Photovoltaic cell panel PID restoration device

Abstract

The present invention provides a photovoltaic cell panel PID (Potential Induced Degradation) restoration device. When a preset condition is satisfied, isolation devices in a positive branch and a negative branch are both in a conduction state, and after an electric potential of a connection point (a virtual neutral point) of the positive branch and the negative branch is lifted by output electricenergy of a direct current power supply, electric potentials of one positive electrode and one negative electrode of each photovoltaic cell panel in a photovoltaic array are lifted by the positive branch and the negative branch, and a PID restoration function is achieved. Even though accesses among the PID restoration device of the photovoltaic cell panels and the positive electrodes and the negative electrodes of the photovoltaic array have faults, it is ensured that the other electric potential of the photovoltaic array is lifted, and compared to the prior art, the PID restoration reliability is improved; and moreover, insulation impedance detection can be performed by controlling on-off of an isolation device in the positive branch or the negative branch with no need for adding extra insulation detection circuit, so that the corresponding implementation cost is avoided.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a photovoltaic panel PID repair device. Background technique [0002] The PID effect (PotenTIal Induced Degradation), also known as potential-induced degradation, is a phenomenon in which the output characteristics of some types of photovoltaic panels are attenuated due to potential induction, which will lead to a decrease in the output power of the photovoltaic system; Perform PID repair. [0003] The existing anti-PID technology at night is an off-line anti-PID technology. Its PID repair device is generally installed on the positive pole (or negative pole) of the photovoltaic cell panel, and the photovoltaic cell panel The potential to earth is raised to positive (or negative). [0004] However, the PID repair device in the prior art is only installed on one of the positive pole or the negative pole of the photovoltaic cell panel. If there is a failure in the path w...

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Problems solved by technology

[0004] However, the PID repair device in the prior art is only installed on one of the positive pole or the negative pole of the photovoltaic cell panel. If there is a failure in the path between the corresponding pole of the photovoltaic cell panel, the PID repair function cannot be realized and the PID will be affected. repair reliability

In addition, the PID repair device in the prior art also needs an additional detection circuit when performing insulation resistance detection, resulting in increased implementation costs

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