Vehicle-mounted DC converter input and output protection circuit, protection method and electric vehicle

Abstract

The invention discloses an input and output protection circuit of a vehicle-mounted DC converter, which comprises: an input and output switch arranged at the input end and / or the output end of the vehicle-mounted DC converter; a fuse and a first capacitor respectively connected with the input and output switches; a power supply battery connected; and a soft start circuit respectively connected with the first capacitor and the power supply battery, which together with the power supply battery, the fuse, the input and output switches and the first capacitor form a series circuit. By connecting the soft-start circuit, the present invention can perform current limiting protection on the entire circuit, avoid the defects of damage or life loss of components in the circuit caused by large inrush current when starting or shutting down the vehicle-mounted DC converter, and reduce the The failure rate and maintenance cost of the whole vehicle are reduced, and the reliability of the whole vehicle is improved. In addition, the present invention also provides an input and output protection method of a vehicle-mounted DC converter and an electric vehicle.

Description

technical field [0001] The invention relates to the technical field of vehicle-mounted electronic device protection, in particular to a vehicle-mounted DC converter input and output protection circuit, a protection method and an electric vehicle. Background technique [0002] At present, in the field of electric vehicles, the existing vehicle-mounted DC converter (DC / DC) access scheme structure is a contactor switch or a main switch of low-voltage electrical appliances controlled by a key at the input end and output end, and the fuse and wiring harness are connected in series. Enter the power battery and low-voltage battery. [0003] An on-board direct current converter (DC / DC) is similar to a generator on a conventional car. For traditional cars, when the engine is running, the electric energy generated by the generator is enough for all the electrical equipment on the car and to charge the battery; when the engine is turned off, the generator cannot generate electricity f...

AI Technical Summary

Problems solved by technology

[0004] The disadvantages of the existing technology are: the input and output of the vehicle-mounted DC converter (DC / DC) are controlled by a key, the contactor switch or the main switch of low-voltage electrical appliances, the fuse and the wiring harness are connected in series to the power battery and the low-voltage battery respectively.

Since the input and output ends of the vehicle-mounted DC converter (DC / DC) have filter capacitors, the contactor switch controlled by the key or the main switch of the low-voltage electrical appliance, the fuse and the wiring harness are connected in series to the power battery and the low-voltage battery respectively, without any current limitation Measures, when the driver turns the key to the ON gear or closes the main switch of the low-voltage electrical appliance (that is, the moment the input circuit and the output circuit are connected), a very large inrush current will be generated, which will cause damage to the components in the circuit, even if there is no Immediate damage, after repeated impacts will also reduce the life of components in the circuit, thereby increasing the failure rate of the vehicle, reducing the reliability of the vehicle and increasing maintenance costs

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