摘要随着近几年分布式发电技术和智能电网概念的不断推进,微电网的概念也开始逐步走进人们的视野。从目前发展的趋势来看,微电网与大电网互补的这种运行方式将成为今后低压配电网发展的主要方向。然而目前国内外有关微电网继电保护技术的研究都才刚刚开始起步,有许多的难题没有攻克,缺少一种行之有效通用的保护策略。本文从广域保护概念得到启发,提出了一种利用搜索树结构和电流综合幅值以及相位比较的新型电流保护方案。
首先本论文根据逆变型微电源原理,结合PQ,VF两种控制方式,并通过MATLAB建模仿真构建了两类控制下的微电源模型,在此基础上实现了含多种控制方式微电源的微电网并网和孤网运行的仿真。其次,通过对微电源和微电网的故障特性的分析,介绍了微电源的接入对传统配电网的各方面影响,得出传统的电流保护在微电网中应用的局限性。随后,对本文所提新型智能电流保护的原理和定位方法进行了阐述,并通过一个实例从理论上定性分析此保护方案的有效性。最后利用前文建立的基于SIMULINK微电网的故障仿真模型,分并网运行和孤网运行两种模式,对微电网三相短路故障和两相短路故障分别进行了仿真验证,通过对仿真得到的综合幅值和相位比较结果的分析,模拟故障定位过程,验证了本文所提的针对微电网系统新型电流保护方案的正确性和可行性。
关键词 微电网 继电保护 电流保护 故障定位 MATLAB/SIMULINK 孤岛运行9742
毕业设计说明书(论文)外文摘要
Title Research on the Technology of Microgrid Protection
Abstract
In recent years, as the concept of distributed generation and smart grid developing , the concept of micro-grid started getting into people's vision. From the current development trend, the micro-grid and grid complementary of this operation mode will become the main direction of development of low voltage distribution network. However, the technology of microgrid protection at home and abroad has only just started. Many problems do not overcome because of the lack of an effective protection strategy. From a wide area protection concept we inspire a new current protection with the search tree structure and amplitude current and phase comparation.
Firstly, according to the principle of DC/AC inverter , combined with PQ and VF which are two control modes, and to construct under the control of two types of micro-generation model with MATLAB modeling and simulation. On this basis, with a variety of micro-generation in different control ways ,we build up the micro-simulation of the power grid and isolated island operation. Secondly, by analyzing the characteristics of micro-generation and micro-grid failure analysis, describes the impact of micro-generation access on all aspects of the traditional distribution network, to come to the limitations of applications for current protection in the micro-grid. Subsequently, the proposed principle of the new smart-current protection and positioning methods are described and an example from theory, qualitative analysis of the effectiveness of this protection program. Finally, the previously established based on the the SIMULINK micro-grid failure simulation model, running with grid or in island operation mode.Three-phase short-circuit fault and two-phase short-circuit fault on the microgrid were carried out by simulation with comparative analysis of the results of the amplitude and phase, analog fault location process, to verify the correctness and feasibility of the proposed new current protection scheme for the micro-grid system.
Keywords : Microgrid Protection Current Protection Fault Location
MATLAB / SIMULINK Island Operation
目 录
1 绪论 1 MATLAB/SIMULINK微电网继电保护技术研究:http://www.youerw.com/zidonghua/lunwen_8554.html