摘要
根据光伏阵列输出特性和电网电压异常时响应要求,选取抑制负序电流以保持三相并网电流平衡作为控制目标,建立含有LCL网侧滤波器的并网逆变器数学模型,计算精确的电流指令。基于正负序双电流环控制,提出电网电压不平衡时的滤波电容电流前馈有源阻尼控制,并引入电网电压前馈以抑制电压跌落瞬间的电流冲击,结合快速的正负序分量提取和精确的电网电压同步信号,保证了大功率光伏并网系统的稳定并网运行和电网故障时的低电压穿越。仿真及实验结果均验证了控制策略的有效性。
Based on output characteristics of photovoltaic（PV） array and the requirement for the response of grid-connected PV inverter under abnormal grid voltage,taking maintaining the balance among three-phase grid-connected currents by suppressing negative-sequence current as control objective,a mathematical model containing LCL filter at grid-side is established to calculate accurate current instruction.Based on positive-and negative-sequence dual closed-loop current control,an active feed-forward damping control of filter capacitor current under unbalanced grid voltage is put forward,and the grid voltage feed-forward control is led in to suppress the current impact at the moment of voltage dip;combining with fast extraction of positive-and negative-sequence components of current and accurate synchronization signal of grid voltage,the stable operation of grid-connected high-power inverter for PV generation system and its low voltage ride-through（LVRT） under fault occurred in power grid can be ensured.Both results from simulation and experiments prove that the proposed control strategy is effective.
出处
《电网技术》
EI
CSCD
北大核心
2013年第7期1799-1807,共9页
Power System Technology
基金
北京市科技新星计划(2009B01)
北京市属市管高等学校人才强教计划资助项目(PHR201008188)
北京市优秀人才培养项目(2012D005002000009)的资助
关键词
大功率光伏逆变器
不平衡控制
有源阻尼
电压前馈
低电压穿越
high-power photovoltaic inverter
unbalanced control
active damping
voltage feed-forward
low voltage ride-through
