动态无功补偿设备在高压直流输电换相失败中的应用研究

发布时间：2018-04-21 03:05

本文选题：高压直流输电 + 换相失败　；参考：《北京交通大学》2014年硕士论文

【摘要】：换相失败是高压直流输电系统最常见也是比较严重的故障之一,可能会导致系统直流电流剧增、换流阀寿命缩短、直流输电功率减少及逆变侧弱交流系统电压不稳定等严重后果。若换相失败后的处理方式不当,可能引发后续的换相失败,连续换相失败可能引起换流站双极闭锁,导致直流传输功率中断。分析了高压直流输电换相失败理论并通过对华东地区的案例进行统计分析,找出这一事故的主要原因,即交流侧电压跌落。提出在逆变站母线处配置一定容量的动态无功补偿设备抑制换相失败。为了对动态无功补偿设备发出动作指令,需选取量化判据。综合考虑了对称故障与不对称故障及换相失败采取措施的安全裕度问题,本文提出抑制换相失败采取措施的动作判据临界值：电压跌落幅值,即临界电压降O.1pu。分析对比现有动态无功补偿设备相关性能后选择STATCOM。详尽分析了STATCOM的需求原则、性能指标、主电路拓扑结构、等效模型,提出了合理的无功容量配置方案、主参数设计,以及STATCOM针对抑制直流输电换相失败的控制目标与控制策略。在PSCAD/EMTDC软件平台上仿真分析了在系统电压不同跌落范围时投入STATCOM对系统电压的动态支撑效果。研究表明：STATCOM可动态地提供电压支撑,等效扩大母线电压安全运行范围,可在一定程度上解决由电压跌落所引起的换相失败及协助换相失败母线电压恢复。
[Abstract]:Commutation failure is one of the most common and serious faults in HVDC transmission system, which may lead to a sharp increase in DC current and shorten the life of commutation valve. DC transmission power reduction and inverter side weak AC system voltage instability and other serious consequences. If the treatment method after the commutation failure is improper, it may lead to subsequent commutation failure, and the continuous commutation failure may cause the bipolar locking of the converter station and lead to the interruption of DC transmission power. The theory of commutation failure of HVDC transmission is analyzed and the case of East China is analyzed. The main cause of the accident is the voltage drop on the AC side. A dynamic reactive power compensation device with a certain capacity at the bus bar of the inverter station is proposed to suppress the commutation failure. In order to issue action instructions to dynamic reactive power compensation equipment, quantization criteria should be selected. Considering the safety margin of symmetric fault, asymmetric fault and commutation failure, this paper presents the critical value of action criterion: voltage drop amplitude, that is, critical voltage drop 0.1 pu. After analyzing and comparing the related performance of the existing dynamic reactive power compensation equipment, select STATCOM. The requirement principle, performance index, topology structure of main circuit, equivalent model of STATCOM are analyzed in detail. A reasonable reactive capacity configuration scheme, main parameter design and control target and control strategy of STATCOM to restrain commutation failure of HVDC are proposed. The dynamic support effect of STATCOM on the system voltage is analyzed by simulation on the PSCAD/EMTDC software platform when the voltage drop range is different. The research shows that: Statcom can dynamically provide voltage support, expand the safe operation range of bus voltage, and solve commutation failure caused by voltage drop and assist commutation failure bus voltage recovery to some extent.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM721.1;TM761.12

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