was derived using the l_infin-norm function approximation. The majority of papers focus on the construction of the so-called residual generator, a comparator of the process and the process-model output that creates a residual signal     

配电网故障判断与负荷均衡化

提出一种配电网简化模型 :将馈线开关当做节点 ,将馈线当做弧 ,从负荷的角度描述配电网 ,并采用邻接表的数据结构加以描述。在此基础上发展了配电网故障区域判断方法 ,讨论了以最少的开关操作隔离故障区域的方法。提出一种以联络开关为核心的用于负荷均衡化的配电网络重构方法 ,将每个联络开关对应的两条馈线看做馈线偶 ,分别定义了馈线偶和配电网的负荷均衡率 ,并以此作为网络重构的评价函数 ,配电网络重构过程由若干馈线偶内负荷均衡化过程组成 ,这种方法具有迭代次数少和不需要量测馈线配电变压器参数等优点。文中给出了典型实例     

燃煤电厂协调控制系统故障诊断与容错控制应用研究

基于多模型自适应滤波技术和线性二次型最优控制提出了电厂锅炉汽机协调控制系统的故障诊断和容错控制方案。建立了包含协调控制系统正常和可能发生的各种故障模式的系统模型集，并根据系统模型集以及系统实时输入输出数据进行多模型自适应滤波，从而实现故障诊断；然后根据故障诊断结果以及针对每个模型设计的线性二次型最优基本控制器，实现控制律的在线重组和主动容错控制。最后将上述故障诊断和容错控制方法应用于某300MW燃煤电厂协调控制系统中，仿真结果表明算法的有效性。     

10 kV智能配网故障定位系统研究

智能化配网故障定位系统在传统定位的基础上采用带有通信功能的前端设备和高效、准确的数据处理系统对线路的运行状态进行实时监控,同时智能配网系统还支持电脑、手机客户端实时查看等功能,为电网的运维和调度提供参考依据。详细分析了配网线路的特征以及智能配网系统的结构组成和工作原理,同时针对故障类型的判定进行了原理分析并通过系统采集的数据进行验证。结果表明,智能化配网定位系统能准确、实时判定故障类型、故障点以及故障时间。     

一种大规模配电网实时重构新方法

提出了一种利用最小树算法和开关交换方法进行大规模配电网重构的新方法。该方法首先利用最小树算法对配电网进行初步重构,重构的结果基本接近最优解,然后利用开关交换方法在最小树初步重构的基础上进行精确重构,最终得到最优解或近似最优解。在最小树初步重构过程中,采用了简化潮流计算方法、近似网损计算方法和只对受影响电路进行潮流计算的方法,使得初步重构的耗用时间大大减少。在开关交换重构中采用了精确潮流计算,保证了最终得到最优解或近似最优解。此外,为了建立适于配电网重构的拓扑关系,文中介绍了配电网图的形成方法。实际系统的算例测试结果表明,该方法效率高,重构效果明显,能够适用于大规模配电网的实时网络重构。     

Control and protection sequence for recovery and reconfiguration of an offshore integrated MMC multi-terminal HVDC system under DC faults

A comprehensive process of the control and protection against a DC fault in a voltage source converter (VSC) based high-voltage direct current (HVDC) system typically includes fault detection, fault isolation and system recovery. Regarding an offshore wind farm (OWF) integrated modular multilevel converter (MMC) based multi-terminal HVDC (MTDC) system with two control paradigms, i.e. master-slave control and droop control under DC faults, this paper presents the fault isolation, including the isolation of the faulted line section, with detailed control and protection sequence, which would be useful for practical engineering. The control and protection sequence at the system recovery/reconfiguration phase is comprehensively investigated, which includes: (1) when to start the recovery/reconfiguration control; (2) the sequence between deblocking the MMCs and reclosing the AC circuit breakers (AC CBs); and (3) the recovery sequence of each HVDC terminal. Based on the analysis of the system characteristics, a preferred recovery/reconfiguration scheme is proposed. Simulation results on the real-time digital simulator (RTDS) validate the proposed scheme and demonstrate the advantages through comparison with a different recovery sequence. The impact of transient and permanent DC faults on the system recovery/reconfiguration control is discussed. In addition, the recovery/reconfiguration control of the MTDC in radial and meshed topologies is compared and demonstrated. Based on the analytical and simulation studies, a general guideline on the recovery/reconfiguration control of MMC MTDC systems is proposed.     

Reconfigurable DC Links for Restructuring Existing Medium Voltage AC Distribution Grids

While the scientific community recognizes the benefits of DC power transfer, the distribution network operators point out the practical and economic constraints in refurbishing the existing AC network at a medium-voltage level. Some apprehensions like reliability, cost of ownership, and safety in adopting a universal DC distribution may merit considerable attention, particularly considering the long operational experience with the existing mature AC system. This paper introduces the novel concept of reconfigurable DC links as a flexible backbone integrated within the future AC distribution grids. Benefits such as hardware reconfiguration for a modular AC–DC cable operation to achieve fault redundancy, control reconfiguration for flexibility and grid-supporting ancillary services, network reconfiguration for system level distribution loss minimization and load redistribution, and fault reconfiguration for improving the grid availability are discussed. The vision, around which the concepts developed in this paper revolve around, is to present a viable way of gradual transition from AC to hybrid AC–DC to finally a universal DC system.     

FDD在电网技术中的应用

故障检测和诊断 (FDD)技术目前已发展为四大类 ,适用于电网故障检测和诊断的有基于状态估算的FDD法和基于人工智能的故障诊断法。基于状态估算的FDD法 ,直接反映被控系统的运行状态 ,通过重构被控过程状态 ,构成残差序列 ,再通过构造模型 ,采用统计检验法 ,并利用状态观测器、滤波器等把故障检测出来 ;基于人工 智能的故障诊断法又细分为专家系统和故障树等诊断法 ,基于专家系统的故障诊断法 ,主要利用计算机的推理能力、电力专家的丰富经验及电网中的因果关系 ,快速找到故障 ;基于故障树的诊断法是一种常用、有效的故障诊断法 ,通过逐级提问 ,构成一个递阶故障树 ,再通过启发性搜索 ,查找到故障。总之 ,运用自动控制中的故障检测和诊断技术来提高电网中计算机在线应用中实时数据库的有效性和可靠性 ,从而成为电力系统遥测校正和状态估算的重要辅助手段。     

污泥脱水、干化、焚烧一体化控制系统

根据污泥脱水、干化、焚烧一体化技术,分析系统的构成,设计自动控制系统。采用PROFIBUS-DP网络实现上位机与PLC之间的连接。根据工艺流程制定系统运行策略,融入智能算法,提高污泥处理的可靠性和效率。应用In Touch 10.1组态软件开发上位机软件,绘制组态画面,实时监控整个系统的运行。针对薄弱环节增加报警参量,设置自动、手动两种运行模式,实现正常情况下工艺流程的自动化和故障检修时人工的灵活操作,提高了控制系统的智能度。     

网络重构中基于配电网拓扑特征的改进遗传算法

网络重构是配电系统运行和控制的重要手段,利用遗传算法求解配电网络重构问题可以较好地利用其智能计算的特点,但也存在计算速度慢与收敛于非可行解等问题.结合配电网络拓扑结构特征和遗传算法特点具体探讨了如何实现遗传算法的网络重构,对遗传操作中的选择、交叉和变异提出了基于配电网络拓扑的改进方法,提高了算法的收敛速度和收敛性,算例验证了所提方法的可行性和正确性.     

极端气象灾害下考虑MESS主动调控的配电网故障恢复策略

针对极端灾害天气下配电网的故障恢复问题,计及极端灾害的时空演变特性,提出了一种利用移动储能(mobile energy storage system, MESS)的灵活性主动参与抑制合环冲击电流,辅助配电网故障恢复的策略。首先,建立了暴风雨等不同气象灾害条件下配电线路的故障率统计模型。其次,将复杂交通网与配电网进行耦合,建立了以最小化MESS调度时空成本的上层预布局模型。然后,分析了MESS出力对冲击电流的影响,以抑制合环冲击电流、最大化负荷恢复率和最小化MESS调度成本为目标,构建了MESS参与网络重构的下层调度模型。最后,在改进的IEEE 123节点系统中进行测试,验证了MESS对配网故障恢复安全性的提升效果。结果表明,采用MESS主动参与调控能够有效应对移动的极端气象灾害引发的配电网动态故障恢复问题,并抑制合解环过程中电流的波动,提升网络重构方案的可行性和增强配电网的韧性。     

面向弹性提升的主动配电网重构与元件修复协同方法

极端事件会导致主动配电网出现多处故障且故障元件修复时间长,传统的故障恢复方法会使得系统的弹性低。针对主动配电网的故障恢复阶段,提出了一种面向弹性提升的重构与故障元件修复协同方法。首先,结合计及负荷重要程度的主动配电网弹性指标,分析出故障恢复阶段弹性提升的主要措施;在此基础上,提出重构与故障元件修复协同策略框架,给出交替协同中线路状态变量和节点负荷供电状态变量的更新与关联。其次,建立全过程故障元件修复和重构的目标函数。针对主动配电网含多分布式电源特点带来的故障元件上下游关系难以判别问题,提出基于消线解故障环法和圈源等效法的判别方法。最后,算例结果表明,所提方法能有效地提升主动配电网的弹性。     

远程智能监控与故障诊断处理系统

针对目前地调自动化主站维护人员工作量大、人员少的矛盾提出本课题,目的是解决SCADA实时监控系统、UPS电源系统、自动化辅助系统、自动化机房环境及设备不能实现远方统一平台的实时监控、故障诊断及事故处理这一问题。提出了基于OPEN3000系统平台的远程在线自动监控与智能诊断处理系统。在网络设计中采用分布式网络结构,保障数据库及视频系统录像记录的安全;采用模块化结构设计,配合了专家系统和数据库知识的规则库设计,解决了SCADA、UPS、视频等多个系统及设备的实时监控和故障诊断整合为统一平台的技术难题。     

A high-precision real-time approach to calculate closest unstable equilibrium points

In this paper, an innovative real-time approach is presented in order to compute the closest unstable equilibrium points of system. The proposed approach estimates unstable equilibrium points of system at the first time step of fault duration and there is no need to post the fault data. To such aim, a new concept of equal area criteria is proposed in this paper which estimates the initial value of critical points of the system. This value is used in order to calculate corrected kinetic energy and as a result the closest unstable equilibrium point by taking into account the fault trajectory. Moreover, the details of power system are considered to calculate unstable equilibrium point by utilizing network preserving model. Finally, several case studies have been conducted on IEEE 9 bus and the New-England 39 bus test systems to illustrate the benefits of the proposed approach. It is worth noting that considering structure preserving in modeling and at the same time simplicity in implementation and low computational burden are the main salient features of the proposed approach. As a result, the proposed method is suitable for real-time applications.     

模糊遗传算法和蚁群算法相结合的配电网络重构

通过开关的优化组合可以提高配电系统运行的可靠性、电能质量和经济性。为改善配电网络重构模糊遗传算法的优化速度,提出了一种模糊遗传算法和蚁群算法相结合的方法。该方法将总的种群分为两部分进行搜索,一方面通过选择算子寻找总的种群中较优个体作为模糊遗传算法的子种群进行交叉、变异操作;另一面通过设定适应度函数阈值筛选总的种群中优秀个体,并将其适应度函数值对网络信息矩阵进行全局更新,用蚁群搜索另一部分子种群。该方法设定适应度函数阈值改进了蚁群算法的信息素更新机制;把模糊遗传算法和蚁群算法的子种群融合构成总的新种群,并用