CN-121986434-A - Battery output blocking circuit and charge/discharge control circuit having the same

Abstract

A battery output blocking circuit for blocking battery output and a charge/discharge control circuit having the same are provided, the battery output blocking circuit including a three-terminal fuse provided on an output path between a battery and a battery output terminal, and an NTC thermistor having one end connected to the three-terminal fuse and the other end connected to a ground terminal.

Inventors

• ZHENG YUANQUAN

Assignees

• 株式会社LG新能源

Dates

Publication Date

20260505

Application Date

20240731

Priority Date

20231124

Claims (8)

1. 1. A battery output blocking circuit that blocks an output of a battery, comprising: a three-terminal fuse provided on an output path between the battery and an output terminal of the battery, and A negative temperature coefficient NTC thermistor having one end connected to the three-terminal fuse and the other end connected to a ground terminal.
2. 2. The battery output blocking circuit of claim 1, wherein, The three-terminal fuse includes: A first fuse having one end connected to a battery side; A second fuse having one end connected to the other end of the first fuse and the other end connected to the output terminal of the battery, and And a fuse resistor having one end connected between the first fuse and the second fuse.
3. 3. The battery output blocking circuit according to claim 2, wherein, One end of the NTC thermistor is connected to the fuse resistor, and the other end thereof is connected to a ground terminal.
4. 4. The battery output blocking circuit according to claim 3, wherein, The resistance value of the fuse resistor is set such that the sum of the resistance value of the fuse resistor and the resistance value of the NTC thermistor at a set output blocking temperature is not less than a fuse blowing current flowing through the first fuse or the second fuse.
5. 5. A charge-discharge control circuit comprising: a battery including a plurality of battery cells; A battery output blocking circuit connected to the battery and including a three-terminal fuse and an NTC thermistor to block an output of the battery according to temperature; A switching unit having one side connected to the battery output blocking circuit and the other side connected to an output terminal of the battery to set a charge and discharge path; a first control unit configured to measure a state of the battery, and And a second control unit configured to control the switching unit according to charge and discharge of the battery.
6. 6. The charge and discharge control circuit according to claim 5, wherein, The three-terminal fuse includes a first fuse having one end connected to a battery side, a second fuse having one end connected to the other end of the first fuse and the other end connected to the switching unit, and a fuse resistor having one end connected between the first fuse and the second fuse, and One end of the NTC thermistor is connected to the fuse resistor, and the other end thereof is connected to a ground terminal.
7. 7. The charge and discharge control circuit according to claim 6, wherein, The resistance of the NTC thermistor decreases at a temperature higher than or equal to a set output blocking temperature and a current flowing through the fusing resistor increases, and the fusing resistor is heated as the current increases to melt and cut at least one of the first fuse and the second fuse.
8. 8. The charge and discharge control circuit according to claim 7, wherein, The resistance value of the fuse resistor is set such that the sum of the resistance value of the fuse resistor and the resistance value of the NTC thermistor at a set output blocking temperature is not less than a fuse blowing current flowing through the first fuse or the second fuse.

Description

Battery output blocking circuit and charge/discharge control circuit having the same Technical Field The present disclosure relates to a battery output blocking circuit, and more particularly, to a battery output blocking circuit that blocks an output of a battery when the battery is overheated, and a charge and discharge control circuit including the same. Background Secondary batteries, i.e., batteries capable of being charged and discharged, are widely used as energy sources for mobile devices such as smart phones. In addition, the battery is used as an energy source for eco-friendly vehicles such as electric vehicles and hybrid electric vehicles proposed as a solution to air pollution caused by gasoline vehicles and diesel vehicles using fossil fuel. The types of applications using batteries are becoming very diverse, and future batteries are expected to be applied to more fields and products than now. Currently commercially available batteries include nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and lithium ion batteries. Among these batteries, lithium ion batteries are attracting attention because of their advantages of free charge and discharge, very low self-discharge rate, and high energy density, because little memory effect is generated compared to nickel-based batteries. In addition, since the lithium ion battery can be manufactured in a small size to be light-weighted, the lithium ion battery is used as a power source of a mobile device, and its use range has been expanded to a power source of an electric vehicle, thereby attracting attention as a next-generation energy storage medium. However, lithium ion batteries are more active than other batteries and therefore have the property of being somewhat less safe. These batteries are typically used in the form of a battery pack, rather than as a single battery cell. The battery pack includes at least one or more battery modules, and the battery modules may include a plurality of battery cells. In addition, a Battery Management System (BMS) is provided to manage the overall state of the battery cells, the battery modules, or the battery pack. The BMS checks the performance and state of the battery and performs battery diagnosis to ensure stable operation of the battery. Meanwhile, as the application field of the battery is further expanded, battery safety is emerging as a very important issue. For example, in the case of notebook computers, mobile phones, electric vehicles, etc., ensuring the safety of batteries is urgent because the number of users is rapidly increasing, and battery explosion may not only cause damage to products but also cause personal injury or fire. In particular, products using high-activity lithium ion batteries require a protection circuit to protect the battery or electrical equipment connected to the battery when an abnormality occurs in the battery in order to ensure safety. Such a protection circuit is a blocking circuit that blocks the output of the battery by cutting off the electrical connection between the battery and the electrical device. The blocking circuit may use, for example, a fuse connected between the output terminal of the battery and the electrical device. The fuse may blow when the battery is overheated, for example, when the battery cell is overcharged or overdischarged. For fusing the fuse, a temperature sensor sensing the temperature of the battery may be used, or a current sensor or a voltage sensor sensing overcharge or overdischarge of the battery cell may be used. However, if a component sensing the temperature of the battery (i.e., a temperature sensor) or a component sensing the overcharge or overdischarge of the battery cell (i.e., a voltage sensor or a current sensor) does not properly operate due to failure or the like, the fuse cannot be fused. Therefore, even if the battery is overheated, the connection between the battery and the electrical device cannot be cut, which may cause a problem that overheating of the electrical device cannot be prevented. Related prior art of the present disclosure includes: patent document 1 Korean registered patent No. 10-1709540 (2017, 2, 17), and Patent document 2 Japanese unexamined patent application publication JP 2003-297206A (10/17/2003). Disclosure of Invention Technical problem The present disclosure provides a battery output blocking circuit capable of fusing a fuse when a battery is overheated even in the event of a failure of a component related to temperature sensing, and a charge and discharge control circuit including the same. The present disclosure provides a battery output blocking circuit that can melt and cut a fuse at high temperature using a three-terminal fuse and a thermistor, and a charge and discharge control circuit including the battery output blocking circuit. Technical proposal According to an exemplary embodiment, a battery output blocking circuit that blocks an output of a battery includes a three