A Method for Tracking the Maximum Power Point of Photovoltaic Array Based on Interval Decrease

Abstract

The invention relates to an interval progressive decrease-based maximum power point tracking method for a photovoltaic array. The method comprises the following steps: constructing a simulation model for an n*m photovoltaic array; analyzing the model of the photovoltaic array and a simulation curve; extracting reference voltage for maximum power point tracking according to the output characteristic of the photovoltaic array under a non uniform condition; constructing an effective search region [Vbegin, Vend] within an output voltage interval of the photovoltaic array by taking Vbase_max as a center and (1-p)Voc as a radius, and interfering the output voltage of the photovoltaic array by a variable step length to realize progressive decrease of a search interval until the global maximum power point of the photovoltaic array is searched. The interval progressive decrease-based maximum power point tracking method has the beneficial effects of high control precision, high tracking speed, low power loss and the like.

Description

technical field [0001] The invention belongs to the technical field of photovoltaic arrays, and in particular relates to a method for tracking the maximum power point of photovoltaic arrays based on interval decrement. Background technique [0002] Photovoltaic array, as the energy conversion unit of photovoltaic power generation system, is one of the research hotspots in the field of photovoltaic power generation technology. The P-V output of a photovoltaic array has complex nonlinear characteristics and is affected by external environments such as temperature and light intensity. When the surface of the photovoltaic array is evenly illuminated, its P-V output presents a single-peak characteristic, and there is a global maximum power point in the P-V curve. When the surface of the photovoltaic array is not uniformly illuminated, such as the photovoltaic array is blocked by fallen leaves, dark clouds and other objects, and there are shadows on the surface of the photovoltai...

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Problems solved by technology

[0003] The traditional maximum power point tracking methods mainly include perturbation and observation method, conductance incremental method, optimal gradient method and fuzzy control method, etc., but under non-uniform illumination conditions, such methods may not be able to quickly track the overall situation of the photovoltaic array. maximum power point

In response to the above problems, researchers have proposed corresponding control methods, including two-stage maximum power point tracking methods, maximum power point tracking methods based on improved Fibonacci search, and maximum power point tracking methods based on state space. Although the global maximum power point of the photovoltaic array can be tracked, the system structure is complex, the response time is long, and the power loss is large

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