A photovoltaic power generation system and its control method

Abstract

The invention provides a photovoltaic power generation system and control method. The photovoltaic power generation system comprises photovoltaic cells and an inversion device which is electrically connected with the photovoltaic cells and is used for converting direct currents generated by the photovoltaic cells to alternating currents, and further comprises a PID circuit, an insulation resistance detection device and a control unit. On the one hand, because first insulation resistance between the positive electrode of photovoltaic cells array and the ground and second insulation resistance between the negative electrode of the photovoltaic cell array and the ground are respectively detected by the insulation resistance detection device and faults can be detected before the whole photovoltaic power generation system operates, the photovoltaic power generation system solves the problem that safety can not be determined because the negative electrode is grounded, and accordingly the insulation state of a negative-electrode cable or the insulation state of a cell panel negative-electrode end can not be determined, and the cell electrodes is grounded and the PID phenomenon is successively eliminated on the other hand.

Description

technical field [0001] The invention relates to the field of photovoltaic power generation, in particular to a photovoltaic power generation system and a control method thereof. Background technique [0002] With the depletion of fossil energy and the serious pollution of the earth's environment, renewable energy and various green energy have been paid more and more attention to and applied, and solar power has become more and more popular. As the scale and application of photovoltaic power plants continue to increase, solar cell components are used in different environments, and various factors affect the power generation of the components, resulting in attenuation of the power of the components. As one of the main causes of component power degradation, the PID phenomenon has attracted widespread attention. [0003] The PID (Potential Induced Degradation) here means "potential induced degradation" in Chinese, which is a phenomenon unique to photovoltaic panels. This phenom...

AI Technical Summary

Problems solved by technology

But simply grounding the negative pole of the photovoltaic panel will bring safety hazards: if the positive pole of the photovoltaic panel is also grounded due to a fault, it will cause a short circuit between the positive and negative poles of the photovoltaic panel, which is very likely to cause major accidents such as equipment burnout and fire.

And if the negative pole of the photovoltaic panel is grounded through a path other than the anti-PID circuit, the fuse in the anti-PID circuit will fail

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