Direct-current input end inverted connection protecting circuit, direct-current input end inverted connection protecting method and direct-current input equipment

Abstract

The invention provides a direct-current input end inverted connection protecting circuit. The direct-current input end inverted connection protecting circuit comprises a controllable disconnection accessory, a voltage detecting unit and a control unit, wherein the controllable disconnection accessory is connected between a direct-current input end and a rear-stage circuit; the voltage detecting unit is connected between a positive pole and a negative pole of the direct-current input end in parallel, and is used for detecting voltage signals between the positive pole and the negative pole of the direct-current input end and transmitting a detection result to the control unit; and the control unit is respectively connected with the voltage detecting unit and the controllable disconnection accessory, is used for judging whether the positive pole and the negative pole of the direct-current input end are in inverted connection or not according to the detection result of the voltage detecting unit, controls the controllable disconnection accessory to perform disconnection if the positive pole and the negative pole of the direct-current input end are in inverted connection, and controls the controllable disconnection accessory to perform connection if the positive pole and the negative pole of the direct-current input end are connected with each other correctly. Correspondingly, the invention provides direct-current input equipment and a direct-current input end inverted connection protecting method. Compared with the prior art, the direct-current input end inverted connection protecting circuit has the advantages that the cost can be reduced, and the power consumption of a system can also be reduced.

Description

technical field [0001] The invention relates to the technical field of anti-reverse connection protection of DC input terminals, in particular to a DC input terminal anti-reverse connection protection circuit and method, and a DC input device. Background technique [0002] In the photovoltaic grid-connected power generation system, the DC input terminal of the inverter is directly connected to the output terminal of the solar panel. When the DC input terminal of the inverter is reversed, its DC input terminal will pass through the switching tube in the inverter. A short circuit caused by a short circuit will damage the switch tube and even cause a fire. Therefore, the reverse connection protection of its DC input terminal in the inverter is required in relevant standards. [0003] In order to prevent reverse connection of the DC input terminal of the inverter, such as figure 1 As shown, in the prior art, a diode is generally provided at its DC input end to protect the inver...

AI Technical Summary

Problems solved by technology

However, the diode will continue to conduct during the normal operation of the inverter and the current will pass through it for a long time, resulting in continuous loss. From the perspective of safety, there are higher requirements for the selection and heat dissipation of the diode, and the cost is higher.

It can be seen that the above-mentioned scheme of installing a diode at the DC input end increases the cost on the one hand, and on the other hand, it will increase the power consumption of the system and reduce the efficiency of the system when the inverter is running normally.

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