一种直接扰动占空比的全局搜索光伏阵列MPPT法

On MPPT for Photovoltaic Arrays with Global Search Capabilities Based on Direct Duty Cycle Perturbation

受环境的影响,露天布置的光伏阵列容易遭到意外遮挡,此时阵列的最大功率输出会发生偏移,及时追踪最大功率输出点是保证光伏阵列能量收集效率的主要手段。使用改进全局比较MPPT方法,在Simulink中通过全局粗略扫描,再经过数据分析,在高峰值占空比附近进行精确扫描,将得出的全局最大功率点附近的占空比作为步长赋值给扰动观察法,并比较功率,以避免陷入局部最优陷阱。仿真结果表明,改进算法能够更快跟踪动态和静态环境的最大功率点,有效提升追踪效率。

Timely tracking the maximum power point is the major means to ensure the efficiency of energy collection of photovoltaic arrays arranged outdoors when they are accidentally covered and excursion of their maximum power output happens.In this paper,a MPPT method with improved global comparison capabilities was used,by means of which a global rough scan was performed in Simulink,followed by a precise scan around duty cycle of high peak power on the basis of data analysis.The duty cycle close to the global maximum power point was obtained and assigned as a step to perturbation-observation method,and the power was compared to avoid local optimum.The simulation results show that the maximum power point in both dynamic and static environments can be tracked faster with improved algorithm,effectively enhancing tracking efficiency.