基于谐波特性的光伏孤岛与低电压穿越同步检测方法  

Simultaneous detection method for photovoltaic islanding and low-voltage-ride-through based on harmonic characteristics

作　　者：赵禹灿 姜旭 孙福寿 葛路明 孙铭徽 于淼[1] ZHAO Yucan;JIANG Xu;SUN Fushou;GE Luming;SUN Minghui;YU Miao(College of Electrical Engineering,Zhejiang University,Hangzhou 310015,China;State Grid Jilin Electric Power Co.,Ltd.,Changchun 130000,China;China Electric Power Research Institute(Nanjing Branch),Nanjing 210000,China)

机构地区：[1]浙江大学电气工程学院,浙江杭州310015 [2]国网吉林省电力有限公司,吉林长春130000 [3]中国电力科学研究院(南京分院),江苏南京210000

出　　处：《电力系统保护与控制》2022年第3期41-50,共10页Power System Protection and Control

基　　金：国家重点研发计划项目(2017YFB0902002);国网吉林省电力有限公司科技项目(SGJL0000DKJS1800321);中国电力科学研究院南京分院科技项目(NYN51201900639)。

摘　　要：针对光伏并网系统孤岛保护与低电压穿越之间的运行冲突问题,提出了一种基于谐波特性的光伏孤岛与低电压穿越同步检测方法。根据系统在并网、孤岛、电压扰动三种运行状态下谐波电压的不同,用傅里叶级数定量分析了频谱泄漏对谐波检测的影响,同时在考虑主电网背景谐波对谐波检测的影响后,推导了谐波电压阈值的整定公式。在此基础上,给出了同步检测实现方案及其算法流程,并在仿真软件平台上验证。从“协鑫边昭光伏电站带边昭变孤岛试验”的数据中提取的谐波特性曲线进一步验证了所提的谐波电压阈值可以识别孤岛现象。理论分析、仿真实验以及现场实验都证明了所提的谐波电压阈值可以作为区分孤岛现象和电压暂态扰动现象的依据,所提的基于谐波特性的同步检测方法可以有效协调光伏并网系统孤岛保护和低电压穿越两种功能。In order to solve the operation conflict between islanding protection and low-voltage-ride-through of grid-connected photovoltaic system,a simultaneous detection method for photovoltaic islanding and low-voltage-ride-through based on harmonic characteristics is proposed.According to the differences of the system harmonic voltages among three operating states,i.e.grid-connected operation,islanding operation and voltage transient perturbation,the influence of spectrum leakage on harmonic detection is quantitatively analyzed by Fourier series.After the influence of the background harmonic in main grid is considered,the setting formula of the harmonic voltage threshold is derived.Based on that the simultaneous detection implementation scheme and its algorithm flow are given,which are verified on simulation software platform.The harmonic characteristic curve extracted from the data of“Islanding Operation Test of Xiexin-Bianzhao Photovoltaic Power Station Carried with Bianzhao Transformer”further verifies that the proposed harmonic voltage threshold can identify the islanding phenomenon.Both theoretical analysis and simulation experiments show that the proposed harmonic voltage threshold can be used as the basis to distinguish the islanding phenomenon from the voltage transient perturbation phenomenon.And the proposed simultaneous detection method based on harmonic characteristics can effectively coordinate the two functions of grid-connected photovoltaic system,i.e.islanding protection and low-voltage-ride-through.

关 键 词：光伏 并网 孤岛保护 低电压穿越 背景谐波 频谱泄漏 同步检测 

分 类 号：TM615[电气工程—电力系统及自动化]