交流防跳回路工程实用设计方案

断路器操作回路中设计防跳回路可有效防止断路器多次跳合,保证断路器的安全运行。大部分变电所(站)都配备直流供电系统,经典直流防跳回路在实践中显示了较高的可靠性。但在不设直流供电系统的小型变电站(所)自动化改造中,生搬硬套经典直流防跳回路设计方案会造成防跳回路动作异常,甚至影响断路器的正常动作。为了完成微机保护装置与断路器交流操作回路的配合,提出了一种简单可靠的断路器交流操作回路防跳设计方案,并给出了进一步的改进方案。上述方案不仅在设计思路上有其合理性,通过工程实践也证实了它的正确性和可靠性。     

总变10kV进线断路器防跳回路分析

断路器跳跃现象对开关及负载具有频繁冲击,防跳回路是保护开关的重要二次部分。以南瑞NSP30C操作机构防跳和西门子3AH5断路器本体防跳为例,分析两种防跳原理。并对总变10k V进线断路器所使用的两套防跳机构配合可能出现状况进行分析,提出几种可避免防跳失效改造,完善防跳回路,保障供电可靠性。     

高压断路器电气防跳回路分析

本文总结了高压断路器电气防跳回路的使用情况,并结合实例详细阐述了并联式防跳回路在实际应用过程中出现的一些问题及相应的解决办法。     

高压断路器防跳及监视回路的方案分析

通过分析操作箱防跳及机构防跳两种断路器防跳原理,对国内主流厂家高压断路器防跳及监视回路进行分析比较,提出适用于智能变电站的防跳及监视回路的方案。     

断路器防跳回路的应用

断路器的防跳回路可有效的防止断路器多次跳合,以保护设备和系统的安全,介绍了两种典型的防跳回路:电气防跳(串联防跳),机构防跳(并联防跳)的工作原理及优缺点.结合工作现场的实际情况对防跳回路的选用、接线方法和防跳继电器的选择问题进行详细的分析阐述.     

关于保护装置防跳回路与操作机构防跳回路的分析

操作机构与保护装置均设有电气防跳回路,因此在断路器控制回路接线过程中,经常存在操作机构与保护装置接口的问题,通过对110 kV断路器弹簧操作机构与110 kV微机保护装置两种防跳回路的分析,说明了如果同时采用两种防跳回路存在的问题,并给出了确定防跳回路是否完整的试验方法。     

浅谈断路器控制回路中的“防跳”

断路器作为变电站中重要的电气设备之一,其运行的稳定性和可靠性至关重要,"防跳"回路就是断路器控制回路中的一个重要保护回路。目前随着电力系统产业的高速发展,断路器的防跳回路设计在不断改进和完善,作为二次安装和调试人员,必须与时俱进,深入理解并领会防跳回路的关键之处,才能保证二次接线和调试的准确性。     

锦屏二级水电站10kV开关保护防跳回路异常分析

分析了锦屏二级水电站10kV厂内渗漏排水泵开关位置指示异常,且断路器分闸后无法再次合上的问题,对比了断路器配置的南瑞保护防跳回路和施耐德开关本体防跳回路的差异,得出保护防跳回路和断路器本体防跳回路应用范围,提出了四种断路器防跳回路的改进方案,并比较了各自的优缺点。     

断路器两套防跳回路配合问题探讨

通过对威海电厂220 kV升压站220 kV断路器防跳回路出现故障现象进行分析,阐述开关本体防跳回路和装置操作箱防跳回路的配合,揭示断路器本体防跳回路与装置操作箱防跳回路之间存在的寄生回路问题,并提出解决技术方案。     

高压断路器防跳回路的应用

分析了高压断路器采用的几种防跳回路并提出了几项实用的防跳方案,探讨了其实际应用中存在的问题。研究表明,为保证防跳装置的工作可靠性,防跳继电器的参数选用必须与操作机构的参数匹配,其动作电流灵敏度应≮2级,动作时间不应大于断路器辅助触点的切换时间。     

A short circuit current study for the power supply system of Taiwanrailway

The western Taiwan railway transportation system consists mainly of a mountain route and ocean route. The Taiwan Railway Administration (TRA) has conducted a series of experiments on the ocean route in recent years to identify the possible causes of unknown events which cause the trolley contact wires to melt down frequently. The conducted tests include the short circuit fault test within the power supply zone of the Ho Long substation (Zhu Nan to Tong Xiao) that had the highest probability for the melt down events. Those test results based on the actual measured maximum short circuit current provide a valuable reference for TRA when comparing against the said events. The Le Blanc transformer is the main transformer of the Taiwan railway electrification system. The Le Blanc transformer mainly transforms the Taiwan Power Company (TPC) generated three phase alternating power supply system (69 kV, 60 Hz) into a two single-phase alternating power distribution system (M phase and T phase) (26 kV, 60 Hz) needed for the trolley traction. As a unique winding connection transformer, the conventional software for fault analysis will not be able to simulate its internal current and phase difference between each phase currents. Therefore, besides extracts of the short circuit test results, this work presents a EMTP model based on a Taiwan Railway substation equivalent circuit model with the Le Blanc transformer. The proposed circuit model can simulate the same short circuit test to verify the actual fault current and accuracy of the equivalent circuit model. Moreover, the maximum short circuit current is further evaluated with reference to the proposed equivalent circuit. Preliminary inspection of trolley contact wire reveals the possible causes of melt down events based on the simulation results     

浅析智能变电站电源系统的设计及应用

交直流电源是智能变电站安全工作的前提。利用网络技术、通信技术及智能运算,将智能变电站中的各种电源设备有效地进行统一的管理,从而形成电源系统的一体化、智能化运行,从而达到可靠、高效、节能、经济的运行效果。     

A hybrid circuit breaker with fault current limiter circuit in a VSC-HVDC application

A conventional hybrid circuit breaker (HCB) is used to protect a voltage source converter-based high voltage direct current transmission system (VSC-HVDC) from a short circuit fault. With the increased converter capacity, the DC protection equipment also requires a regular upgrade. This paper adopts a novel type of HCB with a fault current limiter circuit (FCLC), and focuses on the responses of voltage and current during DC faults, which are associated with parameter selection. PSCAD/EMTDC based simulation of a three-terminal VSC-HVDC system confirms the effectiveness and value of HCB with FCLC, by using an equivalent circuit modelling approach. Laboratory experimental tests validate the simulation results. The peak fault current is reduced according to the current limiting inductor (CLI) increase, and can be isolated more quickly. By adopting parallel metal oxide arrester (MOA) with the main branch of HCB, voltage stresses across the breaker components decrease during transient and continuous operation, and less energy needs to be dissipated by the MOA. The remnant current for all cases is transmitted to power dissipating resistor (PDR) in the final stage, and the fault current is reduced to the lowest possible value. When the current from the main branch is transferred to the FCLC branch, transient voltage spikes occur, while smaller PDR is required to absorb current in the final stage.     

光纤互感器检测电路分析与设计

光纤电流互感器检测电路是实现计量大电流的载体,也是光纤电流互感器向变电站通信网络的传输信息的转接点,为电力控制中心对变电站实施监测、计量、控制和保护提供了信息通路。在理解和遵循IEC61850协议的基础上,分析光学互感器的信号和生存环境特性,设计了以TI的TMS320F2812为核心处理器,包括滤波、采样、时钟同步等模块的高精度、高稳定性、高可靠性的光学互感器检测电路实现方法;经测试其精度达到0.2s级。     

一种新型电动汽车复合电源电路设计

利用超级电容和蓄电池组成电动汽车的复合电源,设计了一种仅采用单个高频电力电子器件的电机传动主电路的新型拓扑结构。所设计电路不仅能对超级电容进行升压变换,与蓄电池协同向电机供电,而且能够在电动汽车再生制动过程中将发电电压升压后对超级电容充电。主电路结构和控制简单,变流装置成本低,工作可靠。实验验证了该电路能够提高电动汽车的性能和能源利用效率。     

断路器操作回路的智能化监测系统设计

为了监测断路器操作回路中跳/合闸回路、压板和保护出口接点的状态,并对其薄弱环节故障进行预警以避免断路器误动或拒动,设计了断路器操作回路的智能化监测系统。该系统改进了现有跳/合闸回路,并给出了系统中元件的选型与参数整定依据,能够实现跳/合闸回路的全工况监视和保护。为了实时监测断路器操作回路压板和保护出口接点的状态,实现压板误操作和保护出口接点故障报警,该系统采取了配合使用电感式接近开关和霍尔电压传感器的方法,并给出了传感器的具体安装位置。该系统采用单片机处理并上传传感器采集的现场信息,利用LabVIEW编写后台软件界面,能够实现实时状态显示、人机交互、历史数据存储和故障报警等功能。     

5 000 A以上断路器显示电流与实际电流差异分析

5 000 A以上的断路器通常是每相由多极并联引出双接线端子的结构,针对5 000 A以上万能式断路器正常工作时显示电流明显大于实测电流的情况,显示误差通常超过企业规定精度的现象。通过理论分析和实际测试,通过理论分析断路器内部以及连接排之间的互感和自感现象,发现断路器每极阻抗不完全一致,它们之间的负载电流数值不相等,同相不同极上的负载电流之间存在明显的相位角,相位角大约为32°。因为断路器内部和外接负载之间的互感和自感现象,断路器显示电流比实际电流大,它们之间的差值约为5%。     

The application of current limiting to distribution circuit protection

Many electric utility systems are reaching the point where available short-circuit currents, during severe faults, exceed the interrupting capability of available circuit interrupters of conventional types such as circuit breakers, distribution-circuit reclosers, and expulsion fuses. The needs are being met by the use of current-limiting fuses to protect individual distribution transformers or, sometimes, groups of distribution transformers, but there are difficult problems of coordination. The current-limiting fuses are not inherently capable of covering the full range of short-circuit currents, so that they must be used in addition to, or in combination with, interrupters of other types. This paper studies these problems in depth and makes recommendations for even wider use of current-limiting fuses to achieve more effective protection of the entire distribution system, including protection of distribution feeders at the substation. This approach also provides effective preventive measures to inhibit disruptive transformer failures which have become a severe problem with increasing short-circuit-current capability.     

利用暂态电流的谐振接地电网故障选线自适应新方法

谐振接地系统(NES)发生单相接地故障时,由于故障电流小及接地点电弧不稳定等原因,其零序故障电流准确获取和定值整定困难,使其故障线路的检出仍是难题。在分析小电流接地系统单相电弧接地故障时各线路零序暂态电流特征的基础上,提出一种基于暂态电流的故障选线自适应方法。利用所有健全线路暂态电流与故障线路暂态电流之差为最小值的原理,构成故障选线算法。新方法不仅能消除故障电流小和接地点电弧不稳定影响,而且还能在短线故障时,克服健全长线电容电流的影响,有很强的抗干扰能力,毋需整定,不涉及极性和方向的判断,具有自适应性,可大大改善保护对故障线路检出性能。大量的数字仿真结果表明,该方法有效。