Global maximum power point tracking method for photovoltaic array

Abstract

The invention discloses a global maximum power point tracking method for a photovoltaic array. The global maximum power point tracking method for the photovoltaic array comprises the following steps: firstly, dispersing and arranging optical sensors in a photovoltaic array, setting the mounting position of an image collection device, conveying the image and irradiance measurement data synchronous with the image to a photovoltaic power generation system control center via a communication network, analyzing and processing a photovoltaic array operation image by the photovoltaic power generation system control center, distinguishing whether a local shadow exists, and distinguishing the distribution range of the local shadow; then, distinguishing the irradiance data of each position in the photovoltaic array by combining with the irradiance data synchronously measured by the optical sensors; and finally, obtaining the output power-voltage characteristic of the photovoltaic array under the current illumination condition by computer simulation analysis, finding voltage corresponding to the current maximum power point, resetting the reference voltage of MPPT (maximum power point tracking) if the deviation of the voltage and the practical operation voltage exceeds a threshold value, and then dynamically tracking the maximum power point with the traditional MPPT method. According to the global maximum power point tracking method for the photovoltaic array, which is disclosed by the invention, the MPPT accuracy of the photovoltaic array can be obviously improved, extra large-margin power oscillation can be prevented from being generated in the global maximum power point tracking process, and high-performance global maximum power point tracking can be realized.

Description

Technical field: [0001] The invention relates to a photovoltaic array maximum power point tracking technology in a photovoltaic power generation system, and belongs to the field of photovoltaic power generation system operation control. Background technique: [0002] Solar photovoltaic power generation technology has become the main new energy power generation method after wind power generation because of its clean and pollution-free, convenient installation, no geographical restrictions, simple operation and maintenance and many other advantages. With the gradual withdrawal of photovoltaic subsidy policies in various countries, the efficient operation of photovoltaic power generation systems has become particularly important for reducing photovoltaic power costs. [0003] The photovoltaic array in the photovoltaic power generation system is composed of a large number of photovoltaic cells in a certain series-parallel structure, which has the function of photoelectric conver...

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Problems solved by technology

[0006] Aiming at the problem that the global MPP changes dynamically with the illumination conditions during the operation of the photovoltaic array, the invention uses image processing technology and computer simulation analysis to obtain the real-time operating illumination data of the photovoltaic array, and quickly obtains the output P-U of the photovoltaic array through computer simulation The characteristic curve and the corresponding global MPP voltage value are used to design the MPPT algorithm

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