【作者】 周卫；

【导师】 张尧； 夏成军；

【作者基本信息】 华南理工大学 ， 电力系统及其自动化， 2010， 硕士

【摘要】 本文基于PSCAD建立地区电网双侧有源110kV线路重合闸仿真模型,并通过模拟现场实际故障验证模型的正确性。在此基础上,仿真分析联络线初始潮流大小对小电源侧孤岛系统电压和频率特性的影响,结果表明:当联络线初始有功潮流较大时,断路器跳闸后小电源侧频率变化较大,而常规检同期重合闸检测断路器两侧压差、频差及相角差是否在整定范围内且持续设定的延迟时间,合闸条件要求较严格,这就使得小电源侧重合闸可靠动作的机率大为降低。为解决这一问题,本文提出双侧有源110kV线路自动准同期重合闸方案,微机准同期重合闸可精确控制合闸越前角使断路器合闸瞬间两侧电压相角差接近于0°,从而避免断路器合闸瞬间两侧电压相角差给机组或系统带来的冲击,同时准同期重合闸的允许频差可以远大于常规检同期重合闸时的允许频差。论文在介绍重合闸国内外研究现状及现有检同期重合闸的概念、原理和整定方法的基础上,通过理论分析和PSCAD仿真验证,指出检同期重合闸应用于双侧有源110kV线路时存在的问题和不足:受负荷类型和联络线初始潮流影响较大。基于此,本文提出微机自动准同期重合闸方案,首先介绍准同期重合闸的原理和优点;其次对准同期重合闸的可行性进行了理论分析,并介绍了微机准同期的实现方法、越前相角和越前时间的整定计算、零相角差的捕捉,以及准同期参数测量方法;最后对准同期重合闸定值进行了整定计算,并提出基于零序电流保护和距离保护的准同期重合闸加速保护方案。更多还原

【Abstract】 This paper established a reclosing simulation mode on 110kV line with bilateral powersource of regional network based on PSCAD, and then verified its correctness by simulatingpractical fault. On this basis, a simulated analysis for voltage and frequency dynamiccharacteristics of the island system with different initial power flow on the contact line wasdone. And the results showed that frequency of the island system changed greatly when theinitial active power flow on the contact line was larger. While the synchronous reclosingneeded to detect frequency and phase angle difference whether within the range and continuedthe setting delay time. The requirement was so strict that the probability of reliable action ofthe closing on island system reduced significantly.To solve this problem, this paper put forward automatic quasi-synchronization reclosing.Microcomputer quasi-synchronization reclosing could accurately control the closing advanceangle and made voltage phase angle difference between both sides near the zero degree at theclosing moment, so that impact on generator or system caused by voltage phase angledifference when circuit breaker closing was avoided. Meanwhile, the allowed frequencydifference of automatic quasi-synchronization reclosing was much larger than that ofsynchronous reclosing. Firstly, the paper introduced the research status of reclosing at homeand abroad, as well as the principle and concepts, principles and setting method ofsynchronous reclosing. Then disadvantages that it greatly affected by load type and the initialpower flow was pointed out when used on 110kV line with bilateral power source throughtheoretical analysis and simulation. So the program of automatic quasi-synchronizationreclosing was proposed. First of all, advantage of quasi-synchronization reclosing wasintroduced. And secondly the theoretical analysis on feasibility of quasi-synchronization wascarried on. Furthermore, this paper researched on setting methods about advance angle andadvance time as well as parameter measurement algorithm of quasi-synchronization reclosing.Finally, the control strategy and setting value for quasi-synchronization reclosing wasproposing. In addition, zero sequence current accelerating protection and distance acceleratingprotection was discussed.更多还原