应用于风力发电系统中的撬棒阻值整定新方法  

A new method of Crowbar resistance setting used in wind power generation system

作　　者：李圣清[1] 明瑶 张煜文 吴文凤 马定寰 LI Shengqing;MING Yao;ZHANG Yuwen;WU Wenfeng;MA Dinghuan(Key Laboratory of Hunan Province, Hunan University of Industry, Zhuzhou 412000, China)

机构地区：[1]湖南省重点实验室(湖南工业大学),湖南株洲412000

出　　处：《电力系统保护与控制》2018年第10期102-107,共6页Power System Protection and Control

基　　金：湖南省自然科学基金资助项目(2017JJ4024);湖南省重点实验室(2016TP1018);湖南省教育厅开放基金项目(15k036)~~

摘　　要：在电网发生电压跌落故障的情况下,双馈异步发电机(Doubly-Fed Induction Generator,DFIG)多采用撬棒保护电路以实现低电压穿越(Low Voltage Ride Though,LVRT),而撬棒阻值的选择对机组的LVRT效果影响很大。从DFIG在电压跌落故障下的暂态数学模型出发,运用空间矢量分析和拉普拉斯变换的方法,推导出风电机组在电压跌落故障下的暂态电流时域表达式、转子侧故障电流的计算式。由此提出一种切合工程实际的撬棒阻值整定方法,解决了投入撬棒保护电路后转子侧出现过电流和直流母线过电压的问题。算例及仿真实验数据均表明,采用该方法可有效抑制暂态故障分量,显著提高风力发电系统的LVRT水平。Doubly-Fed Induction Generator （DFIG） often adopts Crowbar protective circuit to realize Low Voltage Ride Through （LVRT） under voltage drop fault of power grid. Crowbar resistance will affect LVRT effect of the unit significantly. Time domain expression of transient current of the wind turbine generator system under the voltage drop fault and the calculation formula of fault current at the rotor side are deduced through space vector analysis and Laplace transformation based on the transient mathematical model of DFIG system under voltage drop. A Crowbar resistance adjustment method conforming to engineering practices is proposed, which overcomes the overcurrent at the rotor side and overvoltage of DC bus after Crowbar protective circuit is applied. Both case study and the simulation test demonstrate that the proposed method can inhibit the transient fault component effectively and increase the LVRT level of DFIG system significantly.

关 键 词：双馈异步发电机 低电压穿越 撬棒阻值 电压跌落 暂态故障电流 

分 类 号：TM614[电气工程—电力系统及自动化]