Photovoltaic system fault arc detection method under common-mode signal interference condition

Abstract

The invention discloses a photovoltaic system fault arc detection method under the common-mode signal interference condition. The nonzero differential signal output between adjacent photovoltaic clusters through gain calibration, the situation that input signals of a direct-current fault arc detection device are influenced by differential factors except the fault arc events is excluded, detection signals between any adjacent photovoltaic clusters of a photovoltaic system are processed through differential conversion, the fault arc detection is conducted through the direct-current fault arc detection device by means of the differential signals, fault photovoltaic modules are cut off when fault arcs happen, and the photovoltaic system unceasingly runs till the balance gain exceeds the set range. The method solves the problem that when the direct-current fault arc detection module detects the electricity quantity of a normal line, due to the influences of common-mode signals, maloperation is caused. It is avoided that the full system stops running when local fault arcs happen, and the fault arc positioning and protecting capacity of the system under the interference of the common-mode signals is improved.

Description

technical field [0001] The invention belongs to the technical field of photovoltaic electrical fault detection, and specifically relates to a method based on balance gain correction to compensate for non-zero differential signal output when no fault arc event occurs, and to eliminate photovoltaic system detection based on differential conversion processing detection signals between any two adjacent photovoltaic strings The common mode signal component contained in the signal, and the operating status of the photovoltaic system are judged based on the current set value of the balance gain, so as to realize the method that the photovoltaic system can locate and remove the faulty photovoltaic module to stably output the maximum power. Background technique [0002] Along with the requirements of global non-renewable energy intensive development and sustainable development, photovoltaic power generation systems using solar energy as primary energy have been widely promoted and put...

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Problems solved by technology

[0005] The purpose of the present invention is to solve the problem that the DC fault arc protection device is affected by the common mode signal and cause malfunction when the photovoltaic system has a fault arc, and provides a photovoltaic system fault arc detection method under the condition of common mode signal interference

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