微电网继电保护原理方案研究

发布时间：2018-02-22 15:44

本文关键词： 微电网微电源暂态故障特性广域差动保护方案　出处：《华中科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：面对目前的环境问题和能源短缺现象，为了充分地利用新型清洁可再生能源，发挥分布式能源的优势，微电网受到了广泛的关注。微电网使得微电源能以一种有效的方式接入外部大电网，并且能提供高效、可靠、安全的电能供应。凭借着对分布式能源利用的优势，微电网成为了电力系统研究发展的一个重点方向。然而，当微电网与大电网并网运行时，传统的潮流单向辐射状网络变为了一个潮流多方向的多源网络，这对传统的保护方案带来了挑战；并且当微电网处于孤岛模式运行时，基于电力电子设备的变流器故障电流被限制在2倍额定电流以内，传统的保护方案不能满足微电网的内部运行状况需求。所以如果不采取任何技术措施地直接将微电网接入大电网，将会给大电网带来更多的问题甚至使得大电网直接瘫痪，，反而影响人们的生活和对电能的利用，更加不能满足人们的需求。因此，研究适合于微电网的继电保护原理方案很有必要。本文在对微电源和微电网基于PSCAD进行建模仿真的基础上，分析得出了微电网和传统配电网的故障暂态特性的主要区别：（1）微电网内多电源多点分布，使得潮流可以双向流动；（2）组网之后，新能源发电系统的启停将严重影响故障的短路电流；（3）并网和离网状态下，部分保护安装处的短路电流将差异很大；（4）双馈风力发电系统在故障后的前几个周波内，短路电流频率将发生波动。基于仿真所得出微电网暂态特性特点，分析了常规继电保护在微电网中的适用性，分析选择了广域差动保护为主保护的微电网广域差动保护方案，并进行了详细的保护整定。最后，进行了动态模拟试验，验证了微电网的特性和保护方案的适用性。
[Abstract]:Facing the current environmental problems and energy shortage phenomenon , in order to make full use of the new clean renewable energy and to exert the advantages of distributed energy , the micro power grid has attracted extensive attention . The micro power grid enables the micro power supply to access the external large power grid in an efficient way , and can provide efficient , reliable and safe electric energy supply . With the advantage of the distributed energy utilization , the micro power grid becomes a key direction of the research development of the power system . However , when the micro - grid is connected to the large power grid and the grid runs , the traditional one - way radial network becomes a multi - source network with multi - direction trend , which poses a challenge to the traditional protection scheme ; and when the micro - grid is in the island mode operation , the traditional protection scheme can not meet the internal health requirement of the micro - grid . Based on PSCAD modeling of micro power supply and micro power grid , the main differences of fault transient characteristics of micro power grid and traditional distribution network are analyzed : ( 1 ) multi - point distribution of multi - power supply in micro - grid , so that the power flow can flow in two directions ; ( 2 ) after networking , the start - stop of new energy power generation system will seriously affect short - circuit current of fault ; ( 3 ) in grid and off - net state , short - circuit current at the partial protection installation will be greatly different ; and ( 4 ) the frequency of short - circuit current will fluctuate within the first few cycles of fault . Based on the characteristics of the transient characteristics of the micro - grid , the applicability of the conventional relay protection in the micro - grid is analyzed , and the wide - area differential protection scheme of the micro - grid based on the wide - area differential protection is analyzed , and detailed protection setting is carried out . Finally , the dynamic simulation test is carried out to verify the characteristics of the micro - grid and the applicability of the protection scheme .

【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM77

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