摘要
为解决光伏并网发电系统低电压穿越控制存在的直流侧母线过电压问题,提升并网系统故障恢复能力,文中提出一种经济有效的基于柔性工作点追踪的低电压穿越控制策略。首先,通过图形近似法快速估算出减载点工作电压,推导出故障期间光伏参考工作点位置,并提出光伏输出功率快速减载策略;其次,利用拟合出的光伏电流-电压曲线估算光伏短路电流,通过Lambert-W函数计算出最大功率点电压,进一步提出故障快速恢复策略;最后,文中分别通过Matlab仿真和硬件在环测试平台进行仿真和实验分析。分析结果验证了所提控制策略有较好的故障穿越能力和故障恢复效果,有助于光伏并网发电技术的推广应用。
To solve the direct current(DC)bus overvoltage problem existing in low voltage ride through(LVRT)control of the photovoltaic(PV)grid-connected systems and improve the fault recovery capacity of the grid-connected system,a cost-effective LVRT control strategy based on flexible power point tracking(FPPT)is proposed in this paper.To begin with,the graphical approximation method is used to quickly estimate the operating voltage of the power curtailment point,and the position of the PV reference operating point during the fault process is deduced,based on which the rapid active power curtailment control strategy is proposed.Subsequently,the voltage against current curve of PV is fitted to estimate the PV short-circuit current and the voltage of the maximum power point is calculated by using the Lambert-W function,based on which the fast recovery control for faults is proposed.Finally,simulations and experiments are analyzed by Matlab and hardware-in-the-loop testing platform,respectively.The results prove that the proposed control strategy has good fault ride-through capability and fault recovery effect,which contributes to promote the application of grid-connected PV power generation technology.
作者
王琦
徐俊杰
李星硕
李利秋
成硕
WANG Qi;XU Junjie;LI Xingshuo;LI Liqiu;CHENG Shuo(School of Electrical and Automation Engineering,Nanjing Normal University,Nanjing 210023,China)
出处
《电力工程技术》
北大核心
2022年第3期55-63,共9页
Electric Power Engineering Technology
基金
国家自然科学基金资助项目(51807096)。
关键词
光伏并网发电系统
柔性工作点追踪
正负序分离
光伏逆变器
低电压穿越
硬件在环
grid-connected photovoltaic system
flexible power point tracking
separation of positive and negative sequence components
photovoltaic inverter
low voltage ride through
hardware in the loop
