共查询到19条相似文献,搜索用时 234 毫秒
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现代互联电网运行方式灵活多变,对继电保护的要求越来越高.为了使继电保护定值校核和管理更加科学有效,提出了考虑保护重要度的继电保护定值在线校核.首先将风险评估理论和电网连锁故障风险相结合,得出系统综合风险并将其用于衡量各保护的重要度;然后根据重要度从高到低的顺序对所有保护定值进行在线校核.通过IEEE39节点系统的仿真和算法复杂度的分析,验证了该方法的可行性和正确性,避免了传统随机校核各保护定值带来的不足,对提高电力系统的安全稳定运行有着重要意义. 相似文献
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继电保护定值在线校核及预警系统开发与应用 总被引:3,自引:0,他引:3
为解决传统继电保护定值整定及管理存在的问题,文中设计和开发了一套继电保护定值在线校核与预警系统。该系统从能量管理系统和故障信息系统中获取电网模型、在线运行状态和保护运行定值,通过数据匹配、模型拼接和信息融合对电网一二次系统进行综合建模,采用综合定值比较和保护范围比较的方法进行校核计算,利用影响域辨识和故障预备量排序实现定值快速预警。该系统可对全网各类保护定值的性能进行校核,并可在当前运行方式的基础上自动进行方式预想和预警,在实际工程应用中取得了良好应用效果。 相似文献
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在线继电保护智能预警系统的开发 总被引:15,自引:7,他引:8
电力系统继电保护能否正确、合理动作,直接关系到电网的安全稳定运行.提出并开发了基于EMS/DTS的在线继电保护智能预警系统,它能自动跟踪电网的实时运行方式,在线校核保护的配置与定值,并能通过预想事故扫描,自动发现保护中的连锁故障隐患.重点描述了该系统的系统设计、关键技术和基本功能特点,其中包括在线启动条件、用户自定义的规则知识库、自动校核的推理机制以及用于提高实时性能的优化算法.最后,介绍了在某省级电网的在线应用情况,并对未来的研究方向进行了展望. 相似文献
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基于暂态仿真得到动态短路电流计算方法,比较了动态短路电流计算方法与静态阻抗等值方法对电网模型处理的差异,指出了动态短路电流计算方法的优越性。基于动态短路电流计算方法设计,建立了继电保护定值在线校核系统。通过能量管理系统获得当前电网真实的运行状态,自动进行各类故障情况下的暂态仿真计算,获得系统各处的短路电流,实现了对继电保护定值的实时在线校核计算;与继电保护装置的当前定值进行比对,对存在安全隐患的情况进行预警。阐述了继电保护定值在线校核系统的实现方案和具体功能。介绍了继电保护定值在线校核系统在华北电网的应用情况。 相似文献
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电力系统继电保护在线校验系统的研究 总被引:1,自引:0,他引:1
运行方式发生改变时保护定值可能会不满足灵敏性和选择性的要求,如果继电保护工程师不能及时发现,可能会引起保护的误动,进而引发大规模的停电事故.通过分析离线整定计算的局限性,引入继电保护在线校验的概念,重点研究并设计了1套继电保护在线校验系统,在运行方式发生改变时,对当前系统中继电保护定值的性能进行在线校验,对存在误动隐患及异常的所有保护给出报警信息,提高供电可靠性. 相似文献
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As the smart grid concept is employed in the electric power system, network load flow and topology changes intensively to meet the best generation-demand balancing point. These changes must account for protection devices to enhance their performance. The coordination of directional over-current relays is most commonly studied based on fixed network operation and topology within a mesh power system. But sub-transmission and distribution systems constantly operate differently to satisfy the variety of load demand levels throughout the day and year. Hence, if the setting of directional over-current relays changes according to the different operations of the system, then relay operation time and sensitivity can both be enhanced. This can potentially improve the protection performance in a smart grid system. Therefore, this study is carried out based on the comparison among three coordination approaches: conventional (fixed settings), discrete (groups of settings), and continuous or real time (dynamic settings). 相似文献
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由于分布式电源输出功率的随机性与波动性,当分布式电源大量接入配电网后,传统的反时限过电流保护方案很难满足配电网保护选择性和速动性的要求。为此,文章通过研究数字反时限过流保护继电器,提出一种基于用户自定义特征的反时限过电流保护方案。保护方案将反时限继电器的特性常数(A)和反时限的类型常数(B)同继电器的时间整定系数、启动电流共同作为待优化的连续变量,并以最小故障电流时所有保护动作时间之和最小为目标函数,利用内点法求解保护的最优配置。方案保证了线路出口处故障时保护能快速动作,满足了配电网保护选择性和速动性的要求。最后,通过仿真分析,对保护方案进行了验证。 相似文献
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In this article, a communication-based adaptive over-current protection scheme for distribution systems penetrated with distributed generators is proposed. A communication network between the over-current relays, the distributed generators, and the utility grid is employed to automatically update the settings of the protective relays. Moreover, the communication reliability is increased through the addition of a backup communication system. The proposed scheme has the advantage of operating during grid-connected and islanding modes of operation. The scheme employs two simultaneous algorithms. The first algorithm works when the system configuration is changed due to the connection/disconnection of a distributed generator or the utility grid. The second algorithm efficiently uses the exchanged information between the relays to identify the faulted section and hence speeds up fault clearance. The proposed scheme is tested for difierent fault conditions as well as for different system configurations. The results demonstrated that relay operating times, including the communication delay, are greatly reduced when the faulted section is identified and relay settings are adjusted accordingly. In addition, a negligible time delay was experienced when the backup communication network was put in service. 相似文献
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继电保护定值整定计算及现场校核是电力系统安全运行的重要保证,也是继电保护装置发挥电网安全防护作用的基础.提出了一种基于可扩展置标语言(XML)的通用定值标记语言.通过分析保护内部的配置模型,抽象保护的定值语义描述方法,实现保护设备与自动整定及自动测试系统的定值语义匹配.最后,给出了一个通用定值标记语言应用的实例. 相似文献
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The presence of DGs in power networks tends to negatively affect relays coordination. Adding fault current limiters FCLs is one of the possible solutions to mitigate negative impacts of DGs addition on protection systems. Traditional schemes have estimated the minimum value of FCL to restore relays coordination when adding DGs without resetting of any relays. That minimum value of FCL in such case is called a critical value, where below this value the relays coordination will be lost.Nowadays, designing FCL to simultaneously achieve two conflicted objectives of good performance and low cost is considered a great challenge. The paper introduces a new scheme to determine to what extent we could decrease FCL impedance value below its critical value with re-adjusting the original settings of only one adaptive relay to get relays coordination. Decreasing FCL value below its critical value will reduce the cost especially for superconductivity FCL. The proposed scheme can determine the location of that selected relay to be an adaptive one and estimate its re-adjusted new settings to be applied when DGs are added while inserting the reduced value of FCL.Actually the proposed scheme can be applied for any networks irrespective of the number of added DGs and their capacities; while having an adaptive relay is the only requirement to implement it.The proposed approach is implemented and effectively tested on the large well-known interconnected IEEE-39 bus test system with 84 relays. Its results are compared with other approaches where, no re-adjusted relays settings are applied. A noteworthy advantage of the proposed scheme is the ability to implement a reduced FCL value than the critical value, by adjusting only one relay settings in the whole network. The proposed scheme may also be extended to re-adjust settings of more than one relay and get further reduced value of FCL. Furthermore, it is also shown that a more optimum value of the total operating time of all primary relays for near end faults is achieved when applying the proposed method rather than other traditional schemes. 相似文献
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随着风力发电技术日趋成熟,越来越多的大型风电场开始投入运行。由于风电场运行方式的变化及其弱电源特性,会对输电线路的保护造成一定的影响。研究了工频故障量距离保护的基本原理及风电场运行方式的多变性,并在此基础上进一步分析了风电场的运行方式的变化和弱电源特性对保护的影响,通过利用电压相量图分析保护判据的比相表达式提出了对传统距离保护的改进。通过分析可知,在发生金属性故障时,工频变化量距离继电器几乎不受风电场运行方式的影响,但由于风电场正、负序等值阻抗较系统阻抗大,使得相间保护耐受过渡电阻的能力很小,而受风电场零序阻抗较大的影响,接地保护耐受过渡电阻的能力较强。以Matlab/Simulink为平台建立了风电场并网的仿真模型,研究了风电场对保护的影响及对比保护改进前后在故障时的动作行为,仿真结果与理论分析相吻合。 相似文献
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随着越来越多的电力自动化系统集成于调度自动化平台,图形系统的标准化与图形共享是电力自动化系统研究的重要方向之一。针对目前继电保护定值在线校核系统图形建模存在的问题,提出了从整定计算系统、故障信息系统中导出图形文件再导入到定值在线校核系统的方案,实现了上述系统图形之间的无缝连接,达到了图形共享的目的。在简要分析继电保护定值校核图形交互、数据可视化需求的基础上,采用.Net平台反射机制与JavaScript函数之间相互通信,实现了继电保护定值校核结果的动态刷新与良好交互。通过采用多种展示手段,很好地实现了告警功能。目前,所采用的方案在某省级电网公司在线校核系统中得到了成功应用。 相似文献