共查询到20条相似文献，搜索用时 109 毫秒
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515kV直流隔离开关主要安装在±500kV换流站直流场,为换流站直流场主要设备之一.本文通过有限元、边界元数值计算方法.进行隔离开关三维有限元电场计算分析,研究屏蔽环的环径、管径等对整个产品电场分布影响的规律,从抑制电场强度的角度得出了合理的屏蔽结构参数,最终根据试验验证产品的无线电干扰电平满足要求. 相似文献
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软开关技术是今后技术发展的方向,软开关的应用是个重要课题.本文着重介绍谐振开关电路、ZCS/ZVS/ZCT/ZVT-PWM 电路、移相全桥电路、有源钳位电路、移相全桥 ZVS-PWM电路、不对称半桥型电路和 PWM三电平直流开关电路等软开关技术的核心电路的概念、结构和分类,并对软开关技术的电路、工作特性和应用等的分析 相似文献
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在没有备用设备的情况下,当现场的交、直流回路出现异常情况时,例如操作直流保险熔断、直流开关跳闸、电磁机构合闸回路的保险熔断、电池组保险熔断、直流母线电压过低、开关合闸回路辅助接点接触不良、打开过早、合闸回路闭锁、弹簧机构不储能以及其它一些问题的出现,则完全可由运行人员或检修人员通过正确判断快速得到解决,使开关尽快合闸送电,保证系统稳定运行。对于有备用设备时,一些异常情况的及时处理也会事半功倍,大大缩短操作时间。 相似文献
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简要分析了ZGW6-816/J6300-25型高压直流隔离开关的结构、工作原理、安装及调试。 相似文献
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介绍广州地铁二号线1500V直流开关的结构特点,阐述了控制保护原理,举2例分析有关运营故障,并提出对应措施,以确保地铁接触网供电系统的正常稳定运行. 相似文献
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由于组合电器对变压器等电器设备的保护作用比断路器更可靠,更经济,FN25系列组合电器在12KV三相交流50Hz环网或终端供电的市区配电站和工业用电设备中得到了广泛应用.然而,在实际运行中FN25系列负荷开关常常会发生重复合闸现象.笔者通过对其原理进行分析,找到了原因所在,并通过增加继电器的方法解决了问题,增强了产品的性能和稳定. 相似文献
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我公司以前使用的架线直流分区开关没有过流保护、漏电保护,而且耐潮湿能力差,无熄灭直流电弧能力,在架空线出现短路故障时,没有办法自动切断故障线路,维护人员在人工切断故障线路时,极易造成电弧烧伤事故。通过考察研究我公司采用矿用一般型直流架线自动供电系统,该系统由直流输电主干线、分区开关、自动停送电开关、信号指示灯、车载直流逆变电源（内含载波信号器）。它具有自动脱扣功能,能自动分断短路故障线路。它分断能力强,能手动分断带有载荷的直流供电线路,具有驱潮功能,能在潮湿的井下环境长期工作。 相似文献
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刘铭峰 《大科技．科学之谜》2013,(22):137-138
随着经济社会的不断发展,电力系统的规模不断扩大,输送的电能不断增加,其输送电能的技术水平也不断提高。变压器是调节不同电压线路之间的重要装置,对于电力的配送和使用都具有重要的作用。然而,在实际的变压器的调节过程中,经常会出现这样或那样的问题,严重影响了电能的正常使用。本文对供电系统有载电力变压器分接开关带绕组动作特性直流测试波形异常原因进行了分析,重点阐述了直流测试产生电流弹跳断续、不能反映开关正常切换过程等现象的原因,介绍了变压器有载调压分接开关交流测试技术现场的应用情况,希望对相关工作者有所指导和帮助。 相似文献
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赵志东 《科技成果管理与研究》2011,(12):88-90
断路器是电网的重要组成部分,担负着切断负荷电流及故障电流的重要任务;二次回路控制断路器的动作行为,监测断路器的运行状态,同样是电网的重要组成部分。文章对LW36-126断路器控制回路进行分析,解决该型号断路器储能电源空开DK1由于某种原因跳闸,闭锁断路器的储能回路,造成断路器不能合闸或重合闸的问题。 相似文献
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Joseph Slepian 《Journal of The Franklin Institute》1932,214(4):413-442
It is pointed out that the arc performs useful and necessary functions in circuit interruption and that if the arc is eliminated, other devices which are more expensive and less reliable must be used to carry out these functions. The synchronized interruption of the circuit which the arc effects is considered for the ideal reactive circuit and for the oscillatory circuit. The part which the natural period of the circuit plays in circuit interruption is discussed in some detail. The resistance breaker is discussed.Arc characteristics for various conditions are discussed. The theory of the high vacuum switch is given. The great effect turbulence has upon the interrupting capacity of arcs is discussed and to this effect is attributed the efficacy of expulsion fuses, oil circuit breakers, the compressed air switch and the expansion breaker. Other proposed theories of the oil circuit breaker, compressed air switch and the expansion breaker are examined. The use of lightning arresters in circuit interruption is discussed. 相似文献
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介绍了电气化铁路牵引变电所中断路器的应用情况，对SF6和真空断路器的性能进行综合比较，对断路器的选型提出建议。供设计和产品开发参考。 相似文献
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妥平 《科技成果管理与研究》2011,(12):91-92
近年来固原变电所的部分35KV断路器经常出现在手跳或保护动作跳闸后由于控制回路断线而不能再次合闸的情况。这种断路器属于手车式开关。经仔细对断路器控制回路检查分析,找出了造成断路器无法合闸的原因,并采取措施,对断路器二次控制回路进行了整改,很好地解决了这一问题。 相似文献
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SF6断路器是电力系统中的一个重要设备。在110kV及以上电压等级中,最常用的开断电器是SF6断路器。文章分析了其特点,总结了正常巡检定期维护的做法,并提出了在出现常见故障时采取相应的处理措施,为电网运行管理部门提供了预防该类事故的有效途径,从而确保安全优质持续供电。 相似文献
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10KV断路器二次回路整组调试能检验控制回路的正确性,检验保护回路的准确性和可靠性,完整的调试过程对学员理解复杂线路原理起着重要作用. 相似文献
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The Holy Grail in strategic management is the Dynamic Capability (DC) of organizations to realize sustainable competitive advantage. This requires organizations to continuously sense market changes and adapt their resources and routines accordingly, for which they are heavily dependent on knowledge. Knowledge as an antecedent for DC is, however, understudied. Inspired by the recognition of knowledge as an antecedent for DC, this paper sets out to uncover how organizations can foster DC from a knowledge management (KM) perspective. In an empirical survey on 55 knowledge-intensive organizations, we studied DC in organizations from two key perspectives on knowledge: formal, through the adoption of KM policies, and informal, through the availability of social capital. Our research results show that, although a formal KM approach strengthens DC, the availability of social capital appears unrelated to DC. The paper concludes with a practical outlook on advancing DC. 相似文献
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《Journal of The Franklin Institute》2019,356(13):6875-6898
This paper proposes an improved passivity-based control (PBC) technique to provide accurate coordination between AC and DC sides of a grid-tied AC/DC hybrid microgrid. The proposed PBC is based on the passive properties of the system and the energy exchange between the subsystems. To this end, three mathematical formulations for the converters are driven in the first step. Then, using the formulations, the impedance injection is applied to shape the error dynamics of all DC/DC and DC/AC converters. The DC link-connected DC/AC converter is used to help the AC side for maintenance of the power quality factors such as, the grid frequency and voltage magnitude in the presence of any unbalanced power load sharing. The first contribution of the paper is the part of impedance injection to the DC/AC converter, which aims to provide more decoupling and faster convergence rate for both the steady states and the dynamical conditions. Secondly, a Lyapunov function is defined for converters’ error dynamics that provide more accurate statement of the proposed damping injections. Besides, as an attractive control feature, decoupling properties of the suggested method are investigated. Then, through achieving several curves, various operating conditions of DC/DC and DC/AC converters under varying the system errors and proposed damping injections are evaluated as well. For the purpose of validation, the system under study is simulated in the MATLAB/SIMULINK software package against a variety of system errors and converters’ operational conditions. 相似文献
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《International Journal of Information Management》2017,37(6):553-565
Although digital content (DC) business has been increasingly recognized as one of the core industries in a knowledge-based economy, little is known about its value stream from DC users’ perspective. This study suggests a DC value chain framework involving the stream of DC value from DC creation to use from users’ perspective, which has three key components of DC-value stream: (1) DC-value creation, (2) DC-value interaction, and (3) DC-value use. Drawing upon the DC value chain framework, we propose a research model exploring the direct relationships between DC-value creation and DC-value interaction and between DC-value interaction and DC-value use. It also explains the moderating role of DC types between DC-value and DC-value interactions. The empirical results of the study indicate that DC-value interactions play an intermediary role between DC creation value and DC use value and that users’ perceptions of DC value vary in different types of DC. We discuss theoretical contributions and practical implications along with some avenues for future research. 相似文献
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在对中压用户配电系统故障扩散法评估算法研究的基础上,可以知道该算法利用故障扩散法确定断路器动作影响的范围,并确定故障范围与切换开关的有无,从而确定了节点的故障类型。根据节点的类型,可以计算出供电系统的可靠性指标,并提出了提高中压配电系统供电可靠性的技术与管理措施。 相似文献