基于选相控制技术的并联电容器组投切系统

发布时间：2018-04-16 13:07

本文选题：相控投切 + 过零投切　；参考：《华北电力大学》2017年硕士论文

【摘要】：并联电容器组是电力系统无功补偿系统中的重要设备,其运行的安全性、可靠性一直是一个备受关注的问题。电容器组在投切过程中的涌流现象和过电压现象是影响运行安全的关键因素,这在之前运行的系统中一直没有得到很好的解决,也经常引发联锁的事故。传统的方式是从采用加装过电压抑制装置、提高开关设备耐受能力两方面来改善,实际没能从根本上解决问题。智能相控技术可以主动削弱电路切换过程中的电磁暂态过程,通过选相分、合闸可以抑制甚至消除投切开关分、合过程的涌流和过电压,从根本上解决问题。所以研制具有选相分、合闸功能的智能相控电容器投切系统具有十分重要的实际意义。本文主要研究智能相控投切技术在变电站投切电容器过程中的实际应用,大致有下面几个方面:分析研究电容器投切过程中暂态过程的产生机理,详细描述了智能相控投切系统的整体结构,给出了整体性设计方案,采用智能选相控制器绝准控制新型永磁真空断路器来实现中压电容器组选相分/合闸功能。并根据目前实际运行情况,针对星形中性点绝缘方式的电容器组给出了AB+C方式选相控制策略。精心设计了基于MatLab软件系统的整套系统的投切仿真分析系统,最终仿真结果表明选本方案对电容器组投切时的涌流和过电压有显著改善作用。针对10k V电容器组选相投切的智能相控系统设备,进行了整系统在空载及实际负载情况下的选相投切试验。试验结果验证了本智能相控投切系统中压电容器组的选相投切性能。空载测试,系统的选相分合闸时间偏差在±0.5 ms以内,可满足选相要求。负载试验,涌流峰值从十几k A降到了3k A以下,平均过电压不超过2倍。本系统抑制涌流和过电压的效果明显。
[Abstract]:Shunt capacitor bank is an important equipment in power system reactive power compensation system.The inrush and overvoltage phenomena in the switching process of capacitor banks are the key factors affecting the operation safety, which have not been well solved in the previous operation systems, and often lead to interlocking accidents.The traditional way is to use overvoltage suppressor to improve the tolerance of switchgear, but it can not solve the problem fundamentally.Intelligent phase control technology can actively weaken the electromagnetic transient process in the circuit switching process. By phase selection, closing can restrain or even eliminate the inrush current and overvoltage in the switching process, and solve the problem fundamentally.Therefore, it is of great practical significance to develop an intelligent phase-controlled capacitor switching system with the function of phase separation and closing.In this paper, the practical application of intelligent phase-controlled switching technology in the process of switching on capacitors in substations is studied. There are the following aspects: the mechanism of the transient process in the switching process of capacitors is analyzed and studied.The whole structure of the intelligent phase-controlled switching system is described in detail, and the overall design scheme is given. A new type of permanent magnet vacuum circuit breaker is controlled by the intelligent phase selection controller to realize the phase separation / closing function of the medium voltage capacitor group.According to the actual operation situation at present, the phase selection control strategy of ABC mode for star-neutral insulated capacitor banks is presented.The switching simulation analysis system of the whole system based on MatLab software system is carefully designed. The final simulation results show that the selection scheme can improve the inrush current and overvoltage of capacitor banks during switching.For the intelligent phase control system equipment of 10kV capacitor group, the whole system is selected and cut under the condition of no load and actual load.The experimental results verify the switching performance of the voltage capacitor banks in the intelligent phase-controlled switching system.In no-load test, the phase separation time deviation of the system is less than 卤0.5 Ms, which can meet the requirement of phase selection.The load test shows that the peak inrush current decreases from 10 Ka to less than 3 Ka, and the average overvoltage is less than 2 times.The effect of this system on inrush current and overvoltage is obvious.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM53

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