A battery voltage monitoring system and method

Abstract

This invention discloses a battery voltage monitoring system and method, specifically relating to the field of battery voltage measurement technology. It includes multiple autonomous voltage monitoring units: each autonomous voltage monitoring unit corresponds one-to-one with each battery cell in a battery pack, and each autonomous voltage monitoring unit integrates an analog monitoring circuit and a temperature sensor. The temperature sensor is used to collect the operating temperature of the corresponding battery cell in real time, and the analog monitoring circuit is used to collect the cell voltage of the corresponding battery cell in real time. This invention employs a three-layer adjustment approach—preliminary suppression at the front end, accuracy assurance in the middle, and deep correction at the back end—to avoid system failure due to a single module malfunction, thus improving the reliability of battery voltage monitoring. Through high-precision voltage balancing and real-time temperature monitoring, it reduces battery degradation caused by overcharging, undercharging, or imbalance within the battery pack, extending the overall lifespan of the battery pack, avoiding safety risks caused by abnormal voltage, and improving battery application safety.

Description

Technical Field

[0001] This invention relates to the field of battery voltage measurement technology, and more specifically, to a battery voltage monitoring system and method. Background Technology

[0002] With the increasing popularity of energy storage systems and portable devices, series-connected battery packs have become the mainstream power supply solution. For example, electric vehicles require series-connected batteries to reach 800V+. However, the inconsistency of battery cells leads to voltage imbalance among cells in the series system, significantly increasing the risk of overcharging or undercharging, which directly affects lifespan. For example, a single PEMFC cell with a voltage <0.4V will suffer permanent damage and safety risks.

[0003] Traditional battery voltage monitoring units mostly only have a single voltage acquisition function, and the adjustment relies on centralized control at the back end, which poses the risk of response delay and the amplification of local imbalance. At the same time, in order to ensure the measurement accuracy of the upper battery unit in the series battery pack, traditional monitoring often adopts a full-domain boost drive method, which leads to the boost circuit operating under continuous high load, resulting in prominent energy consumption and heat generation issues. If the boost is not applied, the upper unit is prone to measurement errors due to the voltage stacking effect. Furthermore, traditional battery balancing often adopts a single adjustment mode, such as relying solely on centralized balancing or relying solely on local passive balancing, making it difficult to balance adjustment accuracy and efficiency. Summary of the Invention

[0004] In order to overcome the above-mentioned defects of the prior art, the present invention provides a battery voltage monitoring system and method to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a battery voltage monitoring system, comprising:

[0006] Multiple autonomous voltage monitoring units: Each autonomous voltage monitoring unit is configured to correspond one-to-one with each battery cell in the battery pack, and each autonomous voltage monitoring unit integrates an analog monitoring circuit and a temperature sensor;

[0007] The temperature sensor is used to collect the operating temperature of the corresponding battery cell in real time, and the analog monitoring circuit is used to collect the cell voltage of the corresponding battery cell in real time and compare the difference between the cell voltage and the preset reference voltage. When the difference exceeds a first threshold, the analog monitoring circuit dynamically adjusts the duty cycle of the built-in transistor to achieve preliminary current shunting balance for the corresponding battery cell.

[0008] Intelligent drive switching module: The intelligent drive switching module is electrically connected to the plurality of autonomous voltage monitoring units and includes a first buffer amplifier, a second buffer amplifier and a voltage switching unit;

[0009] The voltage switching unit is used to first determine whether the battery cell to be monitored is a higher-level battery cell. A higher-level battery cell is a battery cell in the battery pack that is in a high-series position, has a higher voltage level, and is susceptible to interference from the stacking effect. If it is a higher-level battery cell, the voltage switching unit switches the driving voltage of the first buffer amplifier and the second buffer amplifier to a boost voltage. The boost voltage is higher than the system power supply voltage. If it is not a higher-level battery cell, the voltage switching unit configures the driving voltage of the first buffer amplifier and the second buffer amplifier to the system power supply voltage.

[0010] The intelligent drive switching module is also used to receive the operating temperature collected by the temperature sensor and correct the parameters of the drive voltage according to the operating temperature: when the operating temperature is lower than a preset low temperature threshold, the drive voltage is increased to compensate for signal attenuation; when the operating temperature is higher than a preset high temperature threshold, the drive voltage is decreased to avoid signal distortion.

[0011] Centralized diagnostic module: used to receive in real time the unit voltage and operating temperature output by the autonomous voltage monitoring unit, as well as the amplified voltage signal output by the first buffer amplifier and the second buffer amplifier, and to determine the operating status of the battery unit based on the difference between the unit voltage and the preset reference voltage, the unit voltage difference between each battery unit, and the operating temperature.

[0012] The centralized diagnostic module is electrically connected to the plurality of autonomous voltage monitoring units and the intelligent drive switching module, respectively.

[0013] When the initial current balancing of the autonomous voltage monitoring unit fails to eliminate the abnormal state of the battery cell, the centralized diagnostic module triggers a deep equalization command, which performs a deep equalization operation on the abnormal battery cell through the built-in digital adjustment circuit.

[0014] Preferably, the first threshold is ±5% of the preset reference voltage, that is, when the difference between the unit voltage and the preset reference voltage exceeds ±5% of the preset reference voltage, the analog monitoring circuit (3) starts the initial current balancing.

[0015] Preferably, the logic of the analog monitoring circuit (3) adjusting the transistor duty cycle is as follows: if the cell voltage of the battery cell (2) is higher than the preset reference voltage, the transistor duty cycle is increased to release excess power; if the cell voltage of the battery cell (2) is lower than the preset reference voltage, the transistor duty cycle is decreased to retain power.

[0016] Preferably, the digital adjustment circuit (10) is a bidirectional equalizer, and the deep equalization operation includes: performing directional discharge on overcharged battery cells (2) and performing supplementary charging on undercharged battery cells until the cell voltages of all battery cells tend to be consistent.

[0017] Preferably, the conditions for the centralized diagnostic module to determine the abnormal state of the battery cell include:

[0018] If the cell voltage of a certain battery cell is consistently higher than the preset reference voltage, and the situation does not improve after the autonomous voltage monitoring unit performs a preliminary shunt balancing, it is determined to be a "severe overcharge anomaly".

[0019] If the voltage difference between any two battery cells exceeds the second threshold, it is determined to be an "abnormal imbalance within the group".

[0020] Preferably, the second threshold is ±% of the preset reference voltage, that is, when the voltage difference between any two battery cells exceeds ±% of the preset reference voltage, the "intra-group imbalance anomaly" judgment is triggered.

[0021] A method for monitoring battery voltage is also provided, based on the aforementioned battery voltage monitoring system, comprising the following steps:

[0022] S1. Autonomous monitoring and preliminary balancing: Through an autonomous voltage monitoring unit corresponding to each battery cell, the cell voltage and operating temperature of the battery cell are collected in real time. The cell voltage is compared with the preset reference voltage. If the difference exceeds the first threshold, the transistor duty cycle is adjusted through the analog monitoring circuit to achieve preliminary current balancing.

[0023] S2. Intelligent drive and voltage correction: The intelligent drive switching module determines whether the battery unit to be monitored is a host battery unit, and switches the drive voltage of the buffer amplifier as needed. The host unit uses the boost voltage, and the non-host unit uses the power supply voltage. At the same time, the drive voltage parameters are corrected according to the collected operating temperature to compensate for the influence of the environment on the signal.

[0024] S3. Centralized Diagnosis and Deep Equalization: The centralized diagnosis module summarizes the data collected by the autonomous voltage monitoring unit and the amplified signal of the intelligent drive switching module. Combined with the unit voltage difference and operating temperature, the battery unit status is judged. If the preliminary balancing cannot eliminate the abnormality, the deep equalization command is triggered. The abnormal unit is discharged or recharged through the digital adjustment circuit to achieve full-domain voltage balance.

[0025] Preferably, in step S1, the specific operation of adjusting the transistor duty cycle includes: increasing the conduction duty cycle when the unit voltage is too high, and decreasing the conduction duty cycle when the unit voltage is too low.

[0026] Preferably, in step S2, the specific logic for correcting the driving voltage parameters is as follows: when the operating temperature is lower than the preset low temperature threshold of -10℃, the driving voltage is increased by 10%-15%; when the operating temperature is higher than the preset high temperature threshold of 60℃, the driving voltage is decreased by 8%-12%.

[0027] Preferably, in step S3, the conditions for determining the abnormal state include: the cell voltage continuously exceeds the preset reference voltage and the initial balancing is ineffective, or the voltage difference between cells exceeds the second threshold (±3% of the preset reference voltage). The deep balancing operation is performed by a bidirectional equalizer until the cell voltage deviation of all battery cells is less than ±1%.

[0028] The technical effects and advantages of this invention are as follows:

[0029] Through an autonomous voltage monitoring unit corresponding to each battery cell, the unit voltage is collected in real time to reflect the power, and the operating temperature is collected to reflect the environmental impact. When the voltage difference from the reference voltage exceeds the first threshold, the transistor duty cycle is adjusted immediately to achieve preliminary current shunting balance. If the voltage is too high, the duty cycle is increased to release power; if the voltage is too low, the duty cycle is decreased to retain power. This solves the problem of traditional systems relying on centralized back-end control and response delay leading to the expansion of local imbalance. The preliminary front-end balance can eliminate most minor voltage anomalies, eliminating the need for all anomalies to be transmitted to the back-end for processing. This significantly reduces the adjustment pressure on the centralized diagnostic module and improves the overall operating efficiency of the system.

[0030] By using an intelligent drive switching module, only the upper battery unit susceptible to stacking effect interference is boosted, while the remaining units use the system power supply voltage. This replaces the traditional full-domain boost drive mode, reduces the continuous high-load operation time of the boost circuit, significantly reduces system energy consumption and heat generation, and combines temperature sensor signals to correct the drive voltage. At low temperatures, boosting compensates for signal attenuation, and at high temperatures, de-energizing avoids signal distortion. This solves the problems of large errors in upper unit due to stacking effect and the influence of ambient temperature on accuracy in traditional measurements, ensuring the accuracy of voltage acquisition in complex environments such as high and low temperatures.

[0031] By centrally diagnosing the voltage and temperature data of the autonomous units and combining them with the high-precision amplified signal from the buffer amplifier, and using dual judgment conditions, the system avoids the problem of misjudgment caused by the single judgment dimension of traditional systems. When the initial balance cannot solve the anomaly, the built-in digital adjustment circuit performs overcharged unit discharge and undercharged unit recharging, ultimately ensuring that the voltage deviation of all units is less than ±1%. This solves the problem that the traditional single adjustment mode cannot balance accuracy and efficiency, and achieves high-precision voltage balance across the entire battery pack.

[0032] In summary, through the interaction of the above-mentioned multiple functions, and through the three-layer regulation of initial suppression at the front end, accuracy assurance in the middle end, and deep correction at the back end, each module performs its own function and works together to avoid system failure due to the failure of a single module. This significantly improves the reliability of battery voltage monitoring. Through high-precision voltage balancing and real-time temperature monitoring, it reduces battery degradation caused by overcharging, undercharging, or imbalance within the battery pack, extends the overall lifespan of the battery pack, and avoids safety risks caused by abnormal voltage, thereby improving the safety of battery applications. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the system structure of the present invention.

[0034] The attached figures are labeled as follows: 1. Autonomous voltage monitoring unit; 2. Battery unit; 3. Analog monitoring circuit; 4. Temperature sensor; 5. Intelligent drive switching module; 6. First buffer amplifier; 7. Second buffer amplifier; 8. Voltage switching unit; 9. Centralized diagnostic module; 10. Digital adjustment circuit. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] As attached Figure 1 A battery voltage monitoring system is shown, comprising:

[0037] Multiple autonomous voltage monitoring units 1: Each autonomous voltage monitoring unit 1 is set up in a one-to-one correspondence with each battery cell 2 in the battery pack. Each autonomous voltage monitoring unit 1 integrates an analog monitoring circuit 3 and a temperature sensor 4.

[0038] Temperature sensor 4 is used to collect the operating temperature of the corresponding battery cell 2 in real time. Analog monitoring circuit 3 is used to collect the cell voltage of the corresponding battery cell 2 in real time and compare the difference between the cell voltage and the preset reference voltage. When the difference exceeds the first threshold, analog monitoring circuit 3 dynamically adjusts the duty cycle of the built-in transistor to achieve preliminary current shunting balance for the corresponding battery cell 2.

[0039] Intelligent drive switching module 5: Intelligent drive switching module 5 is electrically connected to multiple autonomous voltage monitoring units 1, including a first buffer amplifier 6, a second buffer amplifier 7 and a voltage switching unit 8;

[0040] The voltage switching unit 8 is used to first determine whether the battery cell 2 to be monitored is a higher-level battery cell. A higher-level battery cell is a battery cell in the battery pack that is in a high position in series, has a higher voltage level, and is easily affected by the stacking effect. If it is a higher-level battery cell, the voltage switching unit 8 switches the driving voltage of the first buffer amplifier 6 and the second buffer amplifier 7 to a boost voltage. The boost voltage is higher than the system power supply voltage. If it is not a higher-level battery cell, the voltage switching unit 8 configures the driving voltage of the first buffer amplifier 6 and the second buffer amplifier 7 to the system power supply voltage.

[0041] The intelligent drive switching module 5 is also used to receive the operating temperature collected by the temperature sensor 4 and correct the parameters of the drive voltage according to the operating temperature: when the operating temperature is lower than the preset low temperature threshold, the drive voltage is increased to compensate for signal attenuation; when the operating temperature is higher than the preset high temperature threshold, the drive voltage is reduced to avoid signal distortion.

[0042] Centralized diagnostic module 9: It is used to receive the unit voltage and operating temperature output by autonomous voltage monitoring unit 1 in real time, as well as the amplified voltage signal output by first buffer amplifier 6 and second buffer amplifier 7. Based on the difference between the unit voltage and the preset reference voltage, the unit voltage difference between each battery unit 2, and the operating temperature, it determines the operating status of battery unit 2.

[0043] The centralized diagnostic module 9 is electrically connected to multiple autonomous voltage monitoring units 1 and intelligent drive switching module 5, respectively.

[0044] When the initial shunt balancing of the autonomous voltage monitoring unit 1 fails to eliminate the abnormal state of the battery unit 2, the centralized diagnostic module 9 triggers a deep equalization command, and performs a deep equalization operation on the abnormal battery unit 2 through the built-in digital adjustment circuit 10.

[0045] The first threshold is ±5% of the preset reference voltage. That is, when the difference between the unit voltage and the preset reference voltage exceeds ±5% of the preset reference voltage, the analog monitoring circuit 3 starts the initial current balancing.

[0046] The logic of the analog monitoring circuit 3 in adjusting the transistor duty cycle is as follows: if the cell voltage of battery cell 2 is higher than the preset reference voltage, the transistor duty cycle is increased to release excess power; if the cell voltage of battery cell 2 is lower than the preset reference voltage, the transistor duty cycle is decreased to retain power.

[0047] The digital adjustment circuit 10 is a bidirectional equalizer. The deep equalization operation includes: performing directional discharge on overcharged battery cells 2 and performing supplementary charging on undercharged battery cells 2 until the cell voltage of all battery cells 2 tends to be consistent.

[0048] The conditions for the centralized diagnostic module 9 to determine the abnormal state of battery cell 2 include:

[0049] The cell voltage of a certain battery cell 2 is consistently higher than the preset reference voltage, and the situation has not improved even after the initial current balancing by the autonomous voltage monitoring unit 1. It is determined to be a "severe overcharge abnormality".

[0050] If the voltage difference between any two battery cells 2 exceeds the second threshold, it is determined as "abnormal imbalance within the group".

[0051] The second threshold is ±3% of the preset reference voltage. That is, when the voltage difference between any two battery cells 2 exceeds ±3% of the preset reference voltage, the "intra-group imbalance anomaly" judgment is triggered.

[0052] A method for monitoring battery voltage is also provided, based on the aforementioned battery voltage monitoring system, comprising the following steps:

[0053] S1. Autonomous monitoring and preliminary balancing: Through the autonomous voltage monitoring unit 1 corresponding to each battery cell 2, the cell voltage and operating temperature of the battery cell 2 are collected in real time. The cell voltage is compared with the preset reference voltage. If the difference exceeds the first threshold, the transistor duty cycle is adjusted through the analog monitoring circuit 3 to achieve preliminary shunt balancing.

[0054] In S1, the specific operations for adjusting the transistor duty cycle include: increasing the duty cycle when the cell voltage is too high, and decreasing the duty cycle when the cell voltage is too low.

[0055] S2. Intelligent drive and voltage correction: The intelligent drive switching module 5 determines whether the battery unit 2 to be monitored is a host battery unit, and switches the drive voltage of the buffer amplifier as needed. The host unit uses the boost voltage, and the non-host unit uses the power supply voltage. At the same time, the drive voltage parameters are corrected according to the collected operating temperature to compensate for the influence of the environment on the signal.

[0056] In S2, the specific logic for correcting the drive voltage parameters is as follows: when the operating temperature is lower than the preset low temperature threshold of -10℃, the drive voltage is increased by 10%-15%; when the operating temperature is higher than the preset high temperature threshold of 60℃, the drive voltage is decreased by 8%-12%.

[0057] S3. Centralized Diagnosis and Deep Equalization: The centralized diagnosis module 9 summarizes the collected data from the autonomous voltage monitoring unit 1 and the amplified signal from the intelligent drive switching module 5. It combines the unit voltage difference and operating temperature to determine the state of the battery unit 2. If the preliminary balancing cannot eliminate the abnormality, the deep equalization command is triggered. The digital adjustment circuit 10 performs directional discharge or supplementary charging on the abnormal unit to achieve full-domain voltage balance.

[0058] In S3, the conditions for judging abnormal states include: the cell voltage continuously exceeds the preset reference voltage and the initial balancing is ineffective, or the voltage difference between cells exceeds the second threshold preset reference voltage by ±3%. The deep balancing operation is performed by the bidirectional equalizer until the cell voltage deviation of all battery cells 2 is less than ±1%.

[0059] Finally, it should be noted that the accompanying drawings of the embodiments disclosed in this invention only involve the structures involved in the embodiments disclosed in this invention. Other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of this invention can be combined with each other.

[0060] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A battery voltage monitoring system, characterized in that: include: Multiple autonomous voltage monitoring units (1): Multiple autonomous voltage monitoring units (1) are set one-to-one with each battery cell (2) in the battery pack. Each autonomous voltage monitoring unit (1) integrates an analog monitoring circuit (3) and a temperature sensor (4). The temperature sensor (4) is used to collect the working temperature of the corresponding battery cell (2) in real time. The analog monitoring circuit (3) is used to collect the cell voltage of the corresponding battery cell (2) in real time and compare the difference between the cell voltage and the preset reference voltage. When the difference exceeds the first threshold, the analog monitoring circuit (3) dynamically adjusts the duty cycle of the built-in transistor to achieve preliminary current shunting balance for the corresponding battery cell (2). Intelligent drive switching module (5): The intelligent drive switching module (5) is electrically connected to the plurality of autonomous voltage monitoring units (1). The intelligent drive switching module (5) includes a first buffer amplifier (6), a second buffer amplifier (7), and a voltage switching unit (8). The voltage switching unit (8) is used to first determine whether the battery cell (2) to be monitored is a higher-level battery cell. The higher-level battery cell is a battery cell in the battery pack that is in a high-level series position, has a high voltage level, and is easily affected by the stacking effect. If it is a higher-level battery cell, the voltage switching unit (8) switches the driving voltage of the first buffer amplifier (6) and the second buffer amplifier (7) to a boost voltage. The boost voltage is higher than the system power supply voltage. If it is not a higher-level battery cell, the voltage switching unit (8) configures the driving voltage of the first buffer amplifier (6) and the second buffer amplifier (7) to the system power supply voltage. The intelligent drive switching module (5) is also used to receive the working temperature collected by the temperature sensor (4) and correct the parameters of the drive voltage according to the working temperature: when the working temperature is lower than the preset low temperature threshold, the drive voltage is increased to compensate for signal attenuation; when the working temperature is higher than the preset high temperature threshold, the drive voltage is decreased to avoid signal distortion. Centralized diagnostic module (9): Used to receive the unit voltage and operating temperature output by the autonomous voltage monitoring unit (1) in real time, as well as the amplified voltage signal output by the first buffer amplifier (6) and the second buffer amplifier (7), and to determine the working status of the battery unit (2) based on the difference between the unit voltage and the preset reference voltage, the difference between the unit voltages of each battery unit (2), and the operating temperature. The centralized diagnostic module (9) is electrically connected to the plurality of autonomous voltage monitoring units (1) and the intelligent drive switching module (5), respectively; When the initial shunt balancing of the autonomous voltage monitoring unit (1) fails to eliminate the abnormal state of the battery cell (2), the centralized diagnostic module (9) triggers a deep equalization command. The centralized diagnostic module (9) performs a deep equalization operation on the abnormal battery cell (2) through the built-in digital adjustment circuit (10).

2. The battery voltage monitoring system according to claim 1, characterized in that: The first threshold is ±5% of the preset reference voltage. That is, when the difference between the unit voltage and the preset reference voltage exceeds ±5% of the preset reference voltage, the analog monitoring circuit (3) starts the initial current balancing.

3. The battery voltage monitoring system according to claim 1, characterized in that: The logic of the analog monitoring circuit (3) to adjust the transistor duty cycle is as follows: if the cell voltage of the battery cell (2) is higher than the preset reference voltage, the transistor duty cycle is increased to release excess power; if the cell voltage of the battery cell (2) is lower than the preset reference voltage, the transistor duty cycle is decreased to retain power.

4. The battery voltage monitoring system according to claim 1, characterized in that: The digital adjustment circuit (10) is a bidirectional equalizer. The deep equalization operation includes: performing directional discharge on overcharged battery cells (2) and performing supplementary charging on undercharged battery cells (2) until the cell voltage of all battery cells (2) tends to be consistent.

5. A battery voltage monitoring system according to claim 1, characterized in that: The conditions for the centralized diagnostic module (9) to determine the abnormal state of the battery cell (2) include: The cell voltage of a certain battery cell (2) is consistently higher than the preset reference voltage, and the problem is not improved after the autonomous voltage monitoring unit (1) performs a preliminary shunt balancing. It is determined to be a "severe overcharge abnormality". If the voltage difference between any two battery cells (2) exceeds the second threshold, it is determined as "abnormal imbalance within the group".

6. The battery voltage monitoring system according to claim 5, characterized in that: The second threshold is ±3% of the preset reference voltage, that is, when the difference between the unit voltages of any two battery cells (2) exceeds ±3% of the preset reference voltage, the "intra-group imbalance abnormality" judgment is triggered.

7. A method for monitoring battery voltage, implemented based on the battery voltage monitoring system according to any one of claims 1-6, characterized in that: Includes the following steps: S1. Autonomous monitoring and preliminary balancing: Through the autonomous voltage monitoring unit (1) corresponding to each battery cell (2), the unit voltage and operating temperature of the battery cell (2) are collected in real time. The unit voltage is compared with the preset reference voltage. If the difference exceeds the first threshold, the transistor duty cycle is adjusted through the analog monitoring circuit (3) to achieve preliminary shunting balance. S2. Intelligent drive and voltage correction: The intelligent drive switching module (5) determines whether the battery unit (2) to be monitored is a host battery unit, and switches the drive voltage of the buffer amplifier as needed. The host unit uses the boost voltage, and the non-host unit uses the power supply voltage. At the same time, the drive voltage parameters are corrected according to the collected working temperature to compensate for the influence of the environment on the signal. S3. Centralized diagnosis and deep equalization: The centralized diagnosis module (9) summarizes the collected data of the autonomous voltage monitoring unit (1) and the amplified signal of the intelligent drive switching module (5), and judges the status of the battery unit (2) by combining the unit voltage difference and the working temperature. If the preliminary equalization cannot eliminate the abnormality, the deep equalization command is triggered, and the abnormal unit is discharged or recharged by the digital adjustment circuit (10) to achieve full-domain voltage balance.

8. The method for monitoring battery voltage according to claim 7, characterized in that: In step S1, the specific operation of adjusting the transistor duty cycle includes: increasing the conduction duty cycle when the unit voltage is too high, and decreasing the conduction duty cycle when the unit voltage is too low.

9. A method for monitoring battery voltage according to claim 7, characterized in that: In S2, the specific logic for correcting the driving voltage parameters is as follows: when the operating temperature is lower than the preset low temperature threshold of -10℃, the driving voltage is increased by 10%-15%; when the operating temperature is higher than the preset high temperature threshold of 60℃, the driving voltage is decreased by 8%-12%.

10. A method for monitoring battery voltage according to claim 7, characterized in that: In S3, the conditions for judging the abnormal state include: the cell voltage continuously exceeds the preset reference voltage and the initial balance is ineffective, or the voltage difference between cells exceeds the second threshold. The deep equalization operation is performed by a bidirectional equalizer until the cell voltage deviation of all battery cells (2) is less than ±1%.

Images