新型限流式统一潮流控制器限流分析与参数设计

发布时间：2018-06-04 11:25

本文选题：限流式UPFC + RLC串联谐振　；参考：《电网技术》2017年02期

【摘要】：统一潮流控制器(unified power flow controller,UPFC)在电网系统发生短路故障时,极易受到大电流冲击而损毁。虽然具有短路限流功能的统一潮流控制器(限流式UPFC)在一定程度上限制了大电流冲击,但短路电流峰值仍然很大,限流时间较长。为此,提出一种采用RLC串联谐振电路的限流器二次侧拓扑结构,分析了其工作原理和限流动态过程,建立了发生故障时的数学模型。针对限流式UPFC直流侧电容电压在限流过程中不断上升,极易超出变换器IGBT耐压水平的缺陷,分析了故障模型中直流侧电容电压上升的原理,设计了用于改变短路电流流通路径的桥式电容限压器。仿真结果表明,改进方案能进一步减小短路电流峰值和上升率,使短路电流迅速衰减至零,同时限制直流侧电容电压的不断增大,确保限流式UPFC安全退出运行。
[Abstract]:Unified power flow controller (UPFC) is liable to be damaged by high current impact when short circuit fault occurs in power system. Although the unified power flow controller (UPFC) with the function of short circuit current limiting (UPFC) limits the large current shock to a certain extent, the peak value of short circuit current is still very large and the current limiting time is longer. In this paper, a secondary topology of current limiter using RLC series resonant circuit is proposed, its working principle and flow limiting state process are analyzed, and the mathematical model of fault is established. In view of the limitation of current limiting UPFC DC side capacitance voltage rising in the current limiting process, it is easy to exceed the IGBT voltage level of the converter. The principle of DC side capacitance voltage rise in the fault model is analyzed. A bridge capacitor limiter is designed to change the flow path of short circuit current. The simulation results show that the improved scheme can further reduce the peak and rise rate of short-circuit current, reduce the short-circuit current to zero rapidly, and limit the constant increase of DC side capacitance voltage, so as to ensure the safe exit of the limit-current UPFC.
【作者单位】：山东理工大学电气与电子工程学院;
【基金】：国家自然科学基金项目(50807034)~~
【分类号】：TM721.2;TM571

【相似文献】