Method for judging short circuit of intelligent lithium battery for battery replacement of two-wheeled vehicle

Abstract

The invention belongs to the technical field of lithium battery control, and particularly relates to a two-wheeled vehicle battery replacement intelligent lithium battery short circuit judgment method, which comprises the following steps: S1, collecting current Ipre of a pre-amplification circuit, and during current collection, removing noise and interference by using low-pass or high-pass filtering, and extracting effective signals; s2, after collection is completed, whether Ipre is larger than a current threshold value Ipre-thd or not is judged, and if the Ipre is larger than the current threshold value Ipre-thd, a pre-amplification short circuit judgment process is started at the moment; s3, the acquisition module periodically acquires the battery voltage within the interval time T; and S4, comparing the acquired voltage data by a comparison module, and judging by adopting a p-acquisition circuit. According to the short-circuit judgment method for the intelligent lithium battery for battery replacement of the two-wheeled vehicle, a p-acquisition circuit is added and used for carrying out short-circuit judgment, an MCU acquires p-voltage, the p-voltage can be reduced to be within an ADC range through resistance voltage division on hardware, meanwhile, an operational amplifier is adopted for building a voltage follower, the stability of signal acquisition is improved, and current is limited.

Description

Technical Field

[0001] The present invention relates to the field of lithium battery control technology, and in particular to a method for determining short circuits in intelligent lithium batteries for battery replacement in two-wheeled vehicles. Background Art

[0002] The existing technology mainly collects the voltage VSRN-SRP across the sampling resistor through the front-end chip. The short-circuit threshold VSCD and the short-circuit protection delay time TSCD are set to perform short-circuit protection. When the collected VSRN-SRP is greater than VSCD and the duration exceeds TSCD, the protection action is triggered, the discharge MOS is turned off, and the fault flag is reported.

[0003] The prior art has the following problems:

[0004] 1. When the short-circuit protection is triggered, the discharge MOS is already turned on, and the safety is low. If an abnormality occurs and protection cannot be achieved, the positive and negative poles will continue to be short-circuited, which is dangerous.

[0005] 2. Rely on the front-end chip for protection. If the front-end chip fails, the protection measures will not take effect. Summary of the invention

[0006] Based on the existing technical problems, the present invention proposes a method for determining short circuit of an intelligent lithium battery for battery replacement of a two-wheeled vehicle.

[0007] The present invention proposes a method for judging short circuit of a two-wheeled vehicle battery replacement intelligent lithium battery, comprising step S1: collecting the current I of the pre-discharge circuit in this step; pre ,When current acquisition, low-pass or high-pass filtering is used to remove noise and interference and extract the effective signal.

[0008] Step S2: After the acquisition is completed, determine I pre Is it greater than the current threshold I pre-thd , if it is greater, then the pre-discharge short circuit judgment process is entered.

[0009] Step S3: the acquisition module periodically acquires the battery voltage within an interval T.

[0010] Step S4: The comparison module compares the collected voltage data and then uses the p-collection circuit to make a judgment.

[0011] Step S5: Determine that the battery pack is short-circuited, execute protection measures, turn off all MOS, and record the short-circuit flag.

[0012] Preferably, the step S3 includes step S31: interval time T p Collect the voltage of p- twice, the results are V p1 、V p2 ;

[0013] Step S32: Collecting the battery voltage V bat .

[0014] Through the above technical solution, real-time monitoring and management of the battery pack status can be achieved through pre-discharge and p-collection circuits. The pre-discharge circuit can provide buffer time when an abnormal situation occurs in the battery pack, so that the system has enough time to react and reduce the damage to the battery pack caused by short circuit. The p-collection circuit can detect short circuits in time by monitoring the voltage changes of the battery pack, and take corresponding measures to improve the accuracy and sensitivity of short circuit protection.

[0015] Preferably, the step 4 comprises step S41: respectively p1 and V p2 With V bat For comparison, V p1 and V p2 Any one with V bat The absolute value of the voltage difference is less than V sc-thd , if satisfied, proceed to the next step, if not satisfied, it is normal discharge.

[0016] Preferably, step S42: determining V p1 and V p2 Are both voltages higher than V P-thd , if satisfied, proceed to the next step, if not satisfied, the p-voltage acquisition is abnormal;

[0017] Step S43: Determine V p1 and V p2 The absolute value of the voltage difference is less than V PP-thd If satisfied, proceed to the next step. If not satisfied, the p-voltage acquisition is abnormal.

[0018] Preferably, the step S6 is further included: delay T Pre-delay Then reopen the pre-amplifier MOS, and the pre-amplifier short circuit judgment count N scd-thd +1 if N scd The number of times is higher than N scd-thd , go to the next step, if not satisfied, return to step S1.

[0019] Preferably, it also includes step S7: N scd The number of times has reached the upper limit, and short-circuit locking measures are implemented to shut down all MOS.

[0020] Preferably, the process further includes step S8: short circuit locking reaches locking time T scd-lock , release the short circuit lock and return to step S1.

[0021] Through the above technical solutions, the self-developed short-circuit protection algorithm is highly accurate, and can quickly and accurately detect and respond to short-circuit conditions in the battery pack, reducing the false alarm rate.

[0022] The beneficial effects of the present invention are:

[0023] 1. Add a pre-amplifier circuit to control the risk. The pre-amplifier circuit is designed to withstand the T scd-time , providing buffer time for software protection and improving security.

[0024] 2. Add a p- acquisition circuit to detect short circuits. The MCU collects the p- voltage, and the hardware can reduce the p- voltage to the ADC range through resistor voltage division. At the same time, an operational amplifier is used to build a voltage follower to improve the stability of signal acquisition and limit the current.

[0025] The pre-discharge and p-collection circuits can realize real-time monitoring and management of the battery pack status. The pre-discharge circuit can provide buffer time when the battery pack has abnormal conditions, so that the system has enough time to react and reduce the damage to the battery pack caused by short circuits. The p-collection circuit can monitor the voltage changes of the battery pack, detect short circuits in time, and take corresponding measures to improve the accuracy and sensitivity of short circuit protection.

[0026] 3. Through the self-developed short-circuit judgment algorithm, the self-developed short-circuit protection algorithm has a high degree of accuracy, can quickly and accurately detect and respond to the short circuit of the battery pack, and reduce the false alarm rate. The algorithm design is intelligent and can be dynamically adjusted according to the battery pack status and external environmental changes, improving the protection effect and avoiding unnecessary intervention, improving battery safety, and reducing short circuit risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic diagram of a two-wheeled vehicle battery replacement intelligent lithium battery short circuit judgment method proposed by the present invention;

[0028] Figure 2 This is a front-end short-circuit protection experimental data diagram in Example 1 of a two-wheeled vehicle battery replacement intelligent lithium battery short-circuit judgment method proposed by the present invention;

[0029] Figure 3 This is a graph of the pre-discharge short-circuit protection experiment data in Example 1 of a two-wheeled vehicle battery replacement intelligent lithium battery short-circuit judgment method proposed by the present invention. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0031] Reference Figure 1A method for judging short circuit of a two-wheeled vehicle battery replacement intelligent lithium battery comprises step S1: in this step, a current I of a pre-discharge circuit is collected. pre ,When current acquisition, low-pass or high-pass filtering is used to remove noise and interference and extract the effective signal.

[0032] Step S2: After the acquisition is completed, determine I pre Is it greater than the current threshold I pre-thd , if it is greater, then the pre-discharge short circuit judgment process is entered.

[0033] By adding a pre-amplifier circuit, the risk can be controlled. The pre-amplifier circuit is designed to withstand the T scd-time , providing buffer time for software protection and improving security.

[0034] Step S3: the acquisition module periodically acquires the battery voltage within an interval T.

[0035] The step S3 includes step S31: interval time T p Collect the voltage of p- twice, the results are V p1 、V p2 .

[0036] Step S32: Collect the battery voltage V bat .

[0037] By adding a p- acquisition circuit, it is used for short circuit judgment. The MCU collects the p- voltage, and the hardware can reduce the p- voltage to the ADC range through resistor voltage division. At the same time, an operational amplifier is used to build a voltage follower to improve the stability of signal acquisition and limit the current.

[0038] The pre-discharge and p-collection circuits can be used to monitor and manage the battery pack status in real time. The pre-discharge circuit can provide buffer time when the battery pack is abnormal, so that the system has enough time to react and reduce the damage to the battery pack caused by short circuit. The p-collection circuit can monitor the voltage changes of the battery pack, detect short circuits in time, and take corresponding measures to improve the accuracy and sensitivity of short circuit protection.

[0039] Step S4: The comparison module compares the collected voltage data and then uses the p-collection circuit to make a judgment.

[0040] The step 4 comprises step S41: respectively setting V p1 and V p2 With V bat For comparison, V p1 and V p2 Any one with V bat The absolute value of the voltage difference is less than V sc-thd, if satisfied, proceed to the next step, if not satisfied, it is normal discharge.

[0041] Step S42: Determine V p1 and V p2 Are both voltages higher than V P-thd , if satisfied, proceed to the next step, if not satisfied, the p-voltage acquisition is abnormal;

[0042] Step S43: Determine V p1 and V p2 The absolute value of the voltage difference is less than V PP-thd If satisfied, proceed to the next step. If not satisfied, the p-voltage acquisition is abnormal.

[0043] Step S5: Determine that the battery pack is short-circuited, execute protection measures, turn off all MOS, and record the short-circuit flag.

[0044] Step S6: Delay T Pre-delay Then reopen the pre-amplifier MOS, and the pre-amplifier short circuit judgment count N scd-thd +1 if N scd The number of times is higher than N scd-thd , go to the next step, if not satisfied, return to step S1.

[0045] Step S7: N scd The number of times has reached the upper limit, and short-circuit locking measures are implemented to shut down all MOS.

[0046] Step S8: Short circuit lock reaches lock time T scd-lock , release the short circuit lock and return to step S1.

[0047] Through the self-developed short-circuit judgment algorithm, the self-developed short-circuit protection algorithm has a high degree of accuracy, can quickly and accurately detect and respond to the short circuit of the battery pack, and reduce the false alarm rate. The algorithm design is intelligent and can be dynamically adjusted according to the battery pack status and external environment changes, improving the protection effect and avoiding unnecessary intervention, improving battery safety, and reducing short circuit risks.

[0048] Example 1

[0049] Reference Figure 1-Figure 3 , a method for judging short circuit of intelligent lithium battery for two-wheeled vehicle battery replacement:

[0050] Step S1: In this step, the current I of the preamplifier circuit is collected. pre ,When current acquisition, low-pass or high-pass filtering is used to remove noise and interference and extract the effective signal.

[0051] Step S2: After the acquisition is completed, determine I pre Is it greater than the current threshold of 500uA? If so, the pre-discharge short-circuit judgment process is entered.

[0052] Step S3: the acquisition module periodically acquires the battery voltage within an interval T.

[0053] The step S3 comprises step S31: interval time T p Collect the voltage of p- twice, the results are V p1 、V p2 .

[0054] Step S32: Collecting the battery voltage V bat .

[0055] Step S4: The comparison module compares the collected voltage data and then uses the p-collection circuit to make a judgment.

[0056] The step 4 comprises step S41: respectively setting V p1 and V p2 With V bat For comparison, V p1 and V p2 Any one with V bat If the absolute value of the voltage difference is less than 5000mV, the system will proceed to the next step. If not, the system will discharge normally.

[0057] Step S42: Determine V p1 and V p2 Are both voltages higher than 27000mV? If yes, proceed to the next step. If not, it indicates that the p-voltage acquisition is abnormal.

[0058] Step S43: Determine V p1 and V p2 The absolute value of the voltage difference is less than 5000mV, which satisfies the condition and proceeds to the next step. If not, it indicates that the p-voltage acquisition is abnormal.

[0059] Step S5: Determine that the battery pack is short-circuited, execute protection measures, turn off all MOS, and record the short-circuit flag.

[0060] Step S6: After a delay of 1S, the pre-discharge MOS is reopened, and the pre-discharge short circuit judgment count N is set. scd-thd +1 if N scd If the number of times is greater than 8, go to the next step. If not satisfied, return to step S1.

[0061] Step S7: N scd The number of times has reached the upper limit, and short-circuit locking measures are implemented to shut down all MOS.

[0062] Step S8: When the short circuit lock reaches the lock time of 5 minutes, the short circuit lock is released and the process returns to step S1.

[0063] Short circuit test data table:

[0064]

[0065]

[0066] in:

[0067] I pre-thd :500uA;V sc-thd :5000mV; V P-thd :27000mV; V PP-thd :5000mV; T Pre-delay : 1S for the first time, 3S for the next seven times; N scd-thd : 8 times; T scd-lock : 5 minutes.

[0068] Combined with the above short circuit test data table Figure 2-Figure 3 As shown, it can be seen that when the MOS control signal is high, the MOS is turned on, and when the MOS control signal is low, the MOS is turned off.

[0069] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A two-wheeled vehicle battery replacement intelligent lithium battery short circuit judgment method, characterized in that: The step S1 includes collecting the current I of the preamplifier circuit. pre ,When current is collected, low-pass or high-pass filtering is used to remove noise and interference and extract the effective signal; Step S2: After the acquisition is completed, determine I pre Is it greater than the current threshold I pre-thd , if it is greater than, then enter the pre-discharge short circuit judgment process; Step S3: the acquisition module periodically acquires the battery voltage within an interval T; Step S4: The comparison module compares the collected voltage data and then uses the p-collection circuit to make a judgment; Step S5: Determine that the battery pack is short-circuited, execute protection measures, turn off all MOS, and record the short-circuit flag.

2. A two-wheeled vehicle battery replacement intelligent lithium battery short circuit judgment method according to claim 1, characterized in that: The step S3 comprises step S31: interval time T p Collect the voltage of p- twice, the results are V p1 、V p2 ; Step S32: Collect the battery voltage V bat .

3. A two-wheeled vehicle battery replacement intelligent lithium battery short circuit judgment method according to claim 2, characterized in that: The step 4 comprises step S41: respectively setting V p1 and V p2 With V bat For comparison, V p1 and V p2 Any one with V bat The absolute value of the voltage difference is less than V sc-thd , if satisfied, proceed to the next step, if not satisfied, it is normal discharge.

4. A two-wheeled vehicle battery replacement intelligent lithium battery short circuit judgment method according to claim 3, characterized in that: Step S42: Determine V p1 and V p2 Are both voltages higher than V P-thd , if satisfied, proceed to the next step, if not satisfied, the p-voltage acquisition is abnormal; Step S43: Determine V p1 and V p2 The absolute value of the voltage difference is less than V PP-thd If satisfied, proceed to the next step. If not satisfied, the p-voltage acquisition is abnormal.

5. A two-wheeled vehicle battery replacement intelligent lithium battery short circuit judgment method according to claim 1, characterized in that: Also includes step S6: delay T Pre-delay Then reopen the pre-amplifier MOS, and the pre-amplifier short circuit judgment count N scd-thd +1 if N scd The number of times is higher than N scd-thd , go to the next step, if not satisfied, return to step S1.

6. A two-wheeled vehicle battery replacement intelligent lithium battery short circuit judgment method according to claim 5, characterized in that: Also includes step S7: N scd The number of times has reached the upper limit, and short-circuit locking measures are implemented to shut down all MOS.

7. A two-wheeled vehicle battery replacement intelligent lithium battery short circuit judgment method according to claim 6, characterized in that: Also includes step S8: short circuit locking reaches locking time T scd-lock , release the short circuit lock and return to step S1.

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