Solar cell grounding device and method

Abstract

The invention discloses a solar cell grounding device and method. The solar cell grounding method comprises the following steps of A, utilizing a DC (direct current) power supply to detect the DC output voltage of a photovoltaic module; B, carrying out step C when the DC output voltage of the photovoltaic module is higher than a predefined threshold and carrying out step D if the DC output voltage of the photovoltaic module is lower than the predefined threshold; C, enabling the DC output cathode of the photovoltaic module to be grounded through a resistor; D, enabling the DC output cathode of the photovoltaic module to be directly grounded. According to the solar cell grounding device and method, the DC power supply is used for detecting the working state of the photovoltaic module, when the photovoltaic module does not work, the output voltage of the DC power supply cannot make a relay to operate, the DC output cathode of the photovoltaic module is directly grounded, electrostatic charges are eliminated, and attenuation of the photovoltaic module can be avoided. When the photovoltaic module works normally, the output power supply of the DC power supply enables the relay to operate, the DC output cathode of the photovoltaic is grounded through the resistor, and the normal operation of the photovoltaic can be guaranteed.

Description

technical field [0001] The invention relates to the technical field of solar cells, in particular to a solar cell grounding device and method. Background technique [0002] After photovoltaic modules are used for a period of time, the power generation will attenuate to a certain extent, because crystalline silicon modules will have a potential-induced degradation (PID) effect, and thin-film modules will cause damage to the transparent conductive oxide (TCO) layer. If no corrective measures are taken, The power generation of the modules will drop significantly, seriously affecting the revenue of the photovoltaic system. [0003] At present, the industry mainly adopts the method of grounding the negative electrode of the inverter to eliminate the static charge on the components to prevent this from happening. However, this grounding method is not applicable in some occasions due to the different topological structure principles of the inverter, and the cost is relatively high...

AI Technical Summary

Problems solved by technology

However, this grounding method is not applicable in some occasions due to the different topological structure principles of the inverter, and the cost is relatively high:

[0004] 1. Since the early photovoltaic projects did not realize that photovoltaic modules would attenuate, many inverters did not have a negative grounding device, and the cost of reinstalling a negative grounding device in the inverter was very high

Moreover, some inverters have no space in the structural layout and the circuit has a spare interface, and it is not possible to install a negative grounding device.

[0005] 2. The working voltage of the inverter is very high when it is normal. From the perspective of safety, the negative grounding method requires the inverter to be electrically isolated. At present, most of the domestic small and medium power string inverters are not electrically isolated. , can not install negative grounding device

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