Energy recovery method, vehicle and storage medium

Abstract

The invention provides an energy recovery method, a vehicle and a storage medium, the method is applied to the technical field of vehicles, and the method comprises the steps that under the condition that the vehicle needs to conduct braking energy recovery, the maximum recovery torque of the vehicle is determined; wherein the maximum recovery torque is the maximum torque of energy recovery allowed by the vehicle; according to the actual vehicle speed of the vehicle, the target torque of vehicle sliding energy recovery is determined, the target torque of vehicle sliding energy recovery is subtracted from the maximum recovery torque, and the target torque of braking energy recovery is obtained; and according to the target torque for braking energy recovery, braking energy recovery is conducted on the vehicle. According to the method, the torque of brake energy recovery can be limited, the problem of overcharge of the battery pack is effectively avoided, and the safety of vehicle brake energy recovery is guaranteed.

Description

Technical Field

[0001] The present application relates to the field of vehicles, and more particularly, to a method, a vehicle and a storage medium for energy recovery in the field of vehicles. Background Art

[0002] In recent years, with the continuous development of society and the improvement of people's living standards, the demand for automobiles has continued to increase. However, the energy shortage and environmental pollution caused by traditional fuel vehicles are becoming increasingly serious, prompting pure electric vehicles powered by electricity to gradually become the mainstream choice. Although pure electric vehicles have significant advantages such as zero emissions and zero pollution, the energy density of power batteries at this stage limits their range and cannot fully meet user needs.

[0003] In order to make up for the problem of insufficient cruising range, energy recovery technology has been widely used and developed in pure electric vehicles. Through braking energy recovery and coasting energy recovery, the kinetic energy of the vehicle during deceleration can be converted into electrical energy and stored in the battery, thereby improving the energy utilization efficiency of the entire vehicle. This technology not only helps to extend the vehicle's cruising range, but also reduces the impact on the environment.

[0004] However, the energy recovery system in the prior art is prone to the problem of over-power feedback, which may cause the battery pack to be overcharged and further cause damage to the battery pack. Summary of the invention

[0005] The present application provides an energy recovery method, a vehicle and a storage medium. The method can limit the torque of braking energy recovery, ensure that the sum of the energy recovery of the entire vehicle does not exceed the maximum energy recovery limit allowed by the vehicle, effectively avoid the problem of battery pack overcharging, and ensure the safety of vehicle braking energy recovery.

[0006] In a first aspect, a method for energy recovery is provided, the method comprising: determining a maximum recovery torque of the vehicle when the vehicle needs to perform braking energy recovery; wherein the maximum recovery torque is the maximum torque that the vehicle is allowed to recover energy; determining a target torque for coasting energy recovery of the vehicle according to an actual vehicle speed, subtracting the target torque for coasting energy recovery from the maximum recovery torque to obtain a target torque for braking energy recovery; and performing braking energy recovery on the vehicle according to the target torque for braking energy recovery.

[0007] In the above technical scheme, when the vehicle needs to perform braking energy recovery, the maximum recovery torque allowed for the vehicle to recover energy is determined, the target torque for coasting energy recovery is determined based on the actual vehicle speed, the torque obtained by subtracting the target torque for coasting energy recovery from the maximum recovery torque is used as the target torque for braking energy recovery, and braking energy recovery is performed on the vehicle. By subtracting the target torque for coasting energy recovery from the maximum recovery torque, the target torque for limiting braking energy recovery is achieved, thereby limiting the energy recovered by the vehicle, ensuring that the energy recovered by the vehicle during braking energy recovery is always less than the maximum energy recovery limit allowed by the vehicle, and even if the vehicle is performing coasting energy recovery while performing braking energy recovery, it can be ensured that the total amount of energy recovered by the vehicle will not exceed the maximum energy recovery limit allowed by the vehicle, thereby effectively avoiding the problem of battery pack overcharging and ensuring the safety of vehicle braking energy recovery.

[0008] In combination with the first aspect, in some possible implementations, determining the maximum recovery torque of the vehicle includes: determining the maximum recovery power of the vehicle based on the charging power of the vehicle's battery pack and the power consumption of the high-voltage load; determining the maximum recovery torque based on the maximum recovery power and the current speed of the vehicle's drive motor.

[0009] In the above technical solution, the maximum recovery power that the whole vehicle can accept can be accurately determined through the charging power of the battery pack and the power consumption of the high-voltage load in the vehicle, and then the maximum recovery torque can be accurately determined based on the maximum recovery power, so that not only the charging power of the battery pack but also the power consumption of the high-voltage load in the vehicle is taken into account during energy recovery, thereby improving the accuracy of energy recovery.

[0010] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the maximum recovery power of the vehicle is determined based on the charging power of the vehicle's battery pack and the power consumption of the high-voltage load, including: obtaining the initial recovery power based on the charging power of the battery pack and the power consumption of the high-voltage load; determining the regeneration efficiency based on the historical recovery power and the current speed of the drive motor; wherein the historical recovery power is the maximum recovery power calculated in the previous cycle of the current cycle; and obtaining the maximum recovery power based on the initial recovery power and the regeneration efficiency.

[0011] In the above technical solution, the initial recovery power represents the energy actually effectively received by the vehicle. By determining the feedback efficiency, the maximum recovery power is determined based on the feedback efficiency and the initial recovery power. It is considered that the energy actually effectively received by the vehicle usually accounts for a certain proportion of the maximum recovery power, that is, the energy recovered by the vehicle based on the maximum recovery power will still have some losses. The losses in the energy recovery process are considered to ensure the accuracy of the maximum recovery power. In addition, the feedback efficiency is determined based on the maximum recovery power calculated in the previous cycle and the current speed of the drive motor, so that the feedback efficiency can be dynamically adjusted, further improving the accuracy of the maximum recovery power and optimizing the vehicle energy recovery process.

[0012] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the feedback efficiency is determined based on the historical recovery power and the current speed of the drive motor, including: determining the initial feedback efficiency corresponding to the historical recovery power and the current speed of the drive motor; determining the correction coefficient corresponding to the coolant temperature at the water outlet of the drive motor; multiplying the initial feedback efficiency by the correction coefficient to obtain the feedback efficiency.

[0013] In the above technical solution, the correction coefficient is determined by obtaining the coolant temperature at the water outlet of the drive motor to correct the feedback efficiency. The influence of the coolant temperature on the working state and efficiency of the drive motor is taken into consideration, thereby ensuring the accuracy of the feedback efficiency, and further ensuring the accuracy of the maximum recovery power, thereby optimizing the braking energy recovery process.

[0014] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, when a vehicle fault occurs, a maximum recovery power is obtained based on the initial recovery power and the regeneration efficiency, including: obtaining a fault limit power of the vehicle; dividing the initial recovery power by the regeneration efficiency to obtain a reference recovery power; and determining the minimum value between the fault limit power and the reference recovery power as the maximum recovery power.

[0015] In the above technical solution, when there is a fault in the vehicle, the fault limiting power is obtained, and the minimum value between the calculated reference recovery power and the fault limiting power is taken as the maximum recovery power for subsequent braking energy recovery. The impact of the fault on the recovery power when a fault occurs in the vehicle is taken into consideration, and the smaller value between the fault limiting power and the reference recovery power is taken, thereby realizing the limitation of the maximum recovery power based on the fault, ensuring that the maximum recovery power is less than or equal to the fault limiting power, so as to avoid the occurrence of unsafe factors as much as possible and improve the safety of energy recovery.

[0016] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the maximum recovery torque is determined based on the maximum recovery power and the current speed of the vehicle's drive motor, including: substituting the maximum recovery power and the current speed of the drive motor into the power formula to calculate the reference recovery torque; wherein the power formula is used to describe the conversion relationship between power, speed and torque; based on the negative value of the reference recovery torque, the maximum recovery torque is determined.

[0017] In the above technical solution, the reference recovery torque is calculated by substituting the maximum recovery power and the current speed of the drive motor into the power formula that describes the conversion relationship between power, speed and torque, and then the maximum recovery torque is determined based on the negative value of the reference recovery torque, thereby ensuring the accuracy of the maximum recovery torque and improving the accuracy of energy recovery.

[0018] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the maximum recovery torque is determined based on the negative value of the reference recovery torque, including: determining the maximum output torque of the drive motor at the current speed; wherein the maximum output torque is a negative value; and determining the maximum value between the negative value of the reference recovery torque and the maximum output torque as the maximum recovery torque.

[0019] In the above technical scheme, the maximum output torque of the motor at the current speed is determined, and the maximum value is taken from the negative value of the maximum output torque and the reference output torque to obtain the maximum recovery torque, thereby ensuring that the absolute value of the maximum recovery torque is less than or equal to the absolute value of the maximum output torque, ensuring that the maximum recovery torque will not exceed the maximum output capacity of the drive motor at the current speed, thereby achieving protection for the drive motor and avoiding some faults caused by overload of the drive motor when the absolute value of the maximum recovery torque is greater than the absolute value of the maximum output torque of the drive motor at the current speed.

[0020] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the regeneration efficiency is determined based on the historical recovery power and the current speed of the drive motor, including: determining whether the initial recovery power is greater than the preset power; when the initial recovery power is greater than the preset power, determining the regeneration efficiency based on the historical recovery power and the current speed of the drive motor; when the initial recovery power is less than or equal to the preset power, determining that the initial recovery power is zero so that the vehicle does not perform braking energy recovery.

[0021] In the above technical solution, by comparing the initial recovery power with the preset power, it is determined whether the vehicle can perform braking energy recovery. When the initial recovery power is less than or equal to the preset power, it is determined that the vehicle cannot perform braking energy recovery. The initial recovery power is set to 0kw, thereby limiting energy recovery when the battery pack is close to a fully charged state, avoiding energy recovery under low-power conditions that may cause overcharging of the battery pack, affecting the battery pack life and even causing safety problems.

[0022] In summary, when the vehicle needs to perform brake energy recovery, the present application can accurately determine the maximum recovery power that the vehicle can accept through the charging power of the battery pack and the power consumption of the high-voltage load in the vehicle, which not only considers the charging power of the battery pack but also the power consumption of the high-voltage load in the vehicle, thereby improving the accuracy of energy recovery. When determining the maximum recovery power, the feedback efficiency is determined, and the loss in the energy recovery process is considered to ensure the accuracy of the maximum recovery power. And the feedback efficiency is corrected based on the correction coefficient determined by the coolant temperature at the outlet of the drive motor, taking into account the influence of the coolant temperature on the working state and efficiency of the drive motor. When there is a fault in the vehicle, the minimum value is taken from the calculated reference recovery power and the fault limit power as the maximum recovery power, taking into account the influence of the fault on the recovery power when the vehicle has a fault, thereby improving the safety of energy recovery. The maximum value is taken from the maximum output torque of the motor at the current speed and the negative value of the reference output torque to obtain the maximum recovery torque, thereby avoiding some faults caused by overload of the drive motor. Subtracting the target torque for coasting energy recovery from the maximum recovery torque achieves the target torque for limiting braking energy recovery, ensuring that the total energy recovered by the vehicle does not exceed the maximum energy recovery limit allowed by the vehicle, effectively avoiding the problem of battery pack overcharging and ensuring the safety of vehicle braking energy recovery.

[0023] In a second aspect, an energy recovery device is provided, which includes: a first determination module, used to determine the maximum recovery torque of the vehicle when the vehicle needs to perform braking energy recovery; wherein the maximum recovery torque is the maximum torque that the vehicle is allowed to recover energy; a second determination module, used to determine the target torque for coasting energy recovery of the vehicle according to the actual vehicle speed, a calculation module, used to subtract the target torque for coasting energy recovery from the maximum recovery torque to obtain the target torque for braking energy recovery; a control module, used to perform braking energy recovery on the vehicle according to the target torque for braking energy recovery.

[0024] In combination with the second aspect, in some possible implementations, the first determination module is specifically used to determine the maximum recovery power of the vehicle based on the charging power of the vehicle's battery pack and the power consumption of the high-voltage load; and to determine the maximum recovery torque based on the maximum recovery power and the current speed of the vehicle's drive motor.

[0025] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the first determination module is specifically used to obtain the initial recovery power based on the charging power of the battery pack and the power consumption of the high-voltage load; determine the feedback efficiency according to the historical recovery power and the current speed of the drive motor; wherein the historical recovery power is the maximum recovery power calculated in the previous cycle of the current cycle; and obtain the maximum recovery power based on the initial recovery power and the feedback efficiency.

[0026] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the first determination module is specifically used to determine the initial feedback efficiency corresponding to the historical recovery power and the current speed of the drive motor; determine the correction coefficient corresponding to the coolant temperature at the water outlet of the drive motor; multiply the initial feedback efficiency by the correction coefficient to obtain the feedback efficiency.

[0027] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, when a vehicle fault occurs, the first determination module is specifically used to obtain the fault limiting power of the vehicle; divide the initial recovery power by the feedback efficiency to obtain the reference recovery power; and determine the minimum value between the fault limiting power and the reference recovery power as the maximum recovery power.

[0028] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the first determination module is specifically used to substitute the maximum recovery power and the current speed of the drive motor into the power formula to calculate the reference recovery torque; wherein the power formula is used to describe the conversion relationship between power, speed and torque; based on the negative value of the reference recovery torque, the maximum recovery torque is determined.

[0029] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the first determination module is specifically used to determine the maximum output torque of the drive motor at the current speed; wherein the maximum output torque is a negative value; and the maximum value between the negative value of the reference recovery torque and the maximum output torque is determined as the maximum recovery torque.

[0030] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the first determination module is specifically used to determine whether the initial recovery power is greater than the preset power; when the initial recovery power is greater than the preset power, the feedback efficiency is determined according to the historical recovery power and the current speed of the drive motor; when the initial recovery power is less than or equal to the preset power, the initial recovery power is determined to be zero so that the vehicle does not perform braking energy recovery.

[0031] In a third aspect, a vehicle is provided, comprising a memory and a processor. The memory is used to store executable program code, and the processor is used to call and run the executable program code from the memory, so that the vehicle executes the method in the first aspect or any possible implementation of the first aspect.

[0032] In a fourth aspect, a computer program product is provided, comprising: a computer program code, which, when executed on a computer, enables the computer to execute the method in the first aspect or any possible implementation of the first aspect.

[0033] In a fifth aspect, a computer-readable storage medium is provided, which stores a computer program code. When the computer program code runs on a computer, the computer executes the method in the above-mentioned first aspect or any possible implementation manner of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic flow chart of an energy recovery method provided in an embodiment of the present application.

[0035] Figure 2 It is a schematic diagram of a process for determining the recovered available power provided in an embodiment of the present application.

[0036] Figure 3 It is a schematic diagram of a correction coefficient curve provided in an embodiment of the present application.

[0037] Figure 4 It is a schematic diagram of a process for determining recovery power provided in an embodiment of the present application.

[0038] Figure 5 It is a schematic diagram of a negative external characteristic curve provided in an embodiment of the present application.

[0039] Figure 6 It is a schematic diagram of a vehicle speed-torque curve for coasting energy recovery provided in an embodiment of the present application.

[0040] Figure 7 It is a flow chart for determining the coasting energy recovery torque provided in an embodiment of the present application.

[0041] Figure 8 It is a structural schematic diagram of an energy recovery device provided in an embodiment of the present application.

[0042] Fig. 9 It is a structural schematic diagram of a vehicle provided in an embodiment of the present application. DETAILED DESCRIPTION

[0043] The technical solution in the present application will be described clearly and in detail below in conjunction with the accompanying drawings. In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B: "and / or" in the text is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0044] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as suggesting or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0045] In the existing technology, energy recovery mainly includes two main forms: braking energy recovery and coasting energy recovery. These two technologies are widely used in hybrid electric vehicles, plug-in hybrid electric vehicles and pure electric vehicles to improve the overall energy efficiency and driving range of the vehicle.

[0046] The principle of braking energy recovery is that when the driver steps on the brake pedal, the electric motor switches to generator mode, converting the vehicle's kinetic energy into electrical energy and storing it in the battery. The braking force is provided by the electric motor's regenerative braking and traditional friction braking. The principle of coasting energy recovery is that when the driver releases the accelerator pedal and the vehicle enters a coasting state, the electric motor can operate as a generator, converting part of the vehicle's kinetic energy into electrical energy and storing it in the battery.

[0047] In the prior art, the vehicle is braked for energy recovery based directly on the calculated maximum limit of recovered energy. In some scenarios, when the driver steps on the brake pedal to slow down or stop, the vehicle may be braking for energy recovery and coasting for energy recovery at the same time. At this time, if the vehicle is braked for energy recovery based on the maximum limit of recovered energy, the sum of braking for energy recovery and coasting for energy recovery will exceed the maximum limit of energy recovery allowed by the vehicle, which may cause the battery pack to be overcharged, thereby causing damage to the battery pack.

[0048] Based on this, the present application proposes a method for energy recovery. When performing braking energy recovery, the maximum limit of the recovered energy is limited by subtracting the target torque of the coasting energy recovery to limit the torque of the braking energy recovery. Even if the vehicle is performing braking energy recovery while also coasting energy recovery, it can be ensured that the sum of the energy recovery will not exceed the maximum energy recovery limit allowed by the vehicle, effectively avoiding the problem of battery pack overcharging and ensuring the safety of the vehicle's braking energy recovery.

[0049] Figure 1It is a schematic flow chart of an energy recovery method provided in an embodiment of the present application.

[0050] For example, Figure 1 As shown, the method 100 includes:

[0051] Step 101, when the vehicle needs to perform brake energy recovery, determine the maximum recovery torque of the vehicle; wherein the maximum recovery torque is the maximum torque that the vehicle is allowed to recover energy;

[0052] Step 102, determining the target torque of the vehicle's coasting energy recovery according to the actual vehicle speed,

[0053] Step 103, subtracting the target torque of coasting energy recovery from the maximum recovery torque to obtain the target torque of braking energy recovery;

[0054] Step 104 , performing braking energy recovery on the vehicle according to the target torque of braking energy recovery.

[0055] exist Figure 1 In the shown embodiment, when the vehicle needs to perform braking energy recovery, the maximum recovery torque allowed for the vehicle to recover energy is determined, the target torque for coasting energy recovery is determined based on the actual vehicle speed, the torque obtained by subtracting the target torque for coasting energy recovery from the maximum recovery torque is used as the target torque for braking energy recovery, and braking energy recovery is performed on the vehicle. The target torque for limiting braking energy recovery is achieved by subtracting the target torque for coasting energy recovery from the maximum recovery torque, thereby limiting the energy recovered by the vehicle, ensuring that the energy recovered by the vehicle during braking energy recovery is always less than the maximum energy recovery limit allowed by the vehicle. Even if the vehicle is performing coasting energy recovery while performing braking energy recovery, it can be ensured that the total amount of energy recovered by the vehicle will not exceed the maximum energy recovery limit allowed by the vehicle, thereby effectively avoiding the problem of battery pack overcharging and ensuring the safety of vehicle braking energy recovery.

[0056] Below Figure 1 The specific implementation of each step in the embodiment shown is described in detail:

[0057] In step 101, the vehicle may be any one of a pure electric vehicle, a hybrid vehicle or a plug-in hybrid vehicle. The vehicle includes a battery pack and a drive motor. In some embodiments, the battery pack is also referred to as a high-voltage battery. The battery pack is used to provide electrical energy to the drive motor so that the drive motor is in a running state. When the drive motor is in a running state, it outputs power to the wheels of the vehicle to drive the vehicle.

[0058] Braking energy recovery refers to the process of converting the vehicle's kinetic energy into electrical energy and storing it in the vehicle's battery pack during vehicle deceleration and braking. During the braking energy recovery process, the drive motor is usually operated as a generator to achieve energy conversion.

[0059] During the driving of the vehicle, it can be detected whether the user releases the accelerator pedal of the vehicle and steps on the brake pedal of the vehicle. When it is detected that the user releases the accelerator pedal and steps on the brake pedal, it is determined that the vehicle needs to perform brake energy recovery.

[0060] In some embodiments, when the vehicle is traveling downhill, the user may release the accelerator pedal of the vehicle, and when the brake pedal is not pressed, the vehicle is in a coasting state. At this time, it can be determined that the vehicle needs to perform coasting energy recovery, and does not need to perform braking energy recovery. In other words, to determine that the vehicle needs to perform braking energy recovery, it is necessary to detect that the user has both released the accelerator pedal and pressed the brake pedal.

[0061] The maximum recovery torque refers to the torque corresponding to the maximum energy that the vehicle is allowed to recover, which is usually related to the maximum energy that the vehicle can accept. The maximum recovery torque of the vehicle can be determined by determining the maximum energy that the vehicle can accept.

[0062] In a possible implementation, determining the maximum recovery torque of the vehicle includes the following steps S11 to S12:

[0063] S11, determining the maximum recovery power of the vehicle according to the charging power of the battery pack of the vehicle and the power consumption of the high-voltage load.

[0064] The maximum recovery power is the maximum energy that the vehicle can accept in the above embodiment.

[0065] The charging power of the battery pack refers to the maximum energy that the battery pack of the vehicle can accept within a specific time. Optionally, the charging power of the battery pack may include: 5-second charging power, 10-second charging power, 30-second charging power, and continuous charging power.

[0066] Among them, the 5-second charging power refers to the maximum power that the battery pack can continuously accept within 5 seconds, and the 10-second charging power refers to the maximum power that the battery pack can continuously accept within 10 seconds. The 30-second charging power refers to the maximum power that the battery pack can continuously accept within 30 seconds. The continuous charging power refers to the maximum power that the battery pack can stably accept over a long period of time (such as several hours).

[0067] It is understandable that energy recovery converts the vehicle's kinetic energy into electrical energy to charge the battery pack, so when determining the maximum energy that the vehicle can accept during energy recovery, the charging power of the battery pack must be considered. Therefore, when determining that the vehicle needs to perform brake energy recovery, the charging power of the battery pack can be obtained.

[0068] The charging power of a battery pack is usually affected by the remaining power and temperature, so the step of obtaining the charging power of the battery pack may include: obtaining the current remaining power and current temperature of the battery pack, and determining the charging power of the battery pack based on the current remaining power and current temperature.

[0069] Specifically, the vehicle may store a first correspondence between power, temperature and charging power. The first correspondence may include multiple power intervals, multiple temperature intervals and multiple charging powers. Different power intervals and different temperature intervals may correspond to different charging powers.

[0070] Table 1

[0071] [20℃，30℃) [30℃，40℃) …… [10％，30％) P1 P2 [30％，70％) P3 P4 ……

[0072] Table 1 is an example of the first corresponding relationship between power, temperature and charging power. As shown in Table 1, the power interval includes: [10%, 30%), [30%, 70%), etc., and the temperature interval includes [20℃, 30℃), [30℃, 40℃), etc. The charging power corresponding to the power interval [10%, 30%) and the temperature interval [20℃, 30℃) is P1, the charging power corresponding to the power interval [10%, 30%) and the temperature interval [30℃, 40℃) is P2, the charging power corresponding to the power interval [30%, 70%) and the temperature interval [20℃, 30℃) is P3, and the charging power corresponding to the power interval [30%, 70%) and the temperature interval [30℃, 40℃) is P4.

[0073] Exemplarily, the current remaining power of the battery pack is obtained to be 50% and the current temperature is 32°C. Based on the current remaining power of 50% and the current temperature of 32°C, Table 1 is looked up. Since the current remaining power of 50% is in the power range [30%, 70%) and the current temperature of 32°C is in the temperature range [30°C, 40°C), it can be obtained that the charging power corresponding to the current remaining power of 50% and the current temperature of 32°C is the charging power P4 corresponding to the power range [30%, 70%) and the temperature range [30°C, 40°C).

[0074] High-voltage load refers to the load in the vehicle that requires a high-voltage battery (i.e. the battery pack mentioned above) to power its operation. The high-voltage load may specifically include: DC-DC converter (Direct Current to Direct Current converter), battery management system, PTC (Positive Temperature Coefficient, heater), air-conditioning compressor, headlights, audio system, and accessories such as large screen of the vehicle.

[0075] It can be understood that when the vehicle is performing braking energy recovery, at least some of the above-mentioned high-voltage loads are in operation, and the high-voltage loads in operation consume a certain amount of power. In addition to charging the battery pack, the braking energy recovered by the vehicle can also be provided to the running high-voltage loads. Therefore, it is necessary to obtain the power consumption of the high-voltage load during energy recovery and consider the power consumed by the high-voltage load.

[0076] Specifically, when it is determined that the vehicle needs to perform energy recovery, the high-voltage loads in the vehicle that are in operation may be detected, and the power consumption of each high-voltage load in the operation state may be obtained.

[0077] In some embodiments, the charging power of the battery pack and the power consumption of the high-voltage load may be added together to determine the maximum recovery power that the vehicle can currently accept.

[0078] Figure 2 It is a schematic diagram of a process for determining the recovered available power provided in an embodiment of the present application.

[0079] For example, Figure 2 As shown, the high-voltage loads currently running in the vehicle include: DC-DC converter, air conditioning compressor and PTC.

[0080] The power consumption of the DC-DC converter is obtained as Figure 2 The DCDC power and the power consumption of the air conditioning compressor are Figure 2 The compressor power and PTC power consumption are: Figure 2 The PTC power in the battery pack is added with the DCDC power, the compressor power and the PTC power to obtain the recovered available power, which can be determined as the maximum recovered power.

[0081] In one possible implementation, the maximum recovery power of the vehicle is determined based on the charging power of the vehicle's battery pack and the power consumption of the high-voltage load, including: obtaining the initial recovery power based on the charging power of the battery pack and the power consumption of the high-voltage load; determining the regeneration efficiency based on the historical recovery power and the current speed of the drive motor; wherein the historical recovery power is the recovery power calculated in the previous cycle of the current cycle; and obtaining the maximum recovery power based on the initial recovery power and the regeneration efficiency.

[0082] The initial recovery power represents the maximum energy that the vehicle can actually accept. The available recovery power obtained by adding the charging power of the battery pack and the power consumption of the high-voltage load in the above embodiment can be determined as the initial recovery power that the vehicle can accept.

[0083] Exemplarily, it is determined that the charging power P4 of the battery pack is 50kw, the DCDC power is 2kw, the compressor power is 5kw, and the PTC power is 6kw. Then, the charging power of the battery pack 50kw, the DCDC power 2kw, the compressor power 5kw and the PTC power 6kw are added together to obtain the initial recovery power = 50kw + 2kw + 5kw + 6kw = 63kw.

[0084] Since the user has released the accelerator pedal and stepped on the brake pedal, the vehicle speed and motor speed gradually decrease, so the vehicle braking energy recovery is a dynamic process, and the maximum recovery power of energy recovery is also calculated and updated in real time based on a certain period. The historical recovery power refers to the maximum recovery power calculated in the previous cycle of the current calculation cycle.

[0085] It is understandable that there is a certain ratio between the energy recovered by the vehicle and the energy actually effectively received by the vehicle, and the ratio of the energy actually effectively received by the vehicle to the energy recovered by the vehicle can be called the feedback efficiency of the vehicle's recovered energy. The energy actually effectively received by the vehicle is the above-mentioned initial recovery power.

[0086] The regeneration efficiency of the vehicle's regenerated energy is usually affected by the vehicle's historical regeneration power in the previous cycle and the current speed of the drive motor. Therefore, the vehicle's historical regeneration power and the current speed of the drive motor can be obtained, and the regeneration efficiency can be determined based on the historical regeneration power and the current speed of the drive motor.

[0087] As a possible implementation, a speed sensor is provided in the vehicle to collect the speed of the drive motor in real time during the operation of the vehicle. After obtaining the initial recovery power, the speed of the drive motor collected by the speed sensor can be obtained to obtain the current speed of the drive motor.

[0088] Specifically, the vehicle may store a second correspondence between historical recovery power, current speed and feedback efficiency. The second correspondence may include multiple power intervals, multiple speed intervals and multiple feedback efficiencies, and different power intervals and different speed intervals may correspond to different feedback efficiencies.

[0089] Table 2

[0090] [100rmp, 1000rmp) [1000rmp, 3000rmp) …… [3kw, 30kw) η1 η2 [30kw, 70kw) η3 η4 ……

[0091] Table 2 is an example of the second corresponding relationship between the historical recovery power, the current speed and the feedback efficiency. As shown in Table 2, the power intervals include: [3kw, 30kw), [30kw, 70kw), etc., and the speed intervals include [100rmp, 1000rmp), [1000rmp, 3000rmp), etc. The feedback efficiency corresponding to the power interval [3kw, 30kw) and the speed interval [100rmp, 1000rmp) is η1, the feedback efficiency corresponding to the power interval [3kw, 30kw) and the speed interval [1000rmp, 3000rmp) is η2, the feedback efficiency corresponding to the power interval [30kw, 70kw) and the speed interval [100rmp, 1000rmp) is η3, and the feedback efficiency corresponding to the power interval [30kw, 70kw) and the speed interval [1000rmp, 3000rmp) is η4.

[0092] Exemplarily, the historical recovery power obtained is 68 kW, and the current speed of the drive motor is 2000 rpm. Based on the historical recovery power of 68 kW and the current speed of the drive motor of 2000 rpm, Table 2 is looked up. Since the historical recovery power of 68 kW is in the power range [30 kW, 70 kW) and the current speed of the drive motor of 2000 rpm is in the speed range [1000 rpm, 3000 rpm), the feedback efficiency η4 corresponding to the historical recovery power of 68 kW and the current speed of the drive motor of 2000 rpm can be obtained.

[0093] The obtained regeneration efficiency is the ratio of the initial regeneration power to the maximum regeneration power. Therefore, after obtaining the initial regeneration power and the regeneration efficiency, the maximum regeneration power can be obtained by dividing the initial regeneration power by the regeneration efficiency.

[0094] Exemplarily, the determined feedback efficiency η4 is 96%, and the calculated initial recovery power is 63 kW, then the maximum recovery power = initial recovery power 63 kW / feedback efficiency 96% = 65.625 kW.

[0095] In some embodiments, when the current cycle in which the vehicle calculates the maximum recovery power is the first cycle, that is, when there is no previous cycle in the current cycle, the regeneration efficiency can be determined based on the calculated initial recovery power and the current speed of the drive motor.

[0096] In the above method, the initial recovery power represents the energy actually effectively received by the vehicle. By determining the feedback efficiency, the maximum recovery power is determined based on the feedback efficiency and the initial recovery power. It is considered that the energy actually effectively received by the vehicle usually accounts for a certain proportion of the maximum recovery power, that is, the energy recovered by the vehicle based on the maximum recovery power will still have some losses. The losses in the energy recovery process are considered to ensure the accuracy of the maximum recovery power. In addition, the feedback efficiency is determined based on the maximum recovery power calculated in the previous cycle and the current speed of the drive motor, so that the feedback efficiency can be dynamically adjusted, further improving the accuracy of the maximum recovery power and optimizing the vehicle energy recovery process.

[0097] In one possible implementation, the regeneration efficiency is determined based on the historical regeneration power and the current speed of the drive motor, including: determining whether the initial regeneration power is greater than the preset power; when the initial regeneration power is greater than the preset power, determining the regeneration efficiency based on the historical regeneration power and the current speed of the drive motor; when the initial regeneration power is less than or equal to the preset power, determining the initial regeneration power to be zero so that the vehicle does not perform braking energy recovery.

[0098] The preset power is a threshold value set in advance to determine whether the vehicle currently allows brake energy recovery. Different types of vehicles may have different battery pack types, and different types of battery packs may have different charging performances, so the preset power of different types of vehicles may be different. The charging performance of the battery pack of the same vehicle in different scenarios may also be different, so the preset power of the same vehicle in different scenarios may also be different. The value of the preset power is not limited in the embodiments of the present application.

[0099] Specifically, after the initial recovery power is calculated, the initial recovery power can be compared with the preset power. When it is determined that the initial recovery power is greater than the preset power, it is determined that the initial recovery power is larger, that is, the energy that the vehicle can currently accept is larger, so it can be determined that the vehicle currently allows braking energy recovery. When it is determined that the initial recovery power is less than or equal to the preset power, it is determined that the initial recovery power is smaller, that is, the energy that the vehicle can currently accept is smaller. At this time, in order to avoid overcharging of the battery pack, it can be determined that the vehicle currently does not allow braking energy recovery.

[0100] It is understandable that the initial recovery power is determined based on the charging power of the battery pack and the power consumption of the high-voltage load. The charging power of the battery pack is related to the power of the battery pack. When the power of the battery pack is close to full power, the charging power of the battery pack will decrease sharply. Therefore, when the determined initial recovery power is less than or equal to the preset power, it can be determined that the vehicle is currently running a small high-voltage load and the power of the battery pack is large, and the energy that the vehicle can accept is small. At this time, if the vehicle is braked for energy recovery, it is easy to cause the battery pack to overcharge. Therefore, when the initial recovery power is less than or equal to the preset power, it can be determined that the vehicle currently does not allow brake energy recovery.

[0101] When it is determined that the initial recovery power is less than or equal to the preset power, the initial recovery power may be set to 0 kW to control the vehicle not to perform braking energy recovery.

[0102] For example, Figure 2 As shown in the figure, the preset power is a calibration value of 3kw, and the initial recovery power is compared with the calibration value of 3kw. If the initial recovery power is greater than 3kw, the switch link selects the initial recovery power as the recovery available power; if the initial recovery power is less than or equal to 3kw, the switch link selects a constant of 0kw as the recovery available power, and the recovery available power is the initial recovery power.

[0103] In the above method, the initial recovery power is compared with the preset power to determine whether the vehicle can perform braking energy recovery. When the initial recovery power is less than or equal to the preset power, it is determined that the vehicle cannot perform braking energy recovery. The initial recovery power is set to 0kw, thereby limiting energy recovery when the battery pack is close to a fully charged state, avoiding energy recovery under low-power conditions that may cause overcharging of the battery pack, affecting the battery pack life and even causing safety problems.

[0104] In one possible implementation, the feedback efficiency is determined based on the historical recovery power and the current speed of the drive motor, including: determining the initial feedback efficiency corresponding to the historical recovery power and the current speed of the drive motor; determining a correction coefficient corresponding to the coolant temperature at the water outlet of the drive motor; and multiplying the initial feedback efficiency by the correction coefficient to obtain the feedback efficiency.

[0105] It can be understood that the drive motor usually includes a cooling circuit. The coolant enters the cooling circuit of the drive motor from the water inlet of the drive motor to cool or heat the drive motor. Thereafter, the coolant can flow out of the cooling circuit of the drive motor from the water outlet of the drive motor. Therefore, the coolant temperature at the water outlet of the drive motor can reflect the state of the drive motor to a certain extent.

[0106] Specifically, the coolant temperature will affect the working state and efficiency of the drive motor. Therefore, the feedback efficiency determined based on the historical recovery power and the current speed of the drive motor in the above embodiment can be used as the initial feedback efficiency. After determining the initial feedback efficiency, it is also necessary to obtain the coolant temperature at the water outlet of the drive motor, and determine the correction coefficient based on the coolant temperature to correct the initial feedback efficiency to obtain the final feedback efficiency.

[0107] As a possible implementation, a temperature sensor is provided at the water outlet of the drive motor of the vehicle to collect the coolant temperature of the water outlet of the drive motor in real time during the operation of the vehicle. After obtaining the initial feedback efficiency, the coolant temperature of the water outlet of the drive motor currently collected by the temperature sensor can be obtained.

[0108] Specifically, the vehicle may store a third correspondence between the coolant temperature and the correction coefficient. The third correspondence includes multiple coolant temperature intervals, and the correspondence between the coolant temperature and the correction coefficient is different in different coolant temperature intervals.

[0109] Figure 3 It is a schematic diagram of a correction coefficient curve provided in an embodiment of the present application.

[0110] For example, Figure 3 As shown, in the third corresponding relationship, the coolant temperature intervals include: [T0, T1), [T1, T2), [T2, T3) and [T3, T4). In the coolant temperature interval [T0, T1), the larger the coolant temperature, the larger the correction coefficient, and the specific correction coefficient gradually increases from C2 to C3. In the coolant temperature interval [T1, T2), the correction coefficient is a fixed value C3. In the coolant temperature interval [T2, T3), the larger the coolant temperature, the smaller the correction coefficient, and the rate at which the correction coefficient decreases is larger, and the specific correction coefficient gradually decreases from C3 to C1. In the coolant temperature interval [T3, T4), the larger the coolant temperature, the smaller the correction coefficient, and the rate at which the correction coefficient decreases is less than the rate of decrease in the coolant temperature interval [T2, T3), and the specific correction coefficient gradually decreases from C1 to 0.

[0111] Exemplarily, the coolant temperature at the outlet of the drive motor is obtained as T, T1<T<T2, Figure 3 The correction coefficient corresponding to the coolant temperature interval [T1, T2) is a fixed value C3, so it can be determined that the correction coefficient corresponding to the coolant temperature T at the water outlet of the drive motor is C3.

[0112] After obtaining the correction coefficient, the initial feedback efficiency is multiplied by the correction coefficient to obtain the final feedback efficiency.

[0113] For example, the coolant temperature T of the drive motor outlet is obtained, and then Figure 3The correction coefficient curve shown in the figure is C3. The initial feedback efficiency determined in the above embodiment is η4, and the feedback efficiency η=C3*η4 can be determined. Assuming η4 is 98% and C3 is 0.95, the feedback efficiency η=98%*0.95=0.931 can be determined.

[0114] In the above method, the correction coefficient is determined by obtaining the coolant temperature at the outlet of the drive motor to correct the feedback efficiency. The influence of the coolant temperature on the working state and efficiency of the drive motor is taken into consideration, thereby ensuring the accuracy of the feedback efficiency, and further ensuring the accuracy of the maximum recovery power, thereby optimizing the braking energy recovery process.

[0115] In one possible implementation, when a vehicle fault occurs, a maximum recovery power is obtained based on an initial recovery power and a regeneration efficiency, including: obtaining a fault limit power of the vehicle; dividing the initial recovery power by the regeneration efficiency to obtain a reference recovery power; and determining the minimum value between the fault limit power and the reference recovery power as the maximum recovery power.

[0116] After the feedback power is calculated, it is also possible to detect whether the vehicle currently has a fault. If the vehicle has a fault, the fault limit power corresponding to the current fault is obtained.

[0117] Fault limit power refers to the recovery power set to ensure vehicle safety when a vehicle fails. For example, if the vehicle fails due to overheating of the battery pack, the recovery power can be limited accordingly based on the overheating of the battery pack, so that the charging power of the battery pack is reduced, thereby protecting the battery pack as much as possible.

[0118] In the embodiment of the present application, different faults of the vehicle may correspond to different fault limiting powers. For example, the faults sent by the vehicle include: battery pack overtemperature fault, drive motor overtemperature fault, etc. The battery pack overtemperature fault may correspond to fault limiting power 1, the drive motor overtemperature fault may correspond to fault limiting power 2, etc. Therefore, when it is determined that the vehicle has a fault, the specific fault type of the vehicle may also be determined, thereby facilitating the determination of the fault limiting power corresponding to the fault type.

[0119] When the vehicle has a fault, the power obtained by dividing the initial recovery power by the regeneration efficiency in the above embodiment can be recorded as the reference recovery power. After obtaining the fault limit power, the fault limit power and the reference recovery power are compared, and the minimum value of the two is determined as the maximum recovery power.

[0120] It is understandable that when there is a fault in the vehicle, the fault in the vehicle may affect the process of energy recovery of the vehicle, resulting in certain unsafe factors in energy recovery. Therefore, when a vehicle fails, it is necessary to limit the maximum recovery power based on the fault, and the smaller of the fault limit power and the reference recovery power can ensure that the maximum recovery power is less than or equal to the fault limit power, so as to avoid the occurrence of unsafe factors as much as possible.

[0121] Figure 4 It is a schematic diagram of a process for determining recovery power provided in an embodiment of the present application.

[0122] For example, Figure 4 As shown, the recovery power is the maximum recovery power calculated in the above embodiment. The recovery available power is the initial recovery power in the above embodiment.

[0123] exist Figure 4 In the calculation, the recovery power is delayed by one cycle, that is, the historical recovery power calculated in the previous cycle is used in the current calculation cycle, and the recovery efficiency MAP (mapping table) is found based on the historical recovery power and the current speed of the drive motor, that is, the above Table 2, to obtain the initial feedback efficiency. Based on the obtained coolant temperature correction coefficient curve of the drive motor outlet, that is, Figure 3 The curve shown in Figure 1 is used to obtain the correction coefficient. The initial regeneration efficiency is multiplied by the correction coefficient to obtain the regeneration efficiency. The available regeneration power is divided by the regeneration efficiency to obtain the reference regeneration power. The minimum value between the reference regeneration power and the fault limit power is taken to obtain the regeneration power, which is the maximum regeneration power allowed for the above vehicle.

[0124] For example, the initial recovery power is 63kw, the initial recovery efficiency is 98%, the correction coefficient is 0.95, the recovery efficiency η=98%*0.95=0.931, and the reference recovery power=63kw / 0.931≈67.669kw. Assuming that the vehicle currently has a battery pack overtemperature fault, the fault limit power 1 corresponding to the battery pack overtemperature fault is 60kw, and the maximum recovery power is the minimum value of the reference recovery power 67.669kw and the fault limit power 60kw, that is, the maximum recovery power can be determined to be 60kw.

[0125] In the above method, when there is a fault in the vehicle, the fault limiting power is obtained, and the minimum value between the calculated reference recovery power and the fault limiting power is taken as the maximum recovery power to facilitate subsequent braking energy recovery. The impact of the fault on the recovery power when a fault occurs in the vehicle is taken into consideration, and the smaller value between the fault limiting power and the reference recovery power is taken, thereby limiting the maximum recovery power based on the fault and ensuring that the maximum recovery power is less than or equal to the fault limiting power, so as to avoid the occurrence of unsafe factors as much as possible and improve the safety of energy recovery.

[0126] S12, determining a maximum regenerative torque according to the maximum regenerative power and the current rotation speed of the driving motor of the vehicle.

[0127] After the maximum recovery power and the current speed of the drive motor are obtained, a torque can be calculated based on the maximum recovery power and the current speed, and the maximum recovery torque is determined based on the calculated torque.

[0128] In the above method, the maximum recovery power that the whole vehicle can accept can be accurately determined through the charging power of the battery pack and the power consumption of the high-voltage load in the vehicle, and then the maximum recovery torque can be accurately determined based on the maximum recovery power, so that not only the charging power of the battery pack but also the power consumption of the high-voltage load in the vehicle is taken into account during energy recovery, thereby improving the accuracy of energy recovery.

[0129] In one possible implementation, the maximum recovery torque is determined based on the recovery power and the current speed of the vehicle's drive motor, including: substituting the maximum recovery power and the current speed of the drive motor into the power formula to calculate the reference recovery torque; wherein the power formula is used to describe the conversion relationship between power, speed and torque; and determining the maximum recovery torque based on the negative value of the reference recovery torque.

[0130] There is a certain conversion relationship between the power, speed and torque of the drive motor. The formula used to describe the conversion relationship between power, speed and torque can be called the power formula. The power formula can be specifically: P = T*N / 9550; where P is power, T is torque, N is speed, and 9550 is a constant coefficient.

[0131] When calculating the reference recovery torque, the power formula P=T*N / 9550 can be transformed first to obtain the transformed power formula: T=P*9550 / N, and then the maximum recovery power and the current speed of the drive motor are substituted into the transformed power formula to obtain the maximum recovery torque.

[0132] For example, the maximum recovery power is 60kw, and the current speed of the drive motor is 2000rpm. Then substitute P equal to 60kw and N=2000rpm into the transformed power formula: T=P*9550 / N, and obtain the reference recovery torque T=60*9550 / 2000=286.5 (NM).

[0133] It can be understood that the torque of the drive motor when it operates as a generator is usually negative torque. Therefore, the reference recovery torque can be multiplied by -1 to obtain the negative value of the reference recovery torque, which is -286.5NM. The negative value of the reference recovery torque is used as the maximum recovery torque.

[0134] In the above method, the reference recovery torque is calculated by substituting the maximum recovery power and the current speed of the drive motor into the power formula that describes the conversion relationship between power, speed and torque, and then the maximum recovery torque is determined based on the negative value of the reference recovery torque, thereby ensuring the accuracy of the maximum recovery torque and improving the accuracy of energy recovery.

[0135] In one possible implementation, the maximum recovery torque is determined based on the negative value of the reference recovery torque, including: determining the maximum output torque of the drive motor at the current speed; wherein the maximum output torque is a negative value; and determining the maximum value between the negative value of the reference recovery torque and the maximum output torque as the maximum recovery torque.

[0136] When the drive motor operates as a generator, there is a negative external characteristic. The maximum output torque is the maximum torque that the drive motor can output at the current speed indicated by the negative external characteristic of the drive motor. The negative external characteristic of the motor usually refers to the performance of the drive motor under different working conditions when it operates as a generator. The torque-speed characteristic curve is usually used to represent the negative external characteristic of the motor.

[0137] Specifically, the torque-speed characteristic curve shows the maximum torque that the drive motor can output at different speeds. The maximum torque output by the drive motor at the current speed can be obtained from the torque-speed characteristic curve to obtain the above-mentioned maximum output torque.

[0138] Figure 5 It is a schematic diagram of a negative external characteristic curve provided in an embodiment of the present application.

[0139] For example, Figure 5 As shown, the negative external characteristic curve of the drive motor is specifically a torque-speed characteristic curve. The negative external characteristic curve includes multiple speed intervals, and the corresponding relationship between the speed and the torque is different in different speed intervals.

[0140] like Figure 5 As shown, the speed ranges specifically include: [n0, n1), [n1, n2], and the torques that the drive motor can output are all negative values. In the speed range [n0, n1), the maximum torque that the drive motor can output remains unchanged, which is torque 1. In the speed range [n1, n2], the maximum torque that the drive motor can output gradually increases from torque 1.

[0141] Assume that the current speed of the drive motor is 2000 rpm, 2000 rpm is greater than n1 and 2000 rpm is less than n2. Figure 5 The torque 2 corresponding to 2000 rpm can be determined from the torque-speed characteristic curve shown, and the torque 2 is used as the maximum output torque of the drive motor at 2000 rpm, and the maximum output torque is a negative value.

[0142] After obtaining the negative values ​​of the maximum output torque and the reference output torque, the maximum value can be taken from the negative values ​​of the maximum output torque and the reference output torque to obtain the maximum recovery torque. It can be understood that the maximum output torque is a negative value, and taking the maximum value from the two negative values ​​is also taking the value with the smallest absolute value from the two negative values.

[0143] It is understandable that the maximum output torque indicated by the negative external characteristic of the motor is the maximum torque that the drive motor can output at the current speed. If the absolute value of the torque output by the drive motor at the current speed exceeds the absolute value of this torque, it may cause the drive motor to overload and then cause some faults. Therefore, the maximum recovery torque also needs to be limited based on the maximum output torque. The maximum value is taken from the negative value of the maximum output torque and the reference output torque to obtain the maximum recovery torque, which ensures that the absolute value of the maximum recovery torque is less than or equal to the absolute value of the maximum output torque, ensuring that the maximum recovery torque does not exceed the maximum output capacity of the drive motor at the current speed, so as to protect the drive motor.

[0144] Exemplarily, the negative value of the reference recovery torque is -286.5 NM. Assuming that the maximum output torque (ie, torque 2) is -280 NM, and the maximum output torque -280 NM is greater than the reference recovery torque -286.5 NM, it can be determined that the maximum recovery torque is the maximum output torque -280 NM.

[0145] In the above method, the maximum output torque of the motor at the current speed is determined, and the maximum value is taken from the negative value of the maximum output torque and the reference output torque to obtain the maximum recovery torque, thereby ensuring that the absolute value of the maximum recovery torque is less than or equal to the absolute value of the maximum output torque, ensuring that the maximum recovery torque will not exceed the maximum output capacity of the drive motor at the current speed, thereby protecting the drive motor and avoiding some faults that may occur when the absolute value of the maximum recovery torque is greater than the absolute value of the maximum output torque of the drive motor at the current speed.

[0146] In step 102, when it is determined that the vehicle needs to perform braking energy recovery, the current actual speed of the vehicle can be obtained to determine the target torque for coasting energy recovery corresponding to the actual speed of the vehicle.

[0147] It is understandable that the actual speed of the vehicle affects the kinetic energy of the vehicle, and the coasting energy recovery process converts the kinetic energy of the vehicle into electrical energy to achieve energy recovery, so the energy recovered by the vehicle will be affected by the actual speed of the vehicle. The vehicle performs coasting energy recovery based on the target torque of coasting energy recovery, so the actual speed of the vehicle affects the target torque of coasting energy recovery. When determining the target torque of coasting energy recovery, it is necessary to obtain the actual speed of the vehicle and determine the target torque of coasting energy recovery based on the actual speed of the vehicle.

[0148] Specifically, a fourth correspondence relationship between vehicle speed and torque may be stored in the vehicle, and the fourth correspondence relationship includes a plurality of vehicle speed intervals, and the correspondence relationship between vehicle speed and torque is different in different vehicle speed intervals.

[0149] Figure 6 It is a schematic diagram of a vehicle speed-torque curve for coasting energy recovery provided in an embodiment of the present application.

[0150] For example, Figure 6 As shown, the torque of the coasting energy recovery is a negative value. In the fourth corresponding relationship, the vehicle speed intervals include: [0, 40), [40, 80), [80, 120) and other intervals. In the vehicle speed interval [0, 40), the greater the vehicle speed, the greater the absolute value of the torque of the coasting energy recovery, and the specific absolute value of the torque of the coasting energy recovery gradually increases from 0 to the absolute value of torque 3. In the vehicle speed interval [40, 80), the torque of the coasting energy recovery is a fixed value torque 3. In the vehicle speed interval [80, 120), the greater the vehicle speed, the smaller the absolute value of the torque of the coasting energy recovery, and the specific absolute value of the torque of the coasting energy recovery gradually decreases from the absolute value of torque 3 to 0.

[0151] For example, the actual vehicle speed is 30 km / h, which is greater than 0 and less than 40 km / h. It can be determined that the actual vehicle speed of 30 km / h is in the speed range [0, 40). Based on the curve corresponding to the actual vehicle speed of 30 km / h in the speed range [0, 40), the torque 4 corresponding to 30 km / h can be determined, that is, the torque 4 can be determined as the target torque for coasting energy recovery.

[0152] Figure 7 It is a flow chart for determining the coasting energy recovery torque provided in an embodiment of the present application.

[0153] For example, Figure 7 As shown, after obtaining the actual speed of the vehicle, a one-dimensional curve (i.e. Figure 6 The vehicle speed-torque curve shown in the figure) is used to obtain the target torque for coasting energy recovery corresponding to the actual vehicle speed.

[0154] In step 103, after the target torque for coasting energy recovery, ie, torque 4, is obtained, the target torque for braking energy recovery can be obtained by subtracting torque 4 from the maximum recovery torque.

[0155] Exemplarily, the torque 4 is -40 NM, and the maximum recovery torque determined in the above embodiment is -280 NM, then the target torque of the braking energy recovery = (-280) NM - (-40) NM = -240 NM.

[0156] It is understandable that the vehicle currently has a scenario where it is performing both braking energy recovery and coasting energy recovery at the same time. For example, when the vehicle is going downhill, the user releases the accelerator pedal of the vehicle. At this time, the user does not step on the brake pedal of the vehicle, and the vehicle starts to coast. During the coasting process, the vehicle starts to recover energy by coasting. After coasting for a distance, the user steps on the brake pedal of the vehicle. At this time, the vehicle needs to perform braking energy recovery. In this scenario, the vehicle is also performing coasting energy recovery. If the vehicle is braked and recovered directly based on the calculated maximum recovery torque at this time, the actual energy recovery torque of the vehicle is equal to the braking energy recovery torque plus the coasting energy recovery torque, which will be greater than the maximum recovery torque allowed by the vehicle, and may cause the battery pack to overcharge. Therefore, regardless of whether the vehicle is currently performing coasting energy recovery, the maximum recovery torque can be subtracted from the target torque for coasting energy recovery corresponding to the actual vehicle speed to ensure that the actual energy recovery torque of the vehicle is less than or equal to the maximum recovery torque allowed by the vehicle.

[0157] In step 104, after obtaining the target torque for braking energy recovery, the drive motor is controlled based on the target torque for braking energy recovery, so that the drive motor generates electricity based on the target torque for braking energy recovery, and the electric energy generated by the drive motor is transmitted to the battery pack and the high-voltage load running in the vehicle, so that the battery pack stores electric energy and the high-voltage load consumes electric energy, thereby realizing braking energy recovery.

[0158] In summary, when the vehicle needs to perform brake energy recovery, the present application can accurately determine the maximum recovery power that the vehicle can accept through the charging power of the battery pack and the power consumption of the high-voltage load in the vehicle, which not only considers the charging power of the battery pack but also the power consumption of the high-voltage load in the vehicle, thereby improving the accuracy of energy recovery. When determining the maximum recovery power, the feedback efficiency is determined, and the loss in the energy recovery process is considered to ensure the accuracy of the maximum recovery power. And the feedback efficiency is corrected based on the correction coefficient determined by the coolant temperature at the outlet of the drive motor, taking into account the influence of the coolant temperature on the working state and efficiency of the drive motor. When there is a fault in the vehicle, the minimum value is taken from the calculated reference recovery power and the fault limit power as the maximum recovery power, taking into account the influence of the fault on the recovery power when the vehicle has a fault, thereby improving the safety of energy recovery. The maximum value is taken from the maximum output torque of the motor at the current speed and the negative value of the reference output torque to obtain the maximum recovery torque, thereby avoiding some faults caused by overload of the drive motor. Subtracting the target torque for coasting energy recovery from the maximum recovery torque achieves the target torque for limiting braking energy recovery, ensuring that the total energy recovered by the vehicle does not exceed the maximum energy recovery limit allowed by the vehicle, effectively avoiding the problem of battery pack overcharging and ensuring the safety of vehicle braking energy recovery.

[0159] Figure 8It is a structural schematic diagram of an energy recovery device provided in an embodiment of the present application.

[0160] For example, Figure 8 As shown, the device 800 includes:

[0161] The first determination module 801 is used to determine the maximum recovery torque of the vehicle when the vehicle needs to perform brake energy recovery; wherein the maximum recovery torque is the maximum torque that the vehicle is allowed to recover energy;

[0162] A second determination module 802 is used to determine a target torque for vehicle coasting energy recovery according to an actual vehicle speed;

[0163] A calculation module 803 is used to subtract the target torque of coasting energy recovery from the maximum recovery torque to obtain the target torque of braking energy recovery;

[0164] The control module 804 is used to perform braking energy recovery on the vehicle according to the target torque of braking energy recovery.

[0165] In one possible implementation, the first determination module 801 is specifically used to determine the maximum recovery power of the vehicle based on the charging power of the vehicle's battery pack and the power consumption of the high-voltage load; and to determine the maximum recovery torque based on the maximum recovery power and the current speed of the vehicle's drive motor.

[0166] In one possible implementation, the first determination module 801 is specifically used to obtain the initial recovery power based on the charging power of the battery pack and the power consumption of the high-voltage load; determine the feedback efficiency according to the historical recovery power and the current speed of the drive motor; wherein the historical recovery power is the maximum recovery power calculated in the previous cycle of the current cycle; and obtain the maximum recovery power according to the initial recovery power and the feedback efficiency.

[0167] In one possible implementation, the first determination module 801 is specifically used to determine the initial feedback efficiency corresponding to the historical recovery power and the current speed of the drive motor; determine the correction coefficient corresponding to the coolant temperature at the water outlet of the drive motor; and multiply the initial feedback efficiency by the correction coefficient to obtain the feedback efficiency.

[0168] In one possible implementation, when a vehicle fault occurs, the first determination module 801 is specifically used to obtain the fault limiting power of the vehicle; divide the initial recovery power by the feedback efficiency to obtain the reference recovery power; and determine the minimum value between the fault limiting power and the reference recovery power as the maximum recovery power.

[0169] In one possible implementation, the first determination module 801 is specifically used to substitute the maximum recovery power and the current speed of the drive motor into the power formula to calculate the reference recovery torque; wherein the power formula is used to describe the conversion relationship between power, speed and torque; and determine the maximum recovery torque based on the negative value of the reference recovery torque.

[0170] In one possible implementation, the first determination module 801 is specifically used to determine the maximum output torque of the drive motor at the current speed; wherein the maximum output torque is a negative value; and the maximum value between the negative value of the reference recovery torque and the maximum output torque is determined as the maximum recovery torque.

[0171] In one possible implementation, the first determination module 801 is specifically used to determine whether the initial recovery power is greater than the preset power; when the initial recovery power is greater than the preset power, the feedback efficiency is determined based on the historical recovery power and the current speed of the drive motor; when the initial recovery power is less than or equal to the preset power, the initial recovery power is determined to be zero so that the vehicle does not perform braking energy recovery.

[0172] Fig. 9 It is a structural schematic diagram of a vehicle provided in an embodiment of the present application.

[0173] For example, Fig. 9 As shown, the vehicle 900 includes: a memory 901 and a processor 902, wherein the memory 901 stores an executable program code 9011, and the processor 902 is used to call and execute the executable program code 9011 to perform an energy recovery method.

[0174] In addition, an embodiment of the present application also protects a device, which may include a memory and a processor, wherein the memory stores executable program code, and the processor is used to call and execute the executable program code to perform an energy recovery method provided by an embodiment of the present application.

[0175] In this embodiment, the functional modules of the device can be divided according to the above method example. For example, each functional module can be corresponded, or two or more functions can be integrated into one processing module. The above integrated module can be implemented in the form of hardware. It should be noted that the division of modules in this embodiment is schematic and is only a logical function division. There may be other division methods in actual implementation.

[0176] In the case of dividing each functional module according to each function, the device may also include a first determination module, a second determination module, a calculation module, a control module, etc. It should be noted that all relevant contents of each step involved in the above method embodiment can be referred to the functional description of the corresponding functional module, which will not be repeated here.

[0177] It should be understood that the device provided in this embodiment is used to execute the above-mentioned energy recovery method, and thus can achieve the same effect as the above-mentioned implementation method.

[0178] In the case of an integrated unit, the device may include a processing module and a storage module. When the device is applied to a vehicle, the processing module may be used to control and manage the actions of the vehicle. The storage module may be used to support the vehicle in executing relevant program codes, etc.

[0179] The processing module may be a processor or a controller, which may implement or execute various exemplary logic blocks, modules and circuits shown in conjunction with the disclosure of the present application. The processor may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and a microprocessor, etc. The storage module may be a memory.

[0180] In addition, the device provided in the embodiments of the present application may specifically be a chip, a component or a module, and the chip may include a connected processor and a memory; wherein the memory is used to store instructions, and when the processor calls and executes the instructions, the chip can execute an energy recovery method provided in the above embodiments.

[0181] This embodiment also provides a computer-readable storage medium, in which a computer program code is stored. When the computer program code is executed on a computer, the computer executes the above-mentioned related method steps to implement an energy recovery method provided in the above embodiment.

[0182] This embodiment also provides a computer program product. When the computer program product is run on a computer, the computer is enabled to execute the above-mentioned related steps to implement an energy recovery method provided by the above-mentioned embodiment.

[0183] Among them, the device, computer-readable storage medium, computer program product or chip provided in this embodiment is used to execute the corresponding method provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding method provided above, and will not be repeated here.

[0184] Through the description of the above implementation methods, technical personnel in the relevant field can understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0185] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0186] The above contents are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for energy recovery, characterized in that: The method comprises: In the case where the vehicle needs to perform brake energy recovery, determining the maximum recovery torque of the vehicle; wherein the maximum recovery torque is the maximum torque that the vehicle is allowed to recover energy; Determining a target torque for coasting energy recovery of the vehicle according to an actual vehicle speed; Subtracting the target torque of coasting energy recovery from the maximum recovery torque to obtain a target torque of braking energy recovery; The vehicle is subjected to braking energy recovery according to the target torque of the braking energy recovery.

2. The method according to claim 1, characterized in that The determining the maximum recovery torque of the vehicle comprises: Determining the maximum recovery power of the vehicle according to the charging power of the battery pack of the vehicle and the power consumption of the high-voltage load; The maximum regenerative torque is determined according to the maximum regenerative power and a current rotation speed of a driving motor of the vehicle.

3. The method according to claim 2, characterized in that The determining the maximum recovery power of the vehicle according to the charging power of the battery pack of the vehicle and the power consumption of the high-voltage load includes: Obtaining initial recovery power based on the charging power of the battery pack and the power consumption of the high-voltage load; Determine the feedback efficiency according to the historical recovery power and the current speed of the drive motor; wherein the historical recovery power is the maximum recovery power calculated in the previous cycle of the current cycle; The maximum recovery power is obtained according to the initial recovery power and the feedback efficiency.

4. The method according to claim 3, characterized in that The step of determining the feedback efficiency according to the historical recovery power and the current speed of the driving motor includes: determining an initial regenerative efficiency corresponding to the historical regenerative power and the current rotation speed of the drive motor; Determining a correction coefficient corresponding to the coolant temperature at the water outlet of the drive motor; The initial feedback efficiency is multiplied by the correction coefficient to obtain the feedback efficiency.

5. The method according to claim 3 or 4, characterized in that: In the case that the vehicle has a fault, obtaining the maximum recovery power according to the initial recovery power and the feedback efficiency includes: Obtaining a fault-limited power of the vehicle; Dividing the initial recovery power by the feedback efficiency to obtain a reference recovery power; The minimum value between the fault limiting power and the reference recovery power is determined as the maximum recovery power.

6. The method according to any one of claims 2 to 4, characterized in that The determining the maximum recovery torque according to the maximum recovery power and the current speed of the driving motor of the vehicle includes: Substituting the maximum regenerative power and the current speed of the drive motor into a power formula to calculate a reference regenerative torque; wherein the power formula is used to describe the conversion relationship between power, speed and torque; The maximum regeneration torque is determined based on a negative value of the reference regeneration torque.

7. The method according to claim 6, characterized in that The determining the maximum recovery torque based on the negative value of the reference recovery torque comprises: Determining the maximum output torque of the drive motor at the current speed; wherein the maximum output torque is a negative value; A maximum value between a negative value of the reference recovery torque and the maximum output torque is determined as the maximum recovery torque.

8. The method according to claim 3, characterized in that The step of determining the feedback efficiency according to the historical recovery power and the current speed of the driving motor includes: Determining whether the initial recovery power is greater than a preset power; When the initial recovery power is greater than the preset power, determining the feedback efficiency according to the historical recovery power and the current speed of the drive motor; When the initial recovery power is less than or equal to the preset power, the initial recovery power is determined to be zero, so that the vehicle does not perform braking energy recovery.

9. A vehicle, characterized in that: The vehicle comprises: A memory for storing executable program codes; A processor, configured to call and run the executable program code from the memory, so that the vehicle executes the method according to any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed, the method according to any one of claims 1 to 8 is implemented.

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