设备状态检修分析系统设计与实现

智能电网中自动化和信息化技术的不断发展,为设备状态检修的实现提供了重要手段。在分析了目前设备管理、设备状态检修和设备现场运维等应用现状与管理需求的基础上,提出了通过构建设备状态检修分析系统实现对设备台账数据、设备运维数据、在线监测数据和电网运行数据等各类数据的高效利用;研究了设备状态检修分析系统中的关键技术,包括基于IEC61850的站端监测数据整合技术、IEC61970与IEC61850的模型融合技术、设备健康档案数据管理技术等,系统实现了设备状态预警、状态评价、风险评估、故障诊断与运维策略决策等功能。通过对设备状态实时监控及图形化展现。为提高设备运维效率、降低电力企业成本、实现设备资产优化管理提供了有益参考。     

Identification of failure root causes using condition based monitoring data on a 33 kV switchgear

The implementation of condition based monitoring (CBM) involves variety of disciplines, such as failure analysis, on-line diagnostics, diagnostic data interpretation, management and communication, corrective actions and program maintenance. However, the most important tasks for a comprehensive CBM analysis are to identify the actual root cause that contributes to equipment failure and the selection of appropriate mitigation techniques to address the root cause of the failure. In this paper, CBM actual site data of a 33 kV switchgear from an electrical utility company in Malaysia (from 2007 to 2010) were used to develop failure root causes database. The database was used to identify the possible root cause of a failure and to propose a failure mitigation plan for any CBM activity. The CBM data were obtained using ultrasound, thermoscanning and transient earth voltage (TEV) methods at different compartments of the switchgear, which yielded specific root causes of failure. In order to verify the effectiveness of the proposed method, the method was tested using actual site data obtained in 2011. Using the proposed method, the actual root cause of a failure can be identified quickly; hence the time and cost of repairs can be reduced.     

采用风力清扫环开展输电线路状态检修

输电线路每年两次停电检修使电力系统和国民经济损失巨大 ,且绝缘子污秽严重以致必须及时清扫又使状态检修一直无法开展。而目前专利产品“绝缘子风力清扫环”可随时清扫绝缘子表面污垢 ,防止污闪 ,免除或减少停电清扫次数和雷击掉闸次数 ,不需装设污秽度在线监测设备 ,安全经济可靠 ,为输电线路开展状态检修打开了新的突破口     

A study on condition assessment method of gas‐insulated switchgear. part II. influence of moisture in the SF6, detection of a partial discharge on a spacer,repetition discharge and overheating by incomplete contact

Rationalization of the maintenance of gas‐insulated equipment under operation and lifetime extension based on the results of appropriate diagnosis are necessary to reduce the cost of gas‐insulated equipment. Therefore, condition‐based maintenance (CBM) is required and accurate methods for observing the inside of equipment are important. In this report, we describe a diagnosis method that can be used for actual gas‐insulated equipment, such as to assess the deterioration of the spacers made of epoxy resin and to detect loose connections in the central conductor. The principal results are summarized as follows: (1) The quantity of decomposition gases depends on the moisture and magnitude of the partial discharge. However, decomposition gases were detected even if SF₆ had low moisture content (less than 100 ppm) similar to that used in actual equipment. This means that our method can be applied to actual equipment. (2) It became clear that CF₄ is a typical gas generated by partial discharge on the spacer surface. Therefore, it is possible to diagnose spacer deterioration by monitoring CF₄. (3) Decomposition gases (SF₄, SO₂, SO₄, SO₂F₂) were generated by impulse breakdown, which was assumed to be due to repetition discharge caused by insulation failure and loose connections. (4) SF₆ gas was assumed to be exposed to a loose connection and was heated from room temperature to 800 °C, and the generated decomposition gases were analyzed by FTIR in real time. As a result, the decomposition gases were generated at temperatures above approximately 500 °C in a heating time of 1.5 minutes. Therefore, a loose connection can be detected by analyzing the decomposition gas. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 176(2): 22–30, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21108     

我国电气设备状态维修的发展与实现

状态维修是国内外电气设备维修的发展方向，在介绍我国电力系统中电气设备维修方式发展过程的基础上，指出实施状态维修的必要性。分析当前设备状态维修所包含的内容，对其所需要的技术支持系统发展状况进行了详细讨论，指出需要深入研究的问题。结合实际情况，在现有的技术条件和管理基础上对具体设备的维修方式进行讨论，提出对不同设备选用合适的维修方式，可提高设备维修的经济效益。     

考虑不完全维修的风机齿轮箱优化检修策略

齿轮箱是风电机组中维修费用最高的部件之一,针对齿轮箱的状态检修策略研究对降低设备维修费用、提高可靠度具有关键作用。针对风机齿轮箱不完全维修这一现状,提出了一种基于比例强度模型的优化检修策略。该方法利用监测到的齿轮箱振动数据、温度数据及历史维修数据建立比例强度模型,确定齿轮箱的强度函数;然后采用物理规划方法权衡最小维修费用和最大可靠度两个优化目标函数,确定最优维修阈值,并制定最优维修策略。结合实际风电场故障数据和在线监测数据,对考虑不完全检修的优化检修策略进行仿真分析,结果验证了所提优化策略的有效性和合理性。     

基于数据挖掘技术的电厂设备状态检修系统

介绍了基于数据挖掘技术的设备状态检修系统设计模型。本系统采用模块化设计,包括3个模块和2个数据库,分别为数据采集模块,诊断分析模块,决策分析模块和历史数据数据库,规则数据库。数据采集模块用于采集设备的运行状态信息;诊断分析模块根据采集到的数据对设备状态进行分析评价,从而确定最佳的检修时间和检修项目,制定合适的检修决策建议;决策分析模块根据诊断分析的结果,决定是否进行检修,进而确定检修计划。各模块完成独立的功能,同时又相互联系。     

A plug‐and‐play method in an ICT system for monitoring and diagnosing power equipment conditions

Power equipment can be maintained more cost effectively by planning based upon their condition. To estimate the condition of a plant, a number of sensors can be used to measure data such as temperature and pressure, which are then collected by means of an information system along with processes and storage. For this purpose, maintenance staff must install software into the information system each time a sensor is installed; the greater the number of such tasks, the less efficient the maintenance. This paper proposes a method to facilitate the installation of software and thus reduce the burden on maintenance staff. The method proposed manages information with respect to software classes, creates instances from the classes according to sensor detection, and activates them based upon related instance states. Results using an experimental system show that the method works as we expected and also seems to be scalable. © 2013 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

电气设备实施状态维修决策方法的探讨

以状态维修逐步取代定期维修已成为电气设备检修的必然趋势,但在复杂大型电网中如何合理选择电气设备开展状态维修工作,如何成功地向状态维修过渡,仍是许多输变电企业在实际检修工作中面临的主要难题.文中考虑到状态维修所需的技术支持、设备状况和人员素质等多方面因素,基于输变电企业现有的技术条件和管理水平,提出了一个依据专家对已知信息做出的决策,应用模糊综合评价方法判断电气设备可否实施状态维修的基本思路.     

基于数据挖掘的电力设备状态检修技术研究综述

介绍了设备状态检修的分类和国内外关于数据挖掘的研究状况,综述了以数据挖掘技术实现变压器、发电厂设备、配电网设备以及高压输电线路状态检修的方法和思路,指出目前我国在这些应用研究中需要解决的问题。     

基于状态检修的N-k故障在线辨识及路径搜索

将状态检修与大面积停电问题结合起来,提出一种基于状态检修(condition based maintenance,CBM)的N-k故障在线辨识方法:根据状态检修实时数据建立设备的故障可能性模型,应用功能组(functional group,FG)理论及相关改进后的搜索方法实现N-k故障路径的在线搜索及筛选,并根据电网实际运行方式以及状态检修的监测情况,建立了N-k故障的概率模型。最后,利用C++语言实现了所提方法,并以安阳电网的3个变电站为例验证了方法的正确性。     

二次系统状态检修技术在智能变电站中的应用

智能变电站虽然减少了传统二次电缆的长度,但也带来了难于对智能二次设备进行有效地监视和分析的问题,以往的二次检修方式已无法满足智能二次设备的运维要求。在提出问题的同时,介绍了220 kV西泾智能变电站的二次系统组网结构,并结合2个二次系统检修案例,说明在智能变电站采取二次状态检修模式的必要性。     

基于故障风险水平的海上风电场机会维护策略

海上风电场的维修费用占发电总成本比例较高。为降低海上风电场的运维成本,在基于可靠度阈值的机会维护策略基础上,针对风电机组子系统间存在的故障相关性与子系统故障风险水平,文中提出一种包含故障风险水平、可靠度双阈值和维护矩阵的海上风电场机会维护策略。首先,采用故障链模型对风电机组子系统间的故障关系进行描述,并建立风电机组各子系统的可靠度模型。其次,引入多级维护的概念,提出考虑故障风险水平的风电场机会维护策略优化模型,采用粒子群算法对子系统机会维护的风险因子进行优化,进而确定单台机组的维护策略。然后,综合考虑海上可及性、备件库存等因素,提出一种基于维护矩阵的海上风电场维护策略优化模型,以单位时间维护成本最小为目标函数,根据子系统的备件库存和故障风险水平来对维护策略进行动态调整。最后,以某海上风电场中单台风电机组为例,分析可及率、多级维护等因素对风电场机会维护策略的影响。结果表明,考虑故障风险水平的机会维护策略相比传统机会维护策略费用率可降低27.34%,验证了所提机会维护策略在降低维护费用方面的有效性。     

Predictive versus preventive maintenance

This paper presents electrical equipment maintenance by condition-based maintenance (CBM). In the CBM approach, equipment maintenance based on a routine schedule can be replaced with an approach based on system wellness diagnostics. This approach might rely on noninvasive monitoring of three-phase induction motors to report equipment condition and enable maintenance intervention before a failure occurs. Pump cavitation, rotational unbalance and mechanical alignment are some of the areas where a mathematical model has been developed using fast Fourier transform (FFT) analysis, enabling online diagnostics during operation. Also discusses mathematical model and field tests to validate the model and introduce a motor-wellness relay that could be used to perform online diagnostics. Alternative system communication architecture to support a wellness platform are also reviewed and discussed.     

Energy storage system utilizing large‐capacity electric double‐layer capacitors for peak‐cut of power demand

Recently, due to a rapid increase of demand for air conditioning in summer, peak power demand is becoming increasingly acute. Therefore, the load factor has a tendency to drop every year. The drop of the load factor is leading to a drop in the utilization factor of the power facilities and an increase in the cost of installation. In this paper, we propose an energy storage system for peak‐cut of power demand, in which we use large‐capacity electric double‐layer capacitors. This energy storage system has some distinctive characteristics, including long life span, maintenance‐free operation, preservation of environment, high efficiency at charge/discharge, and so on. This paper deals with the circuit arrangement of the proposed energy storage system, the charge equalization method of the capacitors, and the control method of the converter at charge/discharge. Finally, the operating characteristics of this system are evaluated by simulation analysis. © 2000 Scripta Technica, Electr Eng Jpn, 133(3): 83‐92, 2000     

基于时间延迟的风机齿轮箱状态优化维修

风电机组运行环境恶劣,故障频发,尤其以齿轮箱的故障居多,造成风机整体维修成本偏高。针对以上问题,提出了一种基于时间延迟的状态优化维修策略,在时间延迟模型的基础上考虑振动监测信号,先结合故障数据和状态监测数据求得齿轮箱的比例危险函数和可靠度函数,再采用单位运行时间内平均维修费用最小的方法优化得到最优状态维修阈值,最后依据该阈值实施风机齿轮箱的优化状态维修。通过对某风电场仿真分析,求得了最优状态维修阈值,并制定了维修策略。仿真结果证实了该策略在避免过度维修和维修不足问题以及节约维修成本方面的有效性。     

考虑最小成本的风机轴承维护周期优化

针对风机主轴承可靠度要求高、维护费用高昂这一现状提出了一种基于单位时间维护成本最低的维护优化模型。首先通过对风机主轴承振动信号进行分析,提取能够较好地反映轴承退化过程的特征值,建立威布尔比例风险模型;其次对主轴承退化期内的失效率曲线进行分析,确定主轴承的失效更换阈值;然后通过改进传统的役龄回退因子对维护后的失效率进行修正,通过对模型运算结果进行分析,避免了定期维护出现欠维护的现象;最后确定单位时间内维护成本最优的维护周期。对维护优化模型进行仿真分析,计算结果表明,通过模型优化可以使单位时间维护费用降低14.4%。     

基于风险的输变电设备状态检修实用化技术研究

论文针对当前状态检修技术在电力系统输变电设备维修应用中存在的问题,建立了基于风险的状态检修体系,该体系是一个完整的、全面的、具备很强操作性的技术体系,分为核心算法实现模块、软件支撑模块、信息支持模块、状态评价模块、风险评估模块及维修辅助决策模块6个模块。针对维修理论与实际维修管理脱节的问题,结合广西电网实情开发了基于风险的状态检修辅助决策系统,将变压器、断路器风险评估理论算法,植入风险评估模型,并应用于辅助决策系统,与多套现有生产系统无缝连接,实现将风险评估理论研究到工程化应用的转变并成功地在地市供电局完成试点。     

基于风险和检修收益的继电保护设备检修决策方法

针对如何合理制订继电保护设备检修策略的问题,提出基于风险和检修收益的继电保护检修决策方法,从检修顺序和检修等级方面对保护设备实现差异化维修.首先采用一次、二次系统综合风险评估模型,以基于保护状态评价得到的实际故障率为风险发生可能性,保护设备故障对一次系统运行的影响作为风险后果,计算出风险值作为确定检修顺序的依据.然后分析了不同检修方式下的检修成本和对继保设备故障率的影响,利用检修风险收益模型确定了保护设备的检修方式.使检修决策不仅保证设备的可靠性,还在一定程度上兼顾检修的经济性.最后利用IEEE 9节点系统进行了仿真计算,结果证明了所提方法的合理性.     

Improving Networks‐on‐Chip performability: A topology‐based approach

The performability metric is commonly used in Networks‐on‐Chip (NoC)‐based systems to represent their abilities to successfully complete specific tasks in finite time intervals. In this paper, we present a novel topology‐based performability model for NoC‐based systems. The model is used to evaluate the performability of NoC‐based systems at early design phases. A comparative study of nine commonly used network architectures is performed using the proposed model. The purpose of the study is to explore the impact of the network topology on the performability of NoC‐based systems. Using the output from this study, a new methodology is proposed to improve the performability of a given application at early design phases. In this methodology, a joint consideration of five design parameters (network topology, target application traffic distribution, mapping of processing elements, noise power, and voltage swing) is carried out. Using the proposed methodology, designers can select the optimal topology for a given application that maximizes system performability. The effectiveness of the proposed methodology in determining the optimal topology is verified by experimental work and validated through a case study of a video application. Copyright © 2010 John Wiley & Sons, Ltd.