带直流电流前馈的光伏逆变器预测控制策略

Predictive Control Strategy with DC Current Feedforward for Photovoltaic Inverters

光伏并网逆变器的控制技术一直是可再生能源发电领域的研究热点。依据单相光伏并网逆变器的特点,在单级式拓扑结构中,通过对传统的电压电流双闭环控制方式的分析,提出了一种带直流电流前馈的光伏并网逆变器电流预测控制方法。该方法首先由并网逆变器的物理模型推导出电流预测控制函数,实现对并网电流的快速控制。分析结果表明,所提方法能加快电压外环的响应速度,使系统的动态响应更加优越,提高发电效率,减少并网电流的谐波。仿真和实验结果证明了所提方法的有效性和实用性。

The control technology for photovoltaic(PV)grid-connected inverters has always been a research hotspot in the field of renewable energy generation.According to the characteristics of single-phase PV grid-connected inverters,a predictive current control method with DC current feed-forward is proposed for these inverters based on the analysis of the traditional voltage and current double closed-loop control in single-stage topologies.The predictive current control function is deduced from the physical model of a grid-connected inverter to achieve the fast control of grid-connected current.The analysis shows that the proposed method can accelerate the response speed of voltage loop,optimize the system’s dynamic response,improve the power generation efficiency,and reduce the harmonics in grid-connected current.Simulation and experimental results prove the effectiveness and practicability of the proposed method.