Battery protection method, battery protection device, and vehicle

Abstract

The application discloses a battery protection method, a battery protection device and a vehicle, and belongs to the technical field of vehicles. The method comprises the following steps: acquiring an actual charging current of a battery and an allowed charging current of the battery; determining whether the battery is in a suspected fault state based on the actual charging current of the battery, the allowed charging current of the battery, a suspected fault current threshold and a suspected fault time threshold; when the battery is in the suspected fault state, determining a first adjustment parameter based on the suspected fault current threshold; and charging the battery based on the first adjustment parameter. Thus, potential faults of the battery can be predicted and adjusted in time, so that the safety of the battery can be better protected.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicles, in particular to a battery protection method, a battery protection device and a vehicle. BACKGROUND

[0002] With the pursuit of low-carbon life, more and more new energy vehicles have entered people's life. New energy vehicles refer to vehicles that use unconventional fuels as power sources and are made by combining advanced technologies in power control and driving. Generally, they use pure battery power supply or hybrid power supply of internal combustion engine and battery. Since the battery is an important power source for new energy vehicles, it is particularly important to protect the battery, especially to avoid the consequences of battery damage due to overcharging.

[0003] In related technologies, a current overcharge threshold is generally set for the battery of a new energy vehicle. When the actual charging current exceeds the current overcharge threshold, the battery management system issues an overcharge fault alarm to stop charging the battery.

[0004] However, the above method protects the battery after the battery has been overcharged to avoid further damage to the battery, but it cannot prevent the overcharging of the battery in advance. SUMMARY

[0005] Therefore, the embodiments of the present application provide a battery protection method, a battery protection device and a vehicle, which can predict and timely adjust the potential faults of the battery to better protect the safety of the battery.

[0006] In one aspect, the embodiments of the present application provide a battery protection method, which comprises:

[0007] obtaining an actual charging current of the battery and an allowed charging current of the battery;

[0008] determining whether the battery is in a suspected fault state based on the actual charging current of the battery, the allowed charging current of the battery, a suspected fault current threshold and a suspected fault time threshold;

[0009] when the battery is in the suspected fault state, determining a first adjustment parameter based on the suspected fault current threshold;

[0010] charging the battery based on the first adjustment parameter.

[0011] Optionally, the determination of whether the battery is in the suspected fault state based on the actual charging current of the battery, the allowed charging current of the battery, the suspected fault current threshold and the suspected fault time threshold comprises:

[0012] determining that the battery is in a first suspected fault state when a difference between the battery actual charging current and the battery allowed charging current is greater than a first suspected fault current threshold.

[0013] Optionally, the determining whether the battery is in a suspected fault state based on the battery actual charging current, the battery allowed charging current, a suspected fault current threshold, and a suspected fault time threshold comprises:

[0014] determining that the battery is in a second suspected fault state when the difference between the battery actual charging current and the battery allowed charging current is greater than a second suspected fault current threshold and a duration is greater than the suspected fault time threshold;

[0015] wherein the second suspected fault current threshold is less than the first suspected fault current threshold.

[0016] Optionally, the determining the first adjustment parameter based on the suspected fault current threshold when the battery is in a suspected fault state comprises:

[0017] when the first adjustment parameter is a first adjustment power, the first adjustment power is determined based on a first formula as follows:

[0018] P1=P0-A×△I×U0

[0019] wherein A is a coefficient and greater than 0, P1 is the first adjustment power, P0 is a current recovery power of the battery, △I is the suspected fault current threshold, and U0 is a voltage corresponding to a current state of charge of the battery.

[0020] Optionally, the determining the first adjustment parameter based on the suspected fault current threshold when the battery is in a suspected fault state comprises:

[0021] when the first adjustment parameter is a first adjustment current, the first adjustment current is determined based on a second formula as follows:

[0022] I1=I0-B×△I

[0023] wherein B is a coefficient and greater than 0, I1 is the first adjustment current, I0 is a current requested charging current of the battery, and △I is the suspected fault current threshold.

[0024] Optionally, the method further comprises:

[0025] determining a recovery number of the battery;

[0026] when the recovery number is equal to a target number, determining a second adjustment parameter based on the first adjustment parameter and a target recovery parameter;

[0027] charging the battery based on the second adjustment parameter.

[0028] Optionally, the method further comprises:

[0029] determining a number of charging times of the battery;

[0030] when the number of charging times is equal to a target number of charging times, determining a third adjustment parameter based on the first adjustment parameter and a target recovery parameter;

[0031] charging the battery based on the third adjustment parameter.

[0032] In one aspect, the embodiments of the present application provide a battery protection device, which comprises:

[0033] an information acquisition module, configured to acquire an actual charging current of a battery and an allowed charging current of the battery;

[0034] a pre-diagnosis module, configured to determine whether the battery is in a suspected fault state based on the actual charging current of the battery, the allowed charging current of the battery, a suspected fault current threshold and a suspected fault time threshold;

[0035] a compensation module, configured to determine a first adjustment parameter based on the suspected fault current threshold when the battery is in the suspected fault state;

[0036] an adjustment module, configured to charge the battery based on the first adjustment parameter.

[0037] Optionally, the pre-diagnosis module is further configured to:

[0038] determine that the battery is in a first suspected fault state when a difference between the actual charging current of the battery and the allowed charging current of the battery is greater than a first suspected fault current threshold.

[0039] Optionally, the pre-diagnosis module is further configured to:

[0040] determine that the battery is in a second suspected fault state when the difference between the actual charging current of the battery and the allowed charging current of the battery is greater than a second suspected fault current threshold and a duration is greater than the suspected fault time threshold;

[0041] wherein the second suspected fault current threshold is less than the first suspected fault current threshold.

[0042] Optionally, the compensation module is further configured to:

[0043] when the first adjustment parameter is a first adjustment power, the first adjustment power is determined based on a first formula as follows:

[0044] P1=P0-A×△I×U0

[0045] Wherein, A is a coefficient and greater than 0, P1 is the first adjustment power, P0 is the current recovery power of the battery, AI is the suspected fault current threshold, U0 is the voltage corresponding to the current state of charge of the battery.

[0046] Optionally, the compensation module is further configured to:

[0047] When the first adjustment parameter is a first adjustment current, the first adjustment current is determined based on a second formula as follows:

[0048] I1 = I0 - B * AI

[0049] Wherein, A is a coefficient and greater than 0, I1 is the first adjustment current, I0 is the current requested charging current of the battery, AI is the suspected fault current threshold.

[0050] Optionally, the pre-diagnosis module is further configured to determine the recovery times of the battery.

[0051] The compensation module is further configured to, when the recovery times is equal to a target times, determine a second adjustment parameter based on the first adjustment parameter and a target recovery parameter.

[0052] The adjustment module is further configured to charge the battery based on the second adjustment parameter.

[0053] Optionally, the pre-diagnosis module is further configured to determine the charging times of the battery.

[0054] The compensation module is further configured to, when the charging times is equal to a target times, determine a third adjustment parameter based on the first adjustment parameter and a target recovery parameter.

[0055] The adjustment module is further configured to charge the battery based on the third adjustment parameter.

[0056] In one aspect, the embodiments of the present application provide a vehicle, which comprises a battery management system, a vehicle controller and a motor controller, wherein the vehicle controller is configured to implement any of the above battery protection methods.

[0057] The technical scheme provided by the embodiments of the present application can determine whether the vehicle is in a suspected fault state by combining the actual charging current of the battery and the allowed charging current of the battery with the suspected fault current threshold and the suspected fault current time threshold, so as to timely discover the potential fault state of the vehicle before the battery of the vehicle reaches the overcharge fault, and further determine the adjustment parameter based on the suspected fault current threshold, and then charge the battery based on the adjustment parameter, thereby not only realizing timely pre-judgment of the potential fault of the battery, but also timely adjusting the charging state of the battery, and more effectively protecting the safety and life of the battery. BRIEF DESCRIPTION OF DRAWINGS

[0058] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced. Obviously, the drawings in the following description only represent some of the embodiments of the present application, and all other drawings obtained by those of ordinary skill in the art without creative effort based on these drawings also belong to the protection scope of the present application.

[0059] Figure 1 is a schematic diagram of a vehicle provided by an embodiment of the present application;

[0060] Figure 2 is a flowchart of a battery protection method provided by an embodiment of the present application;

[0061] Figure 3 is a flowchart of a battery protection method provided by an embodiment of the present application;

[0062] Figure 4 is a flowchart of a battery protection method provided by an embodiment of the present application;

[0063] Figure 5 is a structural schematic diagram of a battery protection device provided by an embodiment of the present application;

[0064] Figure 6 is a flowchart of a battery protection method provided by an embodiment of the present application.

[0065] The various marks in the drawings are as follows:

[0066] 1-battery management system; 2-vehicle controller; 3-motor controller.

[0067] The above drawings have shown the specific embodiments of the present application, and more detailed description will be given in the following. These drawings and textual descriptions are not intended to limit the scope of the concept of the present application by any means, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0068] The technical solutions in the embodiments of the present application will be described clearly and completely in the following by combining the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort also belong to the protection scope of the present application.

[0069] Unless otherwise defined, all the technical terms used in the embodiments of the present application have the same meanings as commonly understood by those skilled in the art.

[0070] In order to make the technical solutions and advantages of the present application clearer, the embodiments of the present application will be further described in detail below with reference to the drawings.

[0071] Reference Figure 1 , Figure 1 is a schematic diagram of a vehicle provided by an embodiment of the present application, which comprises:

[0072] A battery management system 1 is configured to determine a SOC (State of Charge) value of the battery based on a current voltage of the battery. The SOC is a state of the remaining charge available in the battery, and when SOC=0, it represents that the battery is completely discharged; when SOC=1, it represents that the battery is completely charged. The battery management system 1 sends the SOC value to a vehicle controller 2 after determining the SOC value of the battery.

[0073] The vehicle controller 2 is configured to receive the SOC value sent by the battery management system, and determine an adjustment parameter for charging the battery in combination with relevant parameters determined by various modules in the vehicle controller 2, and send the adjustment parameter to a motor controller 3. Alternatively, the vehicle controller 2 sends a charging request to other charging equipment (for example, a charging pile or a charging machine, etc.), and the charging request is used to instruct the other charging equipment to charge the battery with a current value corresponding to the adjustment parameter. The vehicle controller 2 is configured to implement a battery protection method provided by an embodiment of the present application, and the specific implementation process of the battery protection method is described in the following embodiments of the present application, which will not be described here.

[0074] The motor controller 3 is configured to control the motor to output a corresponding torque based on the adjustment parameter sent by the vehicle controller, in combination with a conversion relationship between the adjustment parameter and the motor output torque, so as to control the amount of electricity output by the motor to the battery.

[0075] It should be noted that the battery management system 1, the vehicle controller 2 and the motor controller 3 are in an electrically connected state.

[0076] Reference Figure 2 , Figure 2 is a flowchart of a battery protection method provided by an embodiment of the present application, which comprises the following steps 201 to 204:

[0077] Step 201, obtaining an actual charging current of the battery and an allowed charging current of the battery.

[0078] It should be noted that when the battery is manufactured, an allowed charging current of the battery is set for each battery, and the allowed charging current can also be adjusted according to the actual situation, which is not limited here.

[0079] Step 202, determining whether the battery is in a suspected fault state based on the actual charging current of the battery, the allowed charging current of the battery, a suspected fault current threshold and a suspected fault time threshold.

[0080] In some embodiments, the suspected fault current threshold and the suspected fault time threshold are pre-set and stored in the vehicle controller, and can also be adjusted according to the actual situation of the vehicle.

[0081] It should be noted that if the difference between the actual charging current of the battery and the allowed charging current of the battery is greater than the suspected fault current threshold, and the duration of the greater suspected fault current threshold exceeds the suspected fault time threshold, it is determined that the battery is in an overcharging state, and an overcharging fault alarm is issued. There are many ways to issue an overcharging fault alarm, for example, prompting the driver through voice, or prompting the driver through text, or directly disconnecting the related circuit for charging the battery, etc. The above are only examples of overcharging fault alarm methods, and the specific overcharging fault alarm method is not limited herein.

[0082] It should be noted that the overcharging state refers to the state in which the battery continues to be charged after reaching the full state. If the battery is in an overcharging state, it will cause the battery pressure to rise, the battery to deform, and the battery to leak, thereby reducing or damaging the performance of the battery, i.e., reducing the safety and service life of the battery. The embodiments provided in the present application are to determine whether the battery is in a suspected fault state in time, so as to timely predict and adjust before the battery is in an overcharging state, thereby improving the safety and service life of the battery.

[0083] In some embodiments, the suspected fault state of the battery is divided into two types, one is a short-time large-current state, and the other is a long-time small-current state. When the battery is in the two states, the battery does not issue an overcharging fault alarm, but still has a potential overcharging risk. Therefore, the embodiments provided in the present application are to identify and timely adjust the above two suspected fault states. The above two suspected fault states are identified by the following two ways respectively:

[0084] First, when the difference between the actual charging current of the battery and the allowed charging current of the battery is greater than a first suspected fault current threshold, it is determined that the battery is in a first suspected fault state. It should be noted that the first suspected fault state is the short-time large-current state described above.

[0085] In some embodiments, the suspected fault time threshold includes only one time threshold, and when the difference between the actual charging current of the battery and the allowed charging current of the battery is greater than the first suspected fault current threshold and the duration is less than the suspected fault time threshold, it is determined that the battery is in the first suspected fault state. When the difference between the actual charging current of the battery and the allowed charging current of the battery is greater than the first suspected fault current threshold and the duration is greater than the suspected fault time threshold, it is determined that the battery is in an overcharging state.

[0086] For example, the first suspected fault current threshold is 5A, the actual charging current of the battery is 58A, the allowed charging current of the battery is 50A, and the suspected fault time threshold is 2s. If the difference between the actual charging current of the battery and the allowed charging current of the battery is 8A (greater than 5A) and the duration is less than 2s, it is determined that the battery is currently in the first suspected fault state. In this way, the suspected fault state of the battery can be predicted in time to prevent overcharging.

[0087] In some embodiments, the suspected fault time threshold includes a first time threshold and a second time threshold, and the first time threshold is less than the second time threshold. When the difference between the actual charging current of the battery and the allowed charging current of the battery is greater than the first suspected fault current threshold, and the duration is greater than the first time threshold and less than the second time threshold, it is determined that the battery is in the first suspected fault state. If the duration is less than the first time threshold, it is determined that the battery is in a normal charging state. When the difference between the actual charging current of the battery and the allowed charging current of the battery is greater than the first suspected fault current threshold and the duration is greater than the second time threshold, it is determined that the battery is in an overcharging state.

[0088] For example, the first time threshold is 0.5s, the second time threshold is 2s, the first suspected fault current threshold is 5A, and the allowed charging current of the battery is 50A. In the 0-2s time of the battery, there are three time stages in sequence: the first stage is from 0 to 0.4s (with a duration of 0.4s), the actual charging current of the battery is 58A; the second stage is from 0.4 to 0.6s (with a duration of 0.2s), the actual charging current of the battery is 50A; the third stage is from 0.6 to 2s (with a duration of 1.4s), the actual charging current of the battery is 56A. Only the third stage is determined to be in the first suspected fault state, and the first stage and the second stage are determined to be in the normal charging state.

[0089] By setting two time thresholds, a lower limit value is set for the suspected fault time threshold. Since the short-term current fluctuation of the battery has little effect on the safety and service life of the battery, the short-term current fluctuation of the battery can be ignored by setting the lower limit value, excessive judgment can be avoided to prevent misjudgment, and unnecessary adjustment can be avoided, thereby saving processing resources.

[0090] In some embodiments, the suspected fault time threshold includes a third time threshold, a fourth time threshold and a fifth time threshold, and the fourth time threshold is less than the third time threshold, and the third time threshold is less than the fifth time threshold. If there are multiple current change stages in a period of time, for example, including time sequentially continuous first stage, second stage and third stage, in the first stage, the difference between the actual battery charging current and the allowed battery charging current is greater than the first suspected fault current threshold, and the duration is less than the third time threshold and greater than the fourth time threshold; in the second stage, the difference between the actual battery charging current and the allowed battery charging current is less than the first suspected fault current threshold, and the duration is less than the fourth time threshold; in the third stage, the difference between the actual battery charging current and the allowed battery charging current is greater than the first suspected fault current threshold, and the duration is greater than the third time threshold and less than the fifth time threshold, it is determined that the battery is in the first suspected fault state in the first stage to the third stage. When the difference between the actual battery charging current and the allowed battery charging current is greater than the first suspected fault current threshold, and the duration is greater than the fifth time threshold, it is determined that the battery is in the overcharge state.

[0091] For example, the third time threshold is 0.5s, the fourth time threshold is 0.2s, and the fifth time threshold is 2s. In the 0-1.2s time of the battery, there are three stages: the first stage is from 0 to 0.4s (the duration is 0.4s), the actual battery charging current is 58A; the second stage is from 0.4 to 0.5s (the duration is 0.1s), the actual battery charging current is 50A; the third stage is from 0.5 to 1.2s (the duration is 0.7s), the actual battery charging current is 56A. Only the first stage to the third stage are determined as the first suspected fault state.

[0092] By setting three time thresholds, it can be avoided that the first suspected fault state is missed due to very short normal current fluctuations in a certain charging process of the battery. In the above example, the sum of the durations of the first stage and the third stage exceeds 0.5s and is less than 2s, but the first stage cannot be regarded as a normal charging state because of the very short normal charging current between the first stage and the third stage, which leads to missing the first suspected fault state and not performing subsequent charging parameter adjustment operations, ultimately resulting in reduced safety and service life of the battery due to potential hidden dangers. In other words, this method can avoid missing the current first suspected fault state of the battery, and better ensure the safety and service life of the battery.

[0093] The size of the time threshold or the suspected fault current threshold set above is exemplary and can be adjusted according to actual needs, and is not limited herein. In some embodiments, the number of time thresholds can also be more, and is not limited herein. By this method, it can be ensured that the first suspected fault state of the battery is not missed, and misjudgment is not caused by over-discrimination.

[0094] Secondly, when the difference between the actual charging current of the battery and the allowable charging current of the battery is greater than a second suspected fault current threshold, and the duration is greater than the suspected fault time threshold, it is determined that the battery is in a second suspected fault state. It can be understood that the second suspected fault state is the long-time small-current state described above. It should be noted that in this case, the difference between the actual charging current of the battery and the allowable charging current of the battery is not only greater than the second suspected fault current threshold, but also less than the first suspected fault current threshold.

[0095] Wherein, the second suspected fault current threshold is less than the first suspected fault current threshold, and the actual charging current of the battery is greater than the allowable charging current of the battery.

[0096] In some embodiments, the second suspected fault current threshold includes a current threshold and a suspected fault time threshold, and when the difference between the actual charging current of the battery and the allowable charging current of the battery is greater than the second suspected fault current threshold and less than the first suspected fault current threshold, and the duration is greater than the suspected fault time threshold, it is determined that the battery is in a second suspected fault state.

[0097] For example, the second suspected fault current threshold is 2A, the first suspected fault current is 5A, the suspected fault time threshold is 2s, the actual charging current of the battery is 53A within 0-2s of the battery, and the duration is 3s. Then it is determined that the battery is in a second suspected fault state. By this method, the suspected fault state of the battery charging process can be predicted in time to prevent overcharging.

[0098] In some embodiments, the second suspected fault current threshold includes a first current threshold and a second current threshold, and the first current threshold is less than the second current threshold. When the difference between the actual charging current of the battery and the allowable charging current of the battery is greater than the first current threshold and less than the second current threshold, and the duration is greater than the suspected fault time threshold, it is determined that the battery is in a second suspected fault state. If the difference between the actual charging current of the battery and the allowable charging current of the battery is less than the first current threshold, it is determined that the battery is in a normal charging state.

[0099] For example, the first current threshold is 0.5 A, the second current threshold is 2 A, and the suspected fault time threshold is 2 s. In the 0-5 s, which includes two time-continuous stages, the first stage is 0-2.5 s, and the actual charging current of the battery is 50.4 A. It is determined that the battery is in a normal charging state in the 0-0.5 s. The second stage is 2.5-5 s, and the actual charging current of the battery is 53 A. It is determined that the battery is in a second suspected fault state in the 2.5-5 s.

[0100] It should be noted that if the difference between the actual charging current of the battery and the allowable charging current of the battery is very small, although it has exceeded the allowable charging current of the battery, the impact on the safety and service life of the battery is low, and thus can be ignored, that is, by this method, over-judgment can be avoided, false judgment is caused, and unnecessary adjustment is caused, and processing resources are saved.

[0101] It should be noted that the second suspected fault current threshold can also include three or more, which is not limited here.

[0102] In some embodiments, in the above two cases, a plurality of suspected fault current thresholds and / or a plurality of suspected fault time thresholds can also be set at the same time. In other embodiments, the suspected fault time threshold in the first case and the suspected fault time threshold in the second case can be the same or different, which is not limited here.

[0103] Step 203, when the battery is in a suspected fault state, determining a first adjustment parameter based on the suspected fault current threshold.

[0104] The first adjustment parameter is used as a basis for continuing to charge the battery.

[0105] Step 204, charging the battery based on the first adjustment parameter.

[0106] The technical scheme provided by the embodiments of the present application can determine whether the vehicle is in a suspected fault state by the actual charging current of the battery and the allowable charging current of the battery, in combination with the suspected fault current threshold and the suspected fault current time threshold, so that the potential fault state of the vehicle can be found in time before the battery of the vehicle reaches an overcharge fault. In addition, the adjustment parameter is determined based on the suspected fault current threshold, and then the battery is charged based on the adjustment parameter, so that not only the potential fault of the battery can be timely predicted, but also the charging state of the battery can be timely adjusted, and the safety and life of the battery are more effectively protected. At the same time, the current charging state of the battery can be judged based on a plurality of suspected fault current thresholds and a plurality of suspected fault time thresholds, so that over-discrimination or missed judgment can be avoided while the suspected fault of the battery is timely determined.

[0107] Reference Figure 3 , Figure 3 A flow chart of a battery protection method provided by an embodiment of the present application, the method is applied to a vehicle energy recovery working condition. It should be noted that electric vehicles and hybrid vehicles will appear energy recovery working condition during driving. During driving of an internal combustion engine vehicle, when the vehicle is decelerated or braked, the kinetic energy of the vehicle is converted into heat energy through the braking system and released into the atmosphere. During driving of an electric vehicle and a hybrid vehicle, when the vehicle is decelerated or braked, the kinetic energy of the vehicle is converted into heat energy through the braking system, which can be converted into electrical energy through the motor and stored in the battery, so that the part of electrical energy can be further converted into driving energy subsequently. The method comprises the following steps 301 to 307:

[0108] Step 301, obtaining an actual charging current of a battery and an allowed charging current of the battery.

[0109] Step 302, determining whether the battery is in a suspected fault state based on the actual charging current of the battery, the allowed charging current of the battery, a suspected fault current threshold and a suspected fault time threshold.

[0110] It should be noted that this step is the same as step 202 described above, and will not be repeated here.

[0111] Step 303, when the battery is in the suspected fault state, determining a first adjustment parameter based on the suspected fault current threshold.

[0112] When the first adjustment parameter is a first adjustment power, the first adjustment power is determined based on the following first formula:

[0113] P1=P0-A×△I×U0

[0114] Wherein, A is a coefficient and greater than 0, P1 is the first adjustment power, P0 is the current recovery power of the battery, △I is the suspected fault current threshold, U0 is the voltage corresponding to the current state of charge of the battery. In some embodiments, A is equal to 2, so as to provide a power up space for subsequent step-by-step recovery of charging capacity.

[0115] It should be noted that during the process of converting the part of heat energy into electrical energy, the required motor output power has a corresponding relationship with the SOC of the battery. It should be noted that within a small range of SOC change, the voltage of the battery changes little and can be considered as constant. By timely reducing the output power of the motor, the phenomenon of overcharging of the battery can be avoided.

[0116] Step 304, charging the battery based on the first adjustment parameter.

[0117] In some embodiments, when the first adjustment parameter is the first adjustment power in step 303, the motor torque corresponding to the first adjustment power is determined based on the conversion relationship between the motor power and the motor torque, and then the output power of the motor to the battery is adjusted by adjusting the output torque of the motor, so as to prevent the battery from overcharging. In the motor controller or the vehicle controller, a basic recovery MAP under the energy recovery condition is pre-stored, and the basic recovery MAP is used to reflect the motor efficiency distribution of the motor at different vehicle speeds. After the first adjustment power is determined, the power in the basic recovery MAP is reduced by A x AI x U0, and an adjusted recovery MAP is obtained, which is used as the basis for subsequent energy recovery conditions.

[0118] Step 305: determining the recovery times of the battery.

[0119] The recovery times refer to the number of times that the vehicle is in the energy recovery condition, for example, when the vehicle starts to decelerate, the energy recovery condition is entered, and when the vehicle becomes an acceleration state, it is equivalent to exiting the energy recovery condition. From entering the deceleration to starting the acceleration is regarded as one recovery.

[0120] Step 306: when the recovery times are equal to the target times, the second adjustment parameter is determined based on the first adjustment parameter and the target recovery parameter.

[0121] In some embodiments, when the second adjustment parameter is the second adjustment power, the second adjustment power can be determined based on the following formula:

[0122] P2 = P1 + M x AI x U0

[0123] Wherein, M is a coefficient and greater than 0, P2 is the second adjustment power, P1 is the first adjustment power, AI is the suspected fault current threshold, U0 is the voltage corresponding to the current state of charge of the battery, and M x AI x U0 is the target recovery parameter. It should be noted that in each energy recovery condition, the SOC of the battery changes little, and the voltage of the battery can be regarded as constant. In some embodiments, the target recovery parameter can also be set to a fixed value, and the fixed value is less than the value of A x AI x U0 in step 303. The purpose is to subsequently increase the power multiple times, so as to gradually recover part of the charging capacity, improve the safety and service life of the battery, and also ensure the use performance of the battery. In some embodiments, M is equal to 0.5, and if A is equal to 2 in step 303, the power can be increased at most four times subsequently, so as to gradually recover the charging capacity.

[0124] Wherein, the target number of times can be adjusted as needed, for example, the target number of times is 200 times, that is, within 200 times of recovery, if the battery still does not appear a suspected failure state, then the partial charging capacity can be gradually restored, that is, the self-repairing and regenerative ability of the motor is realized. In some embodiments, the current parameters can be adjusted every time the target number of times is reached, but the finally adjusted parameters cannot be greater than the preset maximum recovery power set in the vehicle controller.

[0125] In some embodiments, if the battery is identified as a suspected failure state within the target number of times, the number of times is reset to zero, the power is adjusted according to the manner in step 303, and then the number of times is counted from zero again. If the battery is not identified as a suspected failure state within the target number of times, the power is adjusted according to the manner in step 306, and then the number of times is counted from zero again.

[0126] Step 307, charging the battery based on the second adjustment parameter.

[0127] It should be noted that this step is similar to step 304, the difference is that step 304 is to reduce the output power of the motor, and this step 307 is to increase the output power of the motor, which will not be repeated here.

[0128] The technical scheme provided by the embodiments of the present application determines whether the vehicle is in a suspected failure state by combining the actual charging current of the battery and the allowable charging current of the battery with the suspected failure current threshold and the suspected failure current time threshold, so that the potential failure state of the vehicle can be discovered in time before the battery of the vehicle reaches an overcharge failure, and further, the adjustment parameter is determined based on the suspected failure current threshold, and then the battery is charged based on the adjustment parameter, so that not only the potential failure of the battery is timely predicted, but also the charging state of the battery is timely adjusted, and the safety and life of the battery are more effectively protected. And, the output power of the motor can be gradually increased after each round of recovery, thereby recovering part of the charging capacity. And, through the self-learning parameter compensation method for the whole life cycle of the battery, the dynamic self-correction and gradual self-repairing functions are realized, and the whole charging state of the battery is adjusted to the optimal state.

[0129] Reference Figure 4 , Figure 4A flowchart of a battery protection method provided by an embodiment of the present application is shown in FIG. 4. The method is applied to a charging condition. It should be noted that electric vehicles and hybrid vehicles not only charge the battery in the energy recovery condition described above, but also charge the battery by external charging equipment such as charging piles or charging machines. This condition is referred to as the charging condition. The charging condition includes alternating current charging and direct current charging. In the charging condition, the vehicle controller determines the battery allowable charging current and the in-vehicle power consumption accessory current consumption, adds the battery allowable charging current and the in-vehicle power consumption accessory current consumption, and obtains the current requested charging current of the vehicle. Based on the current requested charging current, the vehicle controller sends an output current request to the charging pile or the charging machine. The request is used to instruct the charging pile or the charging machine to output the current requested charging current to the vehicle. The method includes the following steps 401 to 407.

[0130] Step 401: Obtain the battery actual charging current and the battery allowable charging current.

[0131] Step 402: Determine whether the battery is in a suspected fault state based on the battery actual charging current, the battery allowable charging current, a suspected fault current threshold, and a suspected fault time threshold.

[0132] It should be noted that this step is the same as step 202 described above, and thus is not described here.

[0133] Step 403: When the battery is in a suspected fault state, determine a first adjustment parameter based on the suspected fault current threshold.

[0134] When the first adjustment parameter is a first adjustment current, the first adjustment current is determined based on the following second formula:

[0135] I1 = I0 - B x AI

[0136] wherein B is a coefficient and is greater than 0, I1 is the first adjustment current, I0 is the current requested charging current of the battery, and AI is the suspected fault current threshold. In some embodiments, B is equal to 2, thereby providing a space for current up-regulation for subsequent step-by-step recovery of charging capability.

[0137] Step 404: Charge the battery based on the first adjustment parameter.

[0138] In some embodiments, when the first adjustment parameter is the first adjustment current in step 403, an adjusted output current request is sent to the charging pile or the charging machine, which is used to instruct the charging pile or the charging machine to output the first adjustment current to the vehicle. The charging MAP is pre-stored in the vehicle control unit, which is used to reflect the relationship among the SOC of the battery, the temperature of the battery and the current charging current of the battery. After the first adjustment current is determined, the currents in the charging MAP are all reduced by BxAI to obtain an adjusted charging MAP, which is used as the basis for subsequent charging conditions.

[0139] Step 405, determining the charging times of the battery.

[0140] The charging times refer to the times of charging the vehicle using external charging equipment, for example, connecting the vehicle to the charging pile and separating the vehicle from the charging pile are regarded as charging once.

[0141] Step 406, when the charging times are equal to the target times, the third adjustment parameter is determined based on the first adjustment parameter and the target recovery parameter.

[0142] In some embodiments, when the third adjustment parameter is the third adjustment current, the third adjustment current can be determined based on the following formula:

[0143] I2=I1+NxAI

[0144] Wherein, N is a coefficient and greater than 0, I2 is the third adjustment current, I1 is the first adjustment current, and AI is the suspected fault current threshold. In some embodiments, the target recovery parameter can also be set as a fixed value, and the fixed value is less than the value of BxAI in step 403, so that the current can be adjusted multiple times subsequently, thereby gradually recovering part of the charging capacity, improving the safety and service life of the battery, and also ensuring the use performance of the battery. In some embodiments, N is equal to 0.5, and if B is equal to 2 in step 403, the current value can be adjusted up to four times subsequently to gradually recover the charging capacity.

[0145] Wherein, the target times can be adjusted as needed, for example, the target times are 200 times, that is, within 200 times of recycling times, if the battery still does not appear a suspected fault state, part of the charging capacity can be gradually recovered, that is, the current output by the charging pile or the charging machine is increased. In some embodiments, the current parameters can be adjusted every time the target times are reached, but the finally adjusted parameter cannot be greater than the preset maximum request current set in the vehicle control unit.

[0146] In some embodiments, if the battery is identified as being in the suspected failure state within the target number of times, the number of times is reset, the current is adjusted in the manner described above in step 403, and then the number of times is counted again from zero. If the battery is not identified as being in the suspected failure state within the target number of times, the current is adjusted in the manner described in step 406, and then the number of times is counted again from zero.

[0147] Step 407, charging the battery based on the third adjustment parameter.

[0148] It should be noted that this step is similar to step 404, except that step 404 is for reducing the output current of the charging pile or the charger, while this step 407 is for increasing the output current of the charging pile or the charger, which will not be described here.

[0149] It should be noted that, Figure 3 The embodiments of the battery protection method provided by the present application provide a suspected failure current or Figure 4 The size of the suspected failure current in the battery protection method provided by the embodiments of the present application can be the same or different, which is not limited here.

[0150] The technical solutions provided by the embodiments of the present application determine whether the vehicle is in a suspected failure state by combining the actual charging current of the battery and the allowable charging current of the battery with the suspected failure current threshold and the suspected failure time threshold, so that the potential failure state of the vehicle can be discovered in time before the battery of the vehicle reaches an overcharge failure, and the charging state of the battery can be adjusted in time based on the adjustment parameter determined based on the suspected failure current threshold and the battery is charged based on the adjustment parameter, so that not only the potential failure of the battery is predicted in time, but also the charging state of the battery is adjusted in time, and the safety and life of the battery are more effectively protected. And subsequently, the output power of the motor can be gradually increased after each round of charging, thereby recovering part of the charging capacity.

[0151] Referring to Figure 5 , Figure 5 A structural schematic diagram of a battery protection device provided by an embodiment of the present application is shown in FIG. 5. The device includes:

[0152] An information acquisition module 501 is configured to acquire an actual charging current of a battery and an allowable charging current of the battery.

[0153] A pre-diagnosis module 502 is configured to determine whether the battery is in a suspected failure state based on the actual charging current of the battery, the allowable charging current of the battery, a suspected failure current threshold, and a suspected failure time threshold.

[0154] In some embodiments, the suspected failure current threshold and the suspected failure time threshold are pre-set and stored in the pre-diagnosis module 502.

[0155] The compensation module 503 is configured to determine a first adjustment parameter based on the suspected fault current threshold when the battery is in a suspected fault state.

[0156] The adjustment module 504 is configured to charge the battery based on the first adjustment parameter.

[0157] In some embodiments, the pre-diagnosis module 502 is further configured to:

[0158] determine that the battery is in a first suspected fault state when the difference between the actual charging current of the battery and the allowed charging current of the battery is greater than a first suspected fault current threshold.

[0159] In some embodiments, the pre-diagnosis module 502 is further configured to:

[0160] determine that the battery is in a second suspected fault state when the difference between the actual charging current of the battery and the allowed charging current of the battery is less than a second suspected fault current threshold and the duration is greater than a suspected fault time threshold.

[0161] It should be noted that the second suspected fault current threshold is less than the first suspected fault current threshold.

[0162] In some embodiments, the compensation module 503 is further configured to:

[0163] when the first adjustment parameter is a first adjustment power, the first adjustment power is determined based on a first formula as follows:

[0164] P1=P0-A×△I×U0

[0165] wherein A is a coefficient and greater than 0, P1 is the first adjustment power, P0 is the current recovery power of the battery, △I is the suspected fault current threshold, and U0 is the voltage corresponding to the current state of charge of the battery.

[0166] In some embodiments, the compensation module 503 is further configured to:

[0167] when the first adjustment parameter is a first adjustment current, the first adjustment current is determined based on a second formula as follows:

[0168] I1=I0-B×△I

[0169] wherein B is a coefficient and greater than 0, I1 is the first adjustment current, I0 is the current requested charging current of the battery, and △I is the suspected fault current threshold.

[0170] In some embodiments, the pre-diagnosis module 502 is further configured to determine the recovery times of the battery.

[0171] It should be noted that the pre-diagnosis module 502 is further configured to perform the recycling frequency statistics in step 306.

[0172] The compensation module 503 is further configured to determine a second adjustment parameter based on the first adjustment parameter and a target recovery parameter when the recycling frequency is equal to a target frequency.

[0173] The adjustment module 504 is further configured to charge the battery based on the second adjustment parameter.

[0174] In some embodiments, the pre-diagnosis module 502 is further configured to determine a charging frequency of the battery.

[0175] It should be noted that the pre-diagnosis module 502 is further configured to perform the recycling frequency statistics in step 406.

[0176] The compensation module 503 is further configured to determine a third adjustment parameter based on the first adjustment parameter and a target recovery parameter when the charging frequency is equal to a target frequency.

[0177] The adjustment module 504 is further configured to charge the battery based on the third adjustment parameter.

[0178] It should be noted that each time the pre-diagnosis module 501 determines that the battery is in a suspected fault state, the suspected fault code needs to be recorded.

[0179] It should be noted that the information acquisition module 501, the pre-diagnosis module 502, the compensation module 503, and the adjustment module 504 can be arranged in the vehicle controller or other suitable devices, and the above modules are used to implement the battery protection method provided in the present application, and the principles are the same, which will not be repeated here.

[0180] The technical scheme provided in the present application determines whether the vehicle is in a suspected fault state by combining the actual charging current of the battery and the allowed charging current of the battery with the suspected fault current threshold and the suspected fault current time threshold, so that the potential fault state of the vehicle can be found in time before the battery of the vehicle reaches the overcharge fault, and the adjustment parameter is determined based on the suspected fault current threshold, and then the battery is charged based on the adjustment parameter, so that not only the potential fault of the battery is timely predicted, but also the charging state of the battery is timely adjusted, and the safety and life of the battery are more effectively protected.

[0181] Reference Figure 6 , Figure 6A flowchart of a battery protection method provided by the embodiments of the present application is provided. The method is applied to a vehicle, and the vehicle includes a battery management system, a vehicle controller, and a motor controller. The vehicle control system includes a starting module, a pre-diagnosis module, a compensation module, and an adjustment module. The method includes the following steps 601 to 607:

[0182] Step 601: The starting module opens a charging state.

[0183] The charging state is realized by the starting module in the vehicle controller. The starting module determines the driving state of the vehicle based on the speed of the vehicle. When the vehicle is decelerating or braking, the energy recovery state is opened, i.e., the charging state is opened. Alternatively, the starting module opens the charging state in response to the user's clicking operation on the button for opening the energy recovery state. It should be noted that in the charging state, the battery management system sends the current charging current of the battery and the SOC of the battery to the pre-diagnosis module. Alternatively, the starting module in the vehicle controller opens the charging state in response to receiving a successful connection signal of the vehicle with an external device such as a charging pile or a charging machine. At the same time, based on the adjustment parameters sent by the adjustment module to the starting module in the subsequent steps, the starting module continues to charge the battery based on the corresponding adjustment parameters.

[0184] Step 602: The pre-diagnosis module determines whether the battery is in a suspected fault state. The specific determination method is the same as that of step 202 described above. The basis for the determination of the pre-diagnosis module is the information obtained by the information acquisition module in step 501 described above. If yes, step 603 is performed. If no, step 604 is performed.

[0185] Step 603: The pre-diagnosis module records the fault code corresponding to the suspected fault state, resets the recovery count to 0, and then performs step 605.

[0186] Step 604: The pre-diagnosis module increments the recovery count or the charging count by 1, and performs step 606.

[0187] Step 605: The compensation module determines a first adjustment parameter. The first adjustment parameter is determined in the same manner as in step 303 or step 403 described above, and will not be described here. Then, the adjustment module continues to charge the battery based on the first adjustment parameter, i.e., step 601 is performed based on the first adjustment parameter.

[0188] Step 606: The pre-diagnosis module determines whether the recovery count is equal to a target number. If yes, step 607 is performed. If no, step 601 is performed.

[0189] Step 607, the compensation module determines the second adjustment parameter or the third adjustment parameter, and sends the second adjustment parameter or the third adjustment parameter to the adjustment module, and then the adjustment module executes step 601 based on the second adjustment parameter or the third adjustment parameter.

[0190] It should be noted that when the first adjustment parameter and the second adjustment parameter are the first adjustment power and the second adjustment power respectively, the adjustment module sends the first adjustment parameter or the second adjustment parameter to the motor controller, so as to adjust the output torque of the motor, and then change the output power of the motor, that is, reduce the electric energy generated by the motor in the vehicle energy recovery working condition, and prevent the battery from overcharging. When the first adjustment parameter and the third adjustment parameter are the first adjustment current and the third adjustment current respectively, the adjustment module sends an output current request to an external device such as a charging pile or a charger, and the request is used to instruct the external device such as the charging pile or the charger to output current to the battery based on the first adjustment current or the third adjustment current. By this method, the potential failure of the battery can be timely predicted, and the charging state of the battery can also be timely adjusted, so as to more effectively protect the safety and life of the battery.

[0191] In the present application, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance. The term "a plurality of" refers to two or more, unless otherwise explicitly limited.

[0192] Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. The present application is intended to cover any variations, uses, or adaptations of the application following the general principles thereof and including such departures from the present disclosure as come within known or customary practice in the art. The specification and examples are to be regarded as illustrative only.

[0193] It should be understood that the present application is not limited to the precise structures described above and illustrated in the drawings, and that various modifications and changes can be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A battery protection method, characterized in that, The method includes: Obtain the actual charging current of the battery and the allowable charging current of the battery; Based on the actual charging current of the battery, the allowable charging current of the battery, the suspected fault current threshold, and the suspected fault time threshold, it is determined whether the battery is in a suspected fault state. When the battery is in a suspected fault state, a first adjustment parameter is determined based on the suspected fault current threshold. Based on the first adjustment parameter, the battery is charged; Under vehicle energy recovery conditions, the method further includes: Determine the number of times the battery can be recycled; When the number of recovery attempts equals the target number of recovery attempts, a second adjustment parameter is determined based on the first adjustment parameter and the target recovery parameter. Based on the second adjustment parameter, the battery is charged, and the number of times the vehicle is in energy recovery mode; Under the vehicle energy recovery operating condition, when the battery is in a suspected fault state, determining the first adjustment parameter based on the suspected fault current threshold includes: The first adjustment parameter is the first adjustment power, which is determined based on the following first formula: P1=P0-A×△I×U0 Where A is a coefficient greater than 0, P1 is the first adjustment power, P0 is the current recovery power of the battery, ΔI is the suspected fault current threshold, and U0 is the voltage corresponding to the current state of charge of the battery. The second adjustment parameter is the second adjustment power, which is determined based on the following formula: P2=P1+M×△I×U0 Where M is a coefficient and is greater than 0, P2 is the second adjustment power, P1 is the first adjustment power, and the value of M×△I×U0 is the target recovery parameter.

2. The battery protection method according to claim 1, characterized in that, The step of determining whether the battery is in a suspected fault state based on the battery's actual charging current, the battery's allowable charging current, the suspected fault current threshold, and the suspected fault time threshold includes: When the difference between the actual charging current of the battery and the allowable charging current of the battery is greater than the first suspected fault current threshold and the duration is less than the suspected fault time threshold, the battery is determined to be in the first suspected fault state.

3. The battery protection method according to claim 2, characterized in that, The step of determining whether the battery is in a suspected fault state based on the battery's actual charging current, the battery's allowable charging current, the suspected fault current threshold, and the suspected fault time threshold includes: When the difference between the actual charging current of the battery and the allowable charging current of the battery is greater than the second suspected fault current threshold, and the duration is greater than the suspected fault time threshold, the battery is determined to be in the second suspected fault state. Wherein, the second suspected fault current threshold is less than the first suspected fault current threshold.

4. The battery protection method according to claim 1, characterized in that, Under charging conditions, when the battery is in a suspected fault state, determining the first adjustment parameter based on the suspected fault current threshold includes: The first adjustment parameter is the first adjustment current, which is determined based on the following second formula: I1 = I0 - B × △I Where B is a coefficient greater than 0, I1 is the first adjustment current, I0 is the current requested charging current of the battery, and ΔI is the suspected fault current threshold.

5. The battery protection method according to claim 4, characterized in that, During charging, the method further includes: Determine the number of times the battery can be charged; When the number of charging cycles equals the target number of cycles, a third adjustment parameter is determined based on the first adjustment parameter and the target recovery parameter; The battery is charged based on the third adjustment parameter.

6. A battery protection device, characterized in that, The device includes: The information acquisition module is used to acquire the actual charging current of the battery and the allowable charging current of the battery. The pre-diagnosis module is used to determine whether the battery is in a suspected fault state based on the battery's actual charging current, the battery's allowable charging current, the suspected fault current threshold, and the suspected fault time threshold. The compensation module is used to determine a first adjustment parameter based on the suspected fault current threshold when the battery is in a suspected fault state. An adjustment module is used to charge the battery based on the first adjustment parameter; The pre-diagnosis module is also used to determine the number of times the battery can be recovered under vehicle energy recovery conditions; The compensation module is further configured to determine a second adjustment parameter based on the first adjustment parameter and the target recovery parameter when the number of recovery attempts equals the target number of recovery attempts; The adjustment module is also used to charge the battery based on the second adjustment parameter, wherein the number of times the vehicle is in the energy recovery mode; Under the vehicle energy recovery operating condition, when the battery is in a suspected fault state, determining the first adjustment parameter based on the suspected fault current threshold includes: The first adjustment parameter is the first adjustment power, which is determined based on the following first formula: P1=P0-A×△I×U0 Where A is a coefficient greater than 0, P1 is the first adjustment power, P0 is the current recovery power of the battery, ΔI is the suspected fault current threshold, and U0 is the voltage corresponding to the current state of charge of the battery. The second adjustment parameter is the second adjustment power, which is determined based on the following formula: P2=P1+M×△I×U0 Where M is a coefficient and is greater than 0, P2 is the second adjustment power, P1 is the first adjustment power, and the value of M×△I×U0 is the target recovery parameter.

7. A vehicle, characterized in that, The vehicle includes a battery management system (1), a vehicle controller (2), and a motor controller (3), wherein the vehicle controller is used to implement the battery protection method as described in any one of claims 1 to 5.

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