A new energy vehicle BMS battery management system

Abstract

A new energy vehicle BMS battery management system relates to the technical field of BMS, comprising a monitoring center, wherein the monitoring center is communicatively connected with a data acquisition module, a charge and discharge power distribution module, a charge and discharge power control module and a battery real-time monitoring module; the battery state parameters and driving state parameters of each single battery in a battery pack are collected, and the collection time is marked, and a collection cycle is set; the charge and discharge power threshold interval of the current collection cycle is obtained according to the battery state parameters and the driving state parameters; the charge and discharge power of each single battery is adjusted to within the charge and discharge power threshold interval according to the charge and discharge power threshold interval of the single battery; the battery state parameters of each single battery are monitored in real time, and active or passive balancing control operations are performed on each single battery according to the monitoring results, so as to optimize the operation of the battery within the optimal working range, improve energy utilization efficiency, and ensure vehicle safety and driving stability.

Description

Technical Field

[0001] The present invention relates to the technical field of BMS, and in particular to a BMS battery management system for new energy vehicles. Background Art

[0002] The prior art CN105904986B "A remote battery management detection method and system for new energy vehicles" includes the following steps: the charging pile obtains the battery pack ID number, remaining power statistics and pre-charging time from the BMS and reports them to the background server; after charging is completed, the charging pile reports the battery pack ID number, actual charging time and total power statistics to the background server, and the background server compares the battery pack charge and discharge curves and outputs multiple weighted average calibration parameters; it is determined whether the calibration parameters are within the allowable range. If so, the background server outputs the calibration parameters to the charging pile, and then calibrates the battery pack parameters in the BMS through the communication between the charging pile and the BMS. If not, the background server sends an early warning message to the manufacturer or the owner. The present invention performs effective online monitoring and parameter compensation on the battery management system of new energy vehicles, thereby greatly improving the battery life and fault prediction, and reducing maintenance costs.

[0003] The prior art CN114670710A "Battery Management System Balancing Control Method, Device, Control Equipment and Automobile" uses the simulation model of the battery management system BMS to work in the first mode of at least two modes, simulates the operation of the BMS, and obtains the simulation results of the simulation model under at least one balancing control strategy; according to the simulation results, determines the target balancing control strategy of the BMS from the at least one balancing control strategy; when the BMS is working, uses the strategy parameters corresponding to the target balancing control strategy to perform balancing control. The above scheme can quickly determine the balancing strategy of the BMS, greatly improve the passive balancing efficiency of the BMS, and thus improve the problem of battery pack consistency to a large extent.

[0004] As one of the main energy sources of electric vehicles, power batteries occupy a very important position in electric vehicles. In order to meet the high-power application requirements of electric vehicles, battery packs consisting of hundreds of batteries connected in series and parallel are usually used to power electric vehicles. How to effectively manage the battery pack composed of such a huge number of batteries has become one of the key technologies for the safe and reliable operation of electric vehicles. At the same time, the complex operating conditions of electric vehicles also increase the difficulty of battery management. In addition, due to defects in the manufacturing process, it is difficult to ensure that all batteries maintain a high degree of consistency. In this way, during use, some batteries may be in a state of overcharge or overdischarge. These batteries that are in a state of overcharge or overdischarge for a long time are easily damaged, which in turn affects the use of the entire battery pack. What's more serious is that severely overcharged batteries are in danger of explosion, threatening human safety. Therefore, how to effectively manage the battery balance and keep the battery performance consistent within the battery pack is an issue that we urgently need to solve. Summary of the invention

[0005] In order to solve the above technical problems, the object of the present invention is to provide a new energy vehicle BMS battery management system, including a monitoring center, the monitoring center is communicatively connected with a data acquisition module, a charge and discharge power distribution module, a charge and discharge power control module and a battery real-time monitoring module;

[0006] The data acquisition module is used to collect the battery status parameters and driving status parameters of each single battery in the battery pack, mark the acquisition time, and set the acquisition cycle;

[0007] The charging and discharging power allocation module is used to obtain the charging and discharging power threshold interval of the current acquisition cycle according to the battery state parameters and the driving state parameters;

[0008] The charge and discharge power control module is used to adjust the charge and discharge power of each single cell to within the charge and discharge power threshold interval according to the charge and discharge power threshold interval of the single cell;

[0009] The battery real-time monitoring module is used to monitor the battery status parameters of each single battery in real time, and perform active balancing control operation or passive balancing control operation on each single battery according to the monitoring result.

[0010] Furthermore, the battery status parameters include the voltage, charge and discharge current, remaining power and temperature of the single cell terminals, and the driving status parameters include the vehicle speed, acceleration and expected mileage.

[0011] Furthermore, the process of the charging and discharging power allocation module acquiring the charging and discharging power threshold interval of the current acquisition cycle according to the battery state parameter and the driving state parameter includes:

[0012] Select evaluation indicators according to the driving state parameters, remaining power and expected mileage of the current collection cycle, set the weight matrix of the evaluation indicators and the charge and discharge power allocation level, and judge the membership matrix of the single battery in the current collection cycle to the charge and discharge power allocation level through fuzzy comprehensive evaluation;

[0013] Obtaining the charge and discharge power allocation level of the single battery in the current collection period according to the membership matrix and the weight matrix, and setting the charge and discharge power threshold interval of the single battery in the current collection period according to the charge and discharge power allocation level;

[0014] Determine whether the current charge and discharge power of each single cell is within the charge and discharge power threshold range. If not, adjust the charge and discharge power of each single cell to within the charge and discharge power threshold range according to the charge and discharge power threshold range of the single cell. If yes, monitor the battery status parameters of the single cell in real time, and perform balancing operations based on the monitoring results.

[0015] Furthermore, the process of the charge and discharge power control module adjusting the charge and discharge power of each single cell to within the charge and discharge power threshold interval according to the charge and discharge power threshold interval of the single cell includes:

[0016] Obtain the remaining power of the single battery, set a healthy power threshold interval, obtain the remaining time period of the current collection cycle, obtain the power consumption corresponding to each charge and discharge power within the charge and discharge power threshold interval according to the remaining time period, obtain the first remaining power corresponding to each charge and discharge power according to the remaining power and the power consumption corresponding to each charge and discharge power, filter out the charge and discharge power whose first remaining power is within the healthy power threshold interval, and construct the charge and discharge power control set of the current collection cycle according to the charge and discharge power;

[0017] The lowest charge and discharge power is selected from the charge and discharge power control set, the voltage and charge and discharge current of the single cell battery at the current moment are obtained, the first charge and discharge current of the single cell battery is obtained according to the voltage and the charge and discharge power, and the charge and discharge current of the single cell battery is adjusted according to the first charge and discharge current, so as to adjust the charge and discharge current of the single cell battery to be consistent with the first charge and discharge current.

[0018] Furthermore, the battery real-time monitoring module monitors the battery status parameters of each single battery in real time, and performs active balancing control operation or passive balancing control operation on each single battery according to the monitoring result, including:

[0019] Preset the voltage threshold interval, current threshold interval and temperature threshold interval of the single cell, monitor the voltage, charge and discharge current, temperature and charge and discharge power of the single cell in real time, and compare the voltage, charge and discharge current, temperature and charge and discharge power of the single cell with the voltage threshold interval, current threshold interval, temperature threshold interval and charge and discharge power threshold interval of the current acquisition cycle in real time;

[0020] When the voltage is not within the voltage threshold interval, the charge and discharge current is not within the current threshold interval, the temperature is not within the temperature threshold interval, or the charge and discharge power is not within the charge and discharge power threshold interval, the abnormal state type of the single cell at the current moment is obtained, and the single cell is marked as an abnormal single cell, and an active balancing control operation is performed;

[0021] When the voltage is within the voltage threshold range, the charge and discharge current is within the current threshold range, the temperature is within the temperature threshold range, and the charge and discharge power is within the charge and discharge power threshold range, the single cell is marked as a normal single cell and a passive balancing control operation is performed.

[0022] Furthermore, the battery real-time monitoring module performs active balancing control operation on abnormal single cells including:

[0023] The abnormal state types of abnormal single cells include overload state and underload state;

[0024] When the abnormal single cell is in an overload state, the remaining power of each normal single cell at the current moment is obtained, and each normal single cell is sorted in reverse order according to the size of the remaining power. The smaller the remaining power, the higher the ranking, and a reverse queue is generated. The first balanceable power of each normal single cell in the reverse queue at the current moment is obtained according to the healthy power threshold interval and the remaining power of each normal single cell at the current moment. At the same time, the current power to be balanced of the abnormal single cell is obtained according to the current charge and discharge power of the abnormal single cell and the upper limit of the charge and discharge power within the charge and discharge power threshold interval;

[0025] According to the first balancing power available at the current moment of each normal single cell and the power to be balanced of the abnormal single cell at the current moment, the balancing target cell in the reverse order queue is obtained, and the redundant current of the balancing target cell is obtained. The abnormal single cell generates a balancing current according to the power to be balanced at the current moment and the redundant current, and transmits the balancing current to the balancing target cell until the transmission of the power to be balanced of the abnormal single cell is completed;

[0026] When the abnormal single cell is in a light-load state, each normal single cell is sorted in positive sequence according to the size of the remaining power. The more the remaining power is, the higher the ranking is, and a positive sequence queue is generated. The second balancing power of each normal single cell in the positive sequence queue at the current moment is obtained according to the healthy power threshold interval and the remaining power of each normal single cell at the current moment. At the same time, the power to be balanced of the abnormal single cell at the current moment is obtained according to the charging and discharging power of the abnormal single cell at the current moment and the lower limit of the charging and discharging power within the charging and discharging power threshold interval. The balancing target battery in the positive sequence queue is obtained according to the second balancing power of each normal single cell at the current moment and the power to be balanced of the abnormal single cell at the current moment, and the redundant current of the balancing target battery is obtained. The balancing target battery generates a balancing current according to the power to be balanced at the current moment and the redundant current, and transmits the balancing current to the abnormal single cell until the transmission of the power to be balanced of the abnormal single cell is completed.

[0027] Furthermore, the process of obtaining the redundant current of the normal single cell includes:

[0028] The highest charge and discharge power is selected from the charge and discharge power control set of normal single cells, the voltage of the single cell at the current moment and the first charge and discharge current are obtained, the second charge and discharge current of the single cell is obtained according to the voltage and the charge and discharge power, and the difference between the second charge and discharge current and the first charge and discharge current is marked as redundant current.

[0029] Furthermore, the process of the battery real-time monitoring module performing passive balancing control operations on normal single cells includes:

[0030] Obtain the charge and discharge current timing sequence of the normal single cell in the current acquisition cycle and the first charge and discharge current corresponding to the normal single cell, obtain the stability coefficient of the normal single cell according to the charge and discharge current timing sequence and the first charge and discharge current, preset a stability coefficient threshold, and generate a warning signal for the normal single cell if the stability coefficient of the normal single cell is less than the stability coefficient threshold.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1. The charging and discharging power distribution module and the charging and discharging power control module dynamically adjust the distribution ratio of charging power and discharging power according to driving state parameters, remaining power and expected mileage to ensure that the battery operates within the optimal working range. For example, if the driver needs to accelerate sharply or drive on a highway, the discharge power will be increased to meet the demand; conversely, if the power demand is low, the discharge power will be reduced. If charging is required, the charging power will be increased. By dynamically adjusting the distribution of charging power and discharging power, the battery can be optimized to operate within the optimal working range according to the remaining power, mileage and driving needs, thereby extending the battery life, improving energy utilization efficiency and ensuring the safety and driving stability of the vehicle.

[0033] 2. The battery real-time monitoring module monitors the battery status parameters of each single cell in real time, and performs active balancing control operations on the single cells with abnormal conditions according to the monitoring results. By dynamically and intelligently adjusting the charge and discharge currents of each single cell in the battery pack, it ensures that the voltage of the entire battery pack is maintained in a relatively balanced state, effectively maintains various performance indicators of the battery pack, extends the battery life and improves the safety and reliability of the system. At the same time, passive balancing control operations are performed on single cells in normal conditions. By analyzing the stability of the charge and discharge currents of normal single cells, early faults of normal single cells before they change from a normal state to a faulty state are predicted, thereby taking preventive measures before the normal single cell fault matures. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic diagram of a new energy vehicle BMS battery management system according to an embodiment of the present application. DETAILED DESCRIPTION

[0035] The following is a clear and complete description of the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0036] like Figure 1 As shown, a new energy vehicle BMS battery management system includes a monitoring center, which is communicatively connected to a data acquisition module, a charge and discharge power distribution module, a charge and discharge power control module, and a battery real-time monitoring module;

[0037] The data acquisition module is used to collect the battery status parameters and driving status parameters of each single battery in the battery pack, mark the acquisition time, and set the acquisition cycle;

[0038] The charge and discharge power allocation module obtains the charge and discharge power threshold interval of the current acquisition cycle according to the battery state parameter and the driving state parameter;

[0039] The charge and discharge power control module adjusts the charge and discharge power of each single cell to within the charge and discharge power threshold interval according to the charge and discharge power threshold interval of the single cell;

[0040] The battery real-time monitoring module monitors the battery status parameters of each single battery in real time, and performs active balancing control operation or passive balancing control operation on each single battery according to the monitoring result.

[0041] It should be further explained that, in the specific implementation process, the battery status parameters include the voltage, charge and discharge current, remaining power and temperature of the single cell terminal, and the driving status parameters include the vehicle speed, acceleration and expected mileage. The expected mileage indicates the mileage that the new energy vehicle needs to travel, and its acquisition process is usually determined based on the driver's historical route information or the destination entered by the driver.

[0042] It should be further explained that, in the specific implementation process, the process of the charge and discharge power allocation module obtaining the charge and discharge power threshold interval of the current acquisition cycle according to the battery state parameter and the driving state parameter includes:

[0043] Select evaluation indicators according to the driving state parameters, remaining power and expected mileage of the current collection cycle, set the weight matrix of the evaluation indicators and the charge and discharge power allocation level, and judge the membership matrix of the single battery in the current collection cycle to the charge and discharge power allocation level through fuzzy comprehensive evaluation;

[0044] Obtaining the charge and discharge power allocation level of the single battery in the current collection period according to the membership matrix and the weight matrix, and setting the charge and discharge power threshold interval of the single battery in the current collection period according to the charge and discharge power allocation level;

[0045] Determine whether the current charge and discharge power of each single cell is within the charge and discharge power threshold range. If not, adjust the charge and discharge power of each single cell to within the charge and discharge power threshold range according to the charge and discharge power threshold range of the single cell. If yes, monitor the battery status parameters of the single cell in real time, and perform balancing operations based on the monitoring results.

[0046] It should be further explained that, in the specific implementation process, the process of obtaining the charging and discharging power distribution level of the single battery in the current collection cycle according to the membership matrix and the weight matrix includes:

[0047] The weight matrix and the membership matrix of the evaluation index are integrated through a formula to obtain a fuzzy comprehensive evaluation matrix of the evaluation index, and the membership of the single cell to different charge and discharge power allocation levels is obtained according to the fuzzy comprehensive evaluation matrix, and the different charge and discharge power allocation levels correspond to different charge and discharge power threshold intervals, and the charge and discharge power allocation level with the highest membership corresponding to the single cell is screened out, and the charge and discharge power threshold interval corresponding to the charge and discharge power allocation level with the highest membership corresponding to the single cell is used as the charge and discharge power threshold interval of the single cell;

[0048] Wherein, the formula is:

[0049] M=αM 1 ×βM 2 ;

[0050] Among them, M is the fuzzy comprehensive evaluation matrix of the evaluation index, M 1 is the indicator weight matrix of the evaluation indicator, M 2 is the membership matrix, "×" represents the multiplication of the weight matrix of the evaluation index and the elements at the corresponding positions of the membership matrix, and α and β are weighting parameters for controlling the balance between the weight matrix and the membership matrix in the fuzzy comprehensive evaluation matrix of the evaluation index.

[0051] According to the driving status parameters, remaining power and expected mileage, the distribution ratio of charging power and discharging power is dynamically adjusted to ensure that the battery operates within the optimal working range. For example, if the driver needs to accelerate sharply or drive on a highway, the discharge power will be increased to meet the demand. Conversely, if the power demand is low, the discharge power will be reduced. If charging is required, the charging power will be increased. By dynamically adjusting the distribution of charging power and discharging power, the battery can be optimized to operate within the optimal working range according to the remaining power, mileage and driving needs, thereby extending battery life, improving energy utilization efficiency and ensuring vehicle safety and driving stability.

[0052] It should be further explained that, in a specific implementation process, the process in which the charge and discharge power control module adjusts the charge and discharge power of each single battery to within the charge and discharge power threshold range according to the charge and discharge power threshold range of the single battery includes:

[0053] Obtain the remaining power of the single cell, set a healthy power threshold interval, the healthy power threshold interval of the battery is determined by the safe charge state of the battery, the safe charge state of the battery is generally between 25% and 75%, if it exceeds 75% or is lower than 25%, the polarization resistance of the battery will increase rapidly, greatly affecting the battery performance, the battery charge state = remaining power / battery capacity, obtain the battery capacity of each single cell in the battery pack, then the upper limit of the healthy power threshold interval is 75% of the battery capacity, and the lower limit is 25% of the battery capacity, obtain the remaining time period of the current acquisition cycle, obtain the power consumption corresponding to each charge and discharge power within the charge and discharge power threshold interval according to the remaining time period, the power consumption = charge and discharge power * time period, obtain the first remaining power corresponding to each charge and discharge power according to the remaining power and the power consumption corresponding to each charge and discharge power, the first remaining power = remaining power - power consumption, filter out the charge and discharge power whose first remaining power is within the healthy power threshold interval, and construct the charge and discharge power control set of the current acquisition cycle according to the charge and discharge power;

[0054] The lowest charge and discharge power is selected from the charge and discharge power control set, the voltage and charge and discharge current of the single cell at the current moment are obtained, the first charge and discharge current of the single cell is obtained according to the voltage and the charge and discharge power, the charge and discharge current of the single cell is adjusted according to the first charge and discharge current, the charge and discharge current of the single cell is adjusted to be consistent with the first charge and discharge current, and the charge and discharge power of the single cell is adjusted to within the charge and discharge power threshold range.

[0055] It should be further explained that, in the specific implementation process, the battery real-time monitoring module monitors the battery status parameters of each single battery in real time, and performs active balancing control operation or passive balancing control operation on each single battery according to the monitoring result, and the process includes:

[0056] Preset the voltage threshold interval, current threshold interval and temperature threshold interval of the single cell, monitor the voltage, charge and discharge current, temperature and charge and discharge power of the single cell in real time, and compare the voltage, charge and discharge current, temperature and charge and discharge power of the single cell with the voltage threshold interval, current threshold interval, temperature threshold interval and charge and discharge power threshold interval of the current acquisition cycle in real time;

[0057] When the voltage is not within the voltage threshold interval, the charge and discharge current is not within the current threshold interval, the temperature is not within the temperature threshold interval, or the charge and discharge power is not within the charge and discharge power threshold interval, the abnormal state type of the single cell at the current moment is obtained, and the single cell is marked as an abnormal single cell, and an active balancing control operation is performed;

[0058] When the voltage is within the voltage threshold range, the charge and discharge current is within the current threshold range, the temperature is within the temperature threshold range, and the charge and discharge power is within the charge and discharge power threshold range, the single cell is marked as a normal single cell and a passive balancing control operation is performed.

[0059] It should be further explained that, in the specific implementation process, the battery real-time monitoring module performs active balancing control operation on abnormal single cells including:

[0060] The abnormal state types of abnormal single cells include an overvoltage state where the voltage exceeds the upper voltage limit within the voltage threshold interval, an overcurrent state where the charge and discharge current exceeds the upper current limit within the current threshold interval, an overtemperature state where the temperature exceeds the upper temperature limit within the temperature threshold interval, an overpower state where the charge and discharge power exceeds the upper charge and discharge power limit within the charge and discharge power threshold interval, a voltage shortage state where the voltage is less than the voltage lower limit within the voltage threshold interval, a current shortage state where the charge and discharge current is less than the current lower limit within the current threshold interval, and a power shortage state where the charge and discharge power is less than the charge and discharge power lower limit within the charge and discharge power threshold interval. The overvoltage state, overcurrent state, overtemperature state and overpower state are marked as overload states, and the voltage shortage state, current shortage state and power shortage state are marked as light load states.

[0061] When the abnormal single cell is in an overload state, the remaining power of each normal single cell at the current moment is obtained, and each normal single cell is sorted in reverse order according to the size of the remaining power. The smaller the remaining power, the higher the ranking, and a reverse queue is generated. The first balancing power of each normal single cell in the reverse queue at the current moment is obtained according to the healthy power threshold interval and the remaining power of each normal single cell at the current moment, where the first balancing power = 75% battery capacity - remaining power. At the same time, the current moment to-be-balanced power of the abnormal single cell is obtained according to the current moment charge and discharge power of the abnormal single cell and the upper limit of the charge and discharge power within the charge and discharge power threshold interval, where the current moment to-be-balanced power = the current moment charge and discharge power - the upper limit of the charge and discharge power;

[0062] According to the first balancing power available at the current moment of each normal single cell and the power to be balanced of the abnormal single cell at the current moment, the balancing target cell in the reverse order queue is obtained, and the redundant current of the balancing target cell is obtained. The abnormal single cell generates a balancing current according to the power to be balanced at the current moment and the redundant current, and transmits the balancing current to the balancing target cell until the transmission of the power to be balanced of the abnormal single cell is completed;

[0063] It should be further explained that, in a specific implementation process, the balancing target battery in the reverse queue is obtained according to the first balancing power of each normal single battery at the current moment and the power to be balanced of the abnormal single battery at the current moment, and the redundant current of the balancing target battery is obtained. The abnormal single battery generates a balancing current according to the power to be balanced and the redundant current at the current moment, and transmits the balancing current to the balancing target battery until the transmission of the power to be balanced of the abnormal single battery is completed. The process includes:

[0064] Determine whether the first balancing power of the normal single cell at the head of the reverse order queue is greater than or equal to the power to be balanced of the abnormal single cell at the current moment. If so, obtain the redundant current of the normal single cell. The abnormal single cell generates a balancing current according to the power to be balanced and the redundant current at the current moment, and transmits the balancing current to the normal single cell until the transmission of the power to be balanced of the abnormal single cell is completed. The normal single cell at the head is the balancing target cell.

[0065] If it is less than, then obtain the sum of the first balancing electricity of the first and second normal single cells in the reverse queue at the current moment, and judge whether the first balancing electricity sum is greater than or equal to the current electricity to be balanced of the abnormal single cell. If it is greater than or equal to, obtain the redundant current of the first normal single cell and the redundant current of the second single cell. The abnormal single cell generates the balancing current and the balancing current transmitted to the first normal single cell according to the current electricity to be balanced and the redundant current of the first normal single cell and the redundant current of the second single cell, until the transmission of the electricity to be balanced of the abnormal single cell is completed. The first and second normal single cells are the balancing target cells. If it is less than, then obtain the sum of the first balancing electricity of the first, second and third normal single cells in the reverse queue at the current moment, and judge whether the first balancing electricity sum is greater than or equal to the current electricity to be balanced of the abnormal single cell, and so on, until the transmission of the electricity to be balanced of the abnormal single cell is completed.

[0066] It should be further explained that, in the specific implementation process, the process of the abnormal single cell generating the balancing current according to the current amount of electricity to be balanced and the redundant current is as follows:

[0067] Obtain the voltage of the abnormal single cell, obtain the balancing current at the current moment according to the voltage of the abnormal single cell and the amount of electricity to be balanced at the current moment, wherein the balancing current = the amount of electricity to be balanced at the current moment / the voltage, and determine whether the balancing current is greater than the redundant current. If the balancing current is greater than the redundant current, adjust the size of the balancing current to be consistent with the redundant current, and then transmit the balancing current to the normal single cell;

[0068] When the abnormal single cell is in a light-load state, each normal single cell is sorted in positive order according to the size of the remaining power. The more the remaining power is, the higher the order is, and a positive order queue is generated. The second balancing power of each normal single cell in the positive order queue is obtained at the current moment according to the healthy power threshold interval and the remaining power of each normal single cell at the current moment. The second balancing power = remaining power - 25% battery capacity. At the same time, the current moment to-be-balanced power of the abnormal single cell is obtained according to the current moment charge and discharge power of the abnormal single cell and the lower limit of the charge and discharge power within the charge and discharge power threshold interval. The to-be-balanced power = lower limit of charge and discharge power - charge and discharge power at the current moment;

[0069] According to the second balancing power of each normal single cell at the current moment and the power to be balanced of the abnormal single cell at the current moment, the balancing target cell in the positive sequence queue is obtained, and the redundant current of the balancing target cell is obtained. The balancing target cell generates a balancing current according to the power to be balanced and the redundant current at the current moment, and transmits the balancing current to the abnormal single cell until the transmission of the power to be balanced of the abnormal single cell is completed;

[0070] It should be further explained that, in a specific implementation process, a balancing target battery in a positive sequence queue is obtained according to the second balancing power of each normal single battery at the current moment and the power to be balanced of the abnormal single battery at the current moment, and a redundant current of the balancing target battery is obtained. The balancing target battery generates a balancing current according to the power to be balanced and the redundant current at the current moment, and transmits the balancing current to the abnormal single battery until the transmission of the power to be balanced of the abnormal single battery is completed. The process includes:

[0071] Determine whether the second balancing power of the first normal single cell in the positive sequence queue is greater than or equal to the power to be balanced of the abnormal single cell at the current moment. If so, obtain the redundant current of the normal single cell. The normal single cell generates a balancing current according to the power to be balanced and the redundant current at the current moment, and transmits the balancing current to the abnormal single cell until the transmission of the power to be balanced of the abnormal single cell is completed. The first normal single cell is the balancing target cell.

[0072] If it is less than, then obtain the sum of the second balancing power of the first and second normal single cells in the positive sequence queue at the current moment, and judge whether the sum of the second balancing power is greater than or equal to the power to be balanced of the abnormal single cell at the current moment. If it is greater than or equal to, obtain the redundant current of the first normal single cell and the redundant current of the second single cell. The first normal single cell generates a balancing current transmitted to the abnormal single cell according to the power to be balanced at the current moment and the redundant current of the first normal single cell, and the second normal single cell generates a balancing current transmitted to the abnormal single cell according to the power to be balanced at the current moment and the redundant current of the second normal single cell, until the transmission of the power to be balanced of the abnormal single cell is completed. The first and second normal single cells are the balancing target cells. If it is less than, then obtain the sum of the second balancing power of the first, second and second second normal single cells in the positive sequence queue at the current moment, and judge whether the sum of the second balancing power is greater than or equal to the power to be balanced of the abnormal single cell at the current moment, and so on, until the transmission of the power to be balanced of the abnormal single cell is completed;

[0073] It should be further explained that, in a specific implementation process, the process of obtaining the redundant current of a normal single cell includes:

[0074] The highest charge and discharge power is selected from the charge and discharge power control set of normal single cells, the voltage of the single cell at the current moment and the first charge and discharge current are obtained, the second charge and discharge current of the single cell is obtained according to the voltage and the charge and discharge power, and the difference between the second charge and discharge current and the first charge and discharge current is marked as redundant current.

[0075] It should be further explained that, in a specific implementation process, the process of the battery real-time monitoring module performing passive balancing control operations on normal single cells includes:

[0076] Obtain the charge and discharge current timing sequence of the normal single cell in the current acquisition cycle and the first charge and discharge current corresponding to the normal single cell, obtain the stability coefficient of the normal single cell according to the charge and discharge current timing sequence and the first charge and discharge current, preset the stability coefficient threshold, and generate a warning signal for the normal single cell if the stability coefficient of the normal single cell is less than the stability coefficient threshold to remind the driver that the battery may be abnormal, thereby ensuring the driver's driving safety.

[0077] It should be further explained that, in the specific implementation process, the calculation formula for obtaining the stability coefficient of the normal single cell according to the charge and discharge current timing sequence and the first charge and discharge current is:

[0078]

[0079] Among them, σ represents the stability coefficient of a normal single cell, D trepresents the charge and discharge current at the tth moment, DA represents the first charge and discharge current, n represents the total number of moments, and δ represents the conversion coefficient.

[0080] The above embodiments are only used to illustrate the technical method of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical method of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical method of the present invention.

Claims

1. A new energy vehicle BMS battery management system, including a monitoring center, characterized in that: The monitoring center is communicatively connected with a data acquisition module, a charge and discharge power distribution module, a charge and discharge power control module and a battery real-time monitoring module; The data acquisition module is used to collect the battery status parameters and driving status parameters of each single battery in the battery pack, mark the acquisition time, and set the acquisition cycle; The charging and discharging power allocation module is used to obtain the charging and discharging power threshold interval of the current acquisition cycle according to the battery state parameters and the driving state parameters; The charge and discharge power control module is used to adjust the charge and discharge power of each single cell to within the charge and discharge power threshold range according to the charge and discharge power threshold range of the single cell, including: Obtain the remaining power of the single battery, set a healthy power threshold interval, obtain the remaining time period of the current collection cycle, obtain the power consumption corresponding to each charge and discharge power within the charge and discharge power threshold interval according to the remaining time period, obtain the first remaining power corresponding to each charge and discharge power according to the remaining power and the power consumption corresponding to each charge and discharge power, filter out the charge and discharge power whose first remaining power is within the healthy power threshold interval, and construct the charge and discharge power control set of the current collection cycle according to the charge and discharge power; Selecting the lowest charge and discharge power from the charge and discharge power control set, obtaining the voltage and charge and discharge current of the single battery at the current moment, obtaining the first charge and discharge current of the single battery according to the voltage and the charge and discharge power, adjusting the charge and discharge current of the single battery according to the first charge and discharge current, and adjusting the charge and discharge current of the single battery to be consistent with the first charge and discharge current; The battery real-time monitoring module is used to monitor the battery status parameters of each single battery in real time, and perform active balancing control operation or passive balancing control operation on each single battery according to the monitoring result, including: Preset the voltage threshold interval, current threshold interval and temperature threshold interval of the single cell, monitor the voltage, charge and discharge current, temperature and charge and discharge power of the single cell in real time, and compare the voltage, charge and discharge current, temperature and charge and discharge power of the single cell with the voltage threshold interval, current threshold interval, temperature threshold interval and charge and discharge power threshold interval of the current acquisition cycle in real time; When the voltage is not within the voltage threshold interval, the charge and discharge current is not within the current threshold interval, the temperature is not within the temperature threshold interval, or the charge and discharge power is not within the charge and discharge power threshold interval, the abnormal state type of the single cell at the current moment is obtained, and the single cell is marked as an abnormal single cell, and an active balancing control operation is performed; When the voltage is within the voltage threshold range, the charge and discharge current is within the current threshold range, the temperature is within the temperature threshold range, and the charge and discharge power is within the charge and discharge power threshold range, the single cell is marked as a normal single cell and a passive balancing control operation is performed; The process of active balancing control of abnormal single cells includes: The abnormal state types of abnormal single cells include overload state and underload state; When the abnormal single cell is in an overload state, the remaining power of each normal single cell at the current moment is obtained, and each normal single cell is sorted in reverse order according to the size of the remaining power. The smaller the remaining power, the higher the ranking, and a reverse queue is generated. The first balanceable power of each normal single cell in the reverse queue at the current moment is obtained according to the healthy power threshold interval and the remaining power of each normal single cell at the current moment. At the same time, the current power to be balanced of the abnormal single cell is obtained according to the current charge and discharge power of the abnormal single cell and the upper limit of the charge and discharge power within the charge and discharge power threshold interval; According to the first balancing power available at the current moment of each normal single cell and the power to be balanced of the abnormal single cell at the current moment, the balancing target cell in the reverse order queue is obtained, and the redundant current of the balancing target cell is obtained. The abnormal single cell generates a balancing current according to the power to be balanced at the current moment and the redundant current, and transmits the balancing current to the balancing target cell until the transmission of the power to be balanced of the abnormal single cell is completed; When the abnormal single cell is in a light-load state, each normal single cell is sorted in positive sequence according to the size of the remaining power. The more the remaining power is, the higher the ranking is, and a positive sequence queue is generated. The second balancing power of each normal single cell in the positive sequence queue at the current moment is obtained according to the healthy power threshold interval and the remaining power of each normal single cell at the current moment. At the same time, the power to be balanced of the abnormal single cell at the current moment is obtained according to the charging and discharging power of the abnormal single cell at the current moment and the lower limit of the charging and discharging power within the charging and discharging power threshold interval. The balancing target battery in the positive sequence queue is obtained according to the second balancing power of each normal single cell at the current moment and the power to be balanced of the abnormal single cell at the current moment, and the redundant current of the balancing target battery is obtained. The balancing target battery generates a balancing current according to the power to be balanced at the current moment and the redundant current, and transmits the balancing current to the abnormal single cell until the transmission of the power to be balanced of the abnormal single cell is completed.

2. A new energy vehicle BMS battery management system according to claim 1, characterized in that: The battery status parameters include the voltage, charge and discharge current, remaining power and temperature of the single cell terminal, and the driving status parameters include vehicle speed, acceleration and expected mileage.

3. A new energy vehicle BMS battery management system according to claim 2, characterized in that: The process of the charge and discharge power allocation module acquiring the charge and discharge power threshold interval of the current acquisition cycle according to the battery state parameter and the driving state parameter includes: Select evaluation indicators according to the driving state parameters, remaining power and expected mileage of the current collection cycle, set the weight matrix of the evaluation indicators and the charge and discharge power allocation level, and judge the membership matrix of the single battery in the current collection cycle to the charge and discharge power allocation level through fuzzy comprehensive evaluation; Obtaining the charge and discharge power allocation level of the single battery in the current collection period according to the membership matrix and the weight matrix, and setting the charge and discharge power threshold interval of the single battery in the current collection period according to the charge and discharge power allocation level; Determine whether the current charge and discharge power of each single cell is within the charge and discharge power threshold range. If not, adjust the charge and discharge power of each single cell to within the charge and discharge power threshold range according to the charge and discharge power threshold range of the single cell. If yes, monitor the battery status parameters of the single cell in real time, and perform balancing operations based on the monitoring results.

4. A new energy vehicle BMS battery management system according to claim 3, characterized in that: The process of obtaining the redundant current of a normal single cell includes: The highest charge and discharge power is selected from the charge and discharge power control set of normal single cells, the voltage of the single cell at the current moment and the first charge and discharge current are obtained, the second charge and discharge current of the single cell is obtained according to the voltage and the charge and discharge power, and the difference between the second charge and discharge current and the first charge and discharge current is marked as redundant current.

5. A new energy vehicle BMS battery management system according to claim 4, characterized in that: The process of the battery real-time monitoring module performing passive balancing control operation on normal single cells includes: Obtain the charge and discharge current timing sequence of the normal single cell in the current acquisition cycle and the first charge and discharge current corresponding to the normal single cell, obtain the stability coefficient of the normal single cell according to the charge and discharge current timing sequence and the first charge and discharge current, preset a stability coefficient threshold, and generate a warning signal for the normal single cell if the stability coefficient of the normal single cell is less than the stability coefficient threshold.

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