Direct-current electric automobile power battery protection device and work method thereof

Abstract

The invention discloses a direct-current electric automobile power battery protection device and a work method thereof. The direct-current electric automobile power battery protection device includesfour branch circuits arranged on an electric automobile power battery main closed circuit, wherein the first branch circuit is alone composed of a power electronic switch, the second branch circuit isalone composed of a direct-current fuse protector, the third branch circuit and the fourth branch circuit are each alone composed of a direct-current mechanical switch, and the first and third branchcircuits are connected in parallel and then are in series connection with the second and fourth branch circuits which are connected in parallel; a control closed circuit of the device is provided with a current detection and control module for detecting the current state of the main closed circuit and controlling all the switches to be switched on and switched off so that different switch-on andswitch-off logic can be achieved. By adopting the device, the main closed circuit load current is on and off flows through the direct-current mechanical switches, the main closed circuit rated load current and overload current is off through when the power electronic switch, and the main closed circuit short-circuit current is off through the direct-current fuse protector; the switch-on and switch-off advantages of all the switches within different fault current ranges are fully exerted, direct-current electric automobile fault current is reliably broken, and therefore the device can replace current protection strategies.

Description

technical field [0001] The invention relates to the technical field of DC switching appliances, in particular to a DC electric vehicle power battery protection device and a working method thereof. Background technique [0002] At present, low-voltage direct current is more and more widely used, such as electric vehicles, which will gradually replace traditional fuel vehicles in the future and become one of the main means of transportation. Take electric vehicles as an example. In electric vehicles, the power battery is its core component. At present, the protection of the power battery adopts the method of connecting an air switch and a fuse in series. Among them, the air switch is responsible for breaking the rated current and small overload current, while the fuse is responsible for breaking the larger overload current and short-circuit current. However, in the actual use process, it is found that the fuses on the market can often effectively break 5 The current above 5 t...

AI Technical Summary

Problems solved by technology

Therefore, the extremely large short-circuit current is likely to cause damage to the power electronic switch, which is caused by the limited ability of the power electronic device to withstand the short-circuit current.

If the electronic electronic switch is damaged, the DC electric vehicle power battery protection device described in this plan can no longer effectively switch the low-fold overload current, reducing the reliability and safety of system protection

At the same time, the price of power electronic switches is relatively high, which will bring certain economic losses

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