单相单级光伏并网系统的改进控制策略研究

Research on Improved Control Strategy of Single-phase Single-stage Grid-connected PV System

以极值搜索算法为基础,提出了基于二次纹波的变积分增益的最大功率点跟踪(MPPT)极值搜索控制(ESC)方法。在不同的光伏阵列工作点采用不同积分增益,提高了功率跟踪的动稳态性能。针对直流侧电压存在二次纹波的特点,通过分别控制直流侧电压中的直流分量和纹波分量,降低了并网电流幅值参考值的谐波含量,提高了并网电流质量。仿真和实验结果验证了改进控制方法的有效性。

Based on extreme search algorithm, a maximum power point tracking （MPPT） extremum search control （ ESC ） method with alterable integral gain based on the inherent ripple is proposed.By varying integral gain in diverse PV array operating point, the dynamic and steady performance of power tracking is improved.To control DC and ripple component in DC voltage respectively,the harmonic content of the reference value of the grid current amplitude is reduced and the grid current quality is improved.Simulation and experimental results confirm the effectiveness of the control method.