A high temperature protection strategy for truck lithium battery systems

Abstract

The present invention discloses a high temperature protection strategy for a truck lithium battery system, including a high temperature protection strategy for lithium battery charging and a high temperature protection strategy for lithium battery discharging. The present invention sets three levels of high temperature protection to protect the high temperature use of lithium batteries to the maximum extent. In the hot summer environment, high temperature protection is performed to avoid property losses caused by thermal runaway of lithium batteries. When charging, high temperature current limiting is performed (to avoid thermal runaway during driving and to ensure the safety of personnel and property to the maximum extent), so that the temperature of the battery cell does not rise and is used at a safe temperature. For discharge, because it is released to the high temperature protection fault threshold when it is stationary, the battery life attenuation or property losses caused by high temperature discharge of the battery are avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of truck lithium batteries, and in particular to a high temperature protection strategy for truck lithium battery systems. Background Art

[0002] Truck 12V / 24V lithium battery starting battery and energy storage battery, lithium battery in high temperature environment, will cause lithium battery life reduction, if not protected, severe cases may cause thermal runaway time leading to lithium battery safety incidents.

[0003] However, the same type of lithium batteries currently on the market have only the most stringent protection mechanism, that is, they will only handle high-temperature faults at the highest level. Moreover, once a lithium battery over-temperature protection failure occurs, the lithium battery system must be forced to cool down to the recovery temperature before it can be used again, causing the lithium battery life to decline and affecting long-term use. At the same time, if the lithium battery is in a high-temperature working environment for a long time, if it is charged or discharged with a large current at this time, the lithium battery life will be seriously shortened. Summary of the invention

[0004] The purpose of the present invention is to provide a high-temperature protection strategy for truck lithium battery systems, which solves the problem raised in the background technology that the same type of lithium batteries currently on the market only have the most stringent protection mechanism, that is, they are only processed when the highest level of high-temperature fault occurs. Moreover, once a lithium battery over-temperature protection fault occurs, the lithium battery system must be forced to cool down to the recovery temperature before it can be reused, causing the lithium battery life to decay and affecting long-term use. At the same time, the lithium battery is in a high-temperature working environment for a long time. If a large current is charged or discharged at this time, the technical problem will cause the lithium battery life to be severely decayed.

[0005] To achieve the above object, the present invention provides the following technical solutions: a high temperature protection strategy for a truck lithium battery system, including a lithium battery charging high temperature protection strategy and a lithium battery discharging high temperature protection strategy, wherein the lithium battery charging high temperature protection strategy comprises the following steps:

[0006] Step 1: First, monitor the working status of the lithium battery in real time. When it is detected that the lithium battery is charging, the temperature of the battery cell will continue to be detected. When the battery cell temperature is higher than the first-level protection threshold: 60°C, it will enter the high-temperature protection limited charging mode. After entering the high-temperature protection limited charging mode, when the battery cell temperature is lower than 55°C, it will exit the high-temperature protection limited charging mode;

[0007] Step 2: When the battery cell temperature is lower than the first-level protection threshold: 60°C, the charging current will be detected. When the charging current is not greater than 50A, the battery cell temperature will continue to be detected. When the battery cell temperature is higher than the second-level protection threshold of 57°C, it will enter the high-temperature protection low-current charging mode. The high-temperature protection low-current charging mode is within 2A. After entering the high-temperature protection low-current charging mode, when the battery cell temperature is lower than 53°C, the high-temperature protection low-current charging mode will be exited;

[0008] Step 3: When the battery cell temperature is lower than the first-level protection threshold: 60℃, the charging current will also be detected. When the charging current is greater than 50A, the battery cell temperature will continue to be detected. When the battery cell temperature is higher than the third-level protection threshold of 55℃, it will enter the high-temperature protection low-current charging mode. The high-temperature protection low-current charging mode is within 2A. After entering the high-temperature protection low-current charging mode, when the battery cell temperature is lower than 53℃, it will exit the high-temperature protection low-current charging mode.

[0009] As an optional solution of the technical solution of the present invention, the lithium battery discharge high temperature protection strategy solution includes the following steps:

[0010] Step 1: First, monitor the working status of the lithium battery in real time. When it is detected that the lithium battery is discharging, the temperature of the battery cell will be detected. When the battery cell temperature is detected to be higher than 60°C, it will enter the high temperature protection limit discharge mode;

[0011] Step 2: After entering the high temperature protection limited discharge mode, when the current battery cell temperature is lower than 55°C, exit the high temperature protection limited discharge mode.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] 1. The present invention provides three levels of high temperature protection to protect the lithium battery from high temperature use to the greatest extent.

[0014] 2. The present invention provides good high temperature protection in hot summer environments to avoid property losses caused by thermal runaway of lithium batteries.

[0015] 3. The present invention performs high temperature current limiting during charging (to avoid thermal runaway during driving and to ensure the safety of personnel and property to the greatest extent possible), so that the temperature of the battery cell does not rise and is used at a safe temperature.

[0016] 4. In the case of discharge, the present invention releases the battery to a high-temperature protection fault threshold when the battery is at rest, thereby avoiding battery life degradation or property loss caused by high-temperature discharge of the battery.

[0017] 5. The present invention can effectively protect the battery cell, make the battery cell work within a safe temperature range as much as possible, ensure the battery life, reduce the risk of thermal runaway of the battery cell, avoid users' safety anxiety about lithium batteries, and provide multi-level high-temperature protection to effectively and reasonably protect the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0019] Figure 1 The present invention is a flowchart of a high temperature protection strategy for a truck lithium battery system. DETAILED DESCRIPTION

[0020] See also Figure 1 The present invention provides a technical solution: a high temperature protection strategy for a truck lithium battery system, including a lithium battery charging high temperature protection strategy and a lithium battery discharging high temperature protection strategy. The lithium battery charging high temperature protection strategy includes the following steps:

[0021] Step 1: First, monitor the working status of the lithium battery in real time. When it is detected that the lithium battery is charging, the temperature of the battery cell will continue to be detected. When the battery cell temperature is higher than the first-level protection threshold: 60°C, it will enter the high-temperature protection limited charging mode. After entering the high-temperature protection limited charging mode, when the battery cell temperature is lower than 55°C, it will exit the high-temperature protection limited charging mode;

[0022] Step 2: When the battery cell temperature is lower than the first-level protection threshold: 60°C, the charging current will be detected. When the charging current is not greater than 50A, the battery cell temperature will continue to be detected. When the battery cell temperature is higher than the second-level protection threshold of 57°C, it will enter the high-temperature protection low-current charging mode. The high-temperature protection low-current charging mode is within 2A. After entering the high-temperature protection low-current charging mode, when the battery cell temperature is lower than 53°C, the high-temperature protection low-current charging mode will be exited;

[0023] Step 3: When the battery cell temperature is lower than the first-level protection threshold: 60℃, the charging current will also be detected. When the charging current is greater than 50A, the battery cell temperature will continue to be detected. When the battery cell temperature is higher than the third-level protection threshold of 55℃, it will enter the high-temperature protection low-current charging mode. The high-temperature protection low-current charging mode is within 2A. After entering the high-temperature protection low-current charging mode, when the battery cell temperature is lower than 53℃, it will exit the high-temperature protection low-current charging mode.

[0024] See also Figure 1 , the lithium battery discharge high temperature protection strategy includes the following steps:

[0025] Step 1: First, monitor the working status of the lithium battery in real time. When it is detected that the lithium battery is discharging, the temperature of the battery cell will be detected. When the battery cell temperature is detected to be higher than 60°C, it will enter the high temperature protection limit discharge mode;

[0026] Step 2: After entering the high temperature protection limited discharge mode, when the current battery cell temperature is lower than 55°C, exit the high temperature protection limited discharge mode.

[0027] When using a high-temperature protection strategy for truck lithium battery systems, three levels of high-temperature protection are set to maximize the protection of lithium batteries from high-temperature use. In hot summer environments, high-temperature protection is performed to avoid property losses caused by thermal runaway of lithium batteries. During charging, high-temperature current limiting is performed (to avoid thermal runaway during driving and to maximize the safety of personnel and property), so that the battery cell temperature does not rise and is used at a safe temperature. For discharge, because it is released to the high-temperature protection fault threshold when it is stationary, battery life attenuation or property losses caused by high-temperature discharge of the battery are avoided. The battery cell can be effectively protected, and the battery cell can be operated within a safe temperature range as much as possible to ensure battery life, reduce the risk of high-temperature thermal runaway of the battery cell, and avoid user anxiety about the safety of lithium batteries. Multi-level high-temperature protection effectively and reasonably protects the battery cell.

Claims

1. A high-temperature protection strategy for truck lithium battery systems, including a high-temperature protection strategy for lithium battery charging and a high-temperature protection strategy for lithium battery discharging, characterized by: The lithium battery charging high temperature protection strategy solution includes the following steps: Step 1: First, monitor the working status of the lithium battery in real time. When it is detected that the lithium battery is charging, the temperature of the battery cell will continue to be detected. When the battery cell temperature is higher than the first-level protection threshold: 60°C, it will enter the high-temperature protection limit charging mode. After entering the high-temperature protection limit charging mode, when the battery cell temperature is lower than 55°C, it will exit the high-temperature protection limit charging mode. Step 2: When the battery cell temperature is lower than the first-level protection threshold: 60°C, the charging current will be detected. When the charging current is not greater than 50A, the battery cell temperature will continue to be detected. When the battery cell temperature is higher than the second-level protection threshold of 57°C, it will enter the high-temperature protection low-current charging mode. The high-temperature protection low-current charging mode is within 2A. After entering the high-temperature protection low-current charging mode, when the battery cell temperature is lower than 53°C, the high-temperature protection low-current charging mode will be exited; Step 3: When the battery cell temperature is lower than the first-level protection threshold: 60℃, the charging current will be detected. When the charging current is greater than 50A, the battery cell temperature will continue to be detected. When the battery cell temperature is higher than the third-level protection threshold of 55℃, it will enter the high-temperature protection low-current charging mode. The high-temperature protection low-current charging mode is within 2A. After entering the high-temperature protection low-current charging mode, when the battery cell temperature is lower than 53℃, the high-temperature protection low-current charging mode will be exited.

2. The high temperature protection strategy for a truck lithium battery system according to claim 1, characterized in that: The lithium battery discharge high temperature protection strategy solution includes the following steps: Step 1: First, monitor the working status of the lithium battery in real time. When it is detected that the lithium battery is discharging, the temperature of the battery cell will be detected. When the battery cell temperature is detected to be higher than 60°C, it will enter the high temperature protection limit discharge mode; Step 2: After entering the high temperature protection limited discharge mode, when the current battery cell temperature is lower than 55°C, exit the high temperature protection limited discharge mode.

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