A method and device for controlling charging and discharging power of a power battery in a vehicle and a vehicle

Abstract

The present invention discloses a method and device for controlling the charging and discharging power of a power battery in a vehicle, and a vehicle, comprising: obtaining the driving parameters of the vehicle in real time during the driving of the vehicle; determining the power parameters of the power battery according to the driving parameters; the power parameters include at least one of maximum discharge power, maximum charging power, continuous discharge power and continuous charging power; controlling the output power of the power battery according to the power parameters, and / or controlling the power recovery power of the power battery according to the power parameters, so that relatively reliable and accurate power parameters can be obtained, so that when controlling the output power and / or recovery power of the power battery, the charging and discharging of the power battery can be controlled according to the power parameters with high reliability and accuracy and more in line with the actual driving state, so that the charging and discharging control of the power battery is more accurate and reliable, which is beneficial to improving the driving effect, braking effect and even driving experience of the vehicle during driving.

Description

Technical Field

[0001] The present invention relates to the field of vehicle control, and in particular to a method and device for controlling the charging and discharging power of a power battery in a vehicle, and a vehicle. Background Art

[0002] The power system of new energy hybrid vehicles has different configuration schemes, and the oil-electric hybrid new energy vehicles mainly obtain power from the engine and motor. The power battery provides electrical energy to the motor. The drive motor can not only achieve pure electric drive, but also work with the engine to drive the vehicle to ensure the vehicle's efficient driving torque output. At the same time, it can also effectively recover energy during the coasting and braking stages, ultimately achieving the goal of energy conservation and emission reduction for the entire vehicle.

[0003] The discharge power of the power battery is an important factor affecting the output torque of the motor, and the charging power will affect the effect of the vehicle's energy recovery. If the discharge and charging power of the power battery cannot be accurately calculated, the driving torque demand and energy recovery torque calculation of the whole vehicle will not be accurate and reliable.

[0004] In the prior art, in the field of electric vehicles, the charge and discharge power of the power battery is mainly calculated based on some inherent performance parameters of the power battery. For example, the charge and discharge power of the power battery is calculated based on the intrinsic parameters of the battery (voltage and current). This is not applicable to hybrid power system configuration vehicles that adopt a hybrid drive mode. As a result, the charge and discharge power calculated using the intrinsic parameters of the battery is not reliable and accurate enough, and thus the charge and discharge of the power battery cannot be accurately controlled, which in turn affects the driving effect, braking effect and even driving experience of the vehicle during driving. Summary of the invention

[0005] The present invention provides a method and device for controlling the charging and discharging power of a power battery in a vehicle, and a vehicle, so as to obtain power parameters with high reliability and accuracy.

[0006] According to one aspect of the present invention, a method for controlling the charging and discharging power of a power battery in a vehicle is provided, comprising:

[0007] During the driving of the vehicle, the driving parameters of the vehicle are obtained in real time;

[0008] Determining a power parameter of the power battery according to the driving parameter; the power parameter includes at least one of a maximum discharge power, a maximum charge power, a continuous discharge power and a continuous charge power;

[0009] The power output of the power battery is controlled according to the power parameter, and / or the power recovery power of the power battery is controlled according to the power parameter.

[0010] Optionally, when the power parameter includes the maximum discharge power, the driving parameters include: powertrain efficiency, vehicle mass, rolling resistance coefficient, air resistance coefficient, road slope, vehicle frontal area, vehicle rotational mass conversion coefficient, vehicle current speed, power battery discharge efficiency, engine friction torque, engine speed and engine maximum output torque;

[0011] Determining the power parameter of the power battery according to the driving parameter includes:

[0012] determining a first discharge power of the power battery according to the powertrain efficiency, the mass of the vehicle, the rolling resistance coefficient, the air resistance coefficient, the frontal area of ​​the vehicle, the rotational mass conversion coefficient of the vehicle, the current speed of the vehicle, and the discharge efficiency of the power battery;

[0013] determining a second discharge power of the power battery according to a current vehicle speed of the vehicle, the engine friction torque, the engine speed, and the maximum output torque of the engine;

[0014] The maximum discharge power of the power battery is determined according to the first discharge power and the second discharge power.

[0015] Optionally, determining the first discharge power of the power battery according to the powertrain efficiency, the mass of the vehicle, the rolling resistance coefficient, the air resistance coefficient, the frontal area of ​​the vehicle, the rotational mass conversion coefficient of the vehicle, the current speed of the vehicle and the discharge efficiency of the power battery includes:

[0016] Based on a first formula, determining the required power of the vehicle according to the powertrain efficiency, the mass of the vehicle, the rolling resistance coefficient, the air resistance coefficient, the frontal area of ​​the vehicle, the rotational mass conversion coefficient of the vehicle and the current speed of the vehicle;

[0017] The first formula is:

[0018] Among them, P s is the required power of the vehicle, η T is the transmission system efficiency, m is the mass of the vehicle, g is the gravitational acceleration, f is the rolling resistance coefficient, C is the air resistance coefficient, A is the frontal area of ​​the vehicle, δ is the rotational mass conversion coefficient of the vehicle, v is the current speed of the vehicle, α is the road slope, is the differential of the current speed of the vehicle with respect to time;

[0019] Based on the second formula, determining a first discharge power according to the required power of the vehicle and the discharge efficiency of the power battery;

[0020] The second formula is:

[0021] in, is the first discharge power, η b is the discharge efficiency of the power battery.

[0022] Optionally, determining the second discharge power of the power battery according to the current vehicle speed, the engine friction torque, the engine speed, and the maximum output torque of the engine includes:

[0023] Determining a current rotation speed of the drive motor according to a current speed of the vehicle;

[0024] Determining the maximum output driving power and the maximum output efficiency of the driving motor at the current speed based on the speed-output torque-output efficiency characteristic curve of the driving motor;

[0025] determining a maximum net engine torque according to the maximum engine output torque and the engine friction torque;

[0026] Determining the maximum net output mechanical power of the engine according to the maximum net torque of the engine and the engine speed;

[0027] Determining the maximum power generation power of the generator according to the maximum net output mechanical power of the engine;

[0028] Determining a first power generation efficiency corresponding to the maximum power generation of the generator based on a power generation efficiency characteristic curve of the generator;

[0029] Based on a third formula, determining the second discharge power according to the maximum output drive power of the drive motor, the maximum output efficiency of the drive motor, the maximum power generation power of the generator and the first power generation efficiency;

[0030] The third formula is:

[0031] in, is the second discharge power, P drv is the maximum output driving power of the driving motor, η drv is the maximum output efficiency of the drive motor, is the maximum power generation of the generator, η gen is the first power generation efficiency.

[0032] Optionally, when the power parameter includes the maximum charging power, the driving parameter includes: vehicle speed, maximum braking deceleration, transmission efficiency, gearbox ratio, final reducer ratio, vehicle mass, wheel radius, current vehicle speed and temperature of the drive motor;

[0033] Determining the power parameter of the power battery according to the driving parameter includes:

[0034] Based on a fourth formula, determining a first recovery torque of a driving motor according to the maximum braking deceleration, the powertrain efficiency, the gearbox speed ratio, the final drive speed ratio, the mass of the vehicle and the wheel radius;

[0035] The fourth formula is:

[0036] in, is the first recovery torque of the driving motor, a rec is the maximum braking recovery deceleration, m is the mass of the vehicle, r is the wheel radius, η T is the transmission efficiency, i g is the gearbox speed ratio, i0 is the final reducer speed ratio;

[0037] Determining a current rotation speed of the drive motor according to a current speed of the vehicle;

[0038] Determining a second recovery torque and a recovery efficiency of the drive motor at the current speed based on a speed-recovery torque-recovery efficiency characteristic curve of the drive motor;

[0039] determining a third recovery torque of the drive motor according to a current rotation speed of the drive motor and a temperature of the drive motor;

[0040] determining a maximum recovery torque of the driving motor according to the first recovery torque, the second recovery torque and the third recovery torque;

[0041] The maximum charging power of the power battery is determined according to the maximum recovery torque of the drive motor, the current rotation speed of the drive motor and the recovery efficiency.

[0042] Optionally, when the power parameter includes continuous discharge power, the driving parameters include: powertrain efficiency, vehicle mass, gravitational acceleration, rolling resistance coefficient, road slope, air resistance coefficient, frontal area, vehicle rotational mass coefficient, and maximum vehicle speed during pure electric driving;

[0043] Determining the power parameter of the power battery according to the driving parameter includes:

[0044] Based on the fifth formula, determining the continuous output power of the drive motor according to the driving parameters;

[0045] The fifth formula is:

[0046] Wherein, PsEv is the continuous output power of the drive motor, η T is the powertrain efficiency, m is the mass of the vehicle, g is the gravitational acceleration, f is the rolling resistance coefficient, C is the air resistance coefficient, A is the frontal area of ​​the vehicle, δ is the rotational mass conversion coefficient of the vehicle, and v e is the maximum speed of the vehicle when driving in pure electric mode, α is the road slope, is the differential of the maximum vehicle speed during pure electric driving with respect to time;

[0047] Based on the efficiency characteristic curve of the driving motor, determining a first output efficiency of the driving motor according to the continuous output power of the driving motor;

[0048] The continuous discharge power of the power battery is determined according to the continuous output power of the drive motor and the first output efficiency.

[0049] Optionally, when the power parameter includes continuous charging power, the driving parameters include: powertrain efficiency, vehicle mass, rolling resistance coefficient, road slope, air resistance coefficient, vehicle frontal area, vehicle rotational mass conversion coefficient, vehicle current speed, gearbox ratio, final reducer ratio and wheel radius;

[0050] Determining the power parameter of the power battery according to the driving parameter includes:

[0051] Based on the sixth formula, determining the current speed of the engine according to the current vehicle speed, the gearbox speed ratio, the final drive speed ratio and the wheel radius;

[0052] The sixth formula is:

[0053] Among them, N 1ENG is the current speed of the engine, r is the wheel radius, v is the current speed of the vehicle, i g is the gearbox speed ratio, i0 is the final reducer speed ratio;

[0054] Based on the seventh formula, the first output torque of the engine is determined according to the powertrain efficiency, the mass of the vehicle, the rolling resistance coefficient, the road slope, the air resistance coefficient, the frontal area of ​​the vehicle, the rotational mass coefficient of the vehicle, and the current speed of the vehicle; the seventh formula is:

[0055]

[0056] Wherein, T1ENG is the first output torque of the engine, η T is the transmission system efficiency, m is the mass of the vehicle, g is the gravitational acceleration, f is the rolling resistance coefficient, C is the air resistance coefficient, A is the frontal area of ​​the vehicle, δ is the rotational mass conversion coefficient of the vehicle, v is the current speed of the vehicle, α is the road slope, is the differential of the current speed of the vehicle with respect to time;

[0057] The continuous charging power of the power battery is determined according to the first output torque of the engine and the current speed of the engine.

[0058] Optionally, when the power parameter includes continuous charging power, the driving parameter includes: the current vehicle speed, gearbox ratio, final reducer ratio and wheel radius of the vehicle;

[0059] Determining the power parameter of the power battery according to the driving parameter includes:

[0060] Based on the sixth formula, determining the current speed of the engine according to the current vehicle speed, the gearbox speed ratio, the final drive speed ratio and the wheel radius;

[0061] The sixth formula is:

[0062] Among them, N 1ENG is the current speed of the engine, r is the wheel radius, v is the current speed of the vehicle, i g is the gearbox speed ratio, i0 is the final reducer speed ratio;

[0063] Determining a second continuous output torque corresponding to a current speed of the engine based on an optimal fuel consumption rate curve of the engine;

[0064] The continuous charging power of the power battery is determined according to the second continuous torque of the engine and the current speed of the engine.

[0065] According to another aspect of the present invention, there is provided a charging and discharging power control device for a power battery in a vehicle, comprising:

[0066] A driving parameter acquisition module, used to acquire the driving parameters of the vehicle in real time during the driving of the vehicle;

[0067] A power parameter determination module, used to determine the power parameter of the power battery according to the driving parameter; the power parameter includes at least one of maximum discharge power, maximum charging power, continuous discharge power and continuous charging power;

[0068] A charge and discharge power control module is used to control the output power of the power battery according to the power parameter, and / or to control the recovery power of the power battery according to the power parameter.

[0069] According to another aspect of the present invention, there is provided a vehicle, comprising: a power system and a controller;

[0070] The power system includes a drive motor, a power battery, an engine and a generator;

[0071] The controller is used to execute the above-mentioned method for controlling the charging and discharging power of the power battery in the vehicle.

[0072] The method for controlling the charging and discharging power of a power battery in a vehicle provided by an embodiment of the present invention obtains driving parameters of the vehicle in real time during driving, so that the power parameters of the power battery that meet the driving state of the vehicle can be determined in real time according to the driving parameters. Compared with the method of determining power parameters according to the intrinsic parameters of the power battery in the prior art, the power parameters obtained by the embodiment of the present invention are more reliable and accurate. Therefore, when controlling the output power and / or recovery power of the power battery, the output power and / or recovery power of the power battery can be controlled according to power parameters with higher reliability and accuracy and more in line with the actual driving state, so that the charging and discharging control of the power battery is more accurate and reliable, which is beneficial to improving the driving effect, braking effect and even driving experience of the vehicle during driving.

[0073] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0075] Figure 1 is a schematic structural diagram of a power system of a vehicle provided by an embodiment of the present invention;

[0076] Figure 2 is a flow chart of a method for controlling the charging and discharging power of a power battery in a vehicle provided by an embodiment of the present invention;

[0077] Figure 3 is a flow chart of another method for controlling the charging and discharging power of a power battery in a vehicle provided by an embodiment of the present invention;

[0078] Figure 4 This is a flow chart of another method for controlling the charging and discharging power of a power battery in a vehicle provided by an embodiment of the present invention.

[0079] Figure 5 is a flow chart of another method for controlling the charging and discharging power of a power battery in a vehicle provided by an embodiment of the present invention;

[0080] Figure 6 is a flow chart of another method for controlling the charging and discharging power of a power battery in a vehicle provided by an embodiment of the present invention;

[0081] Figure 7 is a flow chart of another method for controlling the charging and discharging power of a power battery in a vehicle provided by an embodiment of the present invention;

[0082] Figure 8 is a flow chart of another method for controlling the charging and discharging power of a power battery in a vehicle provided by an embodiment of the present invention;

[0083] Fig. 9 It is a schematic diagram of an optimal fuel consumption rate curve of an engine provided by an embodiment of the present invention;

[0084] Fig.10 It is a structural schematic diagram of a charging and discharging power control device for a power battery in a vehicle provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0085] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0086] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0087] Figure 1 A schematic diagram of a power system of a vehicle provided by an embodiment of the present invention is shown in FIG. Figure 1 As shown: the power system of the vehicle includes a drive motor 1, a power battery 2, an engine 3, a generator 4, a transmission coupling mechanism 5 and a clutch 6. The power battery 2 is electrically connected to the drive motor 1, the drive motor 1 is mechanically connected to the transmission coupling mechanism 5, the transmission coupling mechanism 5 is also mechanically connected to the engine 3 through the clutch 6, the output end of the transmission coupling mechanism 5 is also mechanically connected to the wheel 7, the engine 3 is mechanically connected to the generator 4, and the generator 4 is electrically connected to the power battery 2. In addition, the power system of the vehicle also includes multiple controllers, namely, a motor controller MCU (Motor Control Unit) electrically connected to the drive motor 1, a battery management system BMS (Battery Management System) electrically connected to the power battery 2, an engine control system EMS (Engine Management System) electrically connected to the engine 3, a generator controller GCU (Generator Control Unit) electrically connected to the generator 4, and a vehicle controller VCU (Vehicle Control Unit). The motor controller MCU, the battery management system BMS, the engine control system EMS, and the generator controller GCU all communicate with the vehicle controller VCU in real time through the CAN network. In other feasible embodiments of the present invention, the above controllers also communicate with each other through the CAN network.

[0088] Based on the power system of the above-mentioned vehicle, an embodiment of the present invention provides a method for controlling the charging and discharging power of a power battery in a vehicle. The method for controlling the charging and discharging power of a power battery in a vehicle is suitable for dual-motor hybrid vehicles and can obtain power parameters with high reliability and accuracy. The method for controlling the charging and discharging power of a power battery in the vehicle can be executed by a charge and discharge power control device for a power battery in the vehicle provided by an embodiment of the present invention. The charge and discharge power control device for a power battery in the vehicle can be implemented in the form of hardware and / or software, and the device can be configured in the power system of the vehicle provided by an embodiment of the present invention.

[0089] Figure 2 is a flow chart of a method for controlling the charging and discharging power of a power battery in a vehicle provided by an embodiment of the present invention, such as Figure 2 As shown, the charging and discharging power control method of the power battery in the vehicle includes:

[0090] S110. Acquire driving parameters of the vehicle in real time during driving of the vehicle.

[0091] Specifically, driving parameters may include dynamic driving parameters and static driving parameters. Dynamic driving parameters may include driving parameters that change at any time, such as vehicle speed and road slope, and static driving parameters may include fixed value parameters that do not change, such as powertrain efficiency, vehicle mass, rolling resistance coefficient, air resistance coefficient, vehicle frontal area, and vehicle rotational mass conversion coefficient. Dynamic driving parameters may be obtained through sensors, such as vehicle speed and road slope; static driving parameters may be stored in a storage module of the vehicle controller so that they can be called at any time when needed.

[0092] S120: Determine a power parameter of the power battery according to the driving parameter, wherein the power parameter includes at least one of a maximum discharge power, a maximum charge power, a continuous discharge power, and a continuous charge power.

[0093] Specifically, during the driving process of the vehicle, dynamic driving parameters such as the vehicle speed and road slope change in real time, so that the required driving power of the vehicle also changes in real time. Since the power system of the hybrid configuration can not only be driven by pure electricity through the power battery, but also by the driving mode of the power battery and the engine, the charging and discharging power of the power battery can be calculated in combination with the real-time required driving power and driving mode of the vehicle. Based on this, the power parameters of the power battery can be calculated by the driving parameters obtained in real time. Among them, the power parameters may include at least one of the maximum discharge power, the maximum charging power, the continuous discharge power and the continuous charging power, that is, one, two or three of them can be selected for calculation according to the subsequent control needs, or the power parameters including the maximum discharge power, the maximum charging power, the continuous discharge power and the continuous charging power can be calculated in full, so that they can be directly called according to the use needs in the subsequent control process.

[0094] S130: Controlling the output power of the power battery according to the power parameter, and / or controlling the power recovery power of the power battery according to the power parameter.

[0095] Specifically, after determining relatively accurate and reliable power parameters according to driving parameters, the power battery output power can be controlled according to relatively accurate and reliable power parameters, and / or the power battery recovery power can be controlled according to the power parameters. Exemplarily, the power battery output power can be controlled according to the maximum discharge power and continuous discharge power combined with the driving requirements of the vehicle, so that the power battery output power can more reliably meet the driving requirements; the power battery recovery power can be controlled according to the maximum charging power and continuous charging power combined with the power battery power, temperature and other parameters, so that the power battery can reliably and efficiently recover energy.

[0096] The method for controlling the charging and discharging power of a power battery in a vehicle provided by an embodiment of the present invention obtains driving parameters of the vehicle in real time during driving, so that the power parameters of the power battery that meet the driving state of the vehicle can be determined in real time according to the driving parameters. Compared with the method of determining power parameters according to the intrinsic parameters of the power battery in the prior art, the power parameters obtained by the embodiment of the present invention are more reliable and accurate. Therefore, when controlling the output power and / or recovery power of the power battery, the output power and / or recovery power of the power battery can be controlled according to power parameters with higher reliability and accuracy and more in line with the actual driving state, so that the charging and discharging control of the power battery is more accurate and reliable, which is beneficial to improving the driving effect, braking effect and even driving experience of the vehicle during driving.

[0097] It should be noted that the power parameter may include one, two or three of the maximum discharge power, maximum charging power, continuous discharge power and continuous charging power, or may include all of them. For the sake of convenience of explanation, the following embodiments will respectively provide illustrative explanations for the case where the power parameter includes one of the maximum discharge power, maximum charging power, continuous discharge power and continuous charging power, so as to facilitate an exemplary explanation of the calculation of each power parameter.

[0098] Optionally, when the power parameters include maximum discharge power, the driving parameters include: transmission system efficiency, vehicle mass, rolling resistance coefficient, air resistance coefficient, road slope, vehicle's frontal area, vehicle's rotational mass conversion coefficient, vehicle's current speed, power battery discharge efficiency, engine friction torque, engine speed and engine maximum output torque. Figure 3 A flowchart of another method for controlling the charging and discharging power of a power battery in a vehicle provided by an embodiment of the present invention is shown in FIG. Figure 3 As shown, the method includes:

[0099] S210: Acquire driving parameters of the vehicle in real time during the driving of the vehicle.

[0100] S220, determining a first discharge power of the power battery according to the transmission system efficiency, the mass of the vehicle, the rolling resistance coefficient, the air resistance coefficient, the frontal area of ​​the vehicle, the rotational mass conversion coefficient of the vehicle, the current speed of the vehicle and the discharge efficiency of the power battery.

[0101] Specifically, the first discharge power may be the maximum discharge power of the power battery that can meet the vehicle driving requirements; wherein, the transmission system efficiency may be the overall efficiency of the transmission system consisting of the drive motor, the transmission coupling mechanism and the engine, the rolling resistance coefficient may be the friction resistance coefficient between the vehicle tires and the ground, and the vehicle's rotational mass conversion coefficient may be the overall rotational mass conversion coefficient of rotating elements such as gears and flywheels in the vehicle.

[0102] S230: Determine a second discharge power of the power battery according to the current vehicle speed, the engine friction torque, the engine speed, and the maximum output torque of the engine.

[0103] Specifically, the second discharge power may be the maximum discharge power output by the power battery according to the vehicle speed on the basis of the maximum output torque provided by the engine. The engine friction torque may be the torque to overcome the friction between the mechanical structures of the engine when the engine rotates, and the maximum output torque of the engine may be obtained through the external characteristic curve of the engine.

[0104] S240: Determine the maximum discharge power of the power battery according to the first discharge power and the second discharge power.

[0105] Specifically, the larger of the first discharge power and the second discharge power can be selected as the maximum discharge power of the power battery. For example, it can be calculated by the formula Calculate the maximum discharge power, where is the maximum discharge power of the power battery, is the first discharge power, is the second discharge power, and max is the maximum value function. The larger of the first discharge power and the second discharge power is taken as the maximum discharge power of the power battery. The maximum driving power that the power battery can provide to the driving motor can be determined according to the maximum discharge power, so that the driving mode of the power system can be controlled according to the driving demand of the vehicle, and the output power of the power battery can be controlled, so that the power system can drive the vehicle in an energy-saving and efficient manner.

[0106] S250. Control the power battery output power according to the maximum discharge power.

[0107] Optional, Figure 4 is a flow chart of another method for controlling the charging and discharging power of a power battery in a vehicle provided by an embodiment of the present invention, such as Figure 4 As shown, the method includes:

[0108] S311. Acquire the driving parameters of the vehicle in real time during the driving of the vehicle.

[0109] S312. Based on the first formula, determine the required power of the vehicle according to the transmission system efficiency, the mass of the vehicle, the rolling resistance coefficient, the air resistance coefficient, the frontal area of ​​the vehicle, the rotational mass conversion coefficient of the vehicle and the current speed of the vehicle.

[0110] The first formula is: Where Ps is the required power of the vehicle, η Tis the powertrain efficiency, m is the mass of the vehicle, g is the acceleration due to gravity, f is the rolling resistance coefficient, C is the air resistance coefficient, A is the frontal area of ​​the vehicle, δ is the rotational mass conversion coefficient of the vehicle, v is the current speed of the vehicle, α is the road slope, It is the differential of the vehicle's current speed v with respect to time.

[0111] Specifically, the resistance encountered by the vehicle during driving includes rolling resistance F f , air resistance F w , Slope resistance F i and acceleration resistance F j , the driving force F of the vehicle t Equal to the sum of various resistances, the total torque T generated by the power source (combined engine and motor) s The driving force F is transmitted to the wheels through the transmission mechanism to generate driving force F t Drive the vehicle to move, so the vehicle's driving dynamics equation is: F t =F f +F w +F i +F j , according to the driving dynamics equation, we can further deduce Denoted as the eighth formula, where η T is the powertrain efficiency, m is the mass of the vehicle, g is the acceleration due to gravity, f is the rolling resistance coefficient, C is the air resistance coefficient, A is the frontal area of ​​the vehicle, δ is the rotational mass conversion coefficient of the vehicle, α is the road slope, is the differential of the vehicle's current speed v with respect to time. Multiply both sides of the eighth formula by the vehicle's current speed v and divide by the transmission efficiency η T , the first formula can be derived, that is, the required power of the vehicle can be determined from the perspective of the vehicle's driving requirements.

[0112] S313: Based on the second formula, determine the first discharge power according to the required power of the vehicle and the discharge efficiency of the power battery.

[0113] The second formula is: in, is the first discharge power, η b It is the discharge efficiency of the power battery.

[0114] Specifically, the discharge efficiency η of the power battery b It can be obtained through the discharge characteristic curve of the power battery. When the power battery is discharged, the power used to drive the vehicle is the active power, and the power used for heat generation is the reactive power. The discharge efficiency η b It is the ratio of active power to the total output power of the power battery. Therefore, by reverse reasoning, the vehicle's required power Ps As active power, the first discharge power of the power battery, that is, the maximum discharge power of the battery that meets the vehicle driving demand, can be calculated by the second formula. It can be understood that the first discharge power is obtained based on the overall driving demand of the vehicle.

[0115] S314: Determine the current rotation speed of the drive motor according to the current speed of the vehicle.

[0116] Specifically, after the current speed of the vehicle is acquired, the current rotation speed of the drive motor may be converted according to the current speed of the vehicle.

[0117] S315: Determine the maximum output driving power and the maximum output efficiency of the driving motor at the current speed based on the speed-output torque-output efficiency characteristic curve of the driving motor.

[0118] Specifically, based on the first speed-output torque-output efficiency characteristic curve of the drive motor, the maximum output torque of the drive motor at the current speed can be determined by a table lookup method, and then the maximum output power of the drive motor can be calculated by the maximum output torque; at the same time, the maximum output efficiency of the drive motor at the current speed can also be determined by the table lookup method.

[0119] S316: Determine the maximum net torque of the engine according to the maximum output torque of the engine and the friction torque of the engine.

[0120] Specifically, the maximum output torque T of the engine can be obtained through the external characteristic curve of the engine. EnMax The torque of the friction between the mechanical structures of the engine when the engine rotates can be taken as the engine friction torque T EnFrc , so the maximum net torque of the engine is T EnNetmax The maximum output torque T of the engine EnMax The difference between the friction torque of the engine and EnFrc , that is, T EnNetmax =T Enmax -T EnFrc .

[0121] S317: Determine the maximum net output mechanical power of the engine according to the maximum net torque of the engine and the engine speed.

[0122] Specifically, according to the formula Determine the maximum net mechanical power output of the engine, where It is the maximum net output mechanical power of the engine, N En It is the engine speed, which can be converted from the vehicle speed or detected by a sensor.

[0123] S318. Determine the maximum power generation power of the generator according to the maximum net output mechanical power of the engine.

[0124] Specifically, when the power output of the power battery cannot meet the driving requirements of the vehicle, the generator is required to provide additional driving power to the drive motor on the basis of the power battery outputting the maximum power it can provide, so that the generator and the power battery can jointly provide driving power to the drive motor. Figure 1 , the engine 3 starts to drive the generator 4 to generate electricity, so the maximum net output mechanical power of the engine can be used as the maximum generating power of the generator.

[0125] S319: Determine a first power generation efficiency corresponding to the maximum power generation power of the generator based on the power generation efficiency characteristic curve of the generator.

[0126] Specifically, after the maximum power generation of the generator is determined, the first power generation efficiency corresponding to the maximum power generation of the generator may be determined according to the power generation efficiency characteristic curve of the generator.

[0127] S320. Based on the third formula, determine the second discharge power according to the maximum output driving power of the drive motor, the maximum output efficiency of the drive motor, the maximum power generation power of the generator and the first power generation efficiency.

[0128] The third formula is: in, is the second discharge power, P drv is the maximum output driving power of the driving motor, η drv is the maximum output efficiency of the drive motor, is the maximum power generated by the generator, η gen It is the first power generation efficiency.

[0129] Specifically, the maximum total power required by the vehicle at the current speed The maximum power that the generator can provide By subtracting them, the maximum discharge power of the power battery from the perspective of the driving output of the vehicle power system, that is, the second discharge power, can be obtained, so that the larger of the first discharge power and the second discharge power can be determined as the maximum discharge power of the power battery.

[0130] S321. Determine the maximum discharge power of the power battery according to the first discharge power and the second discharge power.

[0131] S322. Control the power battery output power according to the maximum discharge power.

[0132] The method for controlling the charging and discharging power of a power battery in a vehicle provided by an embodiment of the present invention determines a first discharge power and a second discharge power respectively from two different angles, that is, the first discharge power is determined according to the driving demand of the vehicle, and the second discharge power is determined according to the driving output angle inside the power system, and the larger of the first discharge power and the second discharge power is used as the maximum discharge power of the power battery. The maximum driving power that the power battery can provide to the driving motor can be determined according to the maximum discharge power, so that the driving mode of the power system can be controlled according to the driving demand of the vehicle, and the output power of the power battery can be controlled, so that the power system can drive the vehicle energy-efficiently and efficiently.

[0133] Optionally, when the power parameters include maximum charging power, the driving parameters include: vehicle speed, maximum braking regenerative deceleration, transmission efficiency, gearbox ratio, final reducer ratio, vehicle mass, wheel radius, vehicle current speed and temperature of the drive motor. Figure 5 is a flow chart of another method for controlling the charging and discharging power of a power battery in a vehicle provided by an embodiment of the present invention, such as Figure 5 As shown, the method includes:

[0134] S410. Acquire driving parameters of the vehicle in real time during the driving of the vehicle.

[0135] S420. Based on the fourth formula, determine the first recovery torque of the drive motor according to the maximum braking deceleration, the transmission efficiency, the gearbox speed ratio, the final reducer speed ratio, the mass of the vehicle and the wheel radius.

[0136] The fourth formula is: in, is the first recovery torque of the driving motor, a rec is the maximum braking deceleration, m is the mass of the vehicle, r is the wheel radius, η T is the transmission efficiency, i g is the gearbox speed ratio, and i0 is the final reducer speed ratio.

[0137] Specifically, when the vehicle brakes, the driving motor outputs a torque that reduces the speed to produce a deceleration effect. During the braking process, energy can be recovered to achieve energy saving. Therefore, the torque that reduces the speed can be called a recovery torque. The maximum braking deceleration can be a calibrated value, which can be determined according to the actual situation of the braking system, for example, it can be 2m / s 2 , substituting the maximum braking deceleration into the fourth formula, the first recovery torque determined based on the fourth formula is the maximum recovery torque of the drive motor that meets the maximum braking demand.

[0138] S430: Determine a current rotation speed of the drive motor according to a current vehicle speed.

[0139] S440: Determine a second recovery torque and recovery efficiency of the drive motor at a current speed based on a speed-recovery torque-recovery efficiency characteristic curve of the drive motor.

[0140] Specifically, in addition to calculating the first recovery torque through the maximum braking deceleration, a maximum recovery torque can also be obtained through the characteristic curve. After obtaining the current vehicle speed, the current speed of the drive motor can be converted by the vehicle speed. Then, based on the speed-recovery torque-recovery efficiency characteristic curve of the drive motor, the maximum recovery torque and recovery efficiency corresponding to the current speed can be determined by a table lookup method. The maximum recovery torque is the second recovery torque.

[0141] S450: Determine a third recovery torque of the drive motor according to the current rotation speed of the drive motor and the temperature of the drive motor.

[0142] Specifically, the current speed of the drive motor can be combined with other characteristics of the drive motor to obtain the maximum recovery torque that the drive motor can achieve, that is, the maximum recovery torque that the drive motor can achieve can be calculated by the current speed of the drive motor and the current temperature information of the drive motor, that is, the third recovery torque. The embodiment of the present invention only exemplarily shows that other characteristics include the temperature of the drive motor. It is understandable that other influencing factors may also be included, such as IGBT characteristics, ambient humidity, and aging degree of the drive motor.

[0143] S460: Determine a maximum recovery torque of the driving motor according to the first recovery torque, the second recovery torque, and the third recovery torque.

[0144] Specifically, since the recovery torque is used to charge the power battery, a relatively reliable recovery torque is selected as the torque for charging the power battery to ensure that the power battery can be charged according to the recovery torque. Therefore, the smallest of the first recovery torque, the second recovery torque and the third recovery torque can be selected as the maximum recovery torque of the drive motor. For example, the formula Calculate the maximum regenerative torque of the drive motor, where is the maximum regenerative torque of the drive motor, is the first recovery torque, is the second recovery torque, It is the third recovery torque.

[0145] S470: Determine the maximum charging power of the power battery according to the maximum recovery torque of the drive motor, the current speed of the drive motor, and the recovery efficiency.

[0146] Specifically, the formula Determine the maximum regenerative power at the input of the drive motor, where is the maximum recovery power at the input end of the drive motor, n is the speed of the drive motor, η m The recovery efficiency corresponding to the current speed is determined based on the speed-recovery torque-recovery efficiency characteristic curve of the drive motor; then, through the formula Calculate the maximum charging power of the power battery, where: That is, it is the maximum charging power of the power battery. The coefficient B is a calibrated value, and the value range is 1.05 to 1.2. It can be determined according to the characteristics of the power battery assembly. For example, in the embodiment of the present invention, the value can be 1.1.

[0147] S480. Control the power recovery power of the power battery according to the maximum charging power.

[0148] The method for controlling the charging and discharging power of a power battery in a vehicle provided by an embodiment of the present invention first determines a first recovery torque, a second recovery torque and a third recovery torque according to the maximum deceleration of the vehicle, a speed-recovery torque-recovery efficiency characteristic curve of the drive motor and the real-time state of the drive motor, and selects the smallest of the first recovery torque, the second recovery torque and the third recovery torque as the maximum recovery torque of the drive motor, which is a more reliable recovery torque for charging the power battery. Then, the maximum charging power of the power battery is determined according to the maximum recovery torque of the drive motor, the current speed of the drive motor and the recovery efficiency. That is, the maximum charging power of the power battery is determined in combination with the driving conditions, so that the maximum charging power is more reliable and accurate.

[0149] Optionally, when the power parameters include continuous discharge power, the driving parameters include: transmission system efficiency, vehicle mass, gravity acceleration, rolling resistance coefficient, road slope, air resistance coefficient, frontal area, vehicle rotational mass coefficient, and maximum vehicle speed during pure electric driving. Figure 6 is a flow chart of another method for controlling the charging and discharging power of a power battery in a vehicle provided by an embodiment of the present invention, such as Figure 6 As shown, the method includes:

[0150] S510: Acquire driving parameters of the vehicle in real time during the driving of the vehicle.

[0151] S520: Based on the fifth formula, determine the continuous output power of the drive motor according to the driving parameters.

[0152] The fifth formula is: Among them, P sEv is the continuous output power of the drive motor, η T is the powertrain efficiency, m is the mass of the vehicle, g is the acceleration due to gravity, f is the rolling resistance coefficient, C is the air resistance coefficient, A is the frontal area of ​​the vehicle, δ is the rotational mass conversion coefficient of the vehicle, and v eis the maximum speed of the vehicle when driving in pure electric mode, α is the road slope, is the maximum speed when driving purely on electric power. e For the time differential, it can be understood that the maximum speed v when driving purely electric e is a fixed value, so here

[0153] Specifically, the derivation process of the fifth formula is the same as that of the first formula, except that the current speed v of the vehicle in the first formula is replaced by the maximum vehicle speed v during electric driving. e , that is, the fifth formula can be used to determine the continuous output power that the drive motor can provide under pure electric driving conditions, that is, the active power in the continuous output power of the power battery. Among them, the maximum vehicle speed v when driving purely electric e It can be calibrated according to the actual situation of the vehicle, for example, it can be 80Km / h, which can be understood as the continuous output power of the drive motor when the vehicle is driving steadily at a speed of 80Km / h.

[0154] S530 : Determine a first output efficiency of the driving motor based on the efficiency characteristic curve of the driving motor and according to the continuous output power of the driving motor.

[0155] S540: Determine the continuous discharge power of the power battery according to the continuous output power of the drive motor and the first output efficiency.

[0156] Specifically, after determining the continuous output power that the drive motor can provide under pure electric driving conditions, the first output efficiency corresponding to the continuous output power can be queried based on the efficiency characteristic curve of the drive motor, and the continuous output power of the drive motor under pure electric driving conditions is used as the active power in the continuous output power of the power battery. The formula Calculate the continuous discharge power of the power battery. That is the continuous discharge power of the power battery, η con is the first output efficiency.

[0157] S550. Control the output power of the power battery according to the continuous discharge power.

[0158] The method for controlling the charging and discharging power of a power battery in a vehicle provided by an embodiment of the present invention first determines the continuous output power that the drive motor can provide under pure electric driving conditions, that is, the active power in the continuous output power of the power battery, and then determines the first output efficiency of the drive motor based on the efficiency characteristic curve of the drive motor according to the continuous output power of the drive motor, and determines the continuous discharge power of the power battery in combination with the continuous output power as the active power and the corresponding first output efficiency, so that the determination of the continuous discharge power in combination with the driving conditions is more reliable and accurate.

[0159] Optionally, when the power parameters include continuous charging power, the driving parameters include: transmission efficiency, vehicle mass, rolling resistance coefficient, road slope, air resistance coefficient, vehicle frontal area, vehicle rotational mass conversion coefficient, vehicle current speed, gearbox ratio, final reducer ratio and wheel radius. Figure 7 is a flow chart of another method for controlling the charging and discharging power of a power battery in a vehicle provided by an embodiment of the present invention, such as Figure 7 As shown, the method includes:

[0160] S610: Acquire driving parameters of the vehicle in real time during driving of the vehicle.

[0161] S620. Based on the sixth formula, determine the current speed of the engine according to the current vehicle speed, the transmission speed ratio, the final reducer speed ratio and the wheel radius.

[0162] The sixth formula is: Among them, N 1ENG is the current engine speed, r is the wheel radius, v is the current vehicle speed v, i g is the gearbox speed ratio, and i0 is the final reducer speed ratio.

[0163] S630, based on the seventh formula, determine the first output torque of the engine according to the transmission system efficiency, the mass of the vehicle, the rolling resistance coefficient, the road slope, the air resistance coefficient, the frontal area of ​​the vehicle, the rotational mass coefficient of the vehicle, and the current speed of the vehicle.

[0164] The seventh formula is: Among them, T 1ENG The first output torque of the engine, η T is the powertrain efficiency, m is the mass of the vehicle, g is the acceleration due to gravity, f is the rolling resistance coefficient, C is the air resistance coefficient, A is the frontal area of ​​the vehicle, δ is the rotational mass conversion coefficient of the vehicle, v is the current speed of the vehicle, α is the road slope, It is the differential of the vehicle's current speed v with respect to time.

[0165] Specifically, the seventh formula can be obtained from the eighth formula above: It is deduced that the driving force F t The driving torque T s As the first output torque T of the engine 1ENG , it can be understood that the driving torque required by the vehicle is provided by the engine, that is, the engine generates electricity through the generator, thereby charging the power battery through the generator, and then the power battery outputs power so that the drive motor outputs the driving torque T s .

[0166] S640: Determine the continuous charging power of the power battery according to the first output torque of the engine and the current rotation speed of the engine.

[0167] Specifically, the formula Calculate the engine speed at the current N 1ENG The mechanical power P output by the engine to charge the power battery 1ENG , the mechanical power P 1ENG As the power generated by the generator, it can be expressed by the formula The continuous charging power of the power battery is further determined, wherein the coefficient M is a calibration value, and the value range is usually 0.9 to 1. The value of the coefficient M can be selected according to the characteristics of the power battery assembly. For example, in the embodiment of the present invention, M can be 0.95.

[0168] S650. Control the power recovery of the power battery according to the continuous charging power.

[0169] The method for controlling the charging and discharging power of a power battery in a vehicle provided by an embodiment of the present invention first determines the current speed of the engine in combination with the vehicle speed, and then determines the driving demand of the vehicle in combination with the vehicle speed. It is assumed that the driving demand is provided by the engine. Therefore, based on the principle that the engine charges the power battery through the generator, the continuous charging power of the power battery can be determined, making it more reliable and accurate to determine the continuous charging power in combination with the driving conditions.

[0170] Optionally, the continuous charging power of the power battery can also be determined by the optimal fuel consumption rate curve of the engine. Figure 8 is a flow chart of another method for controlling the charging and discharging power of a power battery in a vehicle provided by an embodiment of the present invention, such as Figure 8 As shown, the method includes:

[0171] S710. Acquire driving parameters of the vehicle in real time while the vehicle is traveling.

[0172] S720. Based on the sixth formula, determine the current speed of the engine according to the current vehicle speed, transmission speed ratio, final reducer speed ratio and wheel radius.

[0173] The sixth formula is: Among them, N 1ENG is the current engine speed, r is the wheel radius, v is the current vehicle speed v, i g is the gearbox speed ratio, and i0 is the final reducer speed ratio.

[0174] S730: Determine a second output torque corresponding to a current speed of the engine based on an optimal fuel consumption rate curve of the engine.

[0175] Specifically, the optimal fuel consumption rate curve of the engine can be determined according to the universal characteristic curve of the engine. Fig. 9 : is a schematic diagram of an optimal fuel consumption rate curve of an engine provided by an embodiment of the present invention, such as Fig. 9 As shown, the optimal fuel consumption rate curve L2 of the engine can be determined based on the universal characteristic curve L1 by global optimization search related data processing method. 1ENG After that, the current speed N can be determined 1ENG The corresponding second output torque T 2ENG , that is, at the current speed N 1ENG Under the condition, the engine outputs the second torque T 2ENG Output can consume the least fuel, which can be further calculated through the formula and formula Calculate the continuous charging power of the power battery.

[0176] S740: Determine the continuous charging power of the power battery according to the second continuous torque of the engine and the current speed of the engine.

[0177] S750. Control the power recovery power of the power battery according to the continuous charging power.

[0178] The method for controlling the charging and discharging power of a power battery in a vehicle provided in an embodiment of the present invention adopts another way to obtain the continuous charging power of the power battery. On the basis of determining the current speed of the engine in combination with the vehicle speed, the second output torque corresponding to the current speed of the engine is determined based on the optimal fuel consumption rate curve of the engine. Therefore, the continuous charging power of the power battery can be determined according to the second continuous torque of the engine and the current speed of the engine. When controlling the charging of the power battery according to the continuous charging power, less fuel can be used, which is beneficial to energy conservation and emission reduction.

[0179] Based on the same inventive concept, an embodiment of the present invention further provides a charge and discharge power control device for a power battery in a vehicle. The charge and discharge power control device for a power battery in a vehicle is suitable for a dual-motor hybrid vehicle, and can obtain power parameters with high reliability and accuracy, and is used to execute the charge and discharge power control method for a power battery in a vehicle provided by any embodiment of the present invention. Therefore, the charge and discharge power control device for a power battery in a vehicle provided by an embodiment of the present invention includes the technical features of the charge and discharge power control method for a power battery in a vehicle provided by any embodiment of the present invention, and can achieve the beneficial effects of the charge and discharge power control method for a power battery in a vehicle provided by any embodiment of the present invention. The similarities can be referred to the above description of the charge and discharge power control method for a power battery in a vehicle provided by an embodiment of the present invention, and will not be repeated here.

[0180] Optional, Fig.10is a schematic diagram of the structure of a charging and discharging power control device for a power battery in a vehicle provided by an embodiment of the present invention, such as Fig.10 As shown, the charge and discharge power control device of the power battery in the vehicle includes: a driving parameter acquisition module 100, which is used to acquire the driving parameters of the vehicle in real time during the driving of the vehicle; a power parameter determination module 200, which is used to determine the power parameters of the power battery according to the driving parameters; the power parameters include at least one of the maximum discharge power, the maximum charging power, the continuous discharge power and the continuous charging power; the charge and discharge power control module 300, which is used to control the output power of the power battery according to the power parameters, and / or, control the power recovery power of the power battery according to the power parameters.

[0181] The charging and discharging power control device for a power battery in a vehicle provided by an embodiment of the present invention obtains driving parameters of the vehicle in real time during driving through a driving parameter acquisition module, so that the power parameters of the power battery that meet the driving state of the vehicle can be determined in real time according to the driving parameters through a power parameter determination module. Compared with the method of determining power parameters according to the intrinsic parameters of the power battery in the prior art, the power parameters obtained by the embodiment of the present invention are more reliable and accurate. Therefore, when the charging and discharging power control module controls the output power and / or recovery power of the power battery, the output power and / or recovery power of the power battery can be controlled according to power parameters with higher reliability and accuracy and more in line with the actual driving state, so that the charging and discharging control of the power battery is more accurate and reliable, which is beneficial to improving the driving effect, braking effect and even driving experience of the vehicle during driving. Optionally, when the power parameters include maximum discharge power, the driving parameters include: transmission system efficiency, vehicle mass, rolling resistance coefficient, air resistance coefficient, road slope, vehicle's frontal area, vehicle's rotational mass conversion coefficient, vehicle's current speed, power battery discharge efficiency, engine friction torque, engine speed and engine maximum output torque; the power parameter determination module includes a first discharge power determination submodule, which is used to determine the first discharge power of the power battery according to the transmission system efficiency, vehicle mass, rolling resistance coefficient, air resistance coefficient, vehicle's frontal area, vehicle's rotational mass conversion coefficient, vehicle's current speed and power battery discharge efficiency; a second discharge power determination submodule, which is used to determine the second discharge power of the power battery according to the vehicle's current speed, engine friction torque, engine speed and engine maximum output torque; and a maximum discharge power determination submodule, which is used to determine the maximum discharge power of the power battery according to the first discharge power and the second discharge power.

[0182] Optionally, the first discharge power determination submodule includes a required power determination unit, which is used to determine the required power of the vehicle based on a first formula according to the powertrain efficiency, the mass of the vehicle, the rolling resistance coefficient, the air resistance coefficient, the frontal area of ​​the vehicle, the rotational mass conversion coefficient of the vehicle and the current speed of the vehicle; the first formula is: Where Ps is the required power of the vehicle, η T is the powertrain efficiency, m is the mass of the vehicle, g is the acceleration due to gravity, f is the rolling resistance coefficient, C is the air resistance coefficient, A is the frontal area of ​​the vehicle, δ is the rotational mass conversion coefficient of the vehicle, v is the current speed of the vehicle, α is the road slope, is the differential of the current vehicle speed v with respect to time; a first discharge power determination unit is used to determine the first discharge power based on the second formula according to the required power of the vehicle and the discharge efficiency of the power battery; the second formula is: in, is the first discharge power, η b It is the discharge efficiency of the power battery.

[0183] Optionally, the second discharge power determination submodule includes a first speed determination unit, which is used to determine the current speed of the drive motor according to the current speed of the vehicle; a drive power and maximum output efficiency determination unit, which is used to determine the maximum output drive power and maximum output efficiency of the drive motor at the current speed based on the speed-output torque-output efficiency characteristic curve of the drive motor; an engine maximum net torque determination unit, which is used to determine the engine maximum net torque according to the engine maximum output torque and the engine friction torque; an engine maximum net output mechanical power determination unit, which is used to determine the engine maximum net output mechanical power according to the engine maximum net torque and the engine speed; a maximum power generation power determination unit, which is used to determine the maximum power generation power of the generator according to the maximum net output mechanical power of the engine; a first power generation efficiency determination unit, which is used to determine the first power generation efficiency corresponding to the maximum power generation power of the generator based on the power generation efficiency characteristic curve of the generator; a second discharge power determination unit, which is used to determine the second discharge power based on the maximum output drive power of the drive motor, the maximum output efficiency of the drive motor, the maximum power generation power of the generator and the first power generation efficiency based on a third formula; the third formula is: in, is the second discharge power, P drv is the maximum output driving power of the driving motor, η drv is the maximum output efficiency of the drive motor, is the maximum power generated by the generator, η gen It is the first power generation efficiency.

[0184] Optionally, when the power parameter includes the maximum charging power, the driving parameters include: vehicle speed, maximum braking deceleration, transmission efficiency, gearbox ratio, final reducer ratio, vehicle mass, wheel radius, current vehicle speed and temperature of the drive motor; the power parameter determination module includes a first recovery torque determination unit, which is used to determine the first recovery torque of the drive motor based on the fourth formula according to the maximum braking deceleration, transmission efficiency, gearbox ratio, final reducer ratio, vehicle mass and wheel radius; the fourth formula is: in, is the first recovery torque of the driving motor, a rec is the maximum regenerative braking deceleration, m is the mass of the vehicle, r is the wheel radius, η T is the transmission efficiency, i g is the gearbox speed ratio, i0 is the main reducer speed ratio; a second speed determination unit is used to determine the current speed of the drive motor according to the current speed of the vehicle; a second recovery torque and recovery efficiency determination unit is used to determine the second recovery torque and recovery efficiency of the drive motor at the current speed based on the speed-recovery torque-recovery efficiency characteristic curve of the drive motor; a third recovery torque determination unit is used to determine the third recovery torque of the drive motor according to the current speed of the drive motor and the temperature of the drive motor; a maximum recovery torque determination unit is used to determine the maximum recovery torque of the drive motor according to the first recovery torque, the second recovery torque and the third recovery torque; a maximum charging power determination unit is used to determine the maximum charging power of the power battery according to the maximum recovery torque of the drive motor, the current speed of the drive motor and the recovery efficiency.

[0185] Optionally, when the power parameter includes continuous discharge power, the driving parameters include: powertrain efficiency, vehicle mass, gravitational acceleration, rolling resistance coefficient, road slope, air resistance coefficient, frontal area, vehicle rotational mass coefficient, and maximum vehicle speed during pure electric driving; the power parameter determination module includes a continuous output power determination unit, which is used to determine the continuous output power of the drive motor according to the driving parameters based on the fifth formula; the fifth formula is: Among them, P sEv is the continuous output power of the drive motor, η T is the powertrain efficiency, m is the mass of the vehicle, g is the acceleration due to gravity, f is the rolling resistance coefficient, C is the air resistance coefficient, A is the frontal area of ​​the vehicle, δ is the rotational mass conversion coefficient of the vehicle, and v e is the maximum speed of the vehicle when driving in pure electric mode, α is the road slope, is the maximum speed when driving purely on electric power. eDifferentiation of time; a first output efficiency determination unit, used to determine the first output efficiency of the drive motor based on the efficiency characteristic curve of the drive motor and the continuous output power of the drive motor; a continuous discharge power determination unit, used to determine the continuous discharge power of the power battery according to the continuous output power of the drive motor and the first output efficiency.

[0186] Optionally, when the power parameter includes continuous charging power, the driving parameters include: powertrain efficiency, vehicle mass, rolling resistance coefficient, road slope, air resistance coefficient, vehicle frontal area, vehicle rotational mass conversion coefficient, vehicle current speed, gearbox ratio, final reducer ratio and wheel radius; the power parameter determination module includes a third speed determination unit, which is used to determine the current speed of the engine based on the sixth formula according to the vehicle current speed, gearbox ratio, final reducer ratio and wheel radius; the sixth formula is: Among them, N 1ENG is the current engine speed, r is the wheel radius, v is the current vehicle speed v, i g is the gearbox speed ratio, i0 is the main reducer speed ratio; a first output torque determination unit is used to determine the first output torque of the engine based on the seventh formula according to the transmission efficiency, the mass of the vehicle, the rolling resistance coefficient, the road slope, the air resistance coefficient, the frontal area of ​​the vehicle, the rotational mass coefficient of the vehicle, and the current speed of the vehicle; the seventh formula is: Among them, T 1ENG The first output torque of the engine, η T is the powertrain efficiency, m is the mass of the vehicle, g is the acceleration due to gravity, f is the rolling resistance coefficient, C is the air resistance coefficient, A is the frontal area of ​​the vehicle, δ is the rotational mass conversion coefficient of the vehicle, v is the current speed of the vehicle, α is the road slope, It is the differential of the vehicle's current speed v with respect to time; a first continuous charging power determination unit is used to determine the continuous charging power of the power battery according to the first output torque of the engine and the current speed of the engine.

[0187] Optionally, when the power parameter includes the continuous charging power, the driving parameter includes: the current speed of the vehicle, the gearbox speed ratio, the final reducer speed ratio and the wheel radius; the power parameter determination module includes a third speed determination unit, which is used to determine the current speed of the engine based on the sixth formula according to the current speed of the vehicle, the gearbox speed ratio, the final reducer speed ratio and the wheel radius; the sixth formula is: Among them, N 1ENG is the current engine speed, r is the wheel radius, v is the current vehicle speed v, i gis the gearbox speed ratio, i0 is the main reducer speed ratio; the second continuous output torque determination unit is used to determine the second continuous output torque corresponding to the current speed of the engine based on the optimal fuel consumption rate curve of the engine; the second continuous charging power determination unit is used to determine the continuous charging power of the power battery according to the second continuous torque of the engine and the current speed of the engine.

[0188] Based on the same inventive concept, an embodiment of the present invention further provides a vehicle, including a controller for executing the charging and discharging power control method of a power battery in a vehicle provided by any embodiment of the present invention. Therefore, the vehicle provided by an embodiment of the present invention includes the technical features of the charging and discharging power control method of a power battery in a vehicle provided by any embodiment of the present invention, and can achieve the beneficial effects of the charging and discharging power control method of a power battery in a vehicle provided by any embodiment of the present invention. The similarities can be referred to the above description of the charging and discharging power control method of a power battery in a vehicle provided by an embodiment of the present invention, and will not be repeated here.

[0189] refer to Figure 1The vehicle also includes at least a power system, which includes a drive motor 1, a power battery 2, an engine 3 and a generator 4, and also includes a transmission coupling mechanism 5 and a clutch 6. The power battery 2 is electrically connected to the drive motor 1, and the drive motor 1 is mechanically connected to the transmission coupling mechanism 5. The transmission coupling mechanism 5 is also mechanically connected to the engine 3 through the clutch 6. The engine 3 is mechanically connected to the generator 4, and the generator 4 is electrically connected to the power battery 2. In addition, the power system of the vehicle also includes multiple controllers, namely, a motor controller MCU (Motor Control Unit) electrically connected to the drive motor 1, a battery management system BMS (Battery Management System) electrically connected to the power battery 2, an engine control system EMS (Engine Management System) electrically connected to the engine 3, a generator controller GCU (Generator Control Unit) electrically connected to the generator 4, and a vehicle controller VCU (Vehicle Control Unit). The motor controller MCU, the battery management system BMS, the engine control system EMS, and the generator controller GCU all communicate with the vehicle controller VCU in real time through a CAN network. In other feasible embodiments of the present invention, the above-mentioned controllers also communicate with each other through a CAN network. The controller for executing the charging and discharging power control method for a power battery in a vehicle provided by any embodiment of the present invention can be integrated into the vehicle controller VCU or the battery management system BMS, or the vehicle controller VCU or the battery management system BMS can be reused as a controller for executing the charging and discharging power control method for a power battery in a vehicle provided by any embodiment of the present invention. In other feasible embodiments of the present invention, the controller for executing the charging and discharging power control method for a power battery in a vehicle provided by any embodiment of the present invention can also be independently arranged in the power system, and connected to other controllers via a CAN network communication.

[0190] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0191] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for controlling the charging and discharging power of a power battery in a vehicle, characterized in that: include: During the driving of the vehicle, the driving parameters of the vehicle are obtained in real time; Determining a power parameter of the power battery according to the driving parameter; Controlling the output power of the power battery according to the power parameter, and / or controlling the power recovery power of the power battery according to the power parameter; The power parameters include the maximum discharge power, and the driving parameters include: powertrain efficiency, vehicle mass, rolling resistance coefficient, air resistance coefficient, road slope, vehicle frontal area, vehicle rotational mass conversion coefficient, vehicle current speed, power battery discharge efficiency, engine friction torque, engine speed and engine maximum output torque; Determining the power parameters of the power battery according to the driving parameters includes: determining a first discharge power of the power battery according to the powertrain efficiency, the mass of the vehicle, the rolling resistance coefficient, the air resistance coefficient, the frontal area of ​​the vehicle, the rotational mass conversion coefficient of the vehicle, the current speed of the vehicle and the discharge efficiency of the power battery; determining a second discharge power of the power battery according to the current speed of the vehicle, the engine friction torque, the engine speed and the maximum output torque of the engine; determining a maximum discharge power of the power battery according to the first discharge power and the second discharge power; Wherein, determining the second discharge power of the power battery according to the current vehicle speed, the engine friction torque, the engine speed, and the maximum output torque of the engine includes: Determining a current rotation speed of the drive motor according to a current speed of the vehicle; Determining the maximum output drive power and the maximum output efficiency of the drive motor at the current speed based on the speed-output torque-output efficiency characteristic curve of the drive motor; determining a maximum net engine torque according to the maximum engine output torque and the engine friction torque; Determining the maximum net output mechanical power of the engine according to the maximum net torque of the engine and the engine speed; Determining the maximum power generation power of the generator according to the maximum net output mechanical power of the engine; Determining a first power generation efficiency corresponding to the maximum power generation of the generator based on a power generation efficiency characteristic curve of the generator; Based on a third formula, determining the second discharge power according to the maximum output drive power of the drive motor, the maximum output efficiency of the drive motor, the maximum power generation power of the generator and the first power generation efficiency; The third formula is: in, is the second discharge power, P drv is the maximum output driving power of the driving motor, η drv is the maximum output efficiency of the driving motor, is the maximum power generation of the generator, η gen is the first power generation efficiency.

2. The method for controlling the charging and discharging power of a power battery in a vehicle according to claim 1, characterized in that: Determining a first discharge power of the power battery according to the powertrain efficiency, the mass of the vehicle, the rolling resistance coefficient, the air resistance coefficient, the frontal area of ​​the vehicle, the rotational mass conversion coefficient of the vehicle, the current speed of the vehicle and the discharge efficiency of the power battery includes: Based on a first formula, determining the required power of the vehicle according to the powertrain efficiency, the mass of the vehicle, the rolling resistance coefficient, the air resistance coefficient, the frontal area of ​​the vehicle, the rotational mass conversion coefficient of the vehicle and the current speed of the vehicle; The first formula is: Among them, P s is the required power of the vehicle, η T is the transmission system efficiency, m is the mass of the vehicle, g is the gravitational acceleration, f is the rolling resistance coefficient, C is the air resistance coefficient, A is the frontal area of ​​the vehicle, δ is the rotational mass conversion coefficient of the vehicle, v is the current speed of the vehicle, α is the road slope, is the differential of the current speed of the vehicle with respect to time; Based on the second formula, determining a first discharge power according to the required power of the vehicle and the discharge efficiency of the power battery; The second formula is: in, is the first discharge power, η b is the discharge efficiency of the power battery.

3. The method for controlling the charging and discharging power of a power battery in a vehicle according to claim 1, characterized in that: The power parameters also include the maximum charging power, and the driving parameters include: vehicle speed, maximum braking deceleration, transmission efficiency, gearbox ratio, final reducer ratio, vehicle mass, wheel radius, current vehicle speed, and temperature of the drive motor; Determining the power parameter of the power battery according to the driving parameter includes: Based on a fourth formula, determining a first recovery torque of a driving motor according to the maximum braking deceleration, the powertrain efficiency, the gearbox speed ratio, the final drive speed ratio, the mass of the vehicle and the wheel radius; The fourth formula is: in, is the first recovery torque of the driving motor, a rec is the maximum braking deceleration, m is the mass of the vehicle, r is the wheel radius, η T is the transmission efficiency, i g is the gearbox speed ratio, i0 is the final reducer speed ratio; Determining a current rotation speed of the drive motor according to a current speed of the vehicle; Determining a second recovery torque and a recovery efficiency of the drive motor at the current speed based on a speed-recovery torque-recovery efficiency characteristic curve of the drive motor; determining a third recovery torque of the drive motor according to a current rotation speed of the drive motor and a temperature of the drive motor; determining a maximum recovery torque of the driving motor according to the first recovery torque, the second recovery torque and the third recovery torque; The maximum charging power of the power battery is determined according to the maximum recovery torque of the drive motor, the current rotation speed of the drive motor and the recovery efficiency.

4. The method for controlling the charging and discharging power of a power battery in a vehicle according to claim 1, characterized in that: The power parameters also include continuous discharge power, and the driving parameters include: powertrain efficiency, vehicle mass, gravitational acceleration, rolling resistance coefficient, road slope, air resistance coefficient, frontal area, vehicle rotational mass coefficient, and maximum vehicle speed during pure electric driving; Determining the power parameter of the power battery according to the driving parameter includes: Based on the fifth formula, determining the continuous output power of the drive motor according to the driving parameters; The fifth formula is: Among them, P sEv is the continuous output power of the drive motor, η T is the powertrain efficiency, m is the mass of the vehicle, g is the gravitational acceleration, f is the rolling resistance coefficient, C is the air resistance coefficient, A is the frontal area of ​​the vehicle, δ is the rotational mass conversion coefficient of the vehicle, and v e is the maximum speed of the vehicle when driving in pure electric mode, α is the road slope, is the differential of the maximum vehicle speed during pure electric driving with respect to time; Based on the efficiency characteristic curve of the driving motor, determining a first output efficiency of the driving motor according to the continuous output power of the driving motor; The continuous discharge power of the power battery is determined according to the continuous output power of the drive motor and the first output efficiency.

5. The method for controlling the charging and discharging power of a power battery in a vehicle according to claim 1, characterized in that: The power parameters also include continuous charging power, and the driving parameters include: powertrain efficiency, vehicle mass, rolling resistance coefficient, road slope, air resistance coefficient, vehicle frontal area, vehicle rotational mass conversion coefficient, vehicle current speed, gearbox ratio, final reducer ratio and wheel radius; Determining the power parameter of the power battery according to the driving parameter includes: Based on the sixth formula, determining the current speed of the engine according to the current vehicle speed, the gearbox speed ratio, the final drive speed ratio and the wheel radius; The sixth formula is: Among them, N 1ENG is the current speed of the engine, r is the wheel radius, v is the current speed of the vehicle, i g is the gearbox speed ratio, i0 is the final reducer speed ratio; Based on the seventh formula, the first output torque of the engine is determined according to the powertrain efficiency, the mass of the vehicle, the rolling resistance coefficient, the road slope, the air resistance coefficient, the frontal area of ​​the vehicle, the rotational mass coefficient of the vehicle, and the current speed of the vehicle; the seventh formula is: Among them, T 1ENG The first output torque of the engine, η T is the transmission system efficiency, m is the mass of the vehicle, g is the gravitational acceleration, f is the rolling resistance coefficient, C is the air resistance coefficient, A is the frontal area of ​​the vehicle, δ is the rotational mass conversion coefficient of the vehicle, v is the current speed of the vehicle, α is the road slope, is the differential of the current speed of the vehicle with respect to time; The continuous charging power of the power battery is determined according to the first output torque of the engine and the current speed of the engine.

6. The method for controlling the charging and discharging power of a power battery in a vehicle according to claim 1, characterized in that: The power parameter also includes continuous charging power, and the driving parameters include: the current vehicle speed, gearbox ratio, final reducer ratio and wheel radius; Determining the power parameter of the power battery according to the driving parameter includes: Based on the sixth formula, determining the current speed of the engine according to the current vehicle speed, the gearbox speed ratio, the final drive speed ratio and the wheel radius; The sixth formula is: Among them, N 1ENG is the current speed of the engine, r is the wheel radius, v is the current speed of the vehicle, i g is the gearbox speed ratio, i0 is the final reducer speed ratio; Determining a second continuous output torque corresponding to a current speed of the engine based on an optimal fuel consumption rate curve of the engine; The continuous charging power of the power battery is determined according to the second continuous torque of the engine and the current speed of the engine.

7. A charge and discharge power control device for a power battery in a vehicle, characterized in that: include: A driving parameter acquisition module, used to acquire the driving parameters of the vehicle in real time during the driving of the vehicle; A power parameter determination module, used to determine the power parameter of the power battery according to the driving parameter; a charge and discharge power control module, used to control the output power of the power battery according to the power parameter, and / or to control the recovery power of the power battery according to the power parameter; The power parameters include the maximum discharge power, and the driving parameters include: powertrain efficiency, vehicle mass, rolling resistance coefficient, air resistance coefficient, road slope, vehicle frontal area, vehicle rotational mass conversion coefficient, vehicle current speed, power battery discharge efficiency, engine friction torque, engine speed and engine maximum output torque; The power parameter determination module includes: a first discharge power determination submodule, used to determine the first discharge power of the power battery according to the powertrain efficiency, the mass of the vehicle, the rolling resistance coefficient, the air resistance coefficient, the frontal area of ​​the vehicle, the rotational mass conversion coefficient of the vehicle, the current speed of the vehicle and the discharge efficiency of the power battery; a second discharge power determination submodule, used to determine the second discharge power of the power battery according to the current speed of the vehicle, the engine friction torque, the engine speed, and the maximum output torque of the engine; a maximum discharge power determination submodule, used to determine the maximum discharge power of the power battery according to the first discharge power and the second discharge power; The second discharge power determination submodule includes: a first speed determination unit, configured to determine the current speed of the drive motor according to the current speed of the vehicle; a driving power and maximum output efficiency determination unit, for determining the maximum output driving power and the maximum output efficiency of the driving motor at the current speed based on a speed-output torque-output efficiency characteristic curve of the driving motor; an engine maximum net torque determination unit, configured to determine the engine maximum net torque according to the engine maximum output torque and the engine friction torque; an engine maximum net output mechanical power determination unit, used to determine the engine maximum net output mechanical power according to the engine maximum net torque and the engine speed; A maximum power generation determining unit, used to determine the maximum power generation of the generator according to the maximum net output mechanical power of the engine; A first power generation efficiency determination unit, configured to determine a first power generation efficiency corresponding to a maximum power generation power of the generator based on a power generation efficiency characteristic curve of the generator; a second discharge power determination unit, configured to determine the second discharge power based on a third formula according to the maximum output drive power of the drive motor, the maximum output efficiency of the drive motor, the maximum power generation power of the generator and the first power generation efficiency; The third formula is: in, is the second discharge power, P drv is the maximum output driving power of the driving motor, η drv is the maximum output efficiency of the driving motor, is the maximum power generation of the generator, η gen is the first power generation efficiency.

8. A vehicle, characterized in that: include: Powertrain and controllers; The power system includes a drive motor, a power battery, an engine and a generator; The controller is used to execute the charging and discharging power control method of the power battery in the vehicle as described in any one of claims 1 to 6.

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