带负载阻抗角反馈的主动频移孤岛检测技术  

Active Frequency Drift Islanding Detection Technology with Feedback of Load Impedance Angle

作　　者：唐忠廷 粟梅[1] 刘尧 韩华[1] 王辉[1] 李鑫[1] TANG Zhongting1 , SU MeiI , LIU Yao2 , HAN Hua1 , WANG Hui1 , LI Xin1(1. School of Information Science and Engineering, Central South University, Changsha 410083, China; 2. Zhuhai Power Supply Bureau of Guangdong Power Grid Co. Ltd., Zhuhai 519000, China)

机构地区：[1]中南大学信息科学与工程学院,湖南省长沙市410083 [2]广东电网有限责任公司珠海供电局,广东省珠海市519000

出　　处：《电力系统自动化》2018年第7期199-207,共9页Automation of Electric Power Systems

基　　金：国家自然科学基金资助项目(61573384);中国南方电网有限责任公司科技项目(GDKJXM20161900)~~

摘　　要：孤岛检测是分布式光伏并网发电系统稳定可靠运行的关键技术之一,而传统的主动式孤岛检测技术难以平衡检测准确性和电能质量之间的矛盾。因此,详细分析了负载特性对孤岛检测的影响,针对并/离网逆变器模型提出了一种带负载阻抗角反馈的主动频移孤岛检测技术,通过反馈实时负载阻抗角改变注入的电流频率扰动,提高了单台逆变器和多逆变器光伏并网发电系统孤岛检测的准确性,消除了检测盲区。同时,通过提出的孤岛检测方法进行分段式改进,降低了由非线性因素引起的并网电流谐波畸变率,改善了系统的电能质量。仿真和实验均验证了所提孤岛检测方法的有效性和可行性。Islanding detection is one of critical technologies for the stable and reliable operation of distributed photovoltaic grid generation system. However, the traditional active island detection method is difficult to balance the accuracy of detection and power quality. The influence of load characteristic for islanding detection is analyzed carefully, and an active frequency shift islanding detection technology is proposed based on the load impedance angle for the grid on/off inverter. The disturbance of the injected current is changed according to the load impedance angle, which improves the detection efficiency for single inverter and multi inverters, and eliminates the non-detection zones. Besides, a segmented improvement method of the proposed detection is adopted to mitigate the grid current distortion caused by the nonlinear factor in practical application, which improves the power quality of the system. Finally, simulation and experimental results both verify the effectiveness and feasibility of the proposed method.

关 键 词：主动频移 孤岛检测 负载阻抗角 多逆变器 非线性因数 

分 类 号：TM732[电气工程—电力系统及自动化]