基于虚拟磁链的光伏并网逆变器同步方法  

STUDY ON GRID-CONNECTED PV INVERTER FOR GRID SYNCHRONIZATION BASED ON VIRTUAL FLUX

作　　者：匡珍春[1] 谢仕义[1] 温雯[2] 

机构地区：[1]广东海洋大学信息学院,湛江524088 [2]广东工业大学计算机学院,广州510006

出　　处：《太阳能学报》2017年第5期1176-1183,共8页Acta Energiae Solaris Sinica

基　　金：国家自然科学基金(61202269);广州市科技计划(12C42111607;201200000031);博士点基金(20134420110010)

摘　　要：在电网发生不平衡故障情况下,光伏并网逆变器会因电网负序分量导致PWM正弦调制失真,电网同步跟踪精度差等问题,为此提出一种基于虚拟磁链(virtual flux,VF)的频率自适应同步方法。该方法结合VF无需电压传感器和二阶广义积分器(second order generalizd integrator,SOGI)无需进行正负序坐标运算双重优点。虚拟磁链可准确观测光伏逆变器定向电压矢量,利用SOGI的谐振特性避免正负序分量计算延时。锁频环(frequency lockedloop,FLL)为VF提供快速准确电网正序频率。仿真和实验结果表明所提虚拟磁链观测方法能够提高自适应同步跟踪的快速性和精确性。When unbalanced fault occurs to power grid, it will distort sinusoidal PWM modulation and make grid tracking inaccurate etc. on grid-connected PV inverter. To solve these problems, an frequency-adaptive synchronization method based on Virtual Flux （VF） is proposed. It presents the virtues of VF estimation on voltage sensorlessly and Second Order Generalized Integrator （SOGI） without calculation of positive and negative sequences. VF can accurately estimate voltage oriented vector of PV inverters. SOGI can avoid delaying on computating negative sequence components. Frequency Locked Loop （FLL） can fast and accurately provide grid positive sequence frequency for VF estimation. The simulation and experiment results present the proposed method with synchronization tracking fast and accurately.

关 键 词：光伏并网逆变器 虚拟磁链 二阶广义积分器 锁频环 

分 类 号：TP29[自动化与计算机技术—检测技术与自动化装置] TM615[自动化与计算机技术—控制科学与工程]