摘要
分析了三相光伏逆变器的工作原理,给出了一种升压型光伏逆变系统的拓扑结构。提出了一种基于矢量变换解耦控制,重复控制与电压前馈相结合的复合控制策略。矢量变换PI控制部分用于保证系统的动态性能和稳定性;重复控制在系统稳定后加入可以抑制网侧的周期性扰动,提高系统的稳态性能获得高质量的并网电流波形;电压前馈控制能够对电网电压和直流母线电压的扰动快速动作,缩短系统的动态过程,有效减小并网过程对电网的冲击。在此基础上搭建了一台3kW的三相光伏逆变器实验样机,通过实验验证了本方案的可行性,系统具有良好的动态和稳态性能。实验得到的三相电流总畸变率均在4%以下,满足并入电网的国家标准。
The principle of three-phase photovoltaic（PV） grid-connected system is analyzed,a nd a boost type topological structure of the system is given.A kind of compositive control strategy based on vector transformation decoupling control,repetitive control and feed-forward control of utility grid voltage is proposed.PI current control can improve the dynamic quality of the system and ensure the stability of the system.Repetitive control is able to restrain the periodic disturbance of the grid.A lso it can ensure steady-state performance and reduce the total harmonic distortion of the grid-connected current.Feed-forward control of utility grid voltage can counteract the influence of utility grid and DC bus.In addition,i t can shorten the dynamic process and reduce the impact to utility power during the initial process of grid.According to the proposed control algorithms,a three-phase photovoltaic grid-connected inverter is developed.E xperimental result shows that the proposed control strategy is validated and has good dynamic and steady-state performance.A good quality output power is achieved which is compliant with the national standards.
出处
《电力系统保护与控制》
EI
CSCD
北大核心
2010年第21期44-47,共4页
Power System Protection and Control
关键词
三相光伏并网
复合控制
PI控制
重复控制
前馈控制
grid-connected system
compound control
PI control
repetitive control
feed-forward control
