Charging control method, controller, and vehicle for vehicle

Abstract

The application discloses a charging control method, a controller and a vehicle, and relates to the technical field of vehicles. The charging control method comprises the following steps: during a voltage-boosting charging process of the vehicle, before a preset charging end condition is met, periodically performing the following steps: acquiring a real-time voltage of a battery pack of the vehicle and a real-time output voltage of a charging pile connected with the vehicle; determining a target voltage adjustment amount according to the real-time voltage, the real-time output voltage, a maximum working voltage of the charging pile and a maximum allowable charging voltage of the battery pack; and adjusting a target charging voltage instruction sent to the charging pile according to the target voltage adjustment amount, so that the output voltage of the charging pile is adjusted by the target voltage adjustment amount. Therefore, the output voltage of the charging pile is dynamically adjusted, the charging voltage smoothly tracks the real-time demand of the battery pack, and the charging efficiency and charging stability during the voltage-boosting charging process can be improved.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and more particularly to a charging control method, controller, and vehicle for a vehicle. Background Technology

[0002] With the rapid development of new energy vehicle technology, the voltage levels of both vehicle voltage platforms and charging infrastructure are constantly improving. In the vehicle sector, the battery pack voltage of new energy vehicles has gradually evolved from the early 400V voltage platform to the 800V voltage platform, and some companies have even launched products with 1000V and higher voltage platforms. However, a large number of early-built low-voltage charging piles (such as 500V and 750V levels) are still widely used. When high-voltage new energy vehicles are connected to low-voltage charging piles, the maximum output voltage of the charging pile is lower than the rated voltage of the battery pack, resulting in the inability to directly charge the battery pack normally. This causes a voltage mismatch problem, which seriously affects the user's charging experience and the utilization efficiency of charging facilities.

[0003] To address this, a boost charging scheme has been proposed in related technologies. However, this boost charging scheme typically employs a relatively fixed voltage control strategy. In actual boost charging, the output voltage of the charging pile and the real-time voltage of the battery pack are in a dynamic state. Existing control strategies are difficult to adapt to these dynamic changes in a timely manner, resulting in problems such as lag in charging voltage regulation or deviation in regulation amount, which adversely affects charging efficiency and the stability of the charging process. Summary of the Invention

[0004] The purpose of this invention is to provide a vehicle charging control method, controller, and vehicle to improve charging efficiency and charging stability.

[0005] In a first aspect, embodiments of the present invention propose a vehicle charging control method, comprising: during the vehicle boost charging process, before satisfying a preset charging termination condition, periodically performing the following steps: acquiring the real-time voltage of the vehicle battery pack and the real-time output voltage of the charging pile connected to the vehicle; determining a target voltage adjustment amount based on the real-time voltage, the real-time output voltage, the maximum operating voltage of the charging pile, and the maximum allowable charging voltage of the battery pack; and adjusting the target charging voltage command sent to the charging pile according to the target voltage adjustment amount, so that the output voltage of the charging pile adjusts the target voltage adjustment amount.

[0006] In some embodiments, determining the target voltage adjustment amount based on the real-time voltage, the real-time output voltage, the maximum operating voltage of the charging pile, and the maximum allowable charging voltage of the battery pack includes: calculating the real-time voltage difference based on the real-time output voltage and the real-time voltage; determining the target voltage difference and determining the required adjustment amount based on the target voltage difference and the real-time voltage difference; determining a first adjustable margin based on the maximum operating voltage and the real-time output voltage, and determining a second adjustable margin based on the maximum allowable charging voltage and the real-time voltage; and obtaining the target voltage adjustment amount based on the required adjustment amount, the first adjustable margin, and the second adjustable margin.

[0007] In some embodiments, determining the target pressure difference includes: calculating the power change rate based on the real-time charging power of the charging pile in the current cycle and the real-time charging power in the previous cycle; and determining the target pressure difference based on the power change rate and the real-time pressure difference.

[0008] In some embodiments, determining the target pressure difference based on the power change rate and the real-time pressure difference includes: when the power change rate is greater than a preset change rate threshold, reducing the step length based on the real-time pressure difference to obtain the target pressure difference; when the power change rate is less than or equal to the preset change rate threshold, increasing the step length based on the real-time pressure difference to obtain the target pressure difference.

[0009] In some embodiments, the difference between the maximum operating voltage and the real-time output voltage is used as the first adjustable margin; the difference between the maximum allowable charging voltage and the real-time voltage is used as the second adjustable margin; and the minimum value among the demand adjustment amount, the first adjustable margin, and the second adjustable margin is used as the target voltage adjustment amount.

[0010] In some embodiments, the method further includes: determining whether to use a direct charging mode or a boost charging mode based on a first charging parameter of the charging pile and a second charging parameter of the battery pack; when using the direct charging mode, controlling a switching component in the vehicle charging system to switch to a first state to directly connect the charging pile to the battery pack for direct charging; when using the boost charging mode, determining whether to reuse the vehicle's motor drive module for boost charging based on the second charging parameter and a third charging parameter of the motor; if so, controlling the switching component to switch to a second state to connect the motor drive module to the charging circuit between the charging pile and the battery pack, so that the output voltage of the charging pile is boosted by the motor drive module to charge the battery pack.

[0011] In some embodiments, the method further includes: before boost charging, controlling the switching component to switch to a third state to connect the pre-charging circuit of the capacitor in the motor drive module to the charging circuit, so that the pre-charging circuit of the capacitor can be pre-charged; when the voltage across the capacitor in the pre-charging circuit reaches the pre-charging voltage threshold, controlling the switching component to switch to a second state to disconnect the pre-charging circuit of the capacitor and connect the inverter and motor winding in the motor drive module to the charging circuit, so that the output voltage of the charging pile is boosted by the inverter and the motor winding to charge the battery pack.

[0012] In some embodiments, the method further includes: during the vehicle direct charging process, determining whether the vehicle meets the direct charging conditions based on the first charging parameters of the charging pile and the second charging parameters of the battery pack; if the direct charging conditions are not met, controlling the switching component to switch from the first state to the second state to connect the motor drive module to the charging circuit, so that the output voltage of the charging pile is boosted by the motor drive module to charge the battery pack.

[0013] Secondly, embodiments of the present invention provide a controller, comprising: a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, it implements the vehicle charging control method described in the first aspect embodiment.

[0014] Thirdly, embodiments of the present invention provide a vehicle comprising: the controller described in the second aspect embodiment.

[0015] The vehicle charging control method, controller, and vehicle of this invention, during the vehicle boost charging process, periodically acquire the real-time voltage of the vehicle's battery pack and the real-time output voltage of the charging pile connected to the vehicle; determine a target voltage adjustment amount based on the real-time voltage, the real-time output voltage, the maximum operating voltage of the charging pile, and the maximum allowable charging voltage of the battery pack; adjust the target charging voltage command sent to the charging pile according to the target voltage adjustment amount, so that the output voltage of the charging pile adjusts to the target voltage adjustment amount; until a preset charging end condition is met. Therefore, by comprehensively considering the real-time voltage of the battery pack, the real-time output voltage of the charging pile, and the voltage boundaries between the two (the maximum operating voltage of the charging pile and the maximum allowable charging voltage of the battery pack) to dynamically determine the target voltage adjustment amount, and adjusting the output voltage command of the charging pile in real time based on this adjustment amount, precise and smooth adjustment of the charging voltage can be achieved during boost charging, avoiding adjustment lag or adjustment deviation caused by a fixed voltage control strategy, thereby improving charging efficiency, ensuring charging safety, and enhancing the stability of the charging process.

[0016] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0017] Figure 1 This is a flowchart of a vehicle charging control method according to an embodiment of the present invention; Figure 2 This is a flowchart of step S2 of an embodiment of the present invention; Figure 3 This is a topology diagram of a charging system according to an embodiment of the present invention; Figure 4 This is a topology diagram of a charging system according to another embodiment of the present invention; Figure 5 This is a topology diagram of a charging system according to another embodiment of the present invention; Figure 6 This is a structural block diagram of a controller according to an embodiment of the present invention; Figure 7 This is a structural block diagram of a vehicle according to an embodiment of the present invention. Detailed Implementation

[0018] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0019] The boost charging scheme in related technologies mainly addresses the voltage matching problem when the output voltage of the charging pile is lower than the battery pack voltage, i.e., realizing the basic charging function of low-voltage piles for high-voltage battery packs. However, in the actual process of boost charging, the battery pack voltage is not constant, but gradually increases as the charging amount increases.

[0020] Specifically, in practical applications, there are mainly the following two situations: Scenario 1: The battery pack's maximum voltage (less than or equal to its maximum allowable charging voltage) is higher than the charging pile's maximum operating voltage, while the battery pack's minimum voltage is lower than the charging pile's maximum operating voltage. In this case, during the initial charging phase, the battery pack voltage is low (lower than the charging pile's maximum operating voltage), and the charging pile can directly charge the battery pack without voltage boosting or only requiring a slight boost. However, in the later stages of charging, as the battery pack voltage gradually increases and exceeds the charging pile's maximum operating voltage, it needs to switch to boost charging mode. Throughout the entire charging process, the system needs to smoothly switch between direct charging mode and boost mode, adapting to the continuously increasing voltage.

[0021] The second scenario: The minimum voltage of the battery pack is already higher than the maximum operating voltage of the charging station. In this case, the output voltage of the charging station remains lower than the battery pack voltage throughout the entire charging process. The system needs to operate in boost charging mode throughout, and as charging progresses, the battery pack voltage continuously increases, leading to a continuous increase in boost demand.

[0022] For the two scenarios mentioned above, especially the first scenario involving the switching of charging conditions due to voltage changes during charging, how to achieve a smooth transition of charging modes and optimal charging across all operating conditions in terms of circuit topology and software control remains an unsolved technical challenge in related technologies. To address this, this invention proposes a vehicle charging control scheme. During boost charging, by acquiring the dynamic changes in battery pack voltage and charging pile output voltage in real time, and combining these with the comprehensive constraints of the charging pile's maximum operating voltage and the battery pack's maximum allowable charging voltage, the output voltage command of the charging pile is dynamically adjusted to achieve adaptive voltage regulation across all charging conditions.

[0023] The charging control method, controller, and vehicle of the present invention are described below with reference to the accompanying drawings.

[0024] Figure 1 This is a flowchart of a vehicle charging control method according to an embodiment of the present invention. The control method can be executed by a controller, which can be any one of a vehicle controller, a battery management system, or a motor controller, or an independently set charging control unit. The controller is communicatively connected to the charging pile and electrically connected to the vehicle battery pack management system.

[0025] like Figure 1 As shown, the vehicle charging control method includes: S1. During the vehicle's boost charging process, before the preset charging termination conditions are met, the following steps S2 to S4 are periodically executed.

[0026] Specifically, steps S2 to S3 are continuously executed in a loop with a preset sampling period. In each control cycle, the controller reacquires the real-time voltage of the battery pack and the real-time output voltage of the charging pile, recalculates the target voltage adjustment amount, and regenerates and sends the target charging voltage command, thereby achieving real-time dynamic adjustment of the charging voltage. At the beginning of each control cycle or before executing S2, the controller checks whether the preset charging end condition is met. If the charging end condition is met, the loop terminates and the boost charging control process ends; if the charging end condition is not met, the loop control steps S2 to S4 continue to be executed.

[0027] For example, the preset charging termination condition may include at least one of the following: The battery pack's SOC reaches a preset target state of charge value, which can be within the range of 80% to 100%, such as 100%; The real-time voltage of the battery pack reaches the maximum voltage of the battery pack; If the charging station stops outputting voltage, for example, due to a malfunction, user operation, or abnormal power grid, the charging control should be terminated. Upon receiving a user's command to stop charging, for example, the user actively issues a command to stop charging via the vehicle's central control screen, mobile app, or charging station control panel; If a charging abnormality is detected, such as a communication timeout, abnormal voltage sampling, over-temperature protection, or insulation failure during the charging process, charging should be stopped immediately to ensure safety.

[0028] When any one of the above charging termination conditions is met, the controller terminates the boost charging control process.

[0029] In some embodiments of the present invention, before ending charging, the controller also sends a stop output command to the charging pile to control the charging pile to disconnect the output and ensure charging safety.

[0030] If the preset charging termination condition is not met, the controller will continue to acquire and regulate the voltage in the next control cycle until the charging termination condition is met.

[0031] S2, obtain the real-time voltage of the vehicle's battery pack and the real-time output voltage of the charging pile to which the vehicle is connected.

[0032] Specifically, after the vehicle connects to the charging station, the controller interacts with the charging station to determine the charging mode based on the charging station's first charging parameters and the battery pack's second charging parameters. The first charging parameters include at least the charging station's maximum output voltage (i.e., the charging station's maximum operating voltage), and the second charging parameters include at least the battery pack's rated voltage or current real-time voltage. If the charging station's maximum output voltage is lower than the battery pack's required charging voltage, a boost charging mode is determined, and a boost charging command is sent to the charging station. Subsequently, the controller initiates the boost charging control process.

[0033] After the boost charging control process is initiated, the controller obtains the real-time voltage of the battery pack from the battery management system and the real-time output voltage of the charging pile from the charging pile communication module, according to a preset sampling period, via the vehicle's CAN (Controller Area Network) bus or internal communication network. The sampling period can be calibrated according to actual control requirements.

[0034] During the boost charging process, step S2 is continuously executed in a loop at a set sampling period to provide real-time and continuous voltage input data for subsequent steps until the preset charging end conditions are met, such as the battery pack SOC (State of Charge) reaching the target value, the charging pile stopping output, or the user actively stopping charging.

[0035] S3 determines the target voltage adjustment amount based on the real-time voltage, real-time output voltage, maximum operating voltage of the charging pile, and maximum allowable charging voltage of the battery pack.

[0036] Specifically, after acquiring the real-time voltage U_bat of the battery pack and the real-time output voltage U_out of the charging pile in each control cycle, the controller reads the pre-stored maximum operating voltage U_max_chg of the charging pile and the maximum allowable charging voltage U_max_bat of the battery pack, and calculates the target voltage adjustment amount ΔU for the current cycle based on the above four parameters.

[0037] In some embodiments of the present invention, such as Figure 2 As shown, step S3 includes: S21 calculates the real-time voltage difference based on the real-time voltage and the real-time output voltage.

[0038] Wherein, the real-time voltage difference ΔU_1 can be the difference between the real-time voltage U_bat and the real-time output voltage U_out, that is, ΔU_1=U_bat-U_out.

[0039] S22, determine the target differential pressure, and determine the demand adjustment amount based on the target differential pressure and the real-time differential pressure.

[0040] Specifically, before determining the target voltage adjustment amount, the controller first determines the target voltage difference expected to be achieved in the current control cycle. This target voltage difference is the expected difference between the charging pile output voltage and the real-time voltage of the battery pack. Then, based on the target voltage difference and the real-time voltage difference in the current cycle, the demand adjustment amount is determined.

[0041] In some examples, step S22 includes: calculating the power change rate based on the real-time charging power of the current cycle and the real-time charging power of the previous cycle; and determining the target pressure difference based on the power change rate and the real-time pressure difference.

[0042] Specifically, the controller obtains the real-time charging power P(k) of the current cycle and the real-time charging power P(k-1) of the previous control cycle, and calculates the power change rate ΔP(k): ΔP(k)=P(k)-P(k-1) The real-time charging power P(k) can be calculated by multiplying the real-time output voltage U_out(k) of the charging pile by the real-time charging current I(k), i.e., P(k) = U_out(k) × I(k), or it can be read directly from the communication message of the charging pile.

[0043] The controller determines the target pressure difference ΔU_t(k) for the current cycle based on the calculated power change rate ΔP(k) and the real-time pressure difference ΔU_1(k) for the current cycle.

[0044] For example, determining the target pressure difference based on the power change rate and the real-time pressure difference includes: when the power change rate is greater than a preset change rate threshold, reducing the first step length based on the real-time pressure difference to obtain the target pressure difference; when the power change rate is less than or equal to the preset change rate threshold, increasing the second step length based on the real-time pressure difference to obtain the target pressure difference.

[0045] The preset rate of change threshold can be pre-calibrated and stored in the controller according to actual control requirements, for example, it can be calibrated to 1kW / cycle or 2kW / cycle. The values ​​of the first step length and the second step length can be the same or different.

[0046] Specifically, when the power change rate ΔP(k) is greater than the preset change rate threshold, it indicates that the current charging power is rising rapidly. If the real-time voltage difference is large, the charging power will fluctuate significantly with the voltage difference, potentially causing charging current oscillations. In this case, the target voltage difference is set to be less than the real-time voltage difference, i.e., the first step length step1 is reduced from the real-time voltage difference, i.e., ΔU_t(k) = ΔU_1(k) - step1. Here, the first step length step1 is a pre-calibrated fixed value (e.g., 5V, 10V), or a variable positively correlated with the power change rate ΔP (i.e., the larger the power change rate, the larger the first step length). By reducing the target voltage difference, the charging pile output voltage is brought closer to the battery pack voltage, thereby reducing the voltage difference, suppressing charging power fluctuations, stabilizing the charging process, reducing energy loss and device heating caused by power oscillations, and improving charging efficiency and system stability.

[0047] When the power change rate ΔP(k) is less than or equal to the preset change rate threshold, it indicates that the current charging power change is gradual and the system is in a stable state. At this time, the target voltage difference is set to a value greater than the real-time voltage difference, i.e., a second step size step2 is added to the real-time voltage difference, i.e.: ΔU_t(k) = ΔU_1(k) + step2. Here, the second step size step2 is a pre-calibrated fixed value (e.g., 5V, 10V), or a variable related to the magnitude of the real-time voltage difference (the larger the real-time voltage difference, the smaller the second step size). By increasing the target voltage difference, the output voltage of the charging pile is further increased, which can reduce the charging current under the same charging power, thereby reducing line losses (I²R losses) in the charging circuit (including charging harness, connectors, battery internal resistance, etc.), and simultaneously improving the output power utilization rate of the charging pile, thus improving charging efficiency.

[0048] In other examples, step S22 includes: obtaining a preset target differential pressure mapping table, which contains target differential pressure values ​​corresponding to different differential pressure ranges; determining the corresponding target differential pressure value based on the target differential pressure range in which the real-time differential pressure of the current period is located, and using it as the target differential pressure of the current period.

[0049] Optionally, the target differential pressure value in the target differential pressure mapping table increases or remains unchanged as the real-time differential pressure increases, so as to ensure that sufficient pressure boosting capacity can be maintained under different operating conditions.

[0050] After determining the target pressure difference ΔU_t(k), the controller can determine the required adjustment amount ΔU_r(k) based on the target pressure difference and the real-time pressure difference. For example, ΔU_r(k) = ΔU_t(k) - ΔU_1(k). When ΔU_r(k) is positive, the output voltage of the charging pile needs to be increased; when ΔU_r(k) is negative, the output voltage of the charging pile needs to be decreased; when ΔU_r(k) is 0, the output voltage of the charging pile needs to be kept constant.

[0051] By employing the above methods, charging stability is prioritized to avoid oscillations when power changes rapidly; and charging voltage is prioritized to reduce losses when power is stable, thereby achieving synergistic optimization of charging efficiency and charging stability.

[0052] S23, determine the first adjustable margin based on the maximum operating voltage and the real-time output voltage, and determine the second adjustable margin based on the maximum allowable charging voltage and the real-time voltage.

[0053] Specifically, the difference between the maximum operating voltage and the real-time output voltage can be used as the first adjustable margin. This first adjustable margin represents the maximum voltage range that the charging pile output voltage can be adjusted upwards based on the current charging pile output voltage, reflecting the upper limit of the voltage regulation capability allowed on the charging pile side. The difference between the maximum allowable charging voltage and the real-time voltage can be used as the second adjustable margin. This second adjustable margin represents the voltage rise that the battery pack can withstand based on the current real-time voltage of the battery pack, reflecting the upper limit of the voltage regulation capability allowed on the battery side.

[0054] It should be noted that both the first and second adjustable margins should be non-negative values. If the first adjustable margin is negative, it indicates that the current real-time output voltage of the charging pile has exceeded its maximum operating voltage, and charging should be stopped or a fault warning should be issued. If the second adjustable margin is negative, it indicates that the real-time voltage of the battery pack has exceeded its maximum allowable charging voltage, and charging should be stopped or a fault warning should be issued.

[0055] S24: Based on the required adjustment amount, the first adjustable margin, and the second adjustable margin, the target voltage adjustment amount is obtained.

[0056] Specifically, the minimum value among the demand adjustment amount, the first adjustable margin, and the second adjustable margin can be used as the target voltage adjustment amount. The reason for determining the target voltage adjustment amount by taking the minimum value is as follows: when the demand adjustment amount is at its minimum, adjustment is made according to actual demand, which can meet the boost control target; when the first adjustable margin is at its minimum, adjustment is limited to the voltage margin on the charging pile side, which can avoid exceeding the maximum operating voltage of the charging pile, thus preventing overload or protective shutdown of the charging pile; when the second adjustable margin is at its minimum, adjustment is limited to the voltage margin on the battery side, which can avoid exceeding the maximum allowable charging voltage of the battery pack, thus preventing overcharging safety risks.

[0057] Therefore, the target voltage regulation can achieve optimal regulation that balances control objectives and system safety, while meeting the boost voltage requirement and being constrained by the two safety boundaries of the charging pile's maximum operating voltage and the battery pack's maximum allowable charging voltage.

[0058] In some embodiments of the present invention, step S3 includes: first, calculating the real-time voltage difference ΔU_1 = U_bat - U_out, which represents the voltage deficiency of the current charging pile output voltage relative to the real-time voltage of the battery pack. If ΔU_1 is greater than zero, then further calculating a second difference ΔU_2 = U_max_chg - U_out, which represents the voltage margin that the charging pile can still increase based on the current output voltage; and calculating a third difference ΔU_3 = U_max_bat - U_bat, which represents the voltage rise space that the battery pack can still withstand based on the current real-time voltage. Wherein, U_max_chg is the maximum operating voltage of the charging pile, and U_max_bat is the maximum allowable charging voltage of the battery pack.

[0059] Then, the controller determines the target voltage adjustment amount ΔU based on the insufficient voltage ΔU_1, the charging pile voltage margin ΔU_2, and the battery pack voltage rise space ΔU_3. This target voltage adjustment amount ΔU is taken as the minimum value among ΔU_1, ΔU_2, and ΔU_3. By taking the minimum value, it is possible to ensure that the output voltage of the charging pile is increased to a level higher than the charging voltage required by the battery pack to meet the voltage boost requirement, while avoiding exceeding the maximum operating voltage capability of the charging pile, which could lead to overload or protective shutdown of the charging pile. At the same time, it is also possible to avoid exceeding the maximum allowable charging voltage of the battery pack, which could cause the battery overcharge safety risk.

[0060] In some embodiments of the present invention, the target voltage adjustment amount ΔU can also be directly determined as ΔU_1 (i.e., insufficient voltage). However, after determining the target adjustment amount and before outputting the adjustment command, it is necessary to verify whether U_out + ΔU is less than or equal to U_max_chg and U_max_bat, respectively. That is, to verify whether the adjusted output voltage exceeds the maximum working voltage of the charging pile and the maximum allowable charging voltage of the battery pack. If the verification passes, the adjustment is performed according to ΔU_1. If the verification fails, ΔU is adjusted to the maximum allowable value that can pass the verification.

[0061] In each control cycle, step S3 recalculates the target voltage adjustment amount based on the real-time voltage and real-time output voltage acquired in the current period, realizing dynamic updating of the target adjustment amount to adapt to changes in operating conditions such as the gradual increase of battery pack voltage and the gradual adjustment of charging pile output voltage during the boost charging process.

[0062] It should be noted that in boost charging mode, if ΔU_1 is less than or equal to zero, it means that the current output voltage of the charging pile can meet the voltage requirements of the battery pack. At this time, the controller determines that there is no need to perform boost adjustment. It can set the target voltage adjustment amount ΔU to zero, or maintain the adjustment amount of the previous cycle, and can choose to send a command to the charging pile to switch to direct charging mode or issue a voltage abnormality prompt message.

[0063] S4, adjust the target charging voltage command sent to the charging pile according to the target voltage adjustment amount, so that the output voltage of the charging pile is adjusted to the target voltage adjustment amount.

[0064] Specifically, after obtaining the target voltage adjustment amount for the current cycle, the controller calculates the sum between the real-time output voltage of the charging pile and the target voltage adjustment amount. Based on this sum, it generates a target charging voltage command and sends it to the charging pile according to the charging pile communication protocol. Upon receiving the command, the charging pile responds by adjusting its actual output voltage to the target value through its internal power control unit. After adjustment, the charging pile feeds back the current actual output voltage to the controller for use in the next control cycle.

[0065] It should be understood that after the target charging voltage command is sent to the charging pile, the current control cycle ends, the process returns to S1, and the next control cycle begins, continuing to sample voltage and calculate and adjust the target adjustment amount to achieve closed-loop control of the boost charging process.

[0066] Through the above-described cyclic control method, the embodiments of the present invention can continuously track the changes in battery pack voltage and charging pile output voltage throughout the entire boost charging process, dynamically adjust the charging pile output voltage command, realize voltage adaptive adjustment throughout the entire charging cycle, and take into account charging efficiency, charging stability and charging safety.

[0067] In some embodiments of the present invention, the vehicle charging system includes a switching assembly and a motor drive module.

[0068] In some examples, such as Figure 3 As shown, the motor drive module includes a front drive module and a rear drive module, and the switch assembly includes switches K1, K3, K5, K6, and K8. K1 and K3 represent the positive and negative contactors of the battery pack, respectively; K5 and K6 represent the positive and negative relays or contactors for DC charging, respectively; and K8 represents the boost charging relay or contactor.

[0069] In other examples, such as Figure 4 As shown, the motor drive module is a rear-drive module, and the switch assembly includes switches K1, K3, K4, K5, K6, K7, and K8. The rear-drive module also includes capacitor C1.

[0070] In some other examples, such as Figure 5 As shown, the motor drive module is a front drive module, and the switch assembly includes switches K1, K3, K5, K6, K8, K9 and K10. The front drive module also includes capacitor C2.

[0071] In this embodiment, the charging control method further includes: determining whether to use a direct charging mode or a boost mode based on the first charging parameters of the charging pile and the second charging parameters of the battery pack; when using the direct charging mode, controlling the switch assembly to switch to the first state to directly connect the charging pile to the battery pack for direct charging; when using the boost mode, determining whether to reuse the motor drive module for boost charging based on the second charging parameters and the third charging parameters of the motor; if so, controlling the switch assembly to switch to the second state to connect the motor drive module to the charging circuit between the charging pile and the battery pack, so that the output voltage of the charging pile is boosted by the motor drive module to charge the battery pack.

[0072] The third charging parameter may include electrical parameters such as phase inductance and phase resistance of the motor windings.

[0073] Specifically, when the maximum output voltage of the charging pile is greater than or equal to the charging voltage required by the battery pack, the direct charging mode can be used; when the maximum output voltage of the charging pile is lower than the charging voltage required by the battery pack, the boost charging mode needs to be used.

[0074] When using direct charging mode, the control switch assembly switches to the first state to directly connect the charging station to the battery pack for direct charging. Figure 3 Taking the circuit shown as an example, K1, K3, K5, and K6 are closed, while K2 and K8 are open, so that the positive and negative output terminals of the charging pile are directly connected to the positive terminal of the battery pack through K5 and K1, and directly connected to the negative terminal of the battery pack through K6 and K3. At this time, the motor drive module is not connected to the charging circuit, and the voltage output by the charging pile directly charges the battery pack.

[0075] When using boost mode, the controller determines whether reusing the current motor drive module for boost charging meets the boost ratio and power requirements based on the real-time voltage of the battery pack and the electrical parameters of the motor windings. (For example, the required boost ratio is determined based on the real-time voltage of the battery pack and the maximum output voltage of the charging pile; the maximum boost ratio that the motor drive module can support is determined based on the phase inductance and phase resistance of the motor windings; and the maximum transmission power is determined based on the rated power of the motor controller. If the required boost ratio is less than or equal to the maximum boost ratio and the output power of the charging pile is less than or equal to the maximum transmission power, then the requirements are met.) If the requirements are met, the controller determines to reuse the motor drive module for boost charging; if not, it can select another motor drive module (such as front-drive / rear-drive switching) or issue a prompt that charging is not possible.

[0076] If it is determined that the motor drive module is used for boost charging, the control switch assembly is switched to the second state, controlling K1, K3, K8, and K6 to close and K2 and K5 to open, so as to connect the motor drive module to the charging circuit between the charging pile and the battery pack, so that the output voltage of the charging pile is boosted by the motor drive module to charge the battery pack.

[0077] After the switching component switches to the second state, the boost charging control method (i.e., S1 to S4) described in the above embodiments of the present invention is executed. By controlling the on and off timing of the power switching transistor inside the electronic control unit, the low-voltage DC power input from the charging pile is converted into high-voltage DC power and output to the battery pack. The target charging voltage command is dynamically adjusted in accordance with the methods of the aforementioned embodiments, so that the output voltage tracks the changes in the battery pack voltage in real time, thereby achieving efficient, stable and safe boost charging.

[0078] Through the above-described switch control strategy, the embodiments of the present invention can flexibly select the corresponding boost topology according to the vehicle's drive configuration (front-wheel drive, rear-wheel drive, or dual-wheel drive), adapt to the boost charging requirements of different vehicle platforms, and have wide applicability and compatibility.

[0079] For example, see Figure 3 , Figure 4 , Figure 5 The charging system also includes a pre-charge resistor R, a pre-charge switch K2, and a fuse F1. The pre-charge resistor and pre-charge switch K2 are connected in series and then in parallel with K1 to pre-charge the battery pack when it supplies power to the vehicle load. F1 can be located at the positive, negative, or middle terminal of the battery and is used to blow in case of abnormal circuit current to protect the charging system.

[0080] In some embodiments of the present invention, see Figure 3 , Figure 4 , Figure 5 The motor drive module includes an inverter, a motor (M), and a capacitor pre-charge circuit. Figure 3 In the example shown, the switching assembly also includes switches K4, K7, K9, and K10, and the capacitor pre-charging circuit includes capacitors C1 and C2. Figure 4 In the example shown, the switching assembly also includes switches K4 and K7, and the capacitor pre-charge circuit includes an open capacitor C1. Figure 5 In the example shown, the switching assembly also includes switches K9 and K10, and the capacitor pre-charging circuit includes capacitor C2. K4 and K7 represent rear-drive boost charging relays or contactors, controlling the rear-drive boost charging; K7 primarily controls the connection and disconnection of C1. K9 and K10 represent front-drive boost charging relays or contactors, controlling the front-drive boost charging; K10 primarily controls the connection and disconnection of C2. K8 is connected in series with both K4 and K9.

[0081] In this embodiment, the charging control method further includes: before boost charging, controlling the switching component to switch to the third state to connect the capacitor pre-charging circuit to the charging circuit, so that the capacitor pre-charging circuit can be pre-charged; when the voltage of the capacitor pre-charging circuit reaches the pre-charging voltage threshold, controlling the switching component to switch to the second state to disconnect the capacitor pre-charging circuit and connect the inverter and motor winding to the charging circuit, so that the output voltage of the charging pile can be boosted by the inverter and motor winding to charge the battery pack.

[0082] by Figure 3 Taking the dual-drive circuit shown as an example, if the rear-drive boost charging mode is selected, after determining that the boost charging mode is adopted, the pre-charge stage is first entered. The controller controls K6, K4, and K7 to close, pre-charging capacitor C1. When the voltage of C1 reaches the pre-charge voltage threshold, the controller controls K8, K1, and K3 to close, entering the boost charging stage. The pre-charge voltage threshold can be set according to the real-time voltage of the battery pack, for example, set to 90% to 95% of the real-time voltage of the battery pack. When the capacitor voltage reaches the pre-charge voltage threshold, the controller determines that the pre-charge is complete and controls the switching components to switch to the second state.

[0083] The above pre-charge control strategy can prevent the capacitor from being directly connected to the high-voltage circuit in a zero-voltage state, thus avoiding instantaneous high-current surges, protecting power switching transistors and relays, and improving system reliability.

[0084] Optionally, the aforementioned motor drive module can be replaced with an additionally configured DC-DC module, whose input is connected to the charging pile and whose output is connected to the battery pack. Boost conversion is achieved through duty cycle adjustment of the internal power switch. The controller communicates with the DC-DC module, sending it a target charging voltage command. The DC-DC module responds to this command by adjusting its output voltage to the target value. This DC-DC module is also applicable to the control methods described in the preceding embodiments, dynamically adjusting the output voltage according to S1 to S4. By independently configuring the DC-DC module, the vehicle can achieve boost charging without relying on the motor drive system, offering greater design flexibility.

[0085] In some embodiments of the present invention, the charging control method further includes: during the vehicle direct charging process, determining whether the vehicle meets the direct charging conditions based on the first charging parameters of the charging pile and the second charging parameters of the battery pack; if the direct charging conditions are not met, controlling the switch assembly to switch from the first state to the second state to connect the motor drive module to the charging circuit, so that the output voltage of the charging pile is boosted by the motor drive module to charge the battery pack.

[0086] Specifically, when the battery pack's maximum voltage is higher than the charging pile's maximum operating voltage, and the battery pack's minimum voltage is lower than the charging pile's maximum operating voltage, in the initial charging phase, the battery pack's real-time voltage is low and lower than the charging pile's maximum operating voltage. The controller keeps the switching assembly in the first state, allowing the charging pile to directly charge the battery pack. As charging continues, the battery pack's real-time voltage gradually increases. When the real-time voltage approaches or exceeds the charging pile's maximum operating voltage, the charging pile can no longer meet the battery pack's charging needs through direct charging. The controller determines that it needs to switch to boost charging mode, switching the switching assembly from the first state to the second state, connecting the motor drive module to the charging circuit. This allows the charging pile's output voltage to be boosted by the motor drive module to charge the battery pack. After the switch is complete, the controller dynamically adjusts the charging pile's output voltage according to steps S1 to S4 until charging is finished. This achieves a smooth switch between direct charging and boost charging modes, adapting to the continuous rise in battery pack voltage across all operating conditions.

[0087] Figure 6 This is a structural block diagram of a controller according to an embodiment of the present invention.

[0088] like Figure 6 As shown, the controller 500 includes a processor 501 and a memory 503. The processor 501 and the memory 503 are connected, for example, via a bus 502. Optionally, the controller 500 may also include a transceiver 504. It should be noted that in practical applications, the transceiver 504 is not limited to one, and the structure of the controller 500 does not constitute a limitation on the embodiments of the present invention.

[0089] Processor 501 may be a CPU (Central Processing Unit), a general-purpose processor, a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It can implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this invention. Processor 501 may also be a combination that implements computational functions, such as including one or more microprocessor combinations, a combination of a DSP and a microprocessor, etc.

[0090] Bus 502 may include a pathway for transmitting information between the aforementioned components. Bus 502 may be a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus, etc. Bus 502 can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 6 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0091] The memory 503 stores a computer program corresponding to the vehicle charging control method of the above embodiments of the present invention. This computer program is controlled and executed by the processor 501. The processor 501 executes the computer program stored in the memory 503 to implement the content shown in the foregoing method embodiments.

[0092] Among them, controller 500 includes, but is not limited to: vehicle controller, battery management system, and motor controller. Figure 6 The controller 500 shown is an example and should not be construed as limiting the functionality and scope of use of embodiments of the present invention.

[0093] This invention also proposes a controller, including a memory and a processor. The memory stores a computer program, and when the computer program is executed by the processor, it implements the vehicle charging control method of the above embodiments.

[0094] Figure 7 This is a structural block diagram of a vehicle according to an embodiment of the present invention.

[0095] like Figure 7 As shown, the vehicle 1000 includes the controller 500 of the above embodiment.

[0096] In summary, the vehicle charging control method, controller, and vehicle of this invention employ a dynamic charging control strategy. This strategy not only solves the charging voltage matching problem under different battery pack voltage platforms and charging pile output voltage conditions, achieving compatible charging of high-voltage battery packs by low-voltage piles, but also dynamically adjusts the target voltage regulation amount and charging pile output voltage command in real time through periodic sampling and closed-loop feedback based on the dynamic changes of operating condition-related parameters such as real-time battery pack voltage, real-time charging pile output voltage, and charging power during the charging process. This achieves dynamic adaptive adjustment throughout the entire charging cycle, adapting to complex operating condition changes such as continuous battery pack voltage rise and switching between direct charging and boost charging modes during boost charging. It effectively avoids adjustment lag or adjustment deviation caused by using a fixed voltage control strategy. While ensuring the safety of the battery pack and charging pile voltage boundaries, it also considers charging efficiency, charging stability, and charging safety, achieving optimal charging control under different operating conditions, improving the user charging experience, and increasing the resource utilization rate of charging facilities.

[0097] 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, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0098] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0099] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0100] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A charging control method for a vehicle, characterized in that, include: During the vehicle's boost charging process, the following steps are periodically executed before the preset charging termination conditions are met: Obtain the real-time voltage of the vehicle battery pack and the real-time output voltage of the charging pile to which the vehicle is connected; The target voltage adjustment amount is determined based on the real-time voltage, the real-time output voltage, the maximum operating voltage of the charging pile, and the maximum allowable charging voltage of the battery pack. According to the target voltage adjustment amount, adjust the target charging voltage command sent to the charging pile so that the output voltage of the charging pile adjusts the target voltage adjustment amount; The step of determining the target voltage adjustment amount based on the real-time voltage, the real-time output voltage, the maximum operating voltage of the charging pile, and the maximum allowable charging voltage of the battery pack includes: Calculate the real-time voltage difference based on the real-time voltage and the real-time output voltage; Determine the target pressure difference, and determine the demand adjustment amount based on the target pressure difference and the real-time pressure difference; A first adjustable margin is determined based on the maximum operating voltage and the real-time output voltage, and a second adjustable margin is determined based on the maximum allowable charging voltage and the real-time voltage. The target voltage adjustment amount is obtained based on the required adjustment amount, the first adjustable margin, and the second adjustable margin.

2. The vehicle charging control method according to claim 1, characterized in that, The determination of the target pressure difference includes: The power change rate is calculated based on the real-time charging power of the charging pile in the current cycle and the real-time charging power in the previous cycle. The target pressure difference is determined based on the power change rate and the real-time pressure difference.

3. The vehicle charging control method according to claim 2, characterized in that, Determining the target pressure difference based on the power change rate and the real-time pressure difference includes: When the power change rate is greater than the preset change rate threshold, the first step length is reduced based on the real-time pressure difference, and this is used as the target pressure difference. When the power change rate is less than or equal to the preset change rate threshold, a second step is added to the real-time pressure difference as the target pressure difference.

4. The vehicle charging control method according to claim 1, characterized in that, The difference between the maximum operating voltage and the real-time output voltage is used as the first adjustable margin; The difference between the maximum allowable charging voltage and the real-time voltage is used as the second adjustable margin; The minimum value among the demand adjustment amount, the first adjustable margin, and the second adjustable margin is taken as the target voltage adjustment amount.

5. The vehicle charging control method according to claim 1, characterized in that, The method further includes: Based on the first charging parameters of the charging pile and the second charging parameters of the battery pack, it is determined whether to use direct charging mode or boost mode. When the direct charging mode is used, the switching component in the vehicle charging system is controlled to switch to the first state so that the charging pile is directly connected to the battery pack for direct charging; When the boost mode is used, it is determined whether to reuse the vehicle's motor drive module for boost charging based on the second charging parameters and the motor's third charging parameters. If so, the switch assembly is controlled to switch to the second state to connect the motor drive module to the charging circuit between the charging pile and the battery pack, so that the output voltage of the charging pile is boosted by the motor drive module to charge the battery pack.

6. The vehicle charging control method according to claim 5, characterized in that, The method further includes: Before boost charging, the switching assembly is controlled to switch to the third state to connect the pre-charging circuit of the capacitor in the motor drive module to the charging circuit, so that the pre-charging circuit of the capacitor can be pre-charged. When the voltage across the capacitor in the pre-charging circuit reaches the pre-charging voltage threshold, the switching assembly is controlled to switch to the second state to disconnect the pre-charging circuit and connect the inverter and motor winding in the motor drive module to the charging circuit, so that the output voltage of the charging pile is boosted by the inverter and motor winding to charge the battery pack.

7. The vehicle charging control method according to claim 5, characterized in that, The method further includes: During the direct charging process of the vehicle, it is determined whether the vehicle meets the conditions for direct charging based on the first charging parameters of the charging pile and the second charging parameters of the battery pack. If the direct charging conditions are not met, the switch assembly is controlled to switch from the first state to the second state to connect the motor drive module to the charging circuit, so that the output voltage of the charging pile is boosted by the motor drive module to charge the battery pack.

8. A controller, characterized in that, include: A memory and a processor, the memory storing a computer program that, when executed by the processor, implements the charging control method for a vehicle as described in any one of claims 1-7.

9. A vehicle, characterized in that, include: The controller as described in claim 8.

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