单周控制光伏并网系统的最大功率控制研究

Research on MPPT applied in a grid-connected photovoltaic system with one cycle control

单周控制的单级全桥光伏并网系统具有容量大、效率高、成本低等优点.但现有基于单周控制的光伏电池最大功率跟踪存在着难以搜索最大功率点、难以稳定工作在最大功率点以及搜索精度差等缺点.针对以上不足,提出了基于增量电导的光伏电池最大功率跟踪算法,该算法将光伏电池输出功率引入到单周控制的输入量中,同时优化了光伏电池输出电压的给定量.该算法在硬件上实现简单,仿真和实验结果表明该算法能够准确跟踪光伏电池最大功率点,并具有较高的精度和稳定性.

Single-stage grid-connected photovoltaic （PV） systems with one cycle control （OCC） have advantages, including large capacity, high efficiency, and low cost. However, the existing maximum power point tracking （MPPT） in combination with OCC has drawbacks, making it difficult to track the maximum power point （MPP）, lack of stability of the MPP and low accuracy of tracking MPP. To solve these problems, a novel MPPT algorithm based on the incremental conductance （INC） method was proposed. It combined the output power of the PV array with the input of the OCC controller and optimized for the output voltage preferences of the PV panels. The algorithm can be applied with simple hardware. Simulations and experimental results showed that the proposed INC based MPPT algorithm tracks MPP accurately and with high stability.