Assembly shutoff device, anti-backflow method thereof and photovoltaic system

Abstract

The invention discloses an assembly shutoff device, an anti-backflow method thereof and a photovoltaic system. A control module of the assembly shutoff device is used for acquiring a detection voltagebetween a second connecting end and a third connecting end in real time when the assembly shutoff device is shutoff; the detection voltage represents the voltage states of two ends of a source electrode and a drain electrode of a first switch tube; when the detection voltage exceeds a first threshold voltage, it is considered that backflow current passes through a body diode of the first switch tube and reversely passes through the first switch tube; at the moment, the control module outputs a driving signal through a first connecting end to control the first switch tube to be switched on, sothat backflow current reversely passes through the conducted first switch tube, and the risk that the first switch tube is burnt by the backflow current is avoided.

Description

Technical field [0001] This application relates to the technical field of automatic control, and more specifically, to a component shut-off device and its anti-overflow method, and a photovoltaic system. Background technique [0002] As an important part of clean energy, photovoltaic power generation has been developing rapidly in recent years. Usually, refer to figure 1 , The photovoltaic system is composed of multiple photovoltaic modules connected in series to form a string, each photovoltaic module outputs a DC voltage, and the DC voltage output by all the photovoltaic modules in the string is superimposed and then connected to the inverter. The inverter realizes the DC voltage to the AC voltage Conversion to achieve grid connection. [0003] In the photovoltaic system, the DC high voltage in the string may cause personal hazards and fire accidents. The on-site photovoltaic system requires the inverter to have arc protection, that is, the inverter must be shut down immediatel...

AI Technical Summary

Problems solved by technology

However, in the actual application process, it is found that when the module disconnector is in the off state, if the voltage of a certain string of photovoltaic modules is lower than that of other strings connected in parallel for some reason, there may be a backflow current in the form of backflow When it flows into the component, at this time, because the component switch is in the off state, the switch tube of the component switch is also in the off state, at this time, the backflow current can easily burn the switch tube, resulting in damage to the component switch

At the same time, during the injection current test of the photovoltaic module, the switch tube of the module shut-off device will also be burned by the reverse flow current.

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