摘要
光伏逆变器并网时必须具备孤岛检测功能,孤岛检测的快速性直接影响逆变器的安全运行。针对滑模频率偏移法(SMS)在负载品质因数变高时检测速度急剧减慢的问题,提出了一种将传统SMS算法所用的正弦曲线改为抛物线的改进SMS算法。抛物线在顶点处的斜率为无穷大,使得孤岛发生后公共耦合点电压的频率快速偏离电网频率,检测时长大幅度缩短。对改进算法进行了盲区分析,根据IEEE Std.2000-929标准规定的最大品质因数确定了曲线参数。仿真和实验研究表明,抛物线型改进SMS算法对电能质量的影响极小,孤岛检测速度大大提高。
The photovoltaic （PV） grid-connected inverter must have the ability of detecting islanding, whose rapidity will directly affect the safe operation of the inverter. For Slide-mode frequency shift （SMS） algorithm, the islanding detection speed reduces rapidly when the load quality factor increases. An improved SMS algorithm is put forward, in which the sine curve used by traditional SMS algorithm is replaced by parabola curve. Since the slope of the selected parabola is infinite at peak, the frequency of the voltage at the point of common coupling rapidly deviates from the grid frequency after islanding and the islanding detection time is substantially shortened. The proposed algorithm is conducted with analysis of the non-detection zone and the parameters of the curve are determined according to the maximum quality factor set by IEEE Std.2000-929. The simulation and experiment results show that the proposed parabolic SMS algorithm has little effect on power quality, and the islanding detection speed using the proposed algorithm is greatly improved.
出处
《电工技术学报》
EI
CSCD
北大核心
2013年第10期233-240,共8页
Transactions of China Electrotechnical Society
基金
高等学校博士学科点专项科研基金(20121333110007)
河北省应用基础研究计划重点基础研究项目(13964304D)资助项目
