三相并网逆变器基于a,b,c坐标系的QPCI控制策略

The QPCI Control Strategy Based ona,b,c Coordinate System in Three-phase Grid-connected Inverter

三相并网逆变器电流控制中,准比例复数积分(QPCI)控制在消除稳态误差和保障系统稳定性方面具有较好的优势。传统观念认为QPCI控制只能在静止a,0坐标系下实现,而无法在三相a,b,c坐标系下实现。为解决这一问题,在此提出一种基于三相a,b,c坐标系下的QPCI控制策略。在a,0坐标系QPCI控制结构图的基础上,推导出QPCI控制器在静止坐标系a,b,c下的数学模型,再结合三相系统特点,构建出三相a,b,c坐标系下QPCI控制结构图,减少坐标变换运算,使得控制结构简单、易于实现。对提出的新策略进行了详细理论分析和仿真研究,并建立了 LC型三相并网逆变器实验平台研究,实验结果验证了提出方法的可行性和有效性。

Quasi-proportional complex number integral (QPCI) control is one of current control solutions for the three- phase grid-connected inverter.lt has a good advantage in eliminating steady state error and ensuring system stability. Compared with the conventional QPCI control strategy that can only be implemented in a stationary a,β coordinate system,a new control strategy is proposed for QPCI control strategy to achieve in a three-phase a,b ,c coordinate system.On the basis of QPCI control structure diagram in a,β coordinate system,a mathematical model in stationary a,b ,c coordinate system of QPCI controller can be deduced,then combining it with the characteristics of three-phase system and establish the QPCI control structure diagram in a,b ,c coordinate system.lt is used to reduce the coordi nate transformation operation and make the control structure simple and easy to implement.The detailed theoretical analysis and simulation research for the proposed new strategy are carried out, and the experimental platform of LC- filter for three-phase grid-connected inverter is established. The experiment results verify the feasibility and effectiveness of the proposed method.