Balanced control method for new energy automobile with multi-pack battery replacement and automobile

Abstract

The invention discloses a balance control method for a multi-pack battery replacement new energy automobile and the automobile, the new energy automobile is provided with a plurality of battery packs with a battery replacement function, the electric quantity of each battery pack is monitored, and balance control is performed on the plurality of battery packs according to an electric quantity monitoring result. According to the invention, the equalization control among a plurality of battery packs for battery replacement is realized, and the endurance experience and safety of the vehicle are improved through the equalization control among the plurality of battery packs.

Description

Technical Field

[0001] The present invention relates to the field of automotive battery control, and particularly to a multi-pack battery swapping balance control method and vehicle for new energy vehicles. Background Art

[0002] Currently, most electric vehicle battery swapping is single-pack battery swapping. The application of the single-pack battery swapping solution enables the vehicle to quickly replenish power and achieve rapid energy replenishment, thus making up for the deficiencies of insufficient battery life and slow charging of electric vehicles. For example, the battery swapping control method of a battery swapping station, the battery swapping control method of a vehicle, the battery swapping control system of a battery swapping station, the battery swapping control system of a vehicle, and a computer storage medium with the patent application number 202310043118.1 can quickly replenish energy through battery swapping control operations.

[0003] However, the existing technology for battery swapping generally uses a single battery pack, that is, the vehicle's battery is regarded as a whole battery pack for whole-pack battery swapping. With the increasing requirements of users for battery life and power, the traditional single battery pack is gradually developing towards the scenario of parallel battery swapping with multiple battery packs. Since multiple battery packs are used, there is a voltage difference between the battery packs after battery swapping, and during use, the battery life of the vehicle is always measured based on the battery pack with the lowest voltage, which affects the user experience. Moreover, the existing technology for battery swapping only uses a single whole battery pack for battery swapping and does not involve the scenario of multiple battery packs for battery swapping, so it is impossible to balance and control multiple battery packs in the battery swapping scenario. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies of the existing technology and provide a multi-pack battery swapping balance control method and vehicle for new energy vehicles, which are used to achieve the balance control between battery packs for multi-pack battery swapping and improve the battery life experience and safety of the vehicle through the balance control between multiple battery packs.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is: a multi-pack battery swapping balance control method for a new energy vehicle, the new energy vehicle having multiple battery packs capable of battery swapping, monitoring the power of each battery pack, and performing balance control on multiple battery packs according to the power monitoring results.

[0006] When the vehicle is in an operating state, the state of the vehicle is monitored in real time. When it is monitored that energy recovery is satisfied, the vehicle energy recovery function is activated through the power balance controller, and at the same time, the power of each battery pack is collected and detected. Through the energy recovery function, the battery packs with relatively lower power are charged until the set conditions are met, and then the power balance controller simultaneously charges each battery pack.

[0007] Meeting the set conditions includes: the pressure difference between the battery pack with the lowest power and the battery pack with the highest power is less than the set power threshold, then the power equalization controller simultaneously charges each battery pack; otherwise, the battery pack with the lowest power is detected and identified in real time and charged until the set conditions are met or the energy recovery ends.

[0008] When the vehicle is in a stationary charging state, the power equalization controller controls the charging of multiple battery packs. At the beginning of charging, the vehicle's overall power is first judged. If the power is lower than the low power threshold, the power equalization controller simultaneously charges and replenishes energy for multiple packs to meet the requirements of fast charging; otherwise, it enters the end charging process.

[0009] In the end charging process, each battery pack conducts a comparative analysis of the power through the power equalization controller. When there are pressure differences and power differences among the battery packs, the battery pack with relatively lower power is preferentially replenished with energy. At this time, the other packs are temporarily stopped from charging and replenishing energy through the power equalization controller, and the battery pack with relatively lower power is monitored in real time and charged. When the set pressure difference is reached for each pack, the purpose of balanced charging for each pack is achieved, and at this time, the charging can be stopped.

[0010] When the vehicle performs multi-pack battery swapping, the power of each battery pack is collected, and the battery packs are replaced in ascending order of power. After each battery pack is replaced, an equilibrium judgment is made on the multiple battery packs in the current vehicle. If it is in an equilibrium state, the battery swapping stops; otherwise, the battery pack replacement continues.

[0011] During the battery swapping process, after the first battery pack is swapped, the power of the swapped battery pack is collected as the reference power. Based on the basic power, the battery packs in the battery swapping station are selected, and the fully charged battery packs in the selected battery swapping station are used to perform battery swapping operations on the remaining battery packs in the vehicle.

[0012] Selecting the battery packs in the battery swapping station based on the basic power parameter includes collecting the power of the fully charged battery packs in the battery swapping station, and selecting the battery packs in the battery swapping station whose power is equal to or slightly higher than the basic power as the battery swapping battery packs to perform battery swapping operations on the in-vehicle battery packs.

[0013] During the vehicle's driving process, the vehicle's power demand is collected in real time. Some battery packs with a power difference lower than the set threshold are selected as partial equilibrium battery packs, and the power that the partial equilibrium battery packs can provide is calculated. If the power that can be provided is greater than the vehicle's demand power, the vehicle switches to be powered by the partial equilibrium battery packs.

[0014] A vehicle, characterized in that: the vehicle is equipped with multiple battery packs and supports battery swapping, and the vehicle uses the described equalization control method to control the vehicle.

[0015] The advantages of the present invention are as follows: achieving the balanced control between battery packs for multi-pack battery swapping, improving the vehicle's endurance experience and safety through the balanced control among multiple battery packs, enhancing the vehicle's endurance mileage ability, and directly improving the user's satisfaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The following briefly describes the content expressed in each drawing of the present invention's specification and the markings in the drawings:

[0017] Figure 1 It is a block diagram of the power balance control principle for a multi-pack battery swapping new energy vehicle of the present invention;

[0018] Figure 2 It is a schematic diagram of the energy flow during the vehicle driving and braking process and the downhill process of the present invention;

[0019] Figure 3 It is a schematic diagram of the energy flow during the vehicle charging process of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] The following further details the specific embodiments of the present invention by describing the optimal embodiments with reference to the drawings.

[0021] The present invention mainly conducts balanced control for vehicles with multi-pack battery swapping. Since vehicles with multi-pack battery swapping have multiple battery packs, and the attenuation and other conditions of each battery pack due to battery swapping are different, it will lead to inconsistent battery levels between the battery packs, and further affect the stability and endurance of the external power supply of the entire battery pack. Therefore, in order to reduce the endurance problems caused by balance issues.

[0022] As Figure 1 shown, it is the composition of the hardware group involved in the balanced control strategy in a multi-pack battery swapping vehicle. Among them, the power balance controller in the present invention connects components such as the vehicle battery swapping pack, the vehicle power system, the vehicle DCDC converter, high-voltage accessories, and the charging interface, as well as corresponding control methods, to achieve the power balance goal during the dynamic driving and static charging processes of the vehicle battery swapping pack, thereby improving the vehicle's endurance mileage ability and directly enhancing the user's satisfaction.

[0023] As Figure 1 shown, it is a block diagram of the principle between the vehicle-end power balance controller and high-voltage components and corresponding controllers, including the high-voltage connection method, the network communication path. The power balance controller has functions such as high-voltage power distribution, voltage acquisition of each pack, power analysis and comparison, and multi-pack on-off control during driving and static charging processes. The battery pack includes multiple independent and then parallel battery swapping packs 1-N. Multiple battery swapping packs form a complete power battery. The battery swapping pack is an independent battery pack, and its power supply output and charging are controlled by the balance controller.

[0024] DuringFigure 1 In the principle block diagram: 1. When the vehicle is in the driving and braking process and the downhill process, the vehicle has the energy recovery function. At this time, the power balance controller distributes the recovered energy to the battery packs with relatively lower power according to the power status of each battery swapping pack. Specifically as follows Figure 2 shown; 2. When the vehicle is charging and replenishing energy, the power balance controller can also perform power balance charging control on each pack according to the power of each pack. Specifically as follows Figure 3 shown. The following will specifically elaborate on the above two methods respectively.

[0025] As Figure 2 shown in

[0026] ① When the vehicle is driving and braking, since the electric drive system has the energy recovery function, the energy recovered by the vehicle is distributed to the battery packs with relatively lower power in multiple packs through the electric drive system and the power balance controller. When the energy is recovered multiple times or for a long time to make the power of multiple packs reach the set target value, the power balance controller replenishes energy for each pack at the same time;

[0027] ② When the vehicle is going downhill, the vehicle's energy recovery can also replenish energy for each pack, and the principle and strategy are the same as those of the driving and braking energy recovery.

[0028] As above Figure 3 shown in the schematic diagram of the energy flow during the vehicle charging process

[0029] When the vehicle is stationary and charging and replenishing energy

[0030] ① When the power is relatively low, the power balance controller simultaneously charges and replenishes energy for multiple packs to meet the demand for fast charging. The schematic diagram of the energy flow is as above Figure 3 shown;

[0031] ② At the end of charging, each pack conducts a comparative analysis of the power through the power balance controller. When there is a pressure difference and power difference among the packs, the battery pack with relatively lower power is preferentially replenished through the set strategy. At this time, the other packs temporarily stop charging and replenishing energy through the control of the power balance controller. By repeating the above steps multiple times, when the pressure difference and power difference of each pack reach the set value, the purpose of balanced energy replenishment for each pack is achieved, and at this time, the charging can be stopped.

[0032] The balanced energy replenishment method of this solution is applicable to all high and low speed new energy vehicles with 2 or more battery swapping packs. The method strategy specifically includes

[0033] A method for balancing control of a new energy vehicle with multiple battery packs for battery replacement is first defined as a new energy vehicle with multiple battery packs for battery replacement, each battery pack is an independent individual, and the battery packs are connected in series and parallel (usually in parallel) to form a whole to provide power to the whole vehicle. The power of each battery pack is collected and monitored, and multiple battery packs are balanced according to the power monitoring results. The main goal of the balanced control is to achieve a balanced power state among multiple battery packs in the multi-pack battery replacement vehicle, thereby reducing the problem of shortened vehicle range caused by imbalance.

[0034] During balancing control, different balancing controls are performed according to the state of the vehicle, which are divided into balancing under the vehicle's driving state, balancing under the vehicle's charging state, and balancing during battery replacement, thereby achieving all-round and multi-angle balancing control.

[0035] The balance control in the vehicle driving state includes:

[0036] When the vehicle is in operation, the status of the vehicle is monitored in real time. When it is monitored that energy recovery is met, the vehicle energy recovery function is started through the power balancing controller. At the same time, the power of each battery pack is collected and detected. The energy recovery function is used to charge the battery packs with relatively low power until the set conditions are met. After that, the power of each battery pack is replenished at the same time through the power balancing controller.

[0037] The set conditions include: if the voltage difference between the battery pack with the lowest power and the battery pack with the highest power is less than the set power threshold, the battery packs are recharged simultaneously through the power balancing controller; otherwise, the battery pack with the lowest power is detected and identified in real time and recharged until the set conditions are met or energy recovery ends. Balancing the battery pack with lower power to the same or close power level as other battery packs can improve battery life.

[0038] The energy recovery status includes the braking status or downhill status during vehicle driving. Energy recovery can be performed in the braking or downhill status. After the energy recovery function is started, the battery pack will be charged due to energy recovery. At this time, in order to make the power of multiple battery packs tend to be consistent, the battery pack with the lowest power can be charged separately through energy recovery, and then the power of each battery pack is dynamically detected in real time. When the power difference between the lowest and highest battery packs is less than the threshold, it means that the balancing is completed. At this time, the overall charging method is used to charge each battery pack at the same time until the energy recovery mode ends at any time, the charging ends, and the external discharge continues.

[0039] During the driving process of the vehicle, the power demand of the vehicle is collected in real time, and some battery packs with a power difference lower than the set threshold are selected as partial balancing battery packs. The power that can be provided by the partial balancing battery pack is calculated. If the power that can be provided is greater than the power required by the vehicle, the vehicle switches to the partial balancing battery pack to power the vehicle. During the driving process of the vehicle, multiple battery packs are connected in parallel to supply power to the vehicle's motor or high-voltage power system. First, by collecting the power information in each battery pack, the battery packs with smaller power differences can be determined. These battery packs with smaller differences are used as partial balancing battery packs. These battery packs can be connected in parallel to directly supply power to the outside without affecting the endurance of the whole vehicle, thereby discharging the battery packs with lower power, and then calculating the power that can be provided by the balancing battery pack. If the function that can be provided is greater than the current power required by the vehicle, the vehicle is powered by controlling the partial balancing battery packs together, otherwise all the battery packs are used to power the vehicle. This method excludes the battery packs with low power as much as possible from the power supply, and uses a combination of several battery packs with the same balancing state to power the vehicle, so as to achieve balance as much as possible. When the power in some balanced battery packs and the power in the remaining battery packs of all battery packs are less than the set threshold, it means that the large power gap between multiple battery packs has been eliminated through discharge, and now all battery packs are restored to supply power to the outside.

[0040] Balancing control under vehicle charging status:

[0041] When the vehicle is in a stationary charging state, the charging of multiple battery packs is controlled by the power balancing controller. At the beginning of charging, the power of the entire vehicle is first determined. If the power is lower than the low power threshold, the power balancing controller will charge and replenish multiple packs at the same time to meet the needs of fast charging; otherwise, the terminal charging process will be entered. In the terminal charging process, each battery pack is compared and analyzed by the power balancing controller. When there is a pressure difference and power difference between the battery packs, the battery pack with relatively low power is given priority to replenish. At this time, the remaining packs are controlled by the power balancing controller to temporarily stop charging and replenishing. The battery pack with relatively low power is monitored in real time and charged and replenished. When each pack reaches the set pressure difference, the purpose of balanced replenishment of each pack is achieved, and charging can be stopped at this time.

[0042] The charging process is divided into an initial fast charging process and a charging terminal process. The fast charging in the initial process meets the need for rapid energy replenishment, while the balancing at the end can make the battery packs more consistent and improve battery life.

[0043] Balance during battery swapping:

[0044] Since the battery swapping station supports multiple vehicles for battery swapping, the battery attenuation of different vehicles may be inconsistent due to issues such as usage time. Therefore, it is necessary to pay attention to the balancing control during battery swapping. When a vehicle undergoes multi-pack battery swapping, the power of each battery pack is collected, and the battery packs are replaced in ascending order of power. After each battery pack is replaced, a balancing judgment is made on the multiple battery packs in the current vehicle. If the state is balanced, the battery swapping stops; otherwise, the battery swapping continues. Since battery swapping does not necessarily mean the battery is out of power, low power or abnormal attenuation of a single battery can also cause problems with the vehicle's overall endurance. In this case, during the battery swapping process, swapping the battery pack with the lowest power can quickly identify the unbalanced battery pack for this vehicle. After obtaining a new battery pack through the battery swapping operation, the power relationship between the new battery pack and the remaining battery packs in the vehicle is judged. If the power difference between the newly swapped battery pack and the remaining unswapped battery packs in the vehicle is less than the set threshold, the battery swapping ends, indicating that the vehicle's battery packs are balanced after replacing the abnormal battery pack, so there is no need to continue battery swapping; otherwise, the battery swapping continues, still in ascending order of power.

[0045] After the first battery pack is swapped, during the battery swapping process for the remaining in-vehicle battery packs, after the first battery pack is swapped, the power of the swapped battery pack is collected as the reference power, and based on the reference power, the battery packs in the battery swapping station are selected, and the fully charged battery packs in the selected battery swapping station are used to perform the battery swapping operation on the remaining battery packs in the vehicle.

[0046] Selecting the battery packs in the battery swapping station based on the reference power parameter includes collecting the power of the fully charged battery packs in the battery swapping station, and selecting the battery packs in the battery swapping station with power equal to or slightly higher than the reference power as the battery packs for swapping to perform the battery swapping operation on the in-vehicle battery packs.

[0047] Using the power of the first swapped battery pack as the reference, the power of the battery packs swapped during the battery swapping operation of other battery packs should be equal to or slightly greater than its power. In this way, during the battery swapping process, the mutual balance between all the batteries obtained after swapping can be ensured. Based on the first swapped battery pack, the power of the remaining battery packs is the same as it. However, due to issues such as battery attenuation, it is unlikely that all are exactly equal. Therefore, it is required that the power be greater than that of the first battery pack, but not too much. So a power threshold is set. Priority is given to selecting the battery packs in the battery swapping station with the same reference power to perform battery swapping on the vehicle, and then selecting the battery packs with power greater than the reference power and the power difference from the reference power less than the power threshold for the battery swapping operation. In this way, the balance during the battery swapping process can be ensured as much as possible.

[0048] Through the above-mentioned balancing strategy, this solution achieves balancing during vehicle driving, charging, and battery swapping processes. The balancing in these three ways can effectively solve the balancing between multiple battery packs in multi-pack battery swapping models, thereby improving the endurance of multi-pack battery swapping vehicles. The vehicle adopting the above-mentioned balancing control solution has the advantages of good balancing effect and improved endurance experience.

[0049] Obviously, the specific implementation of the present invention is not limited by the above methods. As long as various non-substantive improvements are made using the method concept and technical solution of the present invention, they are all within the protection scope of the present invention.

Claims

1. A method for balancing control of a new energy vehicle with multiple battery packs, characterized in that: The new energy vehicle has multiple battery packs with battery replacement capabilities, monitors the power level of each battery pack, and performs balanced control on the multiple battery packs based on the power monitoring results.

2. A method for balancing control of a new energy vehicle with multiple battery swaps as claimed in claim 1, characterized in that: When the vehicle is in operation, the status of the vehicle is monitored in real time. When it is monitored that energy recovery is met, the vehicle energy recovery function is started through the power balancing controller. At the same time, the power of each battery pack is collected and detected. The energy recovery function is used to charge the battery packs with relatively low power until the set conditions are met. After that, the power of each battery pack is replenished at the same time through the power balancing controller.

3. A method for balancing control of a new energy vehicle with multiple battery packs swapped as claimed in claim 2, characterized in that: Meeting the set conditions includes: if the voltage difference between the battery pack with the lowest power and the battery pack with the highest power is less than the set power threshold, then the battery packs are recharged simultaneously through the power balancing controller; otherwise, the battery pack with the lowest power is detected and identified in real time and recharged until the set conditions are met or energy recovery ends.

4. A method for balancing control of a new energy vehicle with multiple battery swaps as claimed in claim 2, characterized in that: When the vehicle is in a stationary charging state, the charging of multiple battery packs is controlled by a power balancing controller. When charging starts, the vehicle's power level is first determined. If the power level is lower than the low power threshold, the power balancing controller will charge multiple packs simultaneously to meet the needs of fast charging; otherwise, it enters the terminal charging process.

5. A method for balancing control of a new energy vehicle with multiple battery replacement as claimed in claim 4, characterized in that: In the terminal charging process, the power of each battery pack is compared and analyzed through the power balancing controller. When there is a voltage difference and power difference between the battery packs, the battery pack with relatively low power is given priority to be recharged. At this time, the remaining packs are controlled by the power balancing controller to temporarily stop charging and recharging. The battery pack with relatively low power is monitored in real time and charged and recharged. When each pack reaches the set voltage difference, the purpose of balanced recharging of each pack is achieved and charging can be stopped at this time.

6. A method for balancing control of a new energy vehicle with multiple battery packs swapped as described in any one of claims 1 to 5, characterized in that: When the vehicle is replacing multiple battery packs, the power level of each battery pack is collected, and the battery packs are replaced in order from low to high power. After each battery pack is replaced, the multiple battery packs in the current vehicle are balanced. If they are in a balanced state, the battery replacement is stopped, otherwise the battery pack replacement continues.

7. A method for balancing control of a new energy vehicle with multiple battery replacement as claimed in claim 6, characterized in that: During the battery replacement process, after the first battery pack is replaced, the power of the battery pack after the replacement is collected as the benchmark power, and the battery packs in the battery replacement station are selected based on the basic power. The fully charged battery packs in the selected battery replacement station are used to replace the remaining battery packs in the vehicle.

8. A method for balancing control of a new energy vehicle with multiple battery packs swapped as claimed in claim 6, characterized in that: The selection of battery packs in the battery swap station based on basic power parameters includes collecting power from fully charged battery packs in the battery swap station, and selecting battery packs in the battery swap station with power equal to or slightly higher than the basic power as battery packs for replacing on-board battery packs.

9. A method for balancing control of a new energy vehicle with multiple battery packs swapped as claimed in any one of claims 1 to 5, characterized in that: During the driving process of the vehicle, the power demand of the vehicle is collected in real time, and some battery packs with power difference lower than the set threshold are selected as partial balancing battery packs. The power that the partial balancing battery pack can provide is calculated. If the power that can be provided is greater than the power required by the vehicle, the vehicle switches to the partial balancing battery pack to power the vehicle.

10. An automobile, characterized in that: The car has multiple battery packs and supports battery replacement, and the car uses the balancing control method described in any one of claims 1-9 to control the vehicle.

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