基于直线近似和扰动观察的MPPT算法研究

针对光伏电池的最大功率点跟踪(MPPT)问题,基于光伏电池的等效电路,分别建立最大功率点电压与光伏电池温度和日照强度之间的近似直线模型,提出一种直线近似法和扰动观察法相结合的新型MPPT算法。该算法通过采集的光伏电池温度和日照强度确定近似直线模型的最大功率点电压,进而使光伏电池调整到最大功率点附近,再通过小步长的扰动观察法精确跟踪到光伏电池的最大功率点。仿真测试结果验证了该算法能准确估算最大功率点电压,并能快速、高效地跟踪到光伏电池最大功率点。

Improved MPPT algorithm based on linear approximation and perturbation and observation

Aiming at the MPPT (maximum power point tracking) problem of PV (photovoltaic) cell, the linear approximation model between MPP (maximum power point) voltage and PV cell temperature and solar irradiation is respectively established based on the equivalent circuit of PV cell. As a result, a new MPPT algorithm combining linear approximation algorithm and the P&O (perturbation and observation) algorithm is presented in this paper. For this algorithm, through determining the MPP voltage of the linear approximation model based on the sampled PV cell temperature and solar irradiation, PV cell can be adjusted to a nearby MPP. Then an accurate tracking of MPP is attained with P&O algorithm of short steps. Finally, the simulation results show that the proposed algorithm can efficiently estimate MPP voltage, and timely track MPP of PV cell with environmental changes.