考虑电网背景谐波影响的直驱风电机组谐波电流建模与分析  

Modeling and Analysis of Harmonic Currents in DDWT Considering Grid Background Harmonics

作　　者：李庆 程鹏 王伟胜 周骐 吴超[2] LI Qing;CHENG Pengl;WANG WeishengI;ZHOU Qi;WU Chao(State Key Laboratory of Operation and Control of Renewable Energy ＆ Storage Systems （China Electric Power Research Institute）, Haidian District, Beijing 100192, China;College of Electrical Engineering, Zhejiang University, Hangzbou 310027, Zhejiang Province, China)

机构地区：[1]新能源与储能运行控制国家重点实验室(中国电力科学研究院有限公司),北京市海淀区100192 [2]浙江大学电气工程学院,浙江省杭州市310027

出　　处：《电网技术》2018年第7期2178-2184,共7页Power System Technology

基　　金：国家电网公司科技项目(NYB17201700081)~~

摘　　要：随着风电产业的持续快速发展,直驱风电机组由于其效率高、故障率低等特点而得到了越来越多的应用,但其并网输出的中频谐波电流超标问题日趋显现。为准确反映直驱风电机组并网中频谐波电流,需建立可准确评估其谐波电流的动态数学模型。以采用典型矢量控制的直驱风电机组为对象,综合考虑电网背景谐波、调制死区效应以及功率因数的影响,建立可准确反映直驱风电机组并网中频谐波电流的动态数学模型。通过仿真分析发现,直驱风电机组并网谐波电流由电网背景谐波、调制死区所产生的同频率谐波电流叠加构成,而功率因数则通过改变同频率谐波电流间的夹角而影响相应频率谐波电流。最后,通过2.0 MW型直驱风电机组的仿真数据、计算数据与实测数据间的对比分析,验证了文中所建立动态数学模型的准确性,为直驱风电机组并网谐波电流定量分析和评估提供了手段和依据。1： With rapid development of wind power industry, direct-drive wind turbines（DDWTs） are more and more applied due to their high efficiency and low failure rate. As the number of DDWTs integrated to power grids continuously grows, middle frequency-band（MFB） harmonics problem cannot be negligible any longer. In order to evaluate MFB harmonic currents of DDWT, it is necessary to develop dynamic mathematic model able to accurately simulate MFB harmonic currents. Taking grid background harmonics, deadtime and power factor into account, a dynamic mathematic model is developed for DDWTs using conventional vector control approach. This mathematic model can clearly describe MFB harmonic currents of DDWTs. Through simulation analysis, it is found out that the harmonic current of DDWT is a superposition of the same frequency harmonic currents caused by grid background harmonics and PWM deadtime. The power factor affects corresponding harmonic current by changing the angle between the same frequency harmonic currents. Accuracy and effectiveness of the developed equivalent harmonic model was verified by comparative analysis of simulation results, calculation results and field test data of a 2.0 MW DDWT. The harmonic model established in this paper provides a tool for quantitative analysis and evaluation of DDWT output harmonic current.

关 键 词：直驱风电机组 谐波电流 谐波模型 谐波电压 死区时间 

分 类 号：TM721[电气工程—电力系统及自动化]