光伏系统MPPT的扰动观测法分析与改进

摘要

In the photovoltaic power generation process, the maximum power point of photovoltaic cell requires tracking control, which aims to improve the battery utilization and power generation efficiency. The principle of the fundamental disturbance observer method is analyzed, as well as its advantages and disadvantages. And then, an improved algorithm is proposed by adding a re-judgment of the climbing slope, which is considered to be the criterion for junction point of variable step size. Combining with the incremental conductance algorithm, the maximum power point of photovoltaic cell is tracked and controlled by using the variable step and weak oscillation method. Finally, the simulation results show the correctness of this algorithm. The results show that the improved tracking algorithm is more stable, and eliminates the oscillation and improves the accuracy. The dynamic response is better.%在光伏并网发电的过程中需要对光伏电池的最大功率点进行跟踪控制，来使得电池的利用率最高，提高发电效率。分析了MPPT的基本扰动观测法的原理，并且分析它的优缺点。在此基础之上提出了一种改进算法，添加对爬坡斜率的再判断，作为变步长交界点的判断依据，结合电导增量算法思想，运用变步长弱振荡的方法对光伏电池的最大功率点进行跟踪控制。最后通过仿真进行了验证，结果表明：该改进算法跟踪更稳定，消除了系统振荡，提高了精度，动态响应更好。