风电变流器在弱电网下的畸变问题和应对策略  

Distortion Problem in Wind Power Converters Under Weak Grid and Corresponding Strategy

作　　者：周党生 陈佳明 张东来 郑大鹏 ZHOU Dang-sheng;CHEN Jia-ming;ZHANG Dong-lai;ZHENG Da-peng(Harbin Institute of Technology,Shenzhen 518055,China)

机构地区：[1]哈尔滨工业大学(深圳)机电工程与自动化学院,广东深圳518055 [2]深圳市禾望电气股份有限公司,广东深圳518055

出　　处：《电力电子技术》2023年第12期94-97,108,共5页Power Electronics

基　　金：国家重点研发计划(2022YFB2402802)。

摘　　要：针对风电机组全功率变流器在弱电网下运行出现的输出电流和并网点电压畸变问题,在此首先将风电场各台并联运行的风电机组等效为一台虚拟的全功率变流器,建立了其网侧模型,在考虑锁相环影响的条件下,推导出网侧电流环的抗扰动能力传递函数。然后,基于所建模型分析了弱电网下引发风电全功率变流器电流、电压畸变的3个主要原因,即虚拟变流器的电流环稳定裕度不足、带宽下降及其抗扰动能力下降。最后,针对性地提出一种降低电流环电压前馈权重、增强电流环控制力度以及降低锁相环带宽相结合的应对策略。实验结果表明,所提的应对策略可以有效地解决风电全功率变流器在弱电网下运行时的输出电流和并网点电压畸变问题,显著提高风电机组的电网适应能力,为风电机组稳定运行提供保障。In response to the output current and grid voltage distortion issues of wind turbine full power converters operating in weak current networks,firstly,derives an equivalent virtual converter for all the wind turbines running parallel in the wind farm.Then the current loop control model for this equivalent virtual converter is built.And the antidisturbance transfer function is built for the converter with consideration of the effect of phase-locked loop.Then based on the constructed models,the main causes of output current and PCC voltage distortion is identified asinsufficient stability margin,and reduced bandwidth as well as the declined anti-disturbance ability of current control loop for the equivalent virtual converter at the same time.To solve the distortion problem,a comprehensive correction strategy is proposed by reducing the voltage feed-forward weight,increasing the current loop bandwidth and decreasing the phase-locked loop bandwidth is proposed.Finally,the field experimental results show that the proposed strategy can effectively solve the current and voltage distortion problem and can increase the grid adaptability of full power converters.

关 键 词：全功率变流器 风电 弱电网 

分 类 号：TM46[电气工程—电器]