Photovoltaic power generation system preventing potential induced degradation

Abstract

A photovoltaic power generation system preventing potential induced degradation includes a photovoltaic array, an inverter square matrix, an alternating current power distribution unit and an isolation transformer. The output end of each battery module in the photovoltaic array is connected with the input end of each inverter in the inverter square matrix; the output end of each inverter is connected with the input end of the alternating current power distribution unit; the output end of the alternating current power distribution unit is connected with the lower voltage side of the isolation transformer, and the high voltage side of isolation transformer is directly connected with a power grid; and each inverter in the inverter square matrix mainly comprises a DC / AC inversion unit, an alternating current auxiliary source, acontroller and an alternating current filtering unit. The photovoltaic power generation system also includes an anti-PID power module arranged at the output end of the alternating current power distribution unit or the low voltage side of the isolation transformer and used for lifting voltage to earth of the alternating current sides and the direct current sides of the inverters; the anti-PID power module can be installed as an independent unit module; and a function of inhibiting a PID effect of the photovoltaic grid-connected power generation system in an inverter working process in the daytime and a function of applying reverse voltage compensation recovery aiming at the PID effect when the inverters are disconnected with a network in the nighttime can be realized.

Description

technical field [0001] The invention relates to the technical field of potential-induced decay (PID) effect of photovoltaic modules, in particular to a photovoltaic power generation system for preventing potential-induced decay. Background technique [0002] The potential-induced decay (PID) effect of photovoltaic modules, the PID effect refers to the leakage current between the glass, packaging materials, aluminum frame and the battery sheet in the photovoltaic module, so that a large amount of charge accumulates on the surface of the battery sheet, resulting in battery fill factor, open circuit The reduction of voltage and short-circuit current will cause the attenuation of battery and module power, and the power generation performance and durability of photovoltaic modules with PID effect will be seriously affected. Traditional methods to solve the PID effect of photovoltaic power plants are as follows: Scheme 1, such as figure 1 As shown, ground the negative pole or pos...

AI Technical Summary

Problems solved by technology

However, the first scheme has safety risks in terms of leakage current and electric shock

The second scheme cannot suppress the PID effect when the inverter is connected to the grid

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