Protection circuit and protection circuit control method

Abstract

The invention provides a protection circuit and protection circuit control method. The purpose of the invention is to, even when a part of a plurality of batteries is removed from a current path, properly operate a protection element according to the output of the remaining batteries. The protection circuit comprises: a battery module (4) formed by connecting a plurality of batteries (3) in parallel; a first protection element (5) provided for each of the batteries (3) and constituting part of the current path for charging or discharging the each of the batteries (3); and a second protection element (7) constituting part of the current path for charging or discharging the battery module (4). The second protection element (7) is equipped with a plurality of fuse portions (20, 21) each having a heat generating resistor and a fusible conductor constituting part of the charging or discharging current path and blown out by the heat of the heat generating resistor or self-heat generation. In the fuse portions (20, 21), the fusible conductors can be individually blown out by the respective heat generating resistors.

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) or EVs (Electric Vehicles: Electric Vehicles) that use 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.

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