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Thermal fuses are the devices most commonly used for effective equipment protection against fault currents within solid-state power systems. Original equipment cost versus additional expenditures for protective devices warrants elaborate means for safeguarding the investment while maintaining cost effectiveness. This has resulted in a vast variety of individually high-priced specialty fuses. Experience indicates that a large number of thyristor current-limiting fuses must be expended during the design phase of solid-state power conversion equipment so as to properly investigate converter circuit malfunctions due to nonrecurrent circuit transients. Thermal fatigue of fuses during field use necessitates a considerable logistic support in order to sustain the bulk of multifused complex power converters. This large demand cannot be satisfied at all times due to the limited number of prime suppliers, and due to the range of size, bulk, and price of present thermal thyristor fuses. Thermal analysis and extensive testing furnishes strong evidence that the desirable low-cost thyristor fuse link is feasible. This low-cost item is well-suited to protect thyristors against catastrophic failures within the constraints of any thermal fuse. Since the fuse is renewable, it compares favorably with presently used commercial thyristor fuses in terms of bulk and potential cost savings as well as in its flexible simplified rating mechanisms. 相似文献
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机组滑环短路造成励磁系统整流桥晶闸管熔断器熔断,然而系统自动切换到备用整流桥运行却引起备用桥晶闸管熔断器再度熔断,滑环损坏加剧。修正励磁系统双整流桥晶闸管自动切换的条件,以避免故障后的再次投入励磁电流而造成的事故扩大。 相似文献
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介绍了晶闸管整流机组的组成;分析了晶闸管整流机组在稳流精度、整流效率、完善的过流保护、无载分闸、控制灵活、操作简单等方面的突出优点;阐述了由于同步信号电压、自动调节系统和触发器、晶闸管和快速熔断器的设计不当的缺陷,以及制造工艺差和维护不当等导致整流器事故频发,降低可靠性的原因.说明其在电解铝应用中的高可靠性性能.而不规范的招标和恶性市场竞争必然降低可靠性. 相似文献
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文章首先叙述晶闸管装置出现过电压的情况和相应的保护措施。过电压包括装置的交流侧与直流侧过电压,以及晶闸管换流过电压。保护措施有交流侧接入过电压吸收电路与加设接地屏蔽绕组,直流侧接入非线性电阻元件,晶闸管并联吸收元件与均压保护。然后介绍了晶闸管装置过电流的情况和相应的保护措施。过电流可以由过电压、短路以及导通角增大引起的,保护措施就是晶闸管串联快速熔断器,且保护措施在实际应用中起到了良好的效果。 相似文献
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Protecting thyristors by means of fuses in electro-chemical rectifiers where more than 100 devices are used in a single unit may cause considerable service interruption when fuses open during temporary faults. This paper considers the thyristor and fuse ratings in conjunction with gate suppression techniques to achieve a protective system which allows a 17.5 MW rectifier to ``ride through' momentary faults without service interruptions. 相似文献
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根据大型全超导托卡马克核聚变实验装置(Experimental Advanced Superconducting Tokamak,简称EAST)中性束注入(Neutral Beam Injection,简称NBI)加速极高压电源的特点,设计了基于晶闸管的脉冲分级调制(Pulse StepModulation,简称PSM)模块CROWBAR控制方法,在系统打火等严重故障情况下及时撤除高压以保护系统设备和人员安全。与传统引燃管CROWBAR保护相比,NBI加速极电源系统在每个PSM模块上并联晶闸管作为快速旁路开关,在CROWBAR动作后通过串联快速直流熔断器迅速切断电网与负载的连接。测试实验表明CROWBAR运行可靠稳定,具备抗干扰和快速动作能力,能够满足EAST对NBI系统的运行要求。 相似文献
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Eriksson L.O. Piccone D.E. Willinger L.J. Tobin W.H. 《Industry Applications Magazine, IEEE》1996,2(5):19-23
State-of-the-art thyristors at the high power end utilizing 77 mm-100 mm diameter silicon and associated fuses should require more precise coordination, particularly because of safety, reliability, and the high cost of these upscale components. For these reasons, any enhancement in the subcycle surge ratings of thyristors is very desirable but should be well verified through supporting tests. It becomes necessary to combine testing with computer modeling that can be used to explore higher ratings potential for specific thyristor and rectifier diode designs while limiting the number of destroyed devices. The testing will be paramount for the purpose of exploring potential secondary failures that may limit reaching the fundamental thermal limitation of devices under test that are not included in the computer model. The authors discuss subcycle surge rating, fuse coordination, semiconductor device evolution, package rupture, and surge testing 相似文献
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三峡———常州高压直流输电的晶闸管换流阀中 ,每个晶闸管都有一块控制电子线路单元 (TCU) ,其功能为控制并检测该晶闸管。另外 ,还具备正向保护 (PF)和反向恢复期保护 (RP)性触发功能。笔者就反向恢复期保护电路中的几个问题进行探讨。 相似文献
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由于晶闸管耐压等级高,在高压动态无功补偿装置中广泛使用,由晶闸管串联构成的晶闸管阀,是晶闸管控制电抗器(TCR)的核心器件,在高电压下晶闸管阀驱动电路以何种方式获取能量是高压动态无功补偿装置必须考虑的问题.为了增加晶闸管串联运行的可靠性,设计了一种电压电流取能电路,能够满足TCR在各触发角下均能取到能量,给驱动电路供电,实现晶闸管阀高位系统自供电.利用PSPICE软件建立各取能电路仿真模型,仿真结果表明:高位取能电路能够减少开关损耗,提高晶闸管运行效率,而且能向驱动电路提供电能,为晶闸管阀的驱动电路稳定供电提供了理论基础. 相似文献
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晶闸管阀组是保证变压器式可控电抗器(CRT)能够正常工作的核心组成,对其结构研究也是CRT结构设计和制造的关键.论文首先基于CRT等效电路,计算CRT阀组的电压和电流,确定描述阀组结构的两个参数(并联级数和串联级数),并分析其影响因素;基于此提出以晶闸管阀组电流为自由量并赋以确定值来对CRT阀组结构进行设计,并给出设计... 相似文献
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晶闸管承受过电压的能力较弱,瞬时过电压可导致晶闸管的击穿。首先研究了直流输电核心设备之一晶闸管换流阀发生晶闸管过电压击穿对直流输电系统的影响,分析了直流输电换流阀晶闸管配置过电压保护的必要性。然后对BTC和BOD两种晶闸管过电压保护方式进行了理论计算与分析,并采用PSPICE软件搭建了仿真模型进行仿真分析。最后在实验室搭建实验电路对两种过电压保护电路性能进行了验证。研究表明两种保护方式均可以实现晶闸管过电压保护的要求。 相似文献
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目前晶闸管控制或晶闸管投切型高压静止无功补偿装置(TCR/TSC型SVC)在电力系统得到广泛应用,其中由晶闸管组成的阀组因功耗大,多用水冷系统散热。在电压等级35 kV及以上、容量120 MVar以上的工程中,晶闸管阀组为满足高电压、大电流系统需要,将要提高晶闸管容量和串联数量,水冷散热系统也要相应增加管路器件来保证散热能力。对原有大容量晶闸管阀组水冷系统管路建立模型,通过理论计算,提出改进方法,并进行试验前后对比,达到提高装置性能并降低成本的优化目的。 相似文献
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通过对鹅城换流站的可控硅结温保护的原理分析,总结可控硅相应的保护配置情况,提出为防止保护误动可取消可控硅结温保护的保护跳闸功能、改为报警方式的建议。 相似文献