Due to the nonlinear volt-ampere characteristics in photovoltaic array,the algorithms are usually stepped nonlinear optimization.In this paper,a novel continuous linear optimization algorithm is proposed for MPPT of solar photovoltaic system.Firstly,a continuous detecting method for photovoltaic array operation point is proposed.Secondly,a close-loop continuous optimization principle and its system structure are analyzed.Finally,a dynamic small signal model of the close-loop continuous optimization system is established in the neighborhood of the maximum power point (MPP),and the system stability is designed.In the case of a single phase photovoltaic grid-connected inverter,the detailed system parameters and simulation re-sults are given.The results of simulation show that when significant changes of irradiation level occur,the operation point can approximate MPP exponentially.%由于光伏阵列的非线性伏安特性,其最大功率点跟踪(MPPT,maximum power point tracking)一般采用非线性步进寻优算法,本文给出一种全新的线性连续动态寻优方法.首先提出一种光伏阵列工作点位置的连续检测方法,然后分析闭环连续寻优的原理和系统结构,最后在最大功率点(MPP,maximum power point)附近建立闭环连续寻优系统的小信号线性动态数学模型,并分析和设计连续寻优系统的稳定性.以某单相光伏并网逆变器为例设计详细的系统参数,并进行仿真研究.结果表明,在光伏阵列的光照强度大幅变动后,其工作点连续地按照指数规律逼近MPP.
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