三相不平衡光伏并网系统间谐波电流产生机理及控制研究  

Generation Mechanism and Control of Interharmonic Current in Three-phase Unbalanced Photovoltaic Grid-connected System

作　　者：尹代杰 奚鑫泽 高贯斌[1] 郭成 YIN Daijie;XI Xinze;GAO Guanbin;GUO Cheng(Faculty of Mechanical and Electrical Engineering,Kunming University of Science and Technology,Kunming 650500,China;Faculty of Electric Power Engineering,Kunming University of Science and Technology,Kunming 650500,China;Electric Power Research Institute of Yunnan Power Grid Co.,Ltd.,Kunming 650217,China)

机构地区：[1]昆明理工大学机电工程学院,云南昆明650500 [2]云南电网有限责任公司电力科学研究院,云南昆明650217 [3]昆明理工大学电力工程学院,云南昆明650500

出　　处：《控制工程》2024年第11期2095-2103,共9页Control Engineering of China

基　　金：国家重点研发计划项目(2017YFB1400301)。

摘　　要：光伏并网系统中存在的间谐波将会直接影响电网电能质量,且当电力系统出现故障时,间谐波现象的产生还极有可能诱发电力系统的失稳。为此,分别针对三相不平衡故障的光伏并网系统间谐波的产生机理和抑制方法进行研究。首先,提出一种基于直流母线电压扰动的逆变器间谐波电流数学模型,并对不同扰动频率下的间谐波分量变化特性进行分析。然后,在电网发生三相不平衡故障时,进一步探究有功功率二倍频分量与直流母线电压高频波动的关系。同时,对该工况下并网电流间谐波分量的来源进行分析,并采用有功功率致稳控制实现对间谐波电流的抑制。最终,通过仿真验证了所提间谐波产生机理和控制策略的正确性和有效性。The interharmonics in photovoltaic grid-connected system will directly affect the quality of power in the grid,and when the power system fails,the interharmonic phenomenon is also likely to induce power system instability.Therefore,under the three-phase unbalanced fault of power grid,the generation mechanism and suppression method of inter-harmonics in photovoltaic grid-connected system are studied respectively.Firstly,a mathematical model of inter-harmonic current of inverter based on DC bus voltage disturbance is proposed,and the variation characteristics of inter-harmonic components are analyzed according to different disturbance frequencies.Then,when three-phase unbalanced fault occurs in power grid,the relationship between double frequency component of active power and high frequency fluctuation of DC bus voltage is further explored.At the same time,the source analysis of the interharmonic component in the grid-connected current under this condition is completed,and the active power stabilization control is used to suppress the interharmonic current.Finally,the correctness and effectiveness of the proposed interharmonic generation mechanism and control strategy are verified by simulation.

关 键 词：光伏并网系统 间谐波电流 直流母线电压波动 间谐波抑制 输出功率控制 

分 类 号：TP18[自动化与计算机技术—控制理论与控制工程]