What is the treatment method of short-circuit protection of a powered lithium-ion battery package?

著者：Iflowpower – Dodavatel přenosných elektráren

About parallel lithium-ion power lithium ion battery modules, when one or several batteries are short, other batteries in the battery module will discharge it, the energy of the battery pack will increase the temperature of the internal battery temperature. Extremely easy to induce heat, eventually leading to a lithium ion battery pack for fire explosion. Lithium-ion battery protection boards must not be angry, and they understand that the use of lithium-ion battery packs or single lithium-ion batteries is performed with overcharge and short circuit protection.

When you find a short and warmed in a certain battery, you can cut off the connection to the battery and other batteries in the module. Assembly TEPPTC or MHP-TA series products on a single battery, when the TE protection device can effectively block the contact of other batteries in the module, the occurrence of malignant accidents. The power lithium-ion battery pack on the number of monomer batteries is high, and the internal resistance consistency of the battery and the device is high, and the MHP-Ta is very good because of its internal bimetal structure, the consistency of the device resistance is very good.

Meet the requirements for battery internal resistance. The system composition of the power lithium-ion battery and the actual road condition are complex, and the protection of passive devices is indispensable. During use, the short-circuit protection circuit is mishaped for alert transient overload, so the short-circuit protection circuit has certain delays.

And due to the error of the current test resistance, the current test signal and the system should be delayed, usually, according to different uses, the short circuit protection time is set at 200μS to 1000μS, this requires power MOSFET to work safely within the high short circuit current, which also improves the design difficulty of the system. High security dynamic lithium ion battery pack discharge short circuit protection control system, using a large power positive temperature coefficient thermistor in the discharge overflow protection field-absorbing transistor circuit, limiting the dynamic lithium ion battery pack short-circuit discharge instant current in a certain range The load short circuit sampling test point voltage is greater than 0.7V, awakens the quick short-circuit testing and control circuitry and turn off the discharge overcurrent protection field-absorbing transistor; when the discharge load is short, once the discharge overflow protection field-absorbing transistor or rapid short-circuit testing and control circuit When failing to turn off the field effect transistor in time, the high-power temperature coefficient thermistor will also become a high-resistance blocking short circuit current in 0.

5s, and the short-circuit current is limited to the MA level, and the system will improve the system Safety reliability; fast short circuit current test and control circuit static current <2μA to protect the discharge overcurrent protection field-absorbing transistor without overtaking, thereby effectively improving the reliability of the power lithium ion battery pack discharge short circuit protection.