New energy vehicle lead-acid storage battery charging control method and system

Abstract

The invention discloses a new energy vehicle lead-acid storage battery charging control method and system, and belongs to the technical field of new energy vehicle battery control, and the method comprises the steps: obtaining a charging message; the intelligent DCDC module is controlled to be connected with the power battery according to the electricity supplementing message, and electricity supplementing is conducted on the lead-acid storage battery through the intelligent DCDC module; when the lead-acid storage battery is charged, a charging termination message and whole vehicle fault information are received in real time; if a power supply termination message or whole vehicle fault information is received, the power supply circuit is disconnected for stopping power supply to the lead-acid storage battery; the intelligent DC-DC module can carry out precise electricity supplement according to the environment temperature, the problem of electricity shortage of the storage battery is prevented, meanwhile, the service life of the storage battery can be prolonged, and the maintenance and replacement cost of the storage battery can be reduced for a user.

Description

Technical Field

[0001] The present invention relates to a method and system for controlling the charging of a lead-acid battery of a new energy vehicle, belonging to the technical field of battery control of new energy vehicles. Background Art

[0002] As competition in the new energy vehicle market becomes increasingly fierce, the cost reduction trend of the lead-acid battery capacity of the whole vehicle is becoming more and more obvious. In addition, new energy vehicles are different from traditional fuel vehicles in that they have high requirements for the starting current. The lead-acid battery of new energy vehicles does not need to drive the starter, but only needs to provide a voltage signal to judge the high-voltage conditions. Therefore, the OEMs often use small-capacity batteries to reduce costs and weight for new energy vehicles. However, when the capacity of the lead-acid battery is reduced, the vehicle will face the risk of running out of power due to long-term parking. The existing charging system generally charges the lead-acid battery through periodic fixed charging time. This charging strategy has certain disadvantages. Since the actual capacity of the lead-acid battery is greatly affected by the ambient temperature, the fixed time charging cannot guarantee the charging effect. Undercharging or overcharging of the battery may occur under different ambient temperatures, thereby affecting the service life of the lead-acid battery. Summary of the invention

[0003] The purpose of the present invention is to provide a new energy vehicle lead-acid battery charging control method and system, which can accurately charge according to the ambient temperature to prevent the battery from running low, while also extending the battery life and reducing the user's battery maintenance and replacement costs.

[0004] In order to solve the above technical problems, the present invention is implemented by adopting the following technical solutions.

[0005] In a first aspect, the present invention provides a method for controlling the charging of a lead-acid battery of a new energy vehicle, comprising:

[0006] Get the power replenishment message;

[0007] Control the intelligent DCDC module to connect to the power battery according to the charging message, so as to charge the lead-acid battery through the intelligent DCDC module;

[0008] When recharging the lead-acid battery, receive the termination message and vehicle fault information in real time;

[0009] If a termination message for charging or vehicle failure information is received, the charging circuit is disconnected to stop charging the lead-acid battery.

[0010] Optionally, obtain the power replenishment message, including:

[0011] When the vehicle ignition lock is turned off, the vehicle intelligent DCDC module is periodically awakened, and the battery voltage is detected in real time through the vehicle intelligent DCDC module;

[0012] The intelligent DCDC module generates a charging message based on the comparison result between the battery voltage and the voltage threshold and sends it to the vehicle controller and battery management system.

[0013] Optionally, the voltage threshold is determined according to the vehicle operating environment temperature and the V-SOC characteristics of the lead-acid battery under different temperature environments.

[0014] Optionally, the intelligent DCDC module generates a charging message based on the comparison result between the battery voltage and the voltage threshold and sends it to the vehicle controller and the battery management system, including:

[0015] If the intelligent DCDC module detects that the battery voltage is lower than the voltage threshold, it generates a charging message and sends a charging request to the vehicle controller and battery management system. In addition, the intelligent DCDC module converts the charging current into voltage through the DCDC converter to provide low-voltage electricity for the lead-acid battery.

[0016] If the battery voltage is greater than or equal to the voltage threshold, the intelligent DCDC module continues to detect the battery voltage.

[0017] Optionally, when the lead-acid battery is being recharged, a message for terminating the recharging is received in real time, including:

[0018] The intelligent DCDC module detects the vehicle's ambient temperature, charging efficiency, charging power and charging current in real time;

[0019] The intelligent DCDC module obtains the correction factor of the actual capacity of the lead-acid battery based on the matching relationship between the pre-stored parameters and the vehicle's ambient temperature;

[0020] Calculate the correction factor, charging efficiency, charging capacity and charging current of the actual capacity of the lead-acid battery to obtain the charging time;

[0021] When the running time of the charging program meets the charging time, a termination charging message is generated.

[0022] Optionally, the correction factor of the actual capacity of the lead-acid battery, the charging efficiency, the charging capacity and the charging current are calculated to obtain the expression of the charging time:

[0023]

[0024] In the formula, For charging time, is the charging capacity, is the charging current, For charging efficiency, is the temperature correction factor.

[0025] Optionally, the correction factor of the actual capacity of the lead-acid battery, the charging efficiency, the charging power and the charging current are calculated to obtain the charging time, and the charging time also includes: the intelligent DCDC module updates the charging current in real time;

[0026] If the charging current is updated, a new charging time is calculated based on the updated charging current.

[0027] Optionally, the charging power is 50%-80% of the battery power.

[0028] In a second aspect, the present invention provides a lead-acid battery charging control system for new energy vehicles, comprising:

[0029] Vehicle controller, battery management system, intelligent DCDC module, power battery, battery disconnect unit and lead-acid battery;

[0030] The vehicle controller and the battery management system communicate with the intelligent DCDC module respectively to execute the steps of the above method;

[0031] The intelligent DCDC module is electrically connected to the power battery through a battery disconnect unit and a high-voltage distribution cabinet;

[0032] The intelligent DCDC module is also electrically connected to the lead-acid battery and the ambient temperature sensor respectively.

[0033] Optionally, the vehicle controller is used to control the disconnection and connection of the main positive relay;

[0034] The vehicle controller is connected to the battery management system, and the vehicle controller controls the disconnection and connection of the main negative relay through the battery management system; wherein the main positive relay is respectively arranged between the intelligent DCDC module and the power battery through the DCDC positive wiring harness and the power battery positive wiring harness;

[0035] The main negative relay is respectively arranged between the intelligent DCDC module and the power battery through the DCDC negative wiring harness and the power battery negative wiring harness;

[0036] The vehicle controller also communicates with other controllers on the vehicle to receive fault information.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] The control method of the present invention can accurately replenish power according to the ambient temperature to prevent the battery from running low. At the same time, during the replenishment process, the charging status of the battery and the fault information of the whole vehicle can be detected in real time to avoid overcharging after the battery capacity is reduced and timely termination of the replenishment when the vehicle has a fault, thereby avoiding potential safety risks to the vehicle.

[0039] Selecting the appropriate voltage threshold under different environments can extend the battery life and reduce the user's battery maintenance and replacement costs.

[0040] The charging time is adjusted in real time according to the charging current of the vehicle's lead-acid battery, and the charging capacity is calculated more accurately according to the impact of the vehicle's ambient temperature on the battery capacity and in combination with the ampere-hour integral. Therefore, the charging time is no longer a preset fixed value, which can ensure that the vehicle will not cause insufficient charging of the lead-acid battery resulting in power loss or overcharging due to long charging time in extremely cold or hot environments. Finally, the lead-acid battery capacity is maintained at the optimal charge state of 50%-80%, which not only improves the user experience but also saves the cost of lead-acid battery maintenance and replacement. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a flow chart of the lead-acid battery charging control method for new energy vehicles of the present invention;

[0042] Figure 2 The graph showing the V-SOC characteristics of a lead-acid battery under different temperature environments;

[0043] Figure 3 Shown is a table diagram of the actual capacity correction factor of the lead-acid battery in the intelligent DCDC module of the present invention;

[0044] Figure 4 Shown is a structural diagram of the lead-acid battery charging control system for new energy vehicles of the present invention.

[0045] In the figure: 1 power battery, 2 power battery positive wiring harness, 3 power battery negative wiring harness, 4 main positive relay, 5 high-voltage distribution cabinet, 6 battery disconnect unit BDU, 7 DCDC positive wiring harness, 8 DCDC negative wiring harness, 9 ambient temperature sensor wiring harness, 10 ambient temperature sensor, 11 intelligent DCDC module, 12 charging positive wiring harness, 13 charging negative wiring harness, 14 lead-acid battery, 15 main negative relay, 16 communication wiring harness, 17 vehicle controller VCU, 18 battery management system BMS. DETAILED DESCRIPTION

[0046] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0047] Example 1

[0048] This embodiment provides a method for controlling the charging of a lead-acid battery in a new energy vehicle. Figure 1 Shown include:

[0049] Step 1: Get the power replenishment message;

[0050] Step 2: The vehicle control unit and the battery management system respectively control the intelligent DCDC module to connect to the power battery according to the charging message, so as to charge the lead-acid battery through the intelligent DCDC module;

[0051] Step 3: When the lead-acid battery is recharged, a termination message and vehicle fault information are received in real time;

[0052] Step 4: If a termination message for charging or vehicle fault information is received, the charging circuit is disconnected to stop charging the lead-acid battery.

[0053] Optionally, obtaining the power replenishment message in step 1 includes:

[0054] Step 1.1: When the vehicle ignition lock is turned off, periodically wake up the vehicle intelligent DCDC module and use the vehicle intelligent DCDC module to detect the battery voltage in real time;

[0055] Step 1.2: The intelligent DCDC module generates a charging message based on the comparison result between the battery voltage and the voltage threshold and sends it to the vehicle controller and battery management system.

[0056] Optionally, the voltage threshold is determined according to the vehicle operating environment temperature and the V-SOC characteristics of the lead-acid battery under different temperature environments. Generally, the voltage corresponding to 50% SOC of the battery is selected as the threshold voltage. The V-SOC characteristic curve of the lead-acid battery under 25°C environment is as follows: Figure 2 As shown in the figure, the battery voltage corresponding to 50% SOC of the lead-acid battery is 12.2V. The whole vehicle is composed of two lead-acid batteries connected in series. Therefore, the threshold voltage is set to 24.4V under 25℃ environment.

[0057] Optionally, in step 1.2, the intelligent DCDC module generates a charging message based on the comparison result between the battery voltage and the voltage threshold and sends it to the vehicle controller and the battery management system, including:

[0058] If the intelligent DCDC module detects that the battery voltage is lower than the voltage threshold, it generates a charging message and sends a charging request to the vehicle controller and battery management system. At the same time, during the charging process, the intelligent DCDC module detects the vehicle's ambient temperature, charging efficiency, charging power and charging current in real time. In addition, the intelligent DCDC module converts the charging current into voltage through a DCDC converter to provide low-voltage electricity for the lead-acid battery.

[0059] If the battery voltage is greater than or equal to the voltage threshold, the intelligent DCDC module continues to detect the battery voltage.

[0060] Optionally, in step 3, when the lead-acid battery is recharged, a message for terminating the recharge is received in real time, including:

[0061] Step 3.1: The intelligent DCDC module detects the vehicle's ambient temperature, charging efficiency, charging power and charging current in real time;

[0062] Step 3.2: The intelligent DCDC module obtains the correction coefficient of the actual capacity of the lead-acid battery according to the matching relationship between the pre-stored parameters and the vehicle's ambient temperature;

[0063] Step 3.3: Calculate the correction factor, charging efficiency, charging capacity and charging current of the actual capacity of the lead-acid battery to obtain the charging time;

[0064] Step 3.4: When the running time of the charging program meets the charging time, a termination charging message is generated.

[0065] Optionally, the correction factor of the actual capacity of the lead-acid battery, the charging efficiency, the charging capacity and the charging current are calculated to obtain the expression of the charging time:

[0066]

[0067] In the formula, For charging time, is the charging capacity, is the charging current, For charging efficiency, Is the temperature correction factor. Add the correction factor of the ambient temperature on the actual capacity of the lead-acid battery to the calculation of the charging time, such as Figure 3 As shown, the intelligent DCDC module of the present invention can make corresponding adjustments according to the use conditions, temperature and altitude based on the pre-stored parameters.

[0068] Optionally, step 3.3 further includes: the intelligent DCDC module updates the charging current in real time;

[0069] If the charging current is updated, a new charging time is calculated based on the updated charging current.

[0070] Optionally, the charging capacity is 50%-80% of the battery capacity. The voltage corresponding to this embodiment is 25.2V. Since the different ambient temperatures of the vehicle have a great influence on the actual capacity of the lead-acid battery, for example, the actual capacity of the lead-acid battery can reach 100% at an ambient temperature of 25°C, but at an ambient temperature of -30°C, the actual capacity of the lead-acid battery can only reach about 64.5% of the nominal value. Therefore, the determination of the charging time when the lead-acid battery is replenished needs to fully consider the influence of the ambient temperature factor.

[0071] Example 2

[0072] This embodiment provides a new energy vehicle lead-acid battery 14 power replenishment control system, such as Figure 4Shown include:

[0073] Vehicle controller VCU17, battery management system BMS18, intelligent DCDC module 11, power battery 1, battery disconnect unit BDU6 and lead-acid battery 14;

[0074] The vehicle controller VCU17 and the battery management system BMS18 communicate with the intelligent DCDC module 11 through the communication harness 16 respectively, so as to execute the steps of the above method;

[0075] The intelligent DCDC module 11 is electrically connected to the power battery 1 through the battery disconnect unit BDU6 and the high-voltage distribution cabinet 5;

[0076] The intelligent DCDC module 11 is also electrically connected to the lead-acid battery 14 and the ambient temperature sensor 10 through the charging positive wiring harness 12, the charging negative wiring harness 13 and the ambient temperature sensor wiring harness 9, and can detect the vehicle's ambient temperature, charging efficiency, charging power and charging current in real time.

[0077] Optionally, the vehicle controller VCU 17 is used to control the disconnection and connection of the main positive relay 4;

[0078] The vehicle controller VCU17 is connected to the battery management system BMS18, and the vehicle controller VCU17 controls the disconnection and connection of the main negative relay 15 through the battery management system BMS18, or the battery management system BMS18 controls the disconnection and connection of the main negative relay 15 by itself; wherein, the main positive relay 4 is respectively arranged between the intelligent DCDC module 11 and the power battery 1 through the power battery positive wiring harness 2 and the DCDC positive wiring harness 7; the main negative relay 15 is respectively arranged between the intelligent DCDC module 11 and the power battery 1 through the power battery negative wiring harness 3 and the DCDC negative wiring harness 8, thereby forming a power replenishment circuit.

[0079] The vehicle controller VCU17 also communicates with other controllers on the vehicle, and the connection method is not limited to wired and wireless connection for receiving fault information.

[0080] In this embodiment, the vehicle intelligent DCDC module 11 will be awakened periodically when the vehicle ignition lock is in the OFF state, and the battery voltage will be detected through the charging positive wiring harness 12 and the charging negative wiring harness 13. When the voltage of the lead-acid battery 14 is detected to be lower than 24.4V, the charging procedure will be started. A request for charging message is sent through the communication harness 16 to request the start of the charging process. After receiving the charging request message, the vehicle controller VCU17 and the battery management system BMS18 control the main positive relay 4 in the high-voltage distribution cabinet 5 to close, and the battery management system BMS18 controls the main negative relay 15 to close. During this period, if any controller has a fault state, it will report the fault and terminate the charging process. Otherwise, the intelligent DCDC module 1111 starts voltage conversion to charge the battery. The charging time is adjusted in real time according to the charging current output by the intelligent DCDC module 1111. After the charging time is over, the intelligent DCDC module 1111 sends a message to end the charging process to terminate the charging process.

[0081] In summary, the control method of the present invention can accurately replenish power according to the ambient temperature to prevent the battery from running low. At the same time, during the replenishment process, the battery charging status and vehicle fault information can be detected in real time to avoid overcharging after the battery capacity is reduced and timely termination of replenishment when the vehicle has a fault, thereby avoiding potential safety risks to the vehicle. Selecting the corresponding voltage threshold in different environments can extend the battery life and reduce the user's battery maintenance and replacement costs.

[0082] The charging time is adjusted in real time according to the charging current of the vehicle's lead-acid battery 14, and the charging power is calculated more accurately according to the influence of the vehicle's ambient temperature on the battery capacity and in combination with the ampere-hour integration; thus, the charging time is no longer a preset fixed value, which can ensure that the vehicle will not cause the lead-acid battery 14 to be insufficiently charged and thus lose power, or the charging time to be too long and thus cause overcharging in extremely cold or extremely hot environments; finally, the power of the lead-acid battery 14 is maintained at the optimal charge state of 50%-80%, which not only improves the user's car experience, but also saves the cost of maintenance and replacement of the lead-acid battery 14.

[0083] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0084] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0085] These computer program instructions may also be stored in a computer readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0086] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0087] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which all fall within the protection of the present invention.

Claims

1. A method for controlling the charging of lead-acid batteries for new energy vehicles, characterized in that: include: Get the power replenishment message; Control the intelligent DCDC module to connect to the power battery according to the charging message, so as to charge the lead-acid battery through the intelligent DCDC module; When recharging the lead-acid battery, receive the termination message and vehicle fault information in real time; If a termination message for charging or vehicle failure information is received, the charging circuit is disconnected to stop charging the lead-acid battery.

2. The method for controlling the charging of lead-acid batteries for new energy vehicles according to claim 1 is characterized in that: Get the power replenishment message, including: When the vehicle ignition lock is turned off, the vehicle intelligent DCDC module is periodically awakened, and the battery voltage is detected in real time through the vehicle intelligent DCDC module; The intelligent DCDC module generates a charging message based on the comparison result between the battery voltage and the voltage threshold and sends it to the vehicle controller and battery management system.

3. The method for controlling the charging of lead-acid batteries for new energy vehicles according to claim 2 is characterized in that: The voltage threshold is determined according to the vehicle operating environment temperature and the V-SOC characteristics of the lead-acid battery under different temperature environments.

4. The method for controlling the charging of lead-acid batteries for new energy vehicles according to claim 2 is characterized in that: The intelligent DCDC module generates a charging message based on the comparison result between the battery voltage and the voltage threshold and sends it to the vehicle controller and battery management system, including: If the intelligent DCDC module detects that the battery voltage is lower than the voltage threshold, it generates a recharge message and sends a recharge request to the vehicle controller and battery management system; If the battery voltage is greater than or equal to the voltage threshold, the intelligent DCDC module continues to detect the battery voltage.

5. The method for controlling the charging of lead-acid batteries for new energy vehicles according to claim 1 is characterized in that: When the lead-acid battery is recharged, a termination message for recharging is received in real time, including: The intelligent DCDC module detects the vehicle's ambient temperature, charging efficiency, charging power and charging current in real time; The intelligent DCDC module obtains the correction factor of the actual capacity of the lead-acid battery based on the matching relationship between the pre-stored parameters and the vehicle's ambient temperature; Calculate the correction factor, charging efficiency, charging capacity and charging current of the actual capacity of the lead-acid battery to obtain the charging time; When the running time of the charging program meets the charging time, a termination charging message is generated.

6. The method for controlling the charging of lead-acid batteries for new energy vehicles according to claim 5 is characterized in that: By calculating the correction factor of the actual capacity of the lead-acid battery, the charging efficiency, the charging capacity and the charging current, the expression for the charging time is obtained: ; In the formula, For charging time, is the charging capacity, is the charging current, For charging efficiency, is the temperature correction factor.

7. The method for controlling the charging of lead-acid batteries for new energy vehicles according to claim 5 is characterized in that: The correction factor, charging efficiency, charging capacity and charging current of the actual capacity of the lead-acid battery are calculated to obtain the charging time, which also includes: the intelligent DCDC module updates the charging current in real time; If the charging current is updated, a new charging time is calculated based on the updated charging current.

8. The method for controlling the charging of lead-acid batteries for new energy vehicles according to claim 5 is characterized in that: The charging power is 50%-80% of the battery power.

9. A lead-acid battery charging control system for new energy vehicles, characterized in that: include: Vehicle controller, battery management system, intelligent DCDC module, power battery, battery disconnect unit and lead-acid battery; The vehicle controller and the battery management system communicate with the intelligent DCDC module respectively, and are used to execute the steps of the method according to claim 1; The intelligent DCDC module is electrically connected to the power battery through a battery disconnect unit and a high-voltage distribution cabinet; The intelligent DCDC module is also electrically connected to the lead-acid battery and the ambient temperature sensor respectively.

10. The lead-acid battery charging control system for new energy vehicles according to claim 9 is characterized in that: The vehicle controller is used to control the disconnection and connection of the main positive relay; The vehicle controller is connected to the battery management system, and the vehicle controller controls the disconnection and connection of the main negative relay through the battery management system; wherein the main positive relay is respectively arranged between the intelligent DCDC module and the power battery through the DCDC positive wiring harness and the power battery positive wiring harness; The main negative relay is respectively arranged between the intelligent DCDC module and the power battery through the DCDC negative wiring harness and the power battery negative wiring harness; The vehicle controller also communicates with other controllers on the vehicle to receive fault information.

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