Battery short circuit protection device and electric vehicle battery management system

Abstract

The invention discloses a battery short-circuit protection device and an electric vehicle battery management system, the battery short-circuit protection device comprises a driving circuit, a first switch tube and a short-circuit control circuit, and the short-circuit control circuit comprises an energy storage capacitor and a second switch tube; the driving circuit comprises a first signal input end and a signal output end, and the driving circuit controls the state of a level signal output by the signal output end according to the state of the level signal of the first signal input end; the positive electrode end of the energy storage capacitor and one switch pin of the second switch tube are electrically connected with the positive electrode end of the battery, the other switch pin of the second switch tube is electrically connected with the first signal input end of the driving circuit, and the control end of the second switch tube is electrically connected with the positive electrode end of the battery. The battery short-circuit protection device with the structure can adapt to the change of short-circuit current caused by the change of internal resistance of the battery, the stability, safety and flexibility of short-circuit protection are improved, and the anti-interference capability to signals is relatively high.

Description

technical field [0001] The invention relates to the technical field of battery short-circuit protection, in particular to a battery short-circuit protection device and an electric vehicle battery management system. Background technique [0002] With the continuous development of battery technology and the social advocacy of energy conservation and environmental protection, electric vehicles are increasingly favored by more and more people. For safety reasons, a short-circuit protection scheme is generally configured for the battery on an electric vehicle. However, the principle of the current battery short-circuit protection scheme is: obtain a sampling voltage through a sampling resistor, calculate the sampling current based on the sampling voltage, and compare the sampling current with the sampling current. Set the current for comparison, and then control the state of the switch tube according to the comparison result. Based on the above protection principle, due to the s...

AI Technical Summary

Problems solved by technology

Based on the above protection principle, due to the small resistance value of the sampling resistance of the short-circuit protection circuit, the generated voltage amplitude is small, and it is easy to be disturbed and cause the short-circuit protection to be triggered by mistake or fail to trigger the short-circuit protection

In addition, the threshold value of the comparator is fixed, and it cannot adapt to the short-circuit current change caused by the change of the internal resistance of the battery (when the internal resistance of the battery increases, the short-circuit current decreases, resulting in the inability to trigger the originally set short-circuit current threshold, resulting in the inability to trigger the short-circuit protection), As a result, effective short circuit protection is not possible, the flexibility is poor, and it is easy to cause damage to the battery cell and BMS

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