【作者】 李洪凤；

【导师】 贾贵玺；

【作者基本信息】 天津大学 ， 电力电子与电力传动， 2005， 硕士

【摘要】 电力系统在运行过程中,最常见且最危险的故障是发生各种类型的短路故障。随着电力系统规模和容量的不断扩大,短路容量成为制约电网发展的一个重要因素。为了减少短路故障对电力系统造成的危害,必须采取措施快速限制电力系统的短路电流,传统的限制短路电流的方法存在各种缺点,因此新型限流技术成为国内外的研究热点之一。本文在天津大学985一期基金项目“关于短路限流器的研究与实现”的资助下,通过阅读大量参考文献,对目前存在的各种短路限流器拓扑结构进行研究,对两种比较优秀的拓扑结构进行了改进,给出了新的控制方法、硬件及软件设计思想。本文对目前国内外研究的几种短路限流器的研究现状进行了介绍,提出了两种比较优秀的拓扑结构:具有可控串补功能的短路限流器及新型桥式固态限流器。本文根据具有可控串补功能的短路限流器的拓扑结构及电力系统的特点,结合神经网络的优点,给出了神经网络的控制策略,并采用MATLAB仿真软件以大同到房山的输电线路为例对整个系统进行了仿真,得出了较满意的结果。并以其为例,比较详细的分析了短路限流器对电力系统稳定性及电能质量的改善。由于具有可控串补功能的短路限流器在电力系统正常运行时起到串联补偿功能,因此这种短路限流器比较适合安装在输电线路中。本文另外提出了一种适合安装在低压配电网的改进桥式固态限流器,并对其进行了仿真研究,对目前浙江大学研究的桥式固态限流器进行了改进,并根据改进后的拓扑结构提出了更简单灵活的新的控制策略,做到正常运行时无谐波、能够自动检测短路电流、无需外加检测装置、能够实现自动重合闸。在本文的最后给出了两种拓扑结构控制策略的硬件电路设计及软件实现思想。更多还原

【Abstract】 As well known, the short circuit fault is one of the most dangerous and frequent faults in Power system. Once it happens, the short circuit current level will become very high within half a period. With the development of power systems, the short circuit capacity becomes a serious limiting factor to it. In order to minish the damage to the Power system, a protection system to limit the short circuit current to a safe level as quickly as possible is required. The traditional methods to limit the short current have many shortcomings. This paper is supported by Tianjin University 985 Foundation under the project of “Research and implement of a novel solid state fault current limiter ”. Having read a lot of references, two novel circuit topologies of solid state current limiter have been developed. A fault current limiter with TCSC(Thyristor Controlled Switched Capacitor) is proposed, which works as TCSC when power system works normally, otherwise works as FCL(Fault Current Limiter). The conversion of different working modes is analyzed in this paper. The simulation of MATLAB proved that it is feasibility. The effect of FCL component values is also analyzed .the control way based on artificial neural network (ANN)is proposed, and is check by simulation using MATLAB. A novel bridge type solid state current limiter and a new control strategy is proposed. The characters and operating principle of a novel bridge solid-state current limiter have been developed in detail. Simulation based on MATLAB/SIMULINK is analyzed. In the end, this paper offers the design thinking about the hardware and the software in 80C196KC (a single chip computer).更多还原