Grounding fault detection device and method

Abstract

The invention relates to the technical field of fault detection, and provides a grounding fault detection device and method. The device comprises a first detection module, a second detection module and a controller, one terminal of the first detection module is connected with a grounding electrode of a photovoltaic generation system, the other terminal of the first detection module is connected tothe ground, the first detection module comprises a first controllable switch and a first current detection unit connected in series, one terminal of the second detection module is connected with a non-grounding electrode of the photovoltaic generation system, the other terminal of the second detection module is connected to the ground, the second detection module comprises a second controllable switch and a second current detection unit, and the controller is used for determining whether grounding faults exist at a DC side before grid connection and at a DC side and an AC side during grid-connected operation of the photovoltaic generation system according to a first sampling current detected by the first detection module and a second sampling current detected by the second detection module and sending an alarm signal if yes. According to the grounding fault detection device, multi-point grounding faults of the photovoltaic generation system can be realized, and the operation securityof the system is guaranteed.

Description

technical field [0001] The invention belongs to the technical field of fault detection, and more specifically relates to a ground fault detection device and method. Background technique [0002] In a photovoltaic power generation system, since photovoltaic cells are affected by polarization effects and transparent conductive oxide (TCO) erosion, this effect will directly lead to a significant drop in the power generation efficiency of the panel, and even cause permanent damage to the panel. Therefore, it is necessary to form a single-point grounding system by grounding the negative pole (or positive pole) of the photovoltaic cell array to solve the above problems. [0003] In traditional technology, a fuse is often used to directly ground the negative pole of the single-point grounding system. When a direct grounding fault occurs, the fault current is much greater than the rated current of the fuse, which triggers the disconnection of the fuse to achieve the effect of ground...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a ground fault detection device and method, aiming to solve the problem that the multi-point ground fault in the photovoltaic power generation system cannot be effectively detected in the prior art, which causes the ground cable to flow a large fault current for a long time. aging of the insulation, and even cause fire problems

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