具有不对称故障穿越能力的双馈风力发电机组短路电流分析与计算  

Analysis and Calculation for Short-Circuit Current Characteristics for Doubly-Fed Induction Generators with Asymmetrical Fault-Ride-Through Capability

作　　者：刘素梅 毕天姝 薛安成 杨奇逊 

机构地区：[1]新能源电力系统国家重点实验室(华北电力大学),北京102206

出　　处：《电工技术学报》2016年第19期182-190,共9页Transactions of China Electrotechnical Society

基　　金：国家重点基础研究发展计划(973计划)(2012CB215206);"111"计划(B08013)资助项目

摘　　要：风电大规模接入电网背景下,电网故障电流特征发生根本性改变,现有电力系统继电保护技术将难以适应。然而,目前国内外关于双馈风力发电机组(DFIG)短路电流特性的研究多依赖于具体指定的变换器控制与保护策略,研究所得结论多样化,从电力系统继电保护需求角度缺乏通用性,且针对不对称故障电流特性的研究仍相对较少。在分析电网发生不对称故障对DFIG自身安全与运行控制影响的基础上,以风电并网故障穿越要求为约束,揭示了DFIG故障穿越控制与其馈出短路电流特性间的关联规律,进一步从理论上推导了不依赖变换器控制策略的DFIG稳态短路电流计算公式;并系统分析了不同电网故障情况下DFIG故障电流变化特性及规律。这些结论能够为含大量DFIG电网继电保护适应性分析及其新原理研究提供支撑。With the increasing penetration of wind power generators （WPGs） in the world-side electrical grid, the fault current characteristics of the grid are greatly altered by the large-scale WPGs. The traditional relay protection strategies are consequently challenged. However, the existing studies on the fault current characteristics of the doubly fed induction generators （DFIG） depend on the specified converter＇ s control and protection schemes. These results are variable, which are lack of universality from the perspective of the demand of the relay protection. Also, the studies are not on the fault current under asymmetrical grid faults. In this paper, the impact of the asymmetrical grid faults on the DFIGs＇ safety and their employed converter＇ control is firstly analyzed. Based on the fault-side through requirement of the newly issued grid code, the relationship between the converter＇ s fault-side through control and DFIG＇ s fault current characteristics is revealed during the entire asymmetrical fault periods. Further, the formula of the steady asymmetrical fault current for the DFIGs is derived, which is independent of the converter＇ s control strategy. Moreover, under different asymmetrical fault conditions, the fault current characteristics of the DFIGs are also systematically studied. The results can be used for assessing and improving the protection schemes of the grid with lots of DFIGs.

关 键 词：双馈风力发电机组 故障电流计算 不对称故障穿越控制 风力发电 故障分析 

分 类 号：TM315[电气工程—电机]