Battery charging and discharging protection method, device and electronic device based on voltage and temperature

Abstract

The present invention provides a battery charge and discharge protection method, device and electronic equipment based on voltage and temperature, and the technical field of battery protection, including: based on the upper and lower limits of the operating voltage of the battery cells in the battery pack, the voltage acquisition deviation value of the battery management system, and the voltage change value during the cut-off relay, respectively determining the undervoltage threshold of the battery cells during the discharge process and the overvoltage threshold of the battery cells during the charging process; according to the upper and lower limits of the operating temperature of the battery cells, the temperature acquisition deviation value of the battery management system, the deviation value of the temperature sensor, and the temperature change value during the cut-off relay, determining the temperature threshold range of the battery cells during the charge and discharge process; based on the undervoltage threshold, overvoltage threshold and temperature threshold range, protecting the battery cells during the charge and discharge process; combining actual influencing factors, accurately determining the voltage threshold and temperature threshold, thereby alleviating the problem of low reliability of current battery charge and discharge safety evaluation.

Description

Technical Field

[0001] The present invention relates to the technical field of battery protection, and in particular to a battery charging and discharging protection method, device and electronic equipment based on voltage and temperature. Background Art

[0002] With the development of electric vehicle technology, people are paying more and more attention to the application safety of vehicle battery packs.

[0003] Currently, the safety of battery packs during the charging and discharging process is generally verified by pre-setting fixed thresholds for the corresponding battery pack parameters. However, the setting of these fixed thresholds has no logical basis and cannot be used as an indicator to determine whether the battery pack is safe during the charging and discharging process. In other words, the safety and reliability of today's battery packs during the charging and discharging process are not high. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a battery charging and discharging protection method, device and electronic equipment based on voltage and temperature, combining actual influencing factors to accurately determine the voltage threshold and temperature threshold, thereby alleviating the problem of low reliability of current battery charging and discharging safety evaluation.

[0005] In a first aspect, an embodiment provides a battery charge and discharge protection method based on voltage and temperature, the method comprising:

[0006] Based on the upper and lower limits of the operating voltage of the battery cells in the battery pack, the voltage acquisition deviation value of the battery management system, and the voltage change value during the disconnection of the relay, the undervoltage threshold of the battery cells during the discharge process and the overvoltage threshold of the battery cells during the charging process are determined respectively;

[0007] Determine the temperature threshold range of the battery cell during the charging and discharging process based on the upper and lower limits of the battery cell's operating temperature, the temperature acquisition deviation value of the battery management system, the deviation value of the temperature sensor, and the temperature change value during the disconnection of the relay;

[0008] Based on the undervoltage threshold, the overvoltage threshold and the temperature threshold range, the battery cell is protected during the charging and discharging process.

[0009] In an optional embodiment, based on the upper and lower limits of the operating voltage of the battery cells in the battery pack, the voltage acquisition deviation value of the battery management system, and the voltage change value during the disconnection of the relay, the steps of determining the undervoltage threshold value of the battery cells during the discharge process and the overvoltage threshold value during the charging process respectively include:

[0010] Determine a first overvoltage threshold of the battery cell during charging based on the upper limit of the operating voltage of the battery cell in the battery pack, the collection deviation value of the battery management system, and the difference between the voltage rise value during the disconnection of the relay;

[0011] The first undervoltage threshold of the battery cell during discharge is determined based on the lower limit of the operating voltage of the battery cell in the battery pack, the collection deviation value of the battery management system, and the sum of the voltage drop value during the relay cut-off process.

[0012] In an optional embodiment, the step of determining the undervoltage threshold of the battery cell during discharge and the overvoltage threshold of the battery cell during charging based on the upper and lower limits of the operating voltage of the battery cell in the battery pack, the voltage acquisition deviation value of the battery management system, and the voltage change value during the disconnection of the relay further includes:

[0013] determining a second overvoltage threshold of the battery cell during charging based on a difference between the first overvoltage threshold and a voltage rise value during a process in which the battery management system requests to cut off the relay;

[0014] A second undervoltage threshold of the battery cell during discharge is determined based on the sum of the first undervoltage threshold and a voltage drop value during a process in which the battery management system requests to cut off the relay.

[0015] In an optional embodiment, the step of determining the temperature threshold range of the battery cell during the charging and discharging process according to the upper and lower limits of the operating temperature of the battery cell, the temperature acquisition deviation value of the battery management system, the deviation value of the temperature sensor, and the temperature change value during the disconnection of the relay includes:

[0016] Determining a first over-temperature threshold of the battery cell during the charging and discharging process according to the upper temperature limit of the battery cell, the temperature acquisition deviation value of the battery management system, the deviation value of the temperature sensor, and the difference between the temperature rise value during the disconnection of the relay;

[0017] Determining a second over-temperature threshold of the battery cell during the discharge process according to the sum of a lower limit of the operating temperature of the battery cell during the discharge process, a temperature acquisition deviation value of a battery management system, and a deviation value of a temperature sensor;

[0018] A third overtemperature threshold of the battery cell during the charging process is determined according to the sum of the lower limit of the operating temperature of the battery cell during the charging process, the temperature acquisition deviation value of the battery management system, and the deviation value of the temperature sensor.

[0019] In an optional embodiment, the step of determining the temperature threshold range of the battery cell during the charging and discharging process based on the upper and lower limits of the operating temperature of the battery cell, the temperature acquisition deviation value of the battery management system, the deviation value of the temperature sensor, and the temperature change value during the disconnection of the relay further includes:

[0020] A fourth over-temperature threshold of the battery cell during the charging and discharging process is determined according to a difference between the first over-temperature threshold and a temperature rise value during the process of cutting off the relay.

[0021] In an optional embodiment, the step of protecting the battery cell during the charging and discharging process based on the undervoltage threshold, the overvoltage threshold, and the temperature threshold range includes:

[0022] If the voltage of the battery cell during charging reaches the first overvoltage threshold, cutting off the relay;

[0023] If the voltage of the battery cell during discharge reaches the first undervoltage threshold, disconnecting the relay;

[0024] If the voltage of the battery cell during charging reaches the second overvoltage threshold, a request signal is sent to a control unit for cutting off the relay;

[0025] If the voltage of the battery cell during discharge reaches the second undervoltage threshold, a request signal is sent to a control unit for cutting off the relay.

[0026] In an optional embodiment, the step of protecting the battery cell during the charging and discharging process based on the undervoltage threshold, the overvoltage threshold, and the temperature threshold range includes:

[0027] If the temperature of the battery cell during the charging and discharging process reaches the first over-temperature threshold, cutting off the relay;

[0028] If the temperature of the battery cell during discharge reaches the second over-temperature threshold, the relay is disconnected and charging and discharging is stopped;

[0029] If the temperature of the battery cell during charging reaches the third over-temperature threshold, stopping charging;

[0030] If the temperature of the battery cell during the charging and discharging process reaches the fourth over-temperature threshold, a request signal is sent to a control unit for cutting off the relay.

[0031] In a second aspect, an embodiment provides a battery charge and discharge protection device based on voltage and temperature, the device comprising:

[0032] A first determination module determines, based on the upper and lower limits of the operating voltage of the battery cells in the battery pack, the voltage acquisition deviation value of the battery management system, and the voltage change value during the disconnection of the relay, the undervoltage threshold value of the battery cells during the discharge process and the overvoltage threshold value during the charging process;

[0033] A second determination module determines a temperature threshold range of the battery cell during the charging and discharging process according to the upper and lower limits of the operating temperature of the battery cell, the temperature acquisition deviation value of the battery management system, the deviation value of the temperature sensor, and the temperature change value during the disconnection of the relay;

[0034] The protection module protects the battery cell during the charging and discharging process based on the undervoltage threshold, the overvoltage threshold and the temperature threshold range.

[0035] In a third aspect, an embodiment provides an electronic device comprising a memory and a processor, wherein the memory stores a computer program that can be run on the processor, and when the processor executes the computer program, the steps of the method described in any of the aforementioned embodiments are implemented.

[0036] In a fourth aspect, an embodiment provides a machine-readable storage medium, wherein the machine-readable storage medium stores machine-executable instructions. When the machine-executable instructions are called and executed by a processor, the machine-executable instructions prompt the processor to implement the steps of the method described in any one of the aforementioned implementation methods.

[0037] An embodiment of the present invention provides a battery charging and discharging protection method, device and electronic device based on voltage and temperature, which improves the reliability of battery evaluation by accurately determining the voltage threshold and temperature threshold. Specifically, the undervoltage threshold of the battery cell during discharge and the overvoltage threshold of the battery cell during charging can be determined based on the upper and lower limits of the battery cell's operating voltage, the voltage acquisition deviation value of the battery management system, and the voltage change value during the cut-off relay process; the temperature threshold range of the battery cell during charging and discharging is determined based on the upper and lower limits of the battery cell's operating temperature, the temperature acquisition deviation value of the battery management system, the deviation value of the temperature sensor, and the temperature change value during the cut-off relay process.

[0038] Other features and advantages of the present disclosure will be set forth in the following description, or some features and advantages may be inferred or unambiguously determined from the description, or may be learned by practicing the above-mentioned technology of the present disclosure.

[0039] In order to make the above-mentioned objectives, features and advantages of the present disclosure more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0041] Figure 1 A flow chart of a battery charge and discharge protection method based on voltage and temperature provided in an embodiment of the present invention;

[0042] Figure 2 A schematic diagram of a voltage protection control method provided by an embodiment of the present invention;

[0043] Figure 3 A schematic diagram of a voltage sampling circuit provided by an embodiment of the present invention;

[0044] Figure 4 A schematic diagram of a time for directly cutting off a relay provided by an embodiment of the present invention;

[0045] Figure 5 A schematic diagram of a time for requesting to disconnect a relay provided by an embodiment of the present invention;

[0046] Figure 6 A schematic diagram of a temperature sampling circuit provided by an embodiment of the present invention;

[0047] Figure 7 A functional module diagram of a battery charge and discharge protection device based on voltage and temperature provided by an embodiment of the present invention;

[0048] Figure 8 A schematic diagram of the hardware architecture of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0049] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0050] The current safety protection scheme for battery packs during the charging and discharging process is generally based on a preset parameter threshold to compare the actual collected value of the corresponding parameter during the battery pack charging and discharging process. If the actual collected value of the parameter reaches the parameter threshold, the control executes the corresponding battery pack protection measure. However, the parameter threshold used to verify battery safety is often pre-set by staff based on experience or according to the factory threshold. It is not adaptable to actual battery application scenarios and does not have a logical basis to ensure its verification reliability. Therefore, the reliability of the current battery pack charging and discharging safety protection scheme implemented based on the above method is not high, which in turn affects the user's driving safety.

[0051] Based on this, the embodiments of the present invention provide a voltage- and temperature-based battery charge and discharge protection method, device, and electronic device, which accurately determine the voltage threshold and temperature threshold based on actual influencing factors, thereby alleviating the problem of low reliability of current battery charge and discharge safety evaluation.

[0052] To facilitate understanding of this embodiment, a battery charge and discharge protection method based on voltage and temperature disclosed in an embodiment of the present invention is first introduced in detail. This method can be applied to vehicle-mounted control devices such as battery management systems (BMS).

[0053] Figure 1 A flow chart of a battery charge and discharge protection method based on voltage and temperature provided by an embodiment of the present invention.

[0054] like Figure 1 As shown, the method includes the following steps:

[0055] Step S102 , based on the upper and lower limits of the operating voltage of the battery cells in the battery pack, the voltage acquisition deviation value of the battery management system, and the voltage change value during the disconnection of the relay, respectively determine the undervoltage threshold of the battery cells during the discharge process and the overvoltage threshold during the charging process.

[0056] Among them, the maximum and minimum values ​​of the battery cell's allowable operating voltage can be known when it leaves the factory, which are the upper and lower limits of the cell's operating voltage; the voltage acquisition deviation value of the battery management system (BMS) can be estimated in advance based on its accuracy or calculated based on its multiple acquisition results; the voltage change value during the process of cutting off the relay refers to the fact that there is a certain delay in the process of cutting off the relay, and the voltage has a certain change value during this delay.

[0057] Step S104 , determining the temperature threshold range of the battery cell during the charging and discharging process according to the upper and lower limits of the battery cell's operating temperature, the temperature acquisition deviation value of the battery management system, the deviation value of the temperature sensor, and the temperature change value during the cut-off relay process.

[0058] It is understandable that, as explained above, battery cells are not only specified for voltage limits but also for other relevant parameters such as temperature limits. Exceeding these limits can affect the safety of the battery cells. The BMS can also determine a temperature deviation based on the temperature data collected. In addition to temperature detection by the BMS, temperature sensors can also be used to collect temperature data and preset or determine the deviation. Furthermore, the delay in relay disconnection involves temperature changes in addition to voltage changes.

[0059] Step S106 , protecting the battery cell during the charging and discharging process based on the undervoltage threshold, overvoltage threshold and temperature threshold range.

[0060] It can be understood that the voltage threshold and temperature threshold determined based on the aforementioned steps can provide more effective and accurate protection for the battery cell charging and discharging process.

[0061] In a preferred embodiment of actual application, the reliability of battery evaluation is improved by accurately determining the voltage threshold and temperature threshold; the undervoltage threshold of the battery cell during discharge and the overvoltage threshold of the battery cell during charging can be determined based on the upper and lower limits of the battery cell's operating voltage, the voltage acquisition deviation value of the battery management system, and the voltage change value during the cut-off relay process; the temperature threshold range of the battery cell during charging and discharging is determined based on the upper and lower limits of the battery cell's operating temperature, the temperature acquisition deviation value of the battery management system, the deviation value of the temperature sensor, and the temperature change value during the cut-off relay process.

[0062] In some embodiments, the inventors have found that the voltage during the charging and discharging process has a significant impact on battery safety. Therefore, the reliability of battery evaluation can be achieved by determining relatively accurate overvoltage thresholds and undervoltage thresholds. For example, step S102 may include:

[0063] Step 1.1) Determine the first overvoltage threshold of the battery cell during charging based on the upper limit of the operating voltage of the battery cell in the battery pack, the collection deviation value of the battery management system, and the difference between the voltage rise value during the relay cut-off process.

[0064] The first overvoltage threshold V1 = the maximum operating voltage of the battery cell - the BMS acquisition deviation value - the voltage rise value during the BMS cut-off relay process; for example, if the upper limit of the battery cell operating voltage is 4.2V, the BMS acquisition deviation value is 0.005V, and the cut-off relay time is 921ms, then the first overvoltage threshold V1 = 4.2V-0.005V-BMS cut-off relay time (921ms)*maximum voltage rise slope.

[0065] Step 1.2) Determine the first undervoltage threshold of the battery cell during discharge based on the lower limit of the operating voltage of the battery cell in the battery pack, the collection deviation value of the battery management system, and the sum of the voltage drop value during the relay cut-off process.

[0066] The first undervoltage threshold V2 = the minimum operating voltage of the battery cell + the BMS acquisition deviation value + the voltage drop value during the BMS cut-off relay process; for example, if the lower limit of the battery cell operating voltage is 2.5V, the BMS acquisition deviation value is 0.005V, and the cut-off relay time is 921ms, then the first undervoltage threshold V2 = 2.5V + 0.005V + BMS cut-off relay time (921ms) * maximum voltage drop slope.

[0067] It is understandable that the voltage change value during the relay cut-off process can be calculated based on the maximum rising or falling slope of the voltage during the cut-off time.

[0068] It should be noted that the maximum BMS acquisition deviation can be ±5mv, and the maximum sampling chip deviation can be ±3.9mv. The BMS sampling deviation is the sampling circuit deviation 0.508mv + chip sampling deviation 3.9mv = 4.408mv, which is recorded as 5mv.

[0069] Among them, the sampling circuit deviation can be determined by the following calculation, such as Figure 3 As shown:

[0070] V1=I1*Rn=1nA*100mΩ=10 -7 mV (negligible);

[0071] V2=I2*(Rn+R1)=1nA*(100mΩ+3KΩ)=0.003mV;

[0072] V3=I3*(Rn+R1+R2)=1nA*(100mΩ+3KΩ+2KΩ)=0.005mV;

[0073] V4=I4*(Rn+R1+R2)=100nA*(100mΩ+3KΩ+2KΩ)=0.5mV;

[0074] Therefore, the dark current of the filter circuit and the sampling terminal affects the voltage deviation by a total of 0.508mV.

[0075] In some embodiments, in order to protect the safety of the battery cells and driving safety, protection values ​​are set from the perspectives of battery cell overvoltage and undervoltage respectively. In addition to the undervoltage threshold and overvoltage threshold determined in the aforementioned steps for directly cutting off the relay, voltage thresholds corresponding to other working conditions are also included, which also have a significant impact on battery charging and discharging. For example, step S102 in the above embodiment may further include:

[0076] Step 2.1) Determine a second overvoltage threshold of the battery cell during charging based on the difference between the first overvoltage threshold and the voltage rise value during the process when the battery management system requests to cut off the relay.

[0077] The second overvoltage threshold V3 = the first overvoltage threshold V1 - the voltage rise value during the BMS request to VCU to cut off the relay = the first overvoltage threshold V1 - the time when BMS requests to cut off the relay * the maximum voltage rise slope.

[0078] Step 2.2) Determine a second undervoltage threshold of the battery cell during discharge based on the sum of the first undervoltage threshold and the voltage drop value during the process when the battery management system requests to cut off the relay.

[0079] The second undervoltage threshold V4 = the first undervoltage threshold V2 + the voltage drop value during the BMS requesting the VCU to cut off the relay = the first undervoltage threshold V2 + the time when the BMS requests to cut off the relay * the maximum voltage drop slope.

[0080] In some embodiments, based on the undervoltage threshold and overvoltage threshold determined in the aforementioned steps, a more accurate protection strategy can be implemented for the battery cell. As an example, step S106 includes:

[0081] Step 3.1): If the voltage of the battery cell during charging reaches the first overvoltage threshold, the relay is disconnected.

[0082] Step 3.2): If the voltage of the battery cell during discharge reaches the first undervoltage threshold, the relay is disconnected.

[0083] If the voltage reaches a first overvoltage threshold or a first undervoltage threshold during the charge and discharge process, the relay is directly controlled to be cut off.

[0084] As an alternative example, Figure 4 As shown, the time required for the BMS to directly cut off the relay is 481ms; the maximum time for the BMS to judge overvoltage is 200ms*4 times. On this basis, considering the 10% cycle deviation, it is 880ms. The execution time of the BMS strategy layer instruction sent to the underlying software is 10ms, and considering the 10% cycle deviation, it is 11ms; the relay cut-off time is 30ms, so the maximum time for the BMS to directly cut off the relay is 880ms+11ms+30ms=921ms.

[0085] Step 3.3): If the voltage of the battery cell during charging reaches the second overvoltage threshold, a request signal is sent to a control unit for cutting off the relay.

[0086] Step 3.4): If the voltage of the battery cell during discharge reaches the second undervoltage threshold, a request signal is sent to a control unit for cutting off the relay.

[0087] Among them, if the voltage reaches the second overvoltage threshold or the second undervoltage threshold during the charging and discharging process, the control unit VCU is requested to cut off the relay. At this time, the relay will not be cut off immediately, but will be cut off after a delay.

[0088] As an optional example, BMS requests VCU to cut off the relay time as follows Figure 5As shown, the maximum time for BMS to judge overvoltage is 200ms*4 times. On this basis, considering the 10% cycle deviation, it is 880ms. The time for BMS to send the fault to VCU is 100ms, considering the 10% deviation, it is 110ms. The time for VCU to process and make the vehicle reach a safe state is 110s. The time for VCU to send the power-off command to BMU is 100ms, considering the 10% deviation, it is 110ms. The time for BMS strategy layer command to be sent to the underlying software for execution is 10ms, considering the 10% cycle deviation, it is 11ms. The relay cut-off time is 30ms, so the maximum time for BMS to request VCU to cut off the relay is 111.141s.

[0089] Figure 2 A schematic diagram of a voltage protection control method provided by an embodiment of the present invention.

[0090] Reference Figure 2 As shown, it can be known that the upper and lower limits of the battery cell are 2.5V and 4.2V respectively. During the battery discharge process, if the battery cell voltage reaches or is lower than the first undervoltage threshold, the relay is directly cut off; if the battery cell voltage reaches or is lower than the second undervoltage threshold, it is requested to cut off the relay; it can be understood that although it is lower than the second undervoltage threshold at this time, it has not yet reached the first undervoltage threshold; during the battery charging process, if the battery cell voltage reaches or is higher than the first overvoltage threshold, the relay is directly cut off; if the battery cell voltage reaches or is higher than the second overvoltage threshold, it is requested to cut off the relay; it can be understood that although it is higher than the second overvoltage threshold at this time, it has not yet reached the first overvoltage threshold.

[0091] In some embodiments, in order to protect the safety of battery cells and driving safety, more accurate protection values ​​are set from the perspectives of battery cell overtemperature and undertemperature, and the safety and reliability of the battery charging and discharging process are further considered from the temperature aspect. For example, step S104 includes:

[0092] Step 4.1) Determine the first overtemperature threshold of the battery cell during the charging and discharging process based on the upper temperature limit of the battery cell, the temperature acquisition deviation value of the battery management system, the deviation value of the temperature sensor and the difference between the temperature rise value during the cut-off relay process.

[0093] Among them, the first overtemperature threshold T1 = the maximum operating temperature of the battery cell - BMS sampling deviation - temperature difference caused by the temperature sensor position - temperature rise during the relay cut-off process.

[0094] It should be noted that the BMS acquisition deviation can be ±1°C. Figure 6 As shown in the figure, by considering the maximum deviation of the voltage divider resistor and the NTC, it is finally concluded that the maximum value of the cell sampling deviation of ±0.9°C (-40~85°C) is approximately equal to ±1°C.

[0095] Furthermore, the temperature sensor's deviation is determined based on the sensor's location within the battery cell. For example, at 40°C, a 30-minute simulated 61.2kW discharge is performed on the vehicle. During this period, the thermal management system is activated for cooling, and the water temperature is 40°C. The deviation between the maximum temperature rise detected at the temperature sensor's location and the actual maximum temperature rise at the battery cell location is measured. Furthermore, at -25°C, thermal management heating is performed, and when the actual minimum temperature reaches -20°C, the deviation between the minimum temperature rise detected at the temperature sensor's location and the actual minimum temperature is measured. The temperature sensor's deviation can be 0.374°C / min.

[0096] Step 4.2) Determine a second over-temperature threshold of the battery cell during the discharge process based on the lower limit of the operating temperature of the battery cell during the discharge process, the temperature acquisition deviation value of the battery management system, and the deviation value of the temperature sensor.

[0097] The second over-temperature threshold T2 = the minimum temperature allowed for cell discharge + BMS acquisition error + temperature difference caused by the temperature sensor position.

[0098] Step 4.3) Determine a third overtemperature threshold of the battery cell during charging based on the lower limit of the operating temperature of the battery cell during charging, the temperature acquisition deviation value of the battery management system, and the sum of the deviation values ​​of the temperature sensor.

[0099] The third over-temperature threshold T3 is calculated as follows: the minimum temperature allowed for charging the battery cell + the BMS acquisition error + the temperature difference caused by the temperature sensor position.

[0100] Based on the steps of the aforementioned embodiment, in addition to the over-temperature threshold determined above, an over-temperature threshold for a warning state is also included, which can provide more comprehensive safety protection for the battery cell. For example, step S104 further includes:

[0101] Step 5.1) Determine a fourth over-temperature threshold of the battery cell during the charge and discharge process based on the difference between the first over-temperature threshold and the temperature rise value during the relay cut-off process.

[0102] The fourth over-temperature threshold T4 = the first over-temperature threshold T1 - the temperature rise during the relay cut-off process.

[0103] In some embodiments, according to the temperature threshold range determined in the above embodiments, a corresponding control strategy can be adopted for the battery cell to achieve a protective effect; illustratively, step S106 includes:

[0104] Step 6.1): If the temperature of the battery cell during the charge and discharge process reaches the first over-temperature threshold, the relay is cut off.

[0105] Step 6.2): ​​If the temperature of the battery cell during discharge reaches the second over-temperature threshold, the relay is cut off and charging and discharging is stopped.

[0106] It should be noted that in order to protect the safety and life of the battery cells, if the temperature of the battery cells reaches the corresponding threshold during the charging and discharging process, the BMS will directly cut off the relay.

[0107] Step 6.3): If the temperature of the battery cell during charging reaches the third over-temperature threshold, charging is stopped.

[0108] It is understandable that the battery cell is not allowed to be charged at this time, but the relay is not cut off.

[0109] Step 6.4): If the temperature of the battery cell during the charge and discharge process reaches the fourth over-temperature threshold, a request signal is sent to a control unit for cutting off the relay.

[0110] Considering the user's driving safety, before the BMS directly cuts off the relay, if the temperature of the battery cell reaches the fourth over-temperature threshold during the charging and discharging process, the VCU is requested to cut off the relay to provide time for the entire vehicle to reach a safe state and avoid the harm caused by power interruption of the entire vehicle.

[0111] It should be noted that since charging and discharging the battery cells will not cause the battery cell temperature to drop, there is no setting to request the VCU to cut off the relay operation in low-temperature discharge and low-temperature charging.

[0112] The embodiments of the present invention respectively determine relatively accurate voltage thresholds and temperature thresholds, and perform safety evaluation on the battery based on the voltage thresholds and temperature thresholds, thereby improving the application reliability of the battery during the charging and discharging process.

[0113] like Figure 7 As shown, an embodiment of the present invention further provides a battery charge and discharge protection device 200 based on voltage and temperature, the device comprising:

[0114] A first determining module 201 determines an undervoltage threshold during discharge and an overvoltage threshold during charge of the battery cell based on upper and lower voltage limits of the battery cell in the battery pack, a voltage acquisition deviation value of the battery management system, and a voltage change value during a relay cutoff process;

[0115] A second determining module 202 determines a temperature threshold range of the battery cell during the charging and discharging process based on the upper and lower limits of the battery cell's operating temperature, a temperature acquisition deviation value of a battery management system, a deviation value of a temperature sensor, and a temperature change value during a cut-off relay process;

[0116] The protection module 203 protects the battery cell during the charging and discharging process based on the undervoltage threshold, the overvoltage threshold and the temperature threshold range.

[0117] In a preferred embodiment of actual application, the first determination module is used to determine the undervoltage threshold of the battery cell during the discharge process and the overvoltage threshold during the charging process. The second determination module is used to determine the temperature threshold range of the battery cell during the charging and discharging process. The protection module is based on the more accurate threshold range determined by the aforementioned determination module, which can realize a more reliable evaluation of the safety of battery charging and discharging in combination with actual influencing factors.

[0118] In some embodiments, the first determination module 201 is further specifically used to determine the first overvoltage threshold of the battery cell during the charging process based on the difference between the upper limit of the operating voltage of the battery cell in the battery pack, the collection deviation value of the battery management system, and the voltage rise value during the cut-off relay process; and to determine the first undervoltage threshold of the battery cell during the discharge process based on the sum of the lower limit of the operating voltage of the battery cell in the battery pack, the collection deviation value of the battery management system, and the voltage drop value during the cut-off relay process.

[0119] In some embodiments, the first determination module 201 is further specifically used to determine the second overvoltage threshold of the battery cell during the charging process based on the difference between the first overvoltage threshold and the voltage rise value during the process when the battery management system requests to cut off the relay; and to determine the second undervoltage threshold of the battery cell during the discharging process based on the sum of the first undervoltage threshold and the voltage drop value during the process when the battery management system requests to cut off the relay.

[0120] In some embodiments, the second determination module 202 is further specifically used to determine the first over-temperature threshold of the battery cell during the charging and discharging process based on the difference between the upper limit of the operating temperature of the battery cell, the temperature acquisition deviation value of the battery management system, the deviation value of the temperature sensor, and the temperature rise value during the cut-off relay process; determine the second over-temperature threshold of the battery cell during the discharging process based on the lower limit of the operating temperature of the battery cell during the discharging process, the temperature acquisition deviation value of the battery management system, and the sum of the deviation value of the temperature sensor; determine the third over-temperature threshold of the battery cell during the charging process based on the lower limit of the operating temperature of the battery cell during the charging process, the temperature acquisition deviation value of the battery management system, and the sum of the deviation value of the temperature sensor.

[0121] In some embodiments, the second determining module 202 is further specifically configured to determine a fourth over-temperature threshold of the battery cell during the charging and discharging process according to a difference between the first over-temperature threshold and a temperature rise value during the process of cutting off the relay.

[0122] In some embodiments, the protection module 203 is further specifically used to cut off the relay if the voltage of the battery cell during charging reaches the first overvoltage threshold; cut off the relay if the voltage of the battery cell during discharging reaches the first undervoltage threshold; send a request signal to the control unit for cutting off the relay if the voltage of the battery cell during charging reaches the second overvoltage threshold; send a request signal to the control unit for cutting off the relay if the voltage of the battery cell during discharging reaches the second undervoltage threshold.

[0123] In some embodiments, the protection module 203 is further specifically used to, if the temperature of the battery cell during the charging and discharging process reaches the first over-temperature threshold, cut off the relay; if the temperature of the battery cell during the discharging process reaches the second over-temperature threshold, cut off the relay and stop charging and discharging; if the temperature of the battery cell during the charging process reaches the third over-temperature threshold, stop charging; if the temperature of the battery cell during the charging and discharging process reaches the fourth over-temperature threshold, send a request signal to the control unit for cutting off the relay.

[0124] Figure 8 Schematic diagram of the hardware architecture of the electronic device 300 provided in an embodiment of the present invention. Figure 8 As shown, the electronic device 300 includes a machine-readable storage medium 301 and a processor 302. It may also include a non-volatile storage medium 303, a communication interface 304, and a bus 305. The machine-readable storage medium 301, the processor 302, the non-volatile storage medium 303, and the communication interface 304 communicate with each other via the bus 305. The processor 302 reads and executes the machine-executable instructions for battery charge and discharge protection based on voltage and temperature in the machine-readable storage medium 301 to perform the battery charge and discharge protection method based on voltage and temperature described in the above embodiment.

[0125] The machine-readable storage medium referred to herein may be any electronic, magnetic, optical, or other physical storage device that can contain or store information, such as executable instructions, data, and the like. For example, the machine-readable storage medium may be: RAM (Random Access Memory), volatile memory, non-volatile memory, flash memory, a storage drive (such as a hard disk drive), any type of storage disk (such as a CD, DVD, etc.), or similar storage media, or a combination thereof.

[0126] The non-volatile medium may be a non-volatile memory, a flash memory, a storage drive (such as a hard drive), any type of storage disk (such as an optical disk, a DVD, etc.), or similar non-volatile storage medium, or a combination thereof.

[0127] It can be understood that the specific operation methods of each functional module in this embodiment can refer to the detailed description of the corresponding steps in the above method embodiment, and will not be repeated here.

[0128] The computer-readable storage medium provided in the embodiments of the present invention stores a computer program. When the computer program code is executed, the battery charge and discharge protection method based on voltage and temperature described in any of the above embodiments can be implemented. For specific implementation, please refer to the method embodiment and will not be repeated here.

[0129] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described systems and devices can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0130] In addition, in the description of the embodiments of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0131] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0132] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present invention, which are used to illustrate the technical solutions of the present invention rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the above-mentioned embodiments, ordinary technicians in this field should understand that any technician familiar with this technical field can still modify the technical solutions recorded in the above-mentioned embodiments within the technical scope disclosed by the present invention, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered by the protection scope of the present invention.

Claims

1. A battery charge and discharge protection method based on voltage and temperature, characterized in that: The method comprises: Based on the upper and lower limits of the operating voltage of the battery cells in the battery pack, the voltage acquisition deviation value of the battery management system, and the voltage change value during the relay cut-off process, the undervoltage threshold of the battery cells during the discharge process and the overvoltage threshold during the charging process are determined respectively; wherein, the relay cut-off process includes the battery management system cutting off the relay process and the battery management system requesting the VCU to cut off the relay process; Determine the temperature threshold range of the battery cell during the charging and discharging process based on the upper and lower limits of the battery cell's operating temperature, the temperature acquisition deviation value of the battery management system, the deviation value of the temperature sensor, and the temperature change value during the disconnection of the relay; Protecting the battery cell during charging and discharging based on the undervoltage threshold, the overvoltage threshold, and the temperature threshold range; The steps of determining the undervoltage threshold during discharge and the overvoltage threshold during charge of the battery cell based on the upper and lower limits of the operating voltage of the battery cell in the battery pack, the voltage acquisition deviation value of the battery management system, and the voltage change value during the disconnection of the relay include: Determine a first overvoltage threshold of the battery cell during charging based on a difference between an upper voltage limit of the battery cell in the battery pack, a collection deviation value of the battery management system, and a voltage rise value during a process in which the battery management system cuts off the relay; Determine a first undervoltage threshold of the battery cell during discharge based on a lower voltage limit of the battery cell in the battery pack, a collection deviation value of the battery management system, and a voltage drop value during a process in which the battery management system cuts off the relay; determining a second overvoltage threshold of the battery cell during charging based on a difference between the first overvoltage threshold and a voltage rise value during a process in which the battery management system requests the VCU to cut off the relay; A second undervoltage threshold of the battery cell during discharge is determined based on the sum of the first undervoltage threshold and a voltage drop value during a process in which the battery management system requests the VCU to cut off the relay.

2. The method according to claim 1, characterized in that The step of determining the temperature threshold range of the battery cell during the charging and discharging process according to the upper and lower limits of the operating temperature of the battery cell, the temperature acquisition deviation value of the battery management system, the deviation value of the temperature sensor, and the temperature change value during the disconnection of the relay includes: Determining a first over-temperature threshold of the battery cell during the charging and discharging process according to the upper temperature limit of the battery cell, the temperature acquisition deviation value of the battery management system, the deviation value of the temperature sensor, and the difference between the temperature rise value during the disconnection of the relay; Determining a second over-temperature threshold of the battery cell during the discharge process according to the sum of a lower limit of the operating temperature of the battery cell during the discharge process, a temperature acquisition deviation value of a battery management system, and a deviation value of a temperature sensor; A third overtemperature threshold of the battery cell during the charging process is determined according to the sum of the lower limit of the operating temperature of the battery cell during the charging process, the temperature acquisition deviation value of the battery management system, and the deviation value of the temperature sensor.

3. The method according to claim 2, characterized in that The step of determining the temperature threshold range of the battery cell during the charging and discharging process according to the upper and lower limits of the operating temperature of the battery cell, the temperature acquisition deviation value of the battery management system, the deviation value of the temperature sensor, and the temperature change value during the disconnection of the relay further includes: A fourth over-temperature threshold of the battery cell during the charging and discharging process is determined according to a difference between the first over-temperature threshold and a temperature rise value during the process of cutting off the relay.

4. The method according to claim 1, wherein The step of protecting the battery cell during the charging and discharging process based on the undervoltage threshold, the overvoltage threshold, and the temperature threshold range includes: If the voltage of the battery cell during charging reaches the first overvoltage threshold, cutting off the relay; If the voltage of the battery cell during discharge reaches the first undervoltage threshold, disconnecting the relay; If the voltage of the battery cell during charging reaches the second overvoltage threshold, a request signal is sent to a control unit for cutting off the relay; If the voltage of the battery cell during discharge reaches the second undervoltage threshold, a request signal is sent to a control unit for cutting off the relay.

5. The method according to claim 3, characterized in that The step of protecting the battery cell during the charging and discharging process based on the undervoltage threshold, the overvoltage threshold, and the temperature threshold range includes: If the temperature of the battery cell during the charging and discharging process reaches the first over-temperature threshold, cutting off the relay; If the temperature of the battery cell during discharge reaches the second over-temperature threshold, the relay is disconnected and charging and discharging is stopped; If the temperature of the battery cell during charging reaches the third over-temperature threshold, stopping charging; If the temperature of the battery cell during the charging and discharging process reaches the fourth over-temperature threshold, a request signal is sent to a control unit for cutting off the relay.

6. A battery charge and discharge protection device based on voltage and temperature, characterized in that: The device comprises: A first determination module determines, based on the upper and lower limits of the operating voltage of the battery cells in the battery pack, the voltage acquisition deviation value of the battery management system, and the voltage change value during the relay cut-off process, the undervoltage threshold of the battery cells during the discharge process and the overvoltage threshold of the battery cells during the charging process; wherein the relay cut-off process includes the battery management system cutting off the relay process and the battery management system requesting the VCU to cut off the relay process; A second determination module determines a temperature threshold range of the battery cell during the charging and discharging process according to the upper and lower limits of the operating temperature of the battery cell, the temperature acquisition deviation value of the battery management system, the deviation value of the temperature sensor, and the temperature change value during the disconnection of the relay; A protection module, which protects the battery cell during the charging and discharging process based on the undervoltage threshold, the overvoltage threshold, and the temperature threshold range; The first determination module is also used to determine the first overvoltage threshold of the battery cell during the charging process based on the upper limit of the operating voltage of the battery cell in the battery pack, the collection deviation value of the battery management system and the difference between the voltage rise value during the process of the battery management system cutting off the relay; determine the first undervoltage threshold of the battery cell during the discharging process based on the lower limit of the operating voltage of the battery cell in the battery pack, the collection deviation value of the battery management system and the sum of the voltage drop value during the process of the battery management system cutting off the relay; determine the second overvoltage threshold of the battery cell during the charging process based on the difference between the first overvoltage threshold and the voltage rise value during the process of the battery management system requesting the VCU to cut off the relay; determine the second undervoltage threshold of the battery cell during the discharging process based on the sum of the first undervoltage threshold and the voltage drop value during the process of the battery management system requesting the VCU to cut off the relay.

7. An electronic device comprising a memory and a processor, wherein the memory stores a computer program that can be run on the processor, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 5 are implemented.

8. A machine-readable storage medium, characterized in that The machine-readable storage medium stores machine-executable instructions. When the machine-executable instructions are called and executed by a processor, the machine-executable instructions prompt the processor to implement the steps of the method according to any one of claims 1 to 5.

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