一种基于电压反馈控制的配电网短路故障柔性限流方法

发布时间：2018-04-04 17:15

本文选题：配电网　切入点：短路故障　出处：《电工技术学报》2017年11期

【摘要】：在短路故障发生初期快速检测出故障并对短路电流进行限制,有利于电力系统安全稳定运行。采用电流半周波曲线与时间轴围成的面积作为判据进行短路故障早期检测,结合配电网短路故障特征与级联H桥变流器输出特性,提出了将3个单相级联H桥多电平变流器应用于配电网短路故障柔性限流。所提限流装置采用电容耦合的方式实现并网。选取电压信号作为反馈量,采用适当的控制方法使装置输出合适的电压以达到限制故障电流的目的。仿真结果表明,在短路故障早期检测的基础上,所提方法能实现对故障电流首个峰值的抑制,减小危害,减轻断路器的开断负担,且投入限流时无需进行故障选相。
[Abstract]:It is beneficial to the safe and stable operation of power system to detect the fault quickly and limit the short-circuit current in the early stage of the short-circuit fault.The early detection of short circuit fault is carried out by using the area formed by current half Zhou Bo curve and time axis as criterion, combined with the characteristics of short circuit fault of distribution network and the output characteristics of cascade H bridge converter.Three single-phase cascaded H-bridge multilevel converters are applied to the flexible current limiting of short-circuit fault in distribution network.The proposed current limiting device uses capacitive coupling to realize grid-connection.In order to limit the fault current, the voltage signal is chosen as the feedback quantity, and the appropriate control method is adopted to make the device output a suitable voltage.The simulation results show that on the basis of early detection of short circuit fault, the proposed method can suppress the first peak value of fault current, reduce the harm, reduce the breaking burden of circuit breaker, and do not need to select the fault phase when input and limiting current.
【作者单位】：福州大学电气工程与自动化学院;国网福建省电力有限公司电力科学研究院;
【基金】：国家自然科学基金项目(51677030,51377023) 福建省自然科学基金项目(2016J01218)资助
【分类号】：TM711;TM732

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