SOC balance control method and rail vehicle

Abstract

The present invention discloses a SOC balancing control method and a rail vehicle. The method is used for a rail vehicle. The rail vehicle includes N carriages, each of which is provided with a power battery pack, and each of which is provided with a corresponding charger. N is an integer greater than 1. The method includes: obtaining the battery SOC value of the power battery pack of the N carriages, and calculating the charging power coefficient of each carriage according to the battery SOC value of the N carriages; calculating the allowable charging power of each carriage according to the charging power coefficient of each carriage respectively; sending the allowable charging power of each carriage to the corresponding charger respectively, so that the charger determines the target charging power according to the received allowable charging power, so as to charge the power battery pack of the corresponding carriage. The purpose of simultaneously fully charging the power batteries of multiple carriages at different initial battery SOC values ​​is achieved, providing a good operating condition for the subsequent operation of the whole vehicle.

Description

Technical Field

[0001] The present invention relates to the technical field of charging control, and in particular to a SOC balancing control method and a rail vehicle. Background Art

[0002] At present, domestic urban rail trains use their own battery packs to provide power for vehicle traction and related high-voltage equipment. This energy supply method will cause inconsistent power levels in different battery packs between different carriages after the vehicle has been running for a long time, resulting in multiple carriages’ battery packs not being fully charged at the same time. The first carriage to be fully charged will enter the discharge process first. When the last carriage is fully charged, the other carriages will have consumed some power to varying degrees, causing the problem of inconsistent initial power levels when the vehicle departs. Summary of the invention

[0003] The present invention aims to solve at least one of the above technical problems to a certain extent. To this end, one purpose of the present invention is to propose a SOC balancing control method to achieve the purpose of simultaneously charging the power batteries of multiple carriages at different initial battery SOC values, thereby providing a good operating condition for the subsequent operation of the whole vehicle.

[0004] A second object of the present invention is to provide a rail vehicle.

[0005] To achieve the above-mentioned purpose, an embodiment of the first aspect of the present invention proposes a SOC balancing control method, which is used for a rail vehicle, wherein the rail vehicle includes N carriages, each of which is provided with a power battery pack, and each of which is provided with a corresponding charger, where N is an integer greater than 1, and the method includes: obtaining the battery SOC value of the power battery pack of the N carriages, and calculating the charging power coefficient of each carriage according to the battery SOC value of the N carriages; calculating the allowable charging power of each carriage according to the charging power coefficient of each carriage; and sending the allowable charging power of each carriage to the corresponding charger, so that the charger determines the target charging power according to the received allowable charging power, so as to charge the power battery pack of the corresponding carriage.

[0006] According to the SOC balancing control method of the embodiment of the present invention, the charging power coefficient of each car is determined according to the battery SOC value of the power battery pack of each car, and each car then determines the allowable charging power of the corresponding car according to the charging power coefficient of the corresponding car. The charger of each car charges the power battery pack of the corresponding car according to the allowable charging power of the corresponding car, so as to achieve the purpose of fully charging the power batteries of multiple cars at different initial battery SOC values ​​at the same time, thereby providing a good operating condition for the subsequent operation of the whole vehicle.

[0007] In addition, the SOC balancing control method proposed in the above embodiment of the present invention may also have the following additional technical features:

[0008] According to one embodiment of the present invention, the method of calculating the charging power coefficient of each of the N carriages based on the battery SOC values ​​of the N carriages includes: determining the minimum battery SOC value based on the battery SOC values ​​of the N carriages; and calculating the charging power coefficient of each of the carriages based on the minimum battery SOC value and the battery SOC value of each of the carriages.

[0009] According to one embodiment of the present invention, the charging power coefficient of the nth carriage is calculated by the following formula: n =1*(1-SOC n ) / (1-SOC min ), where k n represents the charging power coefficient of the nth carriage, SOC min Indicates the minimum battery SOC value, SOC n represents the battery SOC value of the nth carriage, where n is an integer greater than or equal to 1 and less than or equal to N.

[0010] According to one embodiment of the present invention, the allowable charging power of the nth car is calculated based on the charging power coefficient of each n cars, including: obtaining the maximum allowable charging power of the power battery pack of the nth car; calculating the allowable charging power of the nth car based on the charging power coefficient of the nth car and the maximum allowable charging power of the power battery pack; wherein n is an integer greater than or equal to 1 and less than or equal to N.

[0011] According to one embodiment of the present invention, the allowable charging power of the nth carriage is calculated by the following formula: W 允n =W 0n *k n , where W 允n represents the allowable charging power of the nth carriage, k n represents the charging power coefficient of the nth carriage, W 0n Indicates the maximum allowable charging power of the power battery pack of the nth carriage.

[0012] According to one embodiment of the present invention, the target charging power is determined by the charger according to the received allowed charging power to charge the power battery pack of the corresponding compartment, including: obtaining the maximum allowed charging power of the charger itself, and taking the smaller value of the maximum allowed charging power and the received allowed charging power as the target charging power, and charging the power battery pack of the corresponding compartment according to the target charging power.

[0013] To achieve the above-mentioned purpose, a second embodiment of the present invention proposes a rail vehicle, comprising a vehicle control unit and N carriages, each of which is provided with a power battery pack and a battery management controller, and each of which is provided with a corresponding charger, where N is an integer greater than 1; wherein the battery management controller is used to obtain the battery SOC value of the power battery pack of the corresponding carriage, and send the battery SOC value to the vehicle control unit; the vehicle control unit is used to calculate the charging power coefficient of each carriage according to the battery SOC value of the N carriages, and send the charging power coefficient of each carriage to the battery management controller of the corresponding carriage; the battery management controller is also used to calculate the allowable charging power of the corresponding carriage according to the received charging power coefficient, and send the allowable charging power to the corresponding charger, so that the charger can determine the target charging power according to the received allowable charging power, so as to charge the power battery pack of the corresponding carriage.

[0014] According to the rail vehicle of the embodiment of the present invention, the vehicle control unit determines the charging power coefficient of each car according to the battery SOC value of the power battery pack of each car, and each car battery management controller determines the allowable charging power of the corresponding car according to the charging power coefficient of the corresponding car. The charger of each car charges the power battery pack of the corresponding car according to the allowable charging power of the corresponding car, thereby achieving the purpose of fully charging the power batteries of multiple cars at different initial battery SOC values ​​at the same time, providing a good operating condition for the subsequent operation of the whole vehicle.

[0015] In addition, the rail vehicle proposed according to the above embodiment of the present invention may also have the following additional technical features:

[0016] According to one embodiment of the present invention, the vehicle control unit is specifically used to: determine the minimum battery SOC value based on the battery SOC values ​​of the N carriages; and calculate the charging power coefficient of each carriage based on the minimum battery SOC value and the battery SOC value of each carriage.

[0017] According to one embodiment of the present invention, the vehicle control unit calculates the charging power coefficient of the nth carriage by the following formula: n =1*(1-SOC n ) / (1-SOC min ), where k n represents the charging power coefficient of the nth carriage, SOC min Indicates the minimum battery SOC value, SOC n represents the battery SOC value of the nth carriage, where n is an integer greater than or equal to 1 and less than or equal to N.

[0018] According to one embodiment of the present invention, the battery management controller is specifically used to: obtain the maximum allowable charging power of the power battery pack of the nth car; calculate the allowable charging power of the nth car based on the charging power coefficient of the nth car and the maximum allowable charging power of the power battery pack; wherein n is an integer greater than or equal to 1 and less than or equal to N.

[0019] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic structural diagram of a rail vehicle according to an embodiment of the present invention;

[0021] Figure 2 is a flow chart of a SOC balancing control method according to an embodiment of the present invention;

[0022] Figure 3 is a flow chart of determining a charging power coefficient of each carriage according to an embodiment of the present invention;

[0023] Figure 4 is a flow chart of determining the allowable charging power of a carriage according to an embodiment of the present invention;

[0024] Figure 5 is a schematic diagram of the connection between a power battery pack and a charger according to an embodiment of the present invention;

[0025] Figure 6 is a schematic structural diagram of a rail vehicle according to an embodiment of the present invention;

[0026] Figure 7 is a control logic diagram of a vehicle control unit according to an embodiment of the present invention;

[0027] Figure 8 Schematic diagram of control logic of a battery management controller according to an embodiment of the present invention. DETAILED DESCRIPTION

[0028] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0029] In the related art, a backup device is used to transfer and absorb excess power from a battery pack with high power. Firstly, the method of using a backup device to store excess power requires an additional set of equipment to absorb the power, which increases the cost. Secondly, by absorbing and storing energy in a battery pack with high power, the absorbed energy is transferred to a battery pack with low power, and the battery pack with low power is charged to increase its power. There is energy loss in the battery charging and discharging process, which wastes a certain amount of energy.

[0030] The embodiment of the present invention provides a SOC balancing control method and a rail vehicle, so that the initial power of the rail vehicle is kept consistent when the rail vehicle is started. Figure 1-8 The SOC balancing control method and the rail vehicle according to the embodiment of the present invention are described in detail with specific implementation methods.

[0031] Before describing the embodiments of the present application in detail, for ease of understanding, SOC (State of Charge) is first introduced. SOC is used to reflect the remaining capacity of the battery. Its value is defined as the ratio of the remaining capacity to the battery capacity. It is usually expressed as a percentage and its value range is 0-1. When SOC=0, it means that the battery is fully discharged, and when SOC=1, it means that the battery is fully charged. It should be noted that the battery SOC value cannot be measured directly, and its size can only be estimated through parameters such as the battery terminal voltage, charge and discharge current, and internal resistance.

[0032] The SOC balancing control method provided by the embodiment of the present invention is used for rail vehicles. Figure 1 Schematic diagram of the structure of a rail vehicle according to an embodiment of the present invention. Figure 1 As shown, the rail vehicle includes N carriages, each carriage is equipped with a power battery pack, each carriage is correspondingly equipped with a charger, and N is an integer greater than 1.

[0033] Specifically, the rail vehicle has multiple carriages, each of which is equipped with a power battery pack. The power battery pack in each carriage is used to provide electrical energy to the load of the carriage, such as a motor controller, a motor, and an air conditioning system. Each carriage is also equipped with a charger, which is used to charge the power battery pack in the carriage.

[0034] Figure 2 FIG. 1 is a flow chart of a SOC balancing control method according to an embodiment of the present invention. Figure 2 As shown, the SOC balancing control method may include:

[0035] S1, obtaining the battery SOC values ​​of the power battery packs of N carriages, and calculating the charging power coefficient of each carriage according to the battery SOC values ​​of the N carriages.

[0036] Specifically, in order to fully charge the power battery packs in each carriage at the same time, the remaining capacity of the power battery packs in N carriages, that is, the battery SOC value, can be obtained first to understand the current remaining capacity of the power battery packs in each carriage. After understanding the remaining capacity of the power battery pack in each carriage, the charging power coefficient of each carriage is calculated according to the battery SOC value of the N carriages, so that the power batteries in the N carriages can be fully charged at the same time.

[0037] It should be noted that each carriage is equipped with a battery management controller (BMS, Battery Management System), which is used to estimate the battery SOC value of the power battery pack of the carriage, and send the battery SOC value of the power battery pack of the carriage to the rail vehicle's whole vehicle control unit (CCU, Central control unit) in real time. The whole vehicle control unit calculates the charging power coefficient of each carriage according to the battery SOC value of N carriages, so that the power batteries of the N carriages can be fully charged at the same time.

[0038] As a feasible implementation method, Figure 3 As shown, the charging power factor of each carriage is calculated according to the battery SOC value of N carriages, which may include:

[0039] S11, determining a minimum battery SOC value according to the battery SOC values ​​of the N carriages;

[0040] S12, calculating the charging power coefficient of each carriage according to the minimum battery SOC value and the battery SOC value of each carriage.

[0041] Specifically, in order to fully charge the power battery packs of N carriages at the same time, when determining the charging power coefficient of the N carriages according to the battery SOC values ​​of the N carriages, the minimum battery SOC value is determined from the obtained battery SOC values ​​of the N carriages. Among the obtained battery SOC values ​​of the N carriages, the battery SOC value of the power battery pack of the carriage is the smallest, which means that the remaining battery capacity of the power battery pack of the carriage is the smallest, and the power battery pack of the carriage has the largest amount to be charged. In order to ensure that the power battery packs of the N carriages are fully charged at the same time, the charging power coefficient of each carriage can be determined based on the minimum battery SOC value and the battery SOC value of each carriage.

[0042] In this embodiment, the charging power coefficient of the nth carriage can be calculated by the following formula:

[0043] k n =1*(1-SOC n ) / (1-SOC min ),

[0044] Among them, k nIndicates the charging power coefficient of the nth carriage, SOC min Indicates the minimum battery SOC value, SOC n Represents the battery SOC value of the nth carriage, where n is an integer greater than or equal to 1 and less than or equal to N.

[0045] Specifically, SOC min Indicates the minimum battery SOC value in the power battery pack in N carriages, 1-SOC min It indicates the maximum amount of power battery packs in N carriages to be charged. SOC n Indicates the battery SOC value of the nth carriage, 1-SOC n It represents the amount of power battery packs to be charged in N carriages. According to the above formula for the charging power coefficient of the nth carriage, it can be seen that the smaller the battery SOC value, the less power it has left and the more power it needs to be charged. The more power it needs to be charged, the greater its charging power coefficient. On the contrary, the larger the battery SOC value, the more power it has left and the less power it needs to be charged. The less power it needs to be charged, the smaller its charging power coefficient. Based on the battery SOC values ​​of the power battery packs in N carriages, determine the charging power coefficient of the N carriages, and use this to balance the charging rate of the power battery packs in the N carriages so that the power battery packs in the N carriages can be fully charged at the same time.

[0046] S2, calculate the allowable charging power of each carriage according to the charging power coefficient of each carriage.

[0047] Specifically, after determining the charging power coefficient of each carriage, it is also necessary to determine the allowable charging power of the carriage. When determining the allowable charging power of the carriage, calculation can be performed based on the charging power coefficient of each carriage and the maximum allowable charging power of the power battery pack of each carriage.

[0048] As a feasible implementation method, Figure 4 As shown, according to the charging power coefficient of each n carriages, calculating the allowable charging power of the nth carriage may include:

[0049] S21, obtaining the maximum allowable charging power of the power battery pack of the nth carriage;

[0050] S22, calculating the allowable charging power of the nth carriage according to the charging power coefficient of the nth carriage and the maximum allowable charging power of the power battery pack;

[0051] Here, n is an integer greater than or equal to 1 and less than or equal to N.

[0052] Specifically, since the power battery packs in N carriages are charged, after determining the charging power coefficient of the power charging battery in each carriage, it is also necessary to determine the maximum allowable charging power of the power battery pack in each carriage, so as to determine the allowable charging power of this carriage based on the maximum allowable charging power of the power battery pack in this carriage.

[0053] In this embodiment, the allowable charging power of the nth carriage can be calculated by the following formula:

[0054] W 允n =W 0n *k n ,

[0055] Among them, W 允n represents the allowable charging power of the nth carriage, k n Represents the charging power coefficient of the nth carriage, W 0n Indicates the maximum allowable charging power of the power battery pack in the nth carriage.

[0056] Specifically, the charging power factor k of the nth carriage is n The maximum allowable charging power W of the power battery pack in the nth carriage 允n That is, the larger the charging power coefficient, the higher the maximum allowable charging power W. 允n According to the calculation formula for the allowable charging power of the nth carriage, the smaller the SOC value of the power battery pack in the carriage, the larger the amount to be charged, the larger the charging power coefficient k of the carriage, and the allowable charging power W of the carriage. 允n On the contrary, the larger the SOC value of the power battery pack in the car, the less the amount to be charged, the smaller the charging power coefficient k of the car, and the allowable charging power W of the car. 允n That is to say, the smaller the SOC value, the larger the amount to be charged, the larger the charging power coefficient k of the car, and the allowable charging power W of the car. 允 The larger the SOC value, the smaller the amount to be charged, the smaller the charging power coefficient k of the carriage, and the allowable charging power W of the carriage. 允 The smaller it is, the slower its charging efficiency, thereby balancing the charging rates of the power battery packs in the N carriages so that the N carriages can be fully charged at the same time.

[0057] More specifically, after obtaining the charging power coefficient of the current carriage, the allowable charging power of the current carriage is calculated using the calculation formula for the allowable charging power of the nth carriage. Wherein, the allowable charging power of the current carriage = the charging power coefficient k of the current carriage n ×The maximum allowable charging power of the power battery pack in this carriage W 0n .

[0058] In an embodiment of the present invention, when the charging power coefficient of the current carriage is not obtained, the maximum allowable charging power of the power battery pack of the current carriage is used as the allowable charging power of the current carriage.

[0059] S3, sending the allowed charging power of each car to the corresponding charger respectively, so that the charger determines the target charging power according to the received allowed charging power to charge the power battery pack of the corresponding car.

[0060] Specifically, after determining the allowable charging power of the rechargeable battery pack in each carriage, the allowable charging power of this carriage is sent to the charger in this carriage, and the charger in this carriage charges the rechargeable battery pack in this carriage according to the received allowable charging power. However, the charger itself has a maximum allowable charging power, and it needs to determine whether its maximum allowable charging power can be charged according to the allowable charging power. Therefore, the allowable charging power of this carriage is sent to the charger in this carriage, and the charger also needs to determine the target charging power based on the allowable charging power of this carriage to charge the power battery pack in this carriage.

[0061] In an embodiment of the present invention, determining the target charging power according to the received allowed charging power by the charger to charge the power battery pack of the corresponding compartment may include:

[0062] The charger obtains its own maximum allowable charging power, and uses the smaller value between the maximum allowable charging power and the received allowable charging power as the target charging power, and charges the power battery pack of the corresponding car according to the target charging power.

[0063] Specifically, when the charger receives the allowed charging power of the current car, it compares its own maximum allowed charging power with the received allowed charging power and takes the smaller value as the target charging power. More specifically, when the charger's own maximum allowed charging power is less than the received allowed charging power, the power battery pack of the current car is charged with its own maximum allowed charging power. When the charger's own maximum allowed charging power is greater than the received allowed charging power, the power battery pack of the current car is charged with the received allowed charging power.

[0064] In an embodiment of the present invention, Figure 5 As shown in the figure, when the rail carriage is running, the fully charged power battery pack of the N carriages supplies power to the motor controller and motor, air conditioning system and other auxiliary loads inside the carriage. The power battery pack is connected to the charger and multiple loads through the maintenance switch assembly and the high-voltage distribution box assembly. For details, please refer to Figure 5 .

[0065] In an embodiment of the present invention, the battery SOC values ​​of the power battery packs of N carriages are obtained in real time to understand the current remaining battery capacity of the power battery packs of the N carriages, so as to determine the charging power coefficient of each carriage, and then determine the allowable charging power of each carriage according to the charging power coefficient of each carriage. The charger of each carriage then determines the target charging power according to the received allowable charging power and its own maximum allowable charging power to charge the power battery pack of the corresponding carriage, so that the power batteries of the N carriages of the rail vehicle can be fully charged at the same time.

[0066] The SOC balancing control method of the embodiment of the present invention determines the charging power coefficient of each car and the allowable charging power of the car according to the battery SOC value of the power battery pack of each car. The battery SOC value is inversely proportional to the charging power coefficient of the car and the allowable charging power of the car, that is, the smaller the remaining charge capacity, the larger the charging power coefficient of the car and the allowable charging power of the car. According to the battery SOC value of the power battery pack of each car, the allowable charging power of each car is determined to balance the charging efficiency of N cars and achieve the purpose of fully charging the power battery packs of N cars at the same time. Among them, when the charger receives the allowable charging power of the car to charge the power battery pack of the car, it also considers the maximum allowable charging power of the charger itself, and takes the smaller value of its own maximum allowable charging power and the received allowable charging power as the target charging power to ensure that the charger operates normally according to the actual situation.

[0067] The SOC balancing control method of the embodiment of the present invention achieves the purpose of fully charging the power batteries of multiple carriages at different initial battery SOC values ​​at the same time, thereby providing a good operating condition for the subsequent operation of the entire vehicle.

[0068] The present invention provides a rail vehicle.

[0069] Figure 6 Schematic diagram of the structure of a rail vehicle according to an embodiment of the present invention. Figure 6 As shown, the rail vehicle includes a vehicle control unit and N carriages, each carriage is equipped with a power battery pack and a battery management controller, each carriage is equipped with a charger, and N is an integer greater than 1. The rail vehicle also includes a battery management controller (BMS) and a vehicle control unit (CCU).

[0070] Among them, the battery management controller is used to obtain the battery SOC value of the power battery pack of the corresponding car, and send the battery SOC value to the vehicle control unit; the vehicle control unit is used to calculate the charging power coefficient of each car according to the battery SOC value of N cars, and send the charging power coefficient of each car to the battery management controller of the corresponding car; the battery management controller is also used to calculate the allowable charging power of the corresponding car according to the received charging power coefficient, and send the allowable charging power to the corresponding charger, so that the charger can determine the target charging power according to the received allowable charging power, so as to charge the power battery pack of the corresponding car.

[0071] In an embodiment of the present invention, Figure 7 As shown, the vehicle control unit is specifically used to: determine the minimum battery SOC value according to the battery SOC values ​​of N carriages; and calculate the charging power coefficient of each carriage according to the minimum battery SOC value and the battery SOC value of each carriage.

[0072] Specifically, in order to fully charge the power battery packs of N carriages at the same time, when determining the charging power coefficient of the N carriages according to the battery SOC values ​​of the N carriages, the minimum battery SOC value is determined from the obtained battery SOC values ​​of the N carriages. If the battery SOC value of the power battery pack of this carriage is the smallest, it means that the remaining battery capacity of the power battery pack of this carriage is the smallest, and the power battery pack of this carriage has the largest amount to be charged. In order to ensure that the power battery packs of N carriages are fully charged at the same time, the charging power coefficient of each carriage can be calculated based on the minimum battery SOC value and the battery SOC value of each carriage.

[0073] In this embodiment, the vehicle control unit can calculate the charging power coefficient of the nth carriage by the following formula:

[0074] k n =1*(1-SOC n ) / (1-SOC min ),

[0075] Among them, k n Indicates the charging power coefficient of the nth carriage, SOC min Indicates the minimum battery SOC value, SOC n Represents the battery SOC value of the nth carriage, where n is an integer greater than or equal to 1 and less than or equal to N.

[0076] Specifically, SOC min Indicates the minimum battery SOC value in the power battery pack in N carriages, 1-SOC min It indicates the maximum amount of power battery packs in N carriages to be charged. SOC n Indicates the battery SOC value of the nth carriage, 1-SOC nIt represents the amount of power battery packs to be charged in N carriages. According to the above formula for the charging power coefficient of the nth carriage, it can be seen that the smaller the battery SOC value, the less power it has left and the more power it needs to be charged. The more power it needs to be charged, the greater its charging power coefficient. On the contrary, the larger the battery SOC value, the more power it has left and the less power it needs to be charged. The less power it needs to be charged, the smaller its charging power coefficient. Based on the battery SOC values ​​of the power battery packs in N carriages, determine the charging power coefficient of the N carriages, and use this to balance the charging rate of the power battery packs in the N carriages so that the power battery packs in the N carriages can be fully charged at the same time.

[0077] In an embodiment of the present invention, Figure 8 As shown, the battery management controller is specifically used to: obtain the maximum allowable charging power of the power battery pack of the nth car; calculate the allowable charging power of the nth car according to the charging power coefficient of the nth car and the maximum allowable charging power of the power battery pack; wherein n is an integer greater than or equal to 1 and less than or equal to N.

[0078] In this embodiment, the battery management controller can calculate the allowable charging power of the nth carriage by the following formula:

[0079] W 允n =W 0n *k n ,

[0080] Among them, W 允n represents the allowable charging power of the nth carriage, k n Represents the charging power coefficient of the nth carriage, W 0n Indicates the maximum allowable charging power of the power battery pack in the nth carriage.

[0081] Specifically, the charging power factor k of the nth carriage is n The maximum allowable charging power W of the power battery pack in the nth carriage 允n That is, the larger the charging power coefficient, the higher the maximum allowable charging power W. 允n It can be seen that the smaller the SOC value of the power battery pack in the car, the larger the amount to be charged, the larger the charging power coefficient k of the car, and the allowable charging power W of the car 允n The larger the SOC value of the power battery pack in the car, the less the amount to be charged, the smaller the charging power coefficient k of the car, and the allowable charging power W of the car. 允n In other words, the smaller the SOC value, the greater the amount to be charged, the greater the charging power coefficient k of the car, and the allowable charging power W of the car 允 The larger the SOC value, the smaller the amount to be charged, the smaller the charging power coefficient k of the carriage, and the allowable charging power W of the carriage. 允The smaller it is, the slower its charging efficiency, thereby balancing the charging rates of the power battery packs in the N carriages so that the N carriages can be fully charged at the same time.

[0082] Specifically, when calculating the allowable charging power of each carriage, the battery management controller may first determine the maximum allowable charging power of the power battery pack of the carriage, that is, obtain the maximum allowable charging power of the power battery pack of the carriage. The allowable charging power of the carriage is determined based on the maximum allowable charging power of the power battery pack of the carriage.

[0083] More specifically, see Figure 8 When the charging power coefficient of this carriage is obtained, the allowable charging power of this carriage is calculated using the calculation formula of the allowable charging power of the nth carriage. Among them, the allowable charging power of this carriage = the charging power coefficient of this carriage × the maximum allowable charging power of the power battery pack of this carriage.

[0084] In an embodiment of the present invention, when the charging power coefficient of the current carriage is not obtained, the allowable charging power of the current carriage is the maximum allowable charging power of the power battery pack of the current carriage.

[0085] In an embodiment of the present invention, the charger is specifically used to: obtain its own maximum allowable charging power, and use the smaller value of the maximum allowable charging power and the received allowable charging power as the target charging power, and charge the power battery pack of the corresponding car according to the target charging power.

[0086] In the rail vehicle provided by the embodiment of the present invention, the whole vehicle control unit determines the charging power coefficient of each car according to the battery SOC value of the power battery pack of each car, and the battery management controller of each car determines the allowable charging power of the corresponding car according to the charging power coefficient of the corresponding car. The charger of each car charges the power battery pack of the corresponding car according to the allowable charging power of the corresponding car, so as to achieve the purpose of fully charging the power batteries of multiple cars at different initial battery SOC values ​​at the same time, thereby providing a good operating condition for the subsequent operation of the whole vehicle.

[0087] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection portion with one or more wirings (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0088] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0089] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0090] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0091] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0092] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0093] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0094] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A SOC balance control method, characterized in that: The method is used for a rail vehicle, the rail vehicle includes N carriages, each of the carriages is provided with a power battery pack, each of the carriages is provided with a corresponding charger, N is an integer greater than 1, and the method includes: Obtaining the battery SOC values ​​of the power battery packs of the N carriages, and calculating the charging power coefficient of each of the carriages according to the battery SOC values ​​of the N carriages; Calculating the allowable charging power of each carriage according to the charging power coefficient of each carriage; The allowed charging power of each carriage is sent to the corresponding charger respectively, so that the charger determines the target charging power according to the received allowed charging power, so as to charge the power battery pack of the corresponding carriage; The calculating the charging power coefficient of each carriage according to the battery SOC value of the N carriages includes: Determine a minimum battery SOC value according to the battery SOC values ​​of the N carriages; Calculating the charging power coefficient of each carriage according to the minimum battery SOC value and the battery SOC value of each carriage; The charging power factor of the nth carriage is calculated by the following formula: k n =1*(1-SOC n ) / (1-SOC min ), Among them, k n represents the charging power coefficient of the nth carriage, SOC min Indicates the minimum battery SOC value, SOC n represents the battery SOC value of the nth carriage, where n is an integer greater than or equal to 1 and less than or equal to N.

2. The SOC balance control method according to claim 1, characterized in that: According to the charging power coefficient of each carriage, the allowable charging power of each carriage is calculated, including: Obtaining the maximum allowable charging power of the power battery pack of the nth carriage; Calculate the allowable charging power of the nth carriage according to the charging power coefficient of the nth carriage and the maximum allowable charging power of the power battery pack; Here, n is an integer greater than or equal to 1 and less than or equal to N.

3. The SOC balance control method according to claim 2, characterized in that: The allowable charging power of the nth carriage is calculated by the following formula: W 允n =W 0n *k n , Among them, W 允n represents the allowable charging power of the nth carriage, k n represents the charging power coefficient of the nth carriage, W 0n Indicates the maximum allowable charging power of the power battery pack of the nth carriage.

4. The SOC balance control method according to any one of claims 1 to 3, characterized in that: The method of determining the target charging power according to the received allowed charging power by the charger to charge the power battery pack of the corresponding compartment includes: The charger obtains its own maximum allowable charging power through the charger, and uses the smaller value between the maximum allowable charging power and the received allowable charging power as the target charging power, and charges the power battery pack of the corresponding vehicle according to the target charging power.

5. A rail vehicle, characterized in that: It includes a vehicle control unit and N carriages, each of which is equipped with a power battery pack and a battery management controller, and each of which is equipped with a charger, where N is an integer greater than 1; wherein, The battery management controller is used to obtain the battery SOC value of the power battery pack of the corresponding compartment and send the battery SOC value to the vehicle control unit; The vehicle control unit is used to calculate the charging power coefficient of each carriage according to the battery SOC value of the N carriages, and send the charging power coefficient of each carriage to the battery management controller of the corresponding carriage; The battery management controller is further used to calculate the allowable charging power of the corresponding compartment according to the received charging power coefficient, and send the allowable charging power to the corresponding charger, so that the charger determines the target charging power according to the received allowable charging power, so as to charge the power battery pack of the corresponding compartment; The vehicle control unit is specifically used for: Determine the minimum battery SOC value according to the battery SOC values ​​of the N carriages; Calculating the charging power coefficient of each carriage according to the minimum battery SOC value and the battery SOC value of each carriage; The vehicle control unit calculates the charging power coefficient of the nth carriage by the following formula: k n =1*(1-SOC n ) / (1-SOC min ), Among them, k n represents the charging power coefficient of the nth carriage, SOC min Indicates the minimum battery SOC value, SOC n represents the battery SOC value of the nth carriage, where n is an integer greater than or equal to 1 and less than or equal to N.

6. The rail vehicle according to claim 5, characterized in that The battery management controller is specifically used for: Obtaining the maximum allowable charging power of the power battery pack of the nth carriage; Calculate the allowable charging power of the nth carriage according to the charging power coefficient of the nth carriage and the maximum allowable charging power of the power battery pack; Here, n is an integer greater than or equal to 1 and less than or equal to N.

Images