经济型故障限流器研究

【作者】 徐亮；

【导师】 李庆民；

【作者基本信息】 山东大学 ， 高电压与绝缘技术， 2007， 硕士

【摘要】 随着我国电网规模的迅速扩张,电力负荷的迅速增长以及大容量机组的不断投入运行,短路电流水平也日益增高。如何限制短路电流已成为当前电力系统发展中的重要技术课题,故障限流器(FCL,Fault Current Limiter)也因此成为国内外的研究热点。本文介绍了各种不同类型的故障限流器,从技术上的可能性与经济性等各方面考虑,超导型和电力电子型故障限流器在近期内尚难以在电网中付诸实用。基于常规电气设备或元件的非超导、非电力电子的经济型故障限流器,无疑是解决故障限流问题的首选技术。本文提出了一种基于ZnO避雷器的串联谐振型限流拓扑结构,并研制了10kV等级实验室样机,通过模拟实验验证了其有效性,为研制110kV以上等级FCL提供了参考依据。FCL与电网的交互影响的研究是FCL实现工程应用的前提条件,既包括FCL与系统整体性能的交互影响,也包括FCL与电网中各种关键电气设备之间的交互影响。本文深入研究了ZnO避雷器式FCL对断路器开断特性的影响,通过理论分析与推导,给出了描述断路器瞬态恢复电压上升率与限流比、杂散电容以及近区故障距离之间关系的严格数学表达式。基于这些理论公式,研究了各主要参数对瞬态恢复电压上升率的具体影响,并与文献中的有关仿真结果进行了比较,验证了分析方法的有效性。本文的研究结果,为ZnO避雷器式FCL的参数优化和高压断路器开断特性的选型,提供了分析基础和理论依据。本文还通过仿真分析了ZnO避雷器式FCL对配电网电能质量的影响。在配电网中安装FCL,不仅能限制故障电流水平,还可有效抑制电压跌落与高次谐波传递,显著提高电能质量。更多还原

【Abstract】 Along with the scale of our national electric power net expanding rapidly, the electric power loads rising swiftly and big capability units going into function, the short circuit level is increasing day after day. How to limit the short circuit current became an important technical task of the development in electric power net. Therefore Fault Current Limiter (FCL) became the most popular research subject.Various of FCL are present in this article. Considering the feasibility and economy, Superconducting Fault Current Limiter (SFCL) and Flexible Short Current Limiter (FSCL) are difficult to apply in electric power net in the near future. Economical FCL based on general electric equipments which are un-superconducting or un-electronic is undoubtedly the best choice to solve the questions of limiting fault current. An optimized configuration about the series resonant FCL based on ZnO arrester is put forward in this article. Also, the 10W voltage sample in laboratory has been developed. Depending on simulant running experiment, the dynamic characteristic has been checked and the feasibility has been validated. These are the bases of 110kV and higher voltage rank FCL.To investigate the mutual influences between FCL and power net is the precondition of FCL which will achieve project application, including the mutual influence between FCL and the whole system involving various pivotal electric equipments. This article thoroughly simulated the influence of ZnO arrester based FCL on circuit breaker. Strict mathematical formulas were presented, based on theoretical analysis and deduction, to properly describe the relationship between rate of rise of recovery voltage (RRRV) of circuit breakers and current limit factor, stray capacitance as well as short-line fault distance. According to these formulas, detailed computations were carried out to fully account for the concrete impacts on RRRV from every principal parameter, and were correlated with the conclusions drawn by simulations in previous publications available, which verified effectively of the proposed analyzing methodology. The research results present analytical basis and theoretical reference for the parameter optimization of ZnO arrester based FCL andreliable selection of the breaking characteristics of HV circuit breakers.This article also simulated the influence of ZnO arrester based FCL on power quality. Installed in the distribution network, FCL can not only limit fault current level, but also restrain voltage sags and hold back harmonics passing the circuit, thereby can clearly improve power quality.更多还原