Photovoltaic array fault discrimination method based on real-time calculation and comparison of voltage of photovoltaic module

Abstract

The invention discloses a photovoltaic array fault discrimination method based on real-time calculation and comparison of voltage of a photovoltaic module. The method comprises the following steps: step 1, calculating actual sun irradiance G and temperature TC of a position in a photovoltaic array by using information of the photovoltaic array running at a maximum power point; step 2, calculating actual physical parameter values of the photovoltaic module under the actual solar irradiance G and the temperature TC by utilizing the physical parameter values of the photovoltaic module under the standard test condition; step 3, calculating a corresponding photovoltaic module voltage according to the string current in the photovoltaic array; and step 4, performing photovoltaic array fault detection according to the difference between the actually measured voltage value and the calculated voltage value of the photovoltaic array string; the technical problems that in the prior art, blind areas exist in protection of photovoltaic arrays and assemblies, and the sensitivity and reliability of protection cannot be guaranteed are solved.

Description

technical field [0001] The invention belongs to the technical field of photovoltaic array fault diagnosis, and in particular relates to a photovoltaic array fault discrimination method based on real-time calculation and comparison of photovoltaic module voltages. Background technique [0002] According to whether the DC bus of the photovoltaic power station is grounded, it can be divided into grounded photovoltaic system and ungrounded photovoltaic system. The DC bus negative pole of the grounded photovoltaic system is connected to the ground through a ground fault detection and interruption (GFDI) fuse device. GFDI usually uses ordinary fuses to complete the simple overcurrent protection of photovoltaic modules. For photovoltaic arrays and modules There are blind spots in the protection, and the sensitivity and reliability of the protection cannot be guaranteed. Affected by the location of the fault, when a fault occurs, the fault current flowing through the photovoltaic ar...

AI Technical Summary

Problems solved by technology

[0003] The technical problem to be solved by the present invention is to provide a photovoltaic array fault discrimination method based on real-time calculation and comparison of photovoltaic module voltages, so as to solve the problem that there are blind spots in the protection of photovoltaic arrays and modules in the prior art, and the sensitivity and reliability of the protection have to be compromised. to warranty and other technical issues

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