计及变换器输出电压约束的双馈风电机组故障电流特性分析  

Fault Current Characteristic Analysis for DFIG-based Wind Turbine Considering Voltage Constraint of Power Converter

作　　者：马玉梅[1] 黄清军 朱东海[1] 邹旭东[1] MA Yumei;HUANG Qingjun;ZHU Donghai;ZOU Xudong(State Key Laboratory of Advanced Electromagnetic Engineering and Technology(Huazhong University of Science and Technology),Wuhan 430074,Hubei Province,China;State Key Laboratory of Disaster Prevention&Reduction for Power Grid Transmission and Distribution Equipment(Disaster Prevention and Reduction Center,State Grid Hunan Electric Power Company Limited),Changsha 410007,Hunan Province,China)

机构地区：[1]强电磁工程与新技术国家重点实验室(华中科技大学),湖北省武汉市430074 [2]电网输变电设备防灾减灾国家重点实验室(国网湖南省电力有限公司防灾减灾中心),湖南省长沙市410007

出　　处：《电网技术》2021年第11期4233-4241,共9页Power System Technology

基　　金：国家自然科学基金项目(51907072);中央高校基本科研业务费专项资金项目(2021XXJS004)。

摘　　要：随着风电等可再生能源在配电网中渗透率的不断提高,准确分析其故障电流暂态特性已成为智能配电网保护与控制的基石。双馈风电机组是当前最主流的风电机型,当电网发生严重故障时,由于转子侧变换器(Rotor side converter,RSC)的容量约束,其转子电压会限幅输出,此时控制特性会迥异于轻度故障工况。然而,已有研究鲜有考虑RSC输出电压约束对故障电流的影响,从而无法准确反映真实的故障电流特性。针对该问题,首先建立了计及电流闭环控制和输出电压约束的双馈风电机组动态模型。在此基础上,推导出RSC输出限幅后转子故障电流的解析表达式。随后,揭示了RSC输出电压约束导致的控制器参数等效限幅特性,并得出闭环控制下的故障电流取决于控制参数的等效限幅值而非其设计值的结论。最后,在MATLAB/Simulink中搭建了1.5MW双馈风电机组接入电网的仿真模型,仿真结果验证了前述理论分析的正确性。With the increasing penetration of the sustainable energy such as wind power into the distribution network, the accurate analysis of its fault current characteristics has become the cornerstone of the protection and control for the intelligent distribution network. Doubly fed induction generator(DFIG)-based wind turbine(WT) is one of the most mainstream types of the WTs. Its rotor-side output voltage limits under severe grid faults due to the converter capacity constraints. However, the existing research rarely considers the influence of the converter voltage constraint on the fault current, thus the actual fault current characteristics cannot be accurately reflected. To solve this issue, the transient model of DFIG including the current closed-loop control and the voltage constraint is established. Based on this model, the analytical expression of the rotor fault current is derived when the output voltage of the rotor-side converter(RSC) is saturated.Subsequently, the equivalent limiting characteristics of the control parameters caused by the RSC voltage constraints are revealed, and the conclusion is obtained that the fault current under the closed-loop control depends on the equivalent limit value instead of the designed control parameters. Finally, the analysis is validated by the time-domain simulation of a 1.5 MW DFIG-based WT in the MATLAB/Simulink.

关 键 词：双馈风电机组 电流闭环控制 故障电流 变换器输出电压约束 等效限幅 

分 类 号：TM721[电气工程—电力系统及自动化]