饱和铁心型超导限流器的暂态特性分析及对保护的影响研究

发布时间：2018-03-01 18:18

本文关键词： 超导限流器电磁暂态等效磁路零序电流保护反时限过电流保护　出处：《天津大学》2014年硕士论文　论文类型：学位论文

【摘要】：近年来,电网的装机容量和各电压等级网架建设得到高速发展,网架结构大大加强,满足了电网负荷增长和可靠供电的需求,但同时也使电网的短路容量持续增长。超导限流器是限制电网短路电流的有效措施之一,其可对输电线路故障短路电流快速、平稳、有效地限制,为解决输电网安全稳定运行的关键技术难题奠定基础。本文主要研究饱和铁心型超导限流器接入线路后的电磁暂态特性及其对保护的影响。本文对被动式及主动式饱和铁心型超导限流器的工作原理进行了详细分析,对比研究了两种超导限流器各自的优缺点。针对超导限流器的非线性特性及其实际应用结构(采用铁心不等截面积设计,两铁心独立结构或三柱式结构),本文提出了一种新式等效磁路法,有效、精确地分析了饱和铁心型超导限流器接入线路发生故障后的电磁暂态特性。并在Simulink/Stateflow仿真平台实现了饱和铁心型超导限流器的仿真实现,所得结果与理论结果完全吻合。新等效磁路法的提出对于饱和铁心型超导限流器的理论研究与实际应用都有重大意义。分析了超导限流器接入配电线路后对反时限过电流保护和阶段式电流保护的影响。反时限过电流保护在国内外的配电线路得到广泛应用,在配电线路上容易实现上下级配合关系,而且可以保证线路近端故障时的快速动作。在超导限流器接入后,反时限过电流保护的动作时限有所延长,且上下级保护配合的时间级差也增大,但是上下级保护之间的配合关系可以得到有效保证。对超导限流器接入超高压输电线路双回线某线发生单相经过渡电阻接地故障时,当一回线重合于永久性故障时,以及超导限流器在不同运行工况下时对零序电流保护的影响。针对上述可能导致零序电流保护误动的各种情况提出了相应的保护配置方案。
[Abstract]:In recent years, the installed capacity of the power grid and the construction of each voltage grade grid have been developed at a high speed, and the grid structure has been greatly strengthened to meet the demand of power network load growth and reliable power supply. The superconducting current limiter is one of the effective measures to limit the short-circuit current of the power network, which can limit the short-circuit current of the transmission line quickly, smoothly and effectively. In order to solve the key technical problems in the safe and stable operation of transmission network, this paper mainly studies the electromagnetic transient characteristics of saturated-iron core superconducting current limiter after it is connected to the transmission line and its influence on the protection. The working principle of the type saturated iron core superconducting current limiter is analyzed in detail. The advantages and disadvantages of two kinds of superconducting current limiter are compared. The nonlinear characteristics of the superconducting current limiter and its practical application structure are studied. A new equivalent magnetic circuit method is presented in this paper. The electromagnetic transient characteristics of saturated-iron core superconducting current limiter after the fault of the connection line are analyzed accurately, and the simulation of the saturated iron core superconducting current limiter is realized on the Simulink/Stateflow simulation platform. The results are in good agreement with the theoretical results. The new equivalent magnetic circuit method is of great significance for the theoretical study and practical application of the saturated core superconducting current limiter. The reverse time of the superconducting current limiter connected to the distribution line is analyzed. The influence of limiting current protection and stage current protection. Reverse time over-current protection is widely used in distribution lines at home and abroad. It is easy to realize the cooperation between the upper and lower levels on the distribution line, and it can guarantee the fast action of the near end fault of the line. After the superconducting current limiter is connected, the action time limit of the reverse time overcurrent protection is prolonged. The time level difference of upper and lower protection coordination is also increased, but the coordination relationship between upper and lower protection can be effectively guaranteed. When the superconducting current limiter is connected to the double circuit line of EHV transmission line, the fault of single phase passing through the resistance ground occurs, and when the superconducting current limiter is connected to the double circuit line of EHV transmission line, When the primary circuit is overlapped in a permanent fault and the superconducting current limiter affects the zero-sequence current protection under different operating conditions, a corresponding protection configuration scheme is proposed for the various cases mentioned above which may lead to the misoperation of the zero-sequence current protection.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM471

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