Protection circuit and control method of protection circuit

Abstract

Even when some of the plurality of batteries are removed from the current path, the protection element is properly operated in response to the output of the remaining batteries. Equipped with: a battery module (4) in which a plurality of batteries (3) are connected in parallel; a first protection element (5) provided for each battery (3) and constituting a part of a current path for charging or discharging the battery (3) and a second protection element 7 constituting a part of the charging or discharging current path of the battery module (4), the second protection element 7 has a plurality of fuse parts (20), (21), which has a heating resistor, and A fusible conductor that constitutes a part of the current path for charging or discharging and is fused due to the heat of the heating resistor or self-heating, a plurality of fuse parts (20), (21) can be individually fused by each heating resistor. conductor.

Description

technical field [0001] The present invention relates to a protection circuit and a control method of the protection circuit for preventing overcurrent or overvoltage of a battery pack by using a protection element provided with a heating resistor and a fuse element on a substrate. Background technique [0002] In recent years, HEVs (Hybrid Electric Vehicles: Hybrid Electric Vehicles) and EVs (Electric Vehicles: Electric Vehicles) using batteries and electric motors have rapidly spread. As a power source for HEVs or EVs, lithium-ion secondary batteries are used for reasons of energy density and output characteristics. In automotive applications, high voltage and high current are required. Therefore, a dedicated unit capable of withstanding high voltage and high current has been developed, but due to manufacturing cost issues, in many cases, a general-purpose unit is used to secure the necessary voltage and current by connecting multiple battery units in series or parallel. ...

AI Technical Summary

Problems solved by technology

[0003] Lithium-ion secondary batteries have excellent characteristics, but management of charge and discharge characteristics is indispensable. If abnormal battery cells are handled as usual, there is a high risk of fire and explosion.

Therefore, when there are multiple battery cells, the voltage balance among the cells becomes important, and if abnormal cells are included, other normal cells are also affected, and there is a problem that accurate charging and discharging cannot be performed.

Images