基于直流侧电压等效补偿的光伏并网系统间谐波电流抑制策略  

An Interharmonic Suppression Control Strategy in PV System Based on DC-link Voltage Equivalent Compensation

作　　者：葛津铭 尹贻波 李赫 王振浩 王朝斌 尹瑜 GE Jinming;YIN Yibo;LI He;WANG Zhenhao;WANG Chaobin;YIN Yu(Key Laboratory of Modern Power System Simulation and Control&Renewable Energy Technology(Northeast Electric Power University),Ministry of Education,Jilin 132012,Jilin Province,China;Tongliao Power Supply Company of State Grid Inner Mongolia Eastern Power Co.,Ltd.,Tongliao 028000,Inner Mongolia Autonomous Region,China)

机构地区：[1]现代电力系统仿真控制与绿色电能新技术教育部重点实验室(东北电力大学),吉林省吉林市132012 [2]国网内蒙古东部电力有限公司通辽供电公司,内蒙古自治区通辽市028000

出　　处：《电网技术》2024年第12期4886-4895,I0016,I0015,共12页Power System Technology

基　　金：吉林省自然科学基金项目(YDZJ202401582ZYTS);国家电网有限公司科技项目(SGMDTL00DDJS2311472)。

摘　　要：在光伏发电单元并联接入电网的背景下,最大功率点跟踪(maximum power point tracking,MPPT)控制引起的直流侧电压振荡导致低频间谐波电流问题日益严重,极大影响了电能质量。对此,介绍了多个光伏发电单元并联入网的常见形式,建立了含2个光伏单元并联接入电网的模型;然后,利用扰动式MPPT振荡特性建立了间谐波电流模型,分析了扰动步长对光伏并网系统间谐波特性的影响,并定义了间谐波含有率;接着,提出了一种基于直流侧电压等效补偿的光伏并网系统间谐波电流抑制方法,该方法使得多个并联光伏发电单元直流电压振荡相互抵消,兼具MPPT动态性能和抑制效果。最后,通过仿真分析验证了所提方法在降低光伏并网间谐波电流幅值、提高电能质量方面的有效性。Under the background of parallel connection of photovoltaic power generation units to the power grid,the DC-link voltage oscillation caused by the maximum power point tracking(MPPT)control leads to the increasingly serious problem of low-frequency interharmonic current,which greatly affects the power quality.In this regard,this paper introduces the common forms of multiple photovoltaic power generation units connected in parallel to the grid.It establishes a model with two photovoltaic units connected in parallel to the grid.Then,the model of interharmonic current is established by using the perturbation MPPT oscillation characteristics.The influence of the disturbance step size on the interharmonic characteristics of the photovoltaic grid-connected system is analyzed,and the interharmonic content is defined.Then,an interharmonic current suppression method for the photovoltaic grid-connected system based on DC-link voltage equivalent compensation is proposed.This method makes the DC voltage oscillation of multiple parallel photovoltaic power generation units offset each other and has both MPPT dynamic performance and suppression effect.Finally,the effectiveness of the proposed method in reducing the amplitude of interharmonic current and improving power quality is verified by simulation analysis.

关 键 词：光伏发电单元并联 最大功率点跟踪 直流侧电压振荡 间谐波 

分 类 号：TM721[电气工程—电力系统及自动化]