Photovoltaic module grounding device, photovoltaic module grounding monitoring device and monitoring method

Abstract

The invention discloses a photovoltaic module grounding device. One end of the photovoltaic module grounding device is connected with a direct-current bus negative electrode of a photovoltaic power generation system, and the other end of the photovoltaic module grounding device is grounded. The photovoltaic module grounding device is of a series connection structure comprising a wire, a resistor, an inductor, another resistor and another inductor or a parallel connection structure comprising the resistors and the inductors. The photovoltaic module grounding device can restrain a potential induced damping (PID) effect of a photovoltaic module. The invention further discloses a photovoltaic module grounding monitoring device which comprises a ground resistor and a current detector; the current detector comprises a leakage current monitoring element, a control unit and a signal transmitting unit, wherein the leakage current monitoring element, the control unit and the signal transmitting unit are connected in sequence; after the photovoltaic module grounding device and the leakage current monitoring element are connected in series, one end of the photovoltaic module grounding device is connected with the direct-current bus negative electrode of the photovoltaic power generation system, and the other end of the photovoltaic module grounding device is grounded. The photovoltaic module grounding monitoring device can monitor a ground fault of the photovoltaic module. The invention further discloses a monitoring method based on the photovoltaic module grounding monitoring device.

Description

technical field [0001] The invention relates to a protection circuit device, in particular to a photovoltaic module grounding device, a monitoring device and a monitoring method for the grounding device. Background technique [0002] In the photovoltaic power generation system, since photovoltaic modules are usually connected to the inverter after being connected in series, the output voltage after series connection can reach up to 1000V. The frames and brackets of photovoltaic modules usually need to be grounded due to factors such as lightning protection and safety protection. In this way, in the same series of photovoltaic modules, the connection between the electrode (negative potential) of the photovoltaic module with a lower series potential and the frame of the module (ground potential) There is a negative potential difference. This negative potential, which is usually as high as hundreds of volts, will lead to the generation of leakage current between the electrodes...

AI Technical Summary

Problems solved by technology

Since the cables of desert photovoltaic power stations are usually directly buried, affected by the damage of the cable insulation, the positive and negative ground faults of the photovoltaic array occur from time to time

Once a positive ground fault occurs in a photovoltaic power station, it will be difficult to avoid the occurrence of the PID effect of photovoltaic modules, which will lead to a large number of rapid attenuation of photovoltaic modules, causing serious losses to investors in photovoltaic power stations

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