基于复合控制算法的局部阴影下的MPPT

摘要

光伏阵列在局部阴影下时,输出P-U特性曲线会出现多个局部峰值点,而传统最大功率点跟踪(MPPT)算法均不能准确有效地跟踪到全局最大功率点(MPP).因此,提出一种改进的MPPT算法,即将差分进化(DE)算法与变步长扰动观察法结合,其中DE算法用于系统启动和光照情况发生突变后迅速定位近似MPP,根据实际情况变步长扰动观察法会使光伏阵列精确稳定在MPP,改进后的算法在跟踪精度和跟踪速度方面会有所提高.通过实验对新的算法进行分析,并与基础的DE算法和传统的扰动观察法进行比较.%In the case of partial shading,the P-U characteristic curve of the photovoltaic array will appear multiple local peaks.But the traditional maximum power point tracking(MPPT) algorithm failing to work.Therefore,an algorithm is proposed based on differential evolution(DE) algorithm and variable step size perturb & observer method,DE is used to quickly locate approximate maximum power point(MPP) when the MPPT system started or illumination intensity motution occurred,and variable step size perturb & observer method can make the MPP of photovoltaic array precise stable in MPP,the improved algorithm will have advantages in terms of tracking accuracy and tracking speed.The new algorithm is analyzed by experiment,and compares with basic DE algorithm and traditiona perturb & observe method.