三相光伏并网逆变器控制器设计与参数整定

Controller Design and Parameter Tuning of Three-phase Photovoltaic Grid-connected Inverter

针对三相光伏并网逆变器传统控制方法中电流稳态误差无法完全消除,以及使用LCL滤波器带来的谐振问题,提出电流双闭环控制方案,电容电流内环采用比例反馈,并网电流外环采用准比例谐振控制,不仅可减小损耗、抑制电流谐振,还可消除电流稳态误差。对基于LCL滤波器的三相光伏并网逆变控制系统进行建模和理论分析,提出了一种简易,无需反复凑试的参数设计方法。用PSIM软件搭建模型进行验证,结果表明该控制策略损耗小,谐振抑制效果好,具有消除电流稳态误差的能力,并证明了所提出的闭环参数设计方法的有效性。

Current double closed loop control scheme is proposed to solve the current error in traditional control method and resonance caused by LCL filter,which adopts capacitance current active damping method of proportional feedbacking to reduce the loss and suppress the current resonance in inner loop, and grid current proportional complex integral control to eliminate steady-state errors and avoid the interference of grid voltage for grid current in outer loop. The modeling and theoretical analysis of the three-phase PV grid-connected inverting control system based on LCL filter is presented, and a simple parameter design method is proposed. The simulation results in PSIM software show that the control strategy has the advantages of small loss, good resonance suppression, and the ability to eliminate current steady-state error, and proves the validity of the proposed closed-loop parameter design method.