摘要
孤岛检测是光伏并网发电系统必备的功能。针对三相光伏并网逆变器,分析了系统无功电流与公共点电压频率的关系,在此基础上提出一种改进的无功电流—频率正反馈孤岛检测方法,并且,分析了其参数选择与检测盲区问题。该方法通过扰动无功电流影响公共点电压频率,在电网正常时几乎不施加扰动,减小了对系统功率因数的影响;而在电网断开时,可以使频率持续向单一方向偏移,从而有效地检测出孤岛现象,相对于传统的正反馈方法具有更小的检测盲区。仿真与实验结果证明了该方法的有效性。
Islanding detection is a fundamental function for photovoltaic（PV）grid-connected inverters. In this paper the relationship between reactive current and system frequency is analyzed based on the three-phase inverter. An improved reactive current disturbance method with frequency positive feedback is proposed and the parameter selection and non-detection zone are also discussed. When the grid is connected, it doesn＆#39;t inject disturbance to the current which has less impact on power quality. When the grid is disconnected, the disturbance will drive the voltage frequency out of limit until the protection is triggered. It also has a smaller non-detection zone compared to traditional method. The validity of this method is verified by simulation and experimental results.
出处
《电源学报》
CSCD
2016年第5期54-59,67,共7页
Journal of Power Supply
基金
国家自然科学基金资助项目(51377101)
教育部新世纪优秀人才支持计划资助项目(NCET-13-0339)~~
关键词
孤岛检测
正反馈
无功电流
检测盲区
islanding detection
positive feedback
reactive current
non-detection zone
