Methods, devices, and readable storage media for maintaining the charge of vehicles and their power batteries

Abstract

This invention discloses a method, apparatus, and readable storage medium for maintaining the power level of a vehicle and its power battery. The method includes: acquiring a trigger signal for an energy-holding mode in real time when the vehicle is in a power consumption mode; acquiring vehicle operating condition information when the trigger signal is received; the operating condition information includes: the driving capability of the drive motor, the generating capability of the drive motor, the charging capability of the power battery, the discharging capability of the power battery, engine fault status information, and clutch fault status information; determining whether the trigger conditions for the energy-holding mode are met based on the operating condition information; the trigger conditions include: the driving capability of the drive motor is greater than a preset driving capability, the generating capability of the drive motor is greater than a preset generating capability, the discharging capability of the power battery is greater than a preset discharging capability, the charging capability of the power battery is greater than a preset charging capability, and the engine and clutch are fault-free; if so, the energy-holding mode is triggered, which can effectively save fuel consumption.

Description

Technical Field

[0001] This invention relates to the field of electric power control technology for hybrid electric vehicles, and more particularly to a method, apparatus, and readable storage medium for maintaining the electric power of a vehicle and its power battery. Background Technology

[0002] Plug-in hybrid electric vehicles typically operate in two modes: Charge Depleting (CD) and Charge Sustaining (CS). When the battery charge is high (generally above 20%), the vehicle operates in Charge Depleting mode; when the battery charge is low (generally below 20%), the vehicle operates in Charge Sustaining mode. In Charge Depleting mode, the vehicle's powertrain operates in pure electric mode, relying solely on the battery for power. In Charge Sustaining mode, the powertrain uses a hybrid system, with both the engine and battery providing power.

[0003] However, when the vehicle enters the battery hold mode (CS mode), the battery charge is too low. If the vehicle then enters a congested driving area, it will not only start and stop frequently due to traffic congestion, but also frequently due to the low battery charge, leading to excessive fuel consumption. Summary of the Invention

[0004] This invention provides a method, apparatus, and readable storage medium for maintaining the power of a vehicle and its power battery, in order to solve the problem of excessive fuel consumption caused by frequent starts and stops of vehicles in congested traffic due to low battery levels.

[0005] According to one aspect of the present invention, a method for maintaining the charge of a power battery in a vehicle is provided, the vehicle's power system including an engine, a clutch, a drive motor, and a power battery, comprising:

[0006] When the vehicle is in power consumption mode, the trigger signal of energy preservation mode is acquired in real time;

[0007] When the trigger signal is received, the vehicle's operating condition information is acquired; the operating condition information includes: the driving capability of the drive motor, the generating capability of the drive motor, the charging capability of the power battery, the discharging capability of the power battery, the fault status information of the engine, and the fault status information of the clutch.

[0008] The system determines whether the triggering conditions for the energy retention mode are met based on the operating condition information. The triggering conditions include: the driving capability of the drive motor is greater than the preset driving capability; the power generation capability of the drive motor is greater than the preset power generation capability; the discharge capability of the power battery is greater than the preset discharge capability; the charging capability of the power battery is greater than the preset charging capability; and the engine and clutch are fault-free.

[0009] If so, the energy preservation mode is triggered.

[0010] Optionally, the method for maintaining the charge of the power battery in the vehicle further includes:

[0011] When the vehicle is in the energy retention mode, the remaining power, power parameters and preset retention power of the power battery are acquired in real time.

[0012] The engine is started or stopped based on the remaining charge of the power battery, the charge parameters, and the preset charge level.

[0013] Optionally, controlling the engine to start or stop based on the remaining charge of the power battery, the charge parameters, and the preset charge holding level includes:

[0014] Based on the remaining charge of the power battery, the charge parameters, and the preset hold charge, the start-up charge threshold and the shutdown charge threshold of the power battery in the charge hold mode are determined.

[0015] The engine is started based on the remaining charge of the power battery and the starting charge threshold of the power battery;

[0016] After the engine starts, the engine is stopped based on the remaining charge of the power battery and the shutdown charge threshold of the power battery.

[0017] Optionally, the power battery's power parameters include: the power battery's maximum available power SOCmax, the power battery's maximum power offset SOCgapmax, the power battery's default median power value SOCmidauto, the power battery's startup power offset SOCgapst, and the power battery's shutdown power offset SOCgapsp.

[0018] Based on the remaining charge of the power battery, the charge parameters, and the preset hold-up charge, determine the start-up charge threshold and the shutdown charge threshold of the power battery in the charge hold-up mode, including:

[0019] Based on the maximum available capacity (SOCmax), maximum capacity offset (SOCgapmax), default median capacity (SOCmidauto), and the SOC of the power battery when entering the capacity retention mode, a first formula is used to determine the median capacity (SOCmid) of the power battery in the current capacity retention mode; the first formula is:

[0020] SOCmid=min{SOCmax-SOCgapmax,max{SOC,SOCmidauto}};

[0021] Based on the median battery capacity SOCmid in the current battery capacity retention mode and the starting battery capacity offset SOCgapst of the power battery, the starting battery capacity threshold SOCengst of the power battery is determined using a second formula; the second formula is:

[0022] SOCengst = SOCmid - SOCgapst;

[0023] Based on the median battery capacity SOCmid in the current battery capacity retention mode and the battery shutdown capacity offset SOCgapsp, the battery shutdown capacity threshold SOCengsp is determined using a third formula; the third formula is:

[0024] SOCengsp = SOCmid + SOCgapsp.

[0025] Optionally, controlling engine starting based on the remaining charge of the power battery and the starting charge threshold of the power battery includes:

[0026] When the charge of the power battery is lower than the starting charge threshold of the power battery, the engine is controlled to start;

[0027] After the engine starts, the engine is controlled to stop based on the remaining charge of the power battery and the power battery's shutdown charge threshold, including:

[0028] When the charge of the power battery is higher than the shutdown charge threshold of the power battery, the engine is controlled to stop.

[0029] Optionally, the method for maintaining the charge of the power battery in the vehicle further includes:

[0030] When the vehicle is in the energy-saving mode, the required torque of the powertrain is acquired in real time;

[0031] When the engine is stopped, the engine is started when the required torque is greater than the engine's starting torque threshold;

[0032] After the engine is started, the engine is stopped when the required torque is less than the engine's shutdown torque threshold.

[0033] Optionally, the required torque of the power system can be obtained in real time, including:

[0034] The system acquires real-time information on accelerator pedal opening, vehicle speed, the speed ratio from the drive motor to the wheel, high-voltage accessory power, power battery balance charging power, and drive motor rotation speed.

[0035] Based on the correspondence between the accelerator pedal opening information, the vehicle speed information, and the desired torque, the desired torque corresponding to the current accelerator pedal opening information and the vehicle speed information is determined.

[0036] Based on the desired torque, the end speed ratio from the drive motor to the wheel, the power of the high-voltage accessory, the balance charging power of the power battery, and the rotational speed of the drive motor, the required torque of the power system is determined using a fourth formula; the fourth formula is:

[0037] Tsys=Tdriver / Igear+(Pacc-SOCblcPwr)*9550 / Ntm;

[0038] Wherein, Tsys is the required torque of the power system, Tdriver is the desired torque, Igear is the end speed ratio from the drive motor to the wheel, Pacc is the power of the high-voltage accessory, SOCb lcPwr is the balance charging power of the power battery, and Ntm is the rotational speed of the drive motor.

[0039] Optionally, after controlling the engine start based on the remaining charge of the power battery and the starting charge threshold of the power battery, the method further includes:

[0040] The relationship between the required torque and the economic torque of the power system can be obtained in real time.

[0041] The engine output torque is controlled according to the relationship between the required torque and the economical torque.

[0042] According to another aspect of the present invention, a power battery charge retention device for a vehicle is provided, the vehicle's power system including an engine, a clutch, a drive motor, and a power battery, comprising:

[0043] The trigger signal acquisition module is used to acquire the trigger signal of the energy preservation mode in real time when the vehicle is in the power consumption mode;

[0044] The operating condition information acquisition module is used to acquire the operating condition information of the vehicle when the trigger signal is received; the operating condition information includes: the operating parameters of the drive motor, the operating parameters of the power battery, the fault status information of the engine, and the fault status information of the clutch;

[0045] The triggering judgment module is used to determine whether the triggering conditions of the energy preservation mode are met based on the operating condition information.

[0046] The energy retention mode triggering module is used to trigger the energy retention mode when the triggering judgment module determines, based on the operating condition information, that the triggering conditions of the energy retention mode are met.

[0047] According to another aspect of the present invention, a computer-readable storage medium is provided, the computer-readable storage medium storing computer instructions for causing a processor to execute and implement the above-described method for maintaining the charge of a power battery in a vehicle.

[0048] According to another aspect of the present invention, a vehicle is provided, including a controller and a power system;

[0049] The power system includes an engine, a clutch, a drive motor, and a power battery; the controller is used to execute the above-described method for maintaining the charge of the power battery in the vehicle.

[0050] The method for maintaining the charge of a vehicle's power battery provided in this embodiment of the invention allows drivers and passengers to send a trigger signal via a button when road conditions are good. This signal enables the vehicle to automatically enter the energy-holding mode when the vehicle meets the triggering conditions for the energy-holding mode. This allows the power battery in the vehicle to maintain a high charge level, enabling the vehicle to operate in pure electric mode on congested roads. This avoids frequent start-stop situations caused by low battery charge in congested areas, thus saving fuel.

[0051] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0052] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0053] Figure 1 A schematic diagram of the power system of a vehicle provided in an embodiment of the present invention;

[0054] Figure 2 A flowchart illustrating a method for maintaining the charge of a power battery in a vehicle, as provided in an embodiment of the present invention;

[0055] Figure 3 This is a flowchart of another method for maintaining the charge of a power battery in a vehicle, provided by an embodiment of the present invention;

[0056] Figure 4 This is a flowchart of another method for maintaining the charge of a power battery in a vehicle, provided by an embodiment of the present invention;

[0057] Figure 5 This is a schematic diagram of the torque threshold for engine economy provided in an embodiment of the present invention;

[0058] Figure 6 This is a flowchart of another method for maintaining the charge of a power battery in a vehicle, provided by an embodiment of the present invention;

[0059] Figure 7 This is a schematic diagram of the structure of a power battery power retention device in a vehicle provided by an embodiment of the present invention. Detailed Implementation

[0060] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0061] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0062] This invention provides a method for maintaining the charge of a power battery in a vehicle. This method is applicable to plug-in hybrid electric vehicles and can effectively solve the problem of excessive fuel consumption in congested areas. The method can be executed by a power battery charge maintenance device provided in this invention. This power battery charge maintenance device can be implemented in hardware and / or software and can be configured in the power system of the vehicle provided in this invention.

[0063] Figure 1 This is a schematic diagram of the power system of a vehicle provided in an embodiment of the present invention, such as... Figure 1 As shown, the vehicle's powertrain includes an engine 1, a clutch 2, a drive motor 3, and a power battery (not shown in the figure). The engine 1 is dynamically connected to the drive motor 3 via the clutch 2. In addition, the powertrain also includes a flywheel assembly 4 with a torsional damper, a DCT transmission 5, and a differential 6. The flywheel assembly 4 with a torsional damper is located between the engine 1 and the clutch 2. The DCT transmission 5 is mechanically connected between the drive motor 3 and the differential 6. The differential 6 is also mechanically connected between the two drive wheels 7.

[0064] Figure 2 A flowchart illustrating a method for maintaining the charge of a power battery in a vehicle, as provided in an embodiment of the present invention, is shown below. Figure 2 As shown, the method includes:

[0065] S110. When the vehicle is in power consumption mode, acquire the trigger signal of energy retention mode in real time.

[0066] Specifically, the trigger signal for the energy-holding mode can be a signal sent by the driver or passengers via a button. The driver can activate the energy-holding mode by pressing the button, depending on road conditions. This allows the vehicle to operate in hybrid mode on roads with good conditions, maintaining a higher battery charge level to enable pure electric driving in congested areas. In essence, compared to the standard battery hold mode (CS), the energy-holding mode maintains a higher battery charge. When the battery charge is high and road conditions are good, the driver or passengers can activate the energy-holding mode by pressing the button. Therefore, the vehicle receives the energy-holding mode trigger signal in real time while operating in battery-consuming mode.

[0067] S120. When a trigger signal is received, obtain the vehicle's operating condition information.

[0068] The operating condition information includes: the driving capability of the drive motor, the power generation capability of the drive motor, the charging capability of the power battery, the discharging capability of the power battery, the fault status information of the engine, and the fault status information of the clutch.

[0069] Specifically, when the trigger information is obtained, it is also necessary to determine whether the vehicle meets the conditions for entering the energy retention mode based on the vehicle's current operating condition information. The operating condition information may include relevant information that affects the vehicle's use of hybrid drive, such as the current driving and generating capacity of the drive motor, the current charging and discharging capacity of the power battery, the fault status information of the engine, and the fault status information of the clutch.

[0070] S130. Determine whether the triggering conditions for the energy preservation mode are met based on the operating condition information; if so, execute S140.

[0071] The triggering conditions include: the driving capability of the drive motor is greater than the preset driving capability, the power generation capability of the drive motor is greater than the preset power generation capability, the discharge capability of the power battery is greater than the preset discharge capability, the charging capability of the power battery is greater than the preset charging capability, and the engine and clutch are both fault-free.

[0072] S140, Trigger energy retention mode.

[0073] Specifically, when the current operating condition information of the vehicle obtained after receiving the trigger signal for the energy conservation mode meets all the above trigger conditions, it can be determined that the vehicle meets the conditions for using hybrid drive, and then it can enter the energy conservation mode. That is, when the operating condition information meets the following conditions: the driving capability of the drive motor is greater than the preset driving capability, the generating capability of the drive motor is greater than the preset generating capability, the discharging capability of the power battery is greater than the preset discharging capability, the charging capability of the power battery is greater than the preset charging capability, and the engine and clutch are fault-free, the energy conservation mode is triggered. For example, the current driving mode of the vehicle can also be displayed on the in-vehicle display device. The energy conservation mode can be represented by "SAVE". That is, when the driving mode of the vehicle is the power consumption mode, the in-vehicle display device displays "CD", when the driving mode of the vehicle is the energy conservation mode, the in-vehicle display device displays "SAVE", and when the driving mode of the vehicle is the power conservation mode, the in-vehicle display device displays "CS".

[0074] Furthermore, if the acquired operating condition information does not meet any one or more of the above triggering conditions, the driving conditions for hybrid drive are not met. In this case, the trigger signal for energy control mode will not be responded to, that is, the vehicle will not be controlled to enter energy-holding mode, and the current power consumption mode will continue to be maintained. At the same time, the reason for not being able to enter energy-holding mode can also be displayed on the in-vehicle display device. If multiple of the above triggering conditions are not met, one of them can be displayed according to priority. The specific priority can be set according to design requirements. For example, the priority order can be: low charging capacity of power battery > low generating capacity of power battery, low generating capacity of drive motor > low driving capacity of drive motor > engine failure > clutch failure.

[0075] The method for maintaining the charge of a vehicle's power battery provided in this embodiment of the invention allows drivers and passengers to send a trigger signal via a button when road conditions are good. This signal enables the vehicle to automatically enter the energy-holding mode when the vehicle meets the triggering conditions for the energy-holding mode. This allows the power battery in the vehicle to maintain a high charge level, enabling the vehicle to operate in pure electric mode on congested roads. This avoids frequent start-stop situations caused by low battery charge in congested areas, thus saving fuel.

[0076] Optional, Figure 3 This is a flowchart of another method for maintaining the charge of a power battery in a vehicle, provided by an embodiment of the present invention, as shown below. Figure 3 As shown, the method includes:

[0077] S210. When the vehicle is in power consumption mode, the trigger signal of energy retention mode is obtained in real time.

[0078] S220. When a trigger signal is received, obtain the vehicle's operating condition information.

[0079] S230. Determine whether the triggering conditions for the energy preservation mode are met based on the operating condition information; if so, execute S240.

[0080] S240, Trigger Energy Preservation Mode.

[0081] S250: When the vehicle is in energy-holding mode, it acquires the remaining power, power parameters and preset hold power of the power battery in real time.

[0082] S260 controls engine start-up or shutdown based on the remaining charge, charge parameters, and preset charge holding time of the power battery.

[0083] Specifically, the battery's charge parameters can include the battery's maximum available charge, maximum charge offset, and default median charge level. The preset hold-up charge level is the battery's charge level when the energy hold-up mode trigger signal is received. When the vehicle is in energy hold-up mode, the engine can be started or stopped based on the battery's remaining charge, charge parameters, and preset hold-up charge level. This allows the engine to start to charge the battery when its remaining charge is too low, or to stop the engine when it is running and the battery's charge is too high, preventing damage to the battery from excessive charge.

[0084] Optional, Figure 4 This is a flowchart of another method for maintaining the charge of a power battery in a vehicle, provided by an embodiment of the present invention, as shown below. Figure 4 As shown, the method includes:

[0085] S310: When the vehicle is in power consumption mode, acquire the trigger signal of energy retention mode in real time.

[0086] S320. When a trigger signal is received, obtain the vehicle's operating condition information.

[0087] S330: Determine whether the triggering conditions for the energy preservation mode are met based on the operating condition information; if so, execute S340.

[0088] S340, Trigger Energy Preservation Mode.

[0089] S350: When the vehicle is in energy-holding mode, it can obtain the remaining power, power parameters and preset hold power of the power battery in real time.

[0090] S360: Based on the remaining power capacity, power parameters, and preset hold-up power capacity of the power battery, determine the start-up power capacity threshold and the shutdown power capacity threshold of the power battery in the power hold-up mode.

[0091] Specifically, the starting and stopping power battery thresholds in the power battery holding mode can be determined based on the remaining power battery capacity, power parameters, and preset holding power. Compared to setting only one preset power value, which controls the engine to start when the power is below the preset power value and controls the engine to stop when the power is above the preset power value, this avoids the problem of the engine switching back and forth without stopping.

[0092] For example, the power battery's charge parameters include: the power battery's maximum available charge (SOCmax), the power battery's maximum charge offset (SOCgapmax), the power battery's default median charge (SOCmidauto), the power battery's start-up charge offset (SOCgapst), and the power battery's shutdown charge offset (SOCgapsp). Therefore, when determining the power battery's start-up charge threshold and shutdown charge threshold in charge hold mode based on the remaining charge, charge parameters, and preset hold charge, the median charge (SOCmid) in the current charge hold mode can be determined first. That is, based on the power battery's maximum available charge (SOCmax), maximum charge offset (SOCgapmax), default median charge (SOCmidauto), and the power battery's charge (SOC) when entering charge hold mode, the first formula is used to determine the power battery's median charge (SOCmid) in the current charge hold mode. The first formula is: SOCmid = min{SOCmax - SOCgapmax, max{SOC, SOCmidauto}}; then, the start-up power threshold SOCengst and the stop power threshold SOCengsp under the current power hold mode are calculated separately. That is, based on the median power value SOCmid under the current power hold mode and the start-up power offset SOCgapst of the power battery, the start-up power threshold SOCengst of the power battery is determined using the second formula: SOCengst = SOCmid - SOCgapst; based on the median power value SOCmid under the current power hold mode and the stop power offset SOCgapsp of the power battery, the stop power threshold SOCengsp of the power battery is determined using the third formula: SOCengsp = SOCmid + SOCgapsp.

[0093] S370: Controls engine starting based on the remaining charge of the power battery and the starting charge threshold of the power battery.

[0094] S380: After the engine starts, the engine is shut down based on the remaining charge of the power battery and the power battery shutdown charge threshold.

[0095] Specifically, when the power battery charge is determined to be lower than the power battery start-up charge threshold, the engine is controlled to start; and after the engine starts, when the power battery charge is higher than the power battery shutdown charge threshold, the engine is controlled to stop.

[0096] The start-up charge offset SOCgapst and stop-up charge offset SOCgapsp of the power battery can be set according to design requirements. For example, the start-up charge offset SOCgapst can be set to 2%, and the stop-up charge offset SOCgapsp to 3%. If the preset holding charge is 60%, then the start-up charge threshold SOCengst of the power battery determined by the second formula is 58%, and the stop-up charge threshold SOCengsp of the power battery determined by the third formula is 63%. That is, when the power battery charge is lower than 58%, the engine is controlled to start using the power battery. The system charges the battery and stops the engine when the battery level exceeds 63%, thus maintaining the battery level between 58% and 63%, or approximately 60%. To prevent frequent engine start-stops, the shutdown charge offset (SOCgapsp) can be set to 30%, which will keep the battery level between 58% and 90%. This maintains the battery level above 58% while preventing frequent engine start-stops caused by excessively small ranges for the start charge threshold (SOCengst) and shutdown charge offset (SOCgapsp).

[0097] For example, after controlling the engine to start based on the remaining charge of the power battery and the starting charge threshold of the power battery, the method further includes: acquiring the relationship between the required torque and the economic torque of the power system in real time, and controlling the engine output torque based on the relationship between the required torque and the economic torque.

[0098] Specifically, when the engine starts due to low battery charge, the system's torque demand may fall within different economic zones after the engine starts. Figure 5 This is a schematic diagram of the torque threshold for engine economy provided by an embodiment of the present invention, such as... Figure 5 As shown in the figure, curve L1 represents the lower limit torque of the engine's economic zone, curve L2 represents the upper limit torque of the engine's economic zone, and curve L3 represents the engine's external characteristic torque. It can be seen from the figure that the engine's economic threshold varies at different engine speeds. Therefore, the engine's output torque can be controlled based on the relationship between the required torque of the power system and the engine speed. Specifically, the relationship between required torque and economic torque can be as follows: when the required torque is less than the lower limit torque of the engine's economic zone, the engine is controlled to output torque at the lower limit torque; when the required torque is within the engine's economic zone, the engine is controlled to output torque at the required torque; when the required torque is greater than the upper limit torque of the engine's economic zone but does not exceed the engine's external characteristic torque, the engine is controlled to output torque at the upper limit torque; when the required torque is greater than the engine's external characteristic torque, the engine is controlled to output torque at the external characteristic torque, i.e., according to the engine's maximum capacity.

[0099] Optionally, based on the above embodiments, the present invention also proposes a generator start-stop control method in an energy-holding mode that controls the torque demand of the power system. Figure 6 This is a flowchart of another method for maintaining the charge of a power battery in a vehicle, provided by an embodiment of the present invention, as shown below. Figure 6 As shown, the method includes:

[0100] S410: When the vehicle is in power consumption mode, acquire the trigger signal of energy retention mode in real time.

[0101] S420: When a trigger signal is received, obtain the vehicle's operating condition information.

[0102] S430: Determine whether the triggering conditions for the energy preservation mode are met based on the operating condition information; if so, execute S440.

[0103] S440, Trigger Energy Preservation Mode.

[0104] S450: When the vehicle is in energy-saving mode, it obtains the torque required by the powertrain in real time.

[0105] S460: When the engine is stopped, the engine is started when the required torque is greater than the engine's starting torque threshold.

[0106] S470: After the engine starts, the engine is stopped when the required torque is less than the engine's shutdown torque threshold.

[0107] Specifically, when the vehicle is in energy-holding mode, in addition to controlling the engine start or stop through the power battery charge, the engine start or stop can also be controlled according to the torque demand of the power system. Therefore, when the vehicle is in energy-holding mode, the required torque of the power system is obtained in real time; and the start / stop status of the engine is also obtained at the same time. If the required torque of the power system is greater than the engine start torque threshold when the engine is stopped, the engine is controlled to start. And after the engine starts, if the required torque is less than the engine stop torque threshold, the engine is controlled to stop.

[0108] The required torque of the power system can be calculated by comprehensively considering multiple factors in the power system. For example, when obtaining the required torque of the power system in real time, the following can be obtained first: accelerator pedal opening information, vehicle speed information, drive motor to wheel end speed ratio, high-voltage accessory power, power battery balance charging power, and drive motor speed. Then, based on the correspondence between the accelerator pedal opening information, vehicle speed information, and desired torque, the desired torque corresponding to the current accelerator pedal opening information and vehicle speed information is determined. Then, based on the desired torque, drive motor to wheel end speed ratio, high-voltage accessory power, power battery balance charging power, and drive motor speed, the fourth formula is used to determine the required torque of the power system. The fourth formula is: Tsys=Tdriver / Igear+(Pacc-SOCblcPwr)*9550 / Ntm; where Tsys is the required torque of the power system, Tdriver is the desired torque, Igear is the drive motor to wheel end speed ratio, Pacc is the high-voltage accessory power, SOCblcPwr is the power battery balance charging power (i.e., the basic electrical power in the power system), and Ntm is the drive motor speed. The correspondence between the accelerator pedal opening information, vehicle speed information, and desired torque can be represented by a three-dimensional data table of the accelerator pedal opening information, vehicle speed information, and desired torque. The desired torque can be determined by looking up the current accelerator pedal opening information and vehicle speed information in the table.

[0109] Similarly, after starting the engine when the required torque exceeds the engine's starting torque threshold, it is also necessary to control the engine's output torque based on the relationship between the power system's required torque and the economic torque. Generally speaking, the engine's starting torque threshold is greater than the lower limit of the economic zone in the engine's economic torque threshold. Therefore, when the engine starts due to excessive required torque from the power system, it can be directly determined whether the required torque of the power system is within the economic zone, between the upper limit of the economic zone and the external characteristic, or exceeds the external characteristic. When the required torque is within the engine's economic zone, the engine is controlled to output torque according to the required torque; or when the required torque is greater than the upper limit of the engine's economic zone but does not exceed the engine's external characteristic, the engine is controlled to output torque according to the upper limit of the economic zone; or when the required torque is greater than the engine's external characteristic, the engine is controlled to output torque according to the external characteristic. This ensures that the torque requirements of the power system are met when the vehicle is in energy-saving mode, thus avoiding safety accidents.

[0110] Based on the same inventive concept, embodiments of the present invention also provide a power battery charge retention device for a vehicle. This power battery charge retention device is used to execute the power battery charge retention method for a vehicle provided in any embodiment of the present invention. Therefore, the power battery charge retention device for a vehicle provided in the embodiments of the present invention includes the technical features of the power battery charge retention method for a vehicle provided in any embodiment of the present invention, and can achieve the beneficial effects of the power battery charge retention method for a vehicle provided in any embodiment of the present invention. Similarities can be referred to the above description of the power battery charge retention method for a vehicle provided in the embodiments of the present invention, and will not be repeated here.

[0111] Optional, see reference Figure 1 The vehicle's powertrain includes an engine 1, a clutch 2, a drive motor 3, and a power battery (not shown in the diagram). Figure 7 This is a schematic diagram of the structure of a power battery charge retention device in a vehicle according to an embodiment of the present invention, as shown below. Figure 7 As shown, the power battery power retention device in this vehicle includes a trigger signal acquisition module 100, used to acquire the trigger signal of the energy retention mode in real time when the vehicle is in power consumption mode; an operating condition information acquisition module 200, used to acquire the vehicle's operating condition information when the trigger signal is acquired; the operating condition information includes: the operating parameters of the drive motor, the operating parameters of the power battery, the fault status information of the engine, and the fault status information of the clutch; a trigger judgment module 300, used to determine whether the trigger conditions of the energy retention mode are met based on the operating condition information; and an energy retention mode trigger module 400, used to trigger the energy retention mode when the trigger judgment module determines that the trigger conditions of the energy retention mode are met based on the operating condition information.

[0112] The power battery charge retention device provided in this embodiment of the invention allows the driver and passengers to send a trigger signal via a button when road conditions are good. This signal enables the vehicle to automatically enter the energy retention mode when the vehicle meets the trigger conditions for the energy retention mode. This allows the power battery in the vehicle to maintain a high charge level, enabling the vehicle to drive in pure electric mode on congested roads. This avoids frequent start-stop situations caused by low power battery charge in congested areas, thus saving fuel.

[0113] Optionally, the power battery power retention device in the vehicle also includes a power information acquisition module, used to acquire the remaining power, power parameters and preset retention power of the power battery in real time when the vehicle is in energy retention mode; and a first engine control module, used to control the engine to start or stop according to the remaining power, power parameters and preset retention power of the power battery.

[0114] Optionally, the first engine control module includes: a power threshold determination unit, used to determine the starting power threshold and the stopping power threshold of the power battery in the power battery holding mode based on the remaining power of the power battery, power parameters, and preset holding power; an engine starting control unit, used to control the engine to start based on the remaining power of the power battery and the starting power threshold of the power battery; and an engine stopping control unit, used to control the engine to stop based on the remaining power of the power battery and the stopping power threshold of the power battery after the engine starts.

[0115] Optionally, the power battery's energy parameters include: the maximum available energy (SOCmax) of the power battery, the maximum energy offset (SOCgapmax) of the power battery, the default median energy (SOCmidauto) of the power battery, the start-up energy offset (SOCgapst) of the power battery, and the shutdown energy offset (SOCgapsp) of the power battery; the energy threshold determination unit includes an energy median determination unit, used to determine the energy median (SOCmid) of the power battery in the current energy storage mode based on the maximum available energy (SOCmax), the maximum energy offset (SOCgapmax), the default median energy (SOCmidauto), and the power battery's energy (SOC) when entering the energy storage mode, using a first formula; the first formula is: SOCmid = min{SO Cmax-SOCgapmax,max{SOC,SOCmidauto}}; Start-up power threshold determination unit, used to determine the start-up power threshold SOCengst of the power battery according to the median power value SOCmid in the current power holding mode and the start-up power offset SOCgapst of the power battery using the second formula; the second formula is: SOCengst=SOCmid-SOCgapst; Stop power threshold determination unit, used to determine the stop power threshold SOCengsp of the power battery according to the median power value SOCmid in the current power holding mode and the stop power offset SOCgapsp of the power battery using the third formula; the third formula is: SOCengsp=SOCmid+SOCgapsp.

[0116] Optionally, the engine start control unit includes an engine start control subunit, used to control the engine to start when the power battery charge is lower than the power battery start charge threshold; the engine stop control unit includes an engine stop control subunit, used to control the engine to stop when the power battery charge is higher than the power battery stop charge threshold.

[0117] Optionally, the power battery charge retention device in the vehicle also includes a demand torque acquisition module, used to acquire the demand torque of the power system in real time when the vehicle is in energy retention mode; an engine start control module, used to control the engine to start when the demand torque is greater than the engine start torque threshold when the engine is stopped; and an engine stop control module, used to control the engine to stop after the engine has started when the demand torque is less than the engine stop torque threshold.

[0118] Optionally, the required torque acquisition module includes a torque information acquisition unit for real-time acquisition of accelerator pedal opening information, vehicle speed information, drive motor to wheel end speed ratio, high-voltage accessory power, power battery balance charging power, and drive motor speed; a desired torque determination unit for determining the desired torque corresponding to the current accelerator pedal opening information and vehicle speed information based on the correspondence between the accelerator pedal opening information, vehicle speed information, and desired torque; and a required torque determination unit for determining the required torque of the power system using a fourth formula based on the desired torque, drive motor to wheel end speed ratio, high-voltage accessory power, power battery balance charging power, and drive motor speed. The fourth formula is: Tsys=Tdriver / Igear+(Pacc-SOCblcPwr)*9550 / Ntm; where Tsys is the required torque of the power system, Tdriver is the desired torque, Igear is the drive motor to wheel end speed ratio, Pacc is the high-voltage accessory power, SOCblcPwr is the power battery balance charging power, and Ntm is the drive motor speed.

[0119] Optionally, the engine control module also includes a demand torque and economic torque correspondence acquisition unit, used to acquire the demand torque and economic torque correspondence of the power system in real time after the engine start control unit controls the engine to start according to the remaining power battery charge and the start-up power battery charge threshold; and an output torque control unit, used to control the engine output torque according to the demand torque and economic torque correspondence.

[0120] Optionally, embodiments of the present invention also provide a computer-readable storage medium storing computer instructions for causing a processor to execute and implement the method for maintaining the charge of a power battery in a vehicle provided in any embodiment of the present invention. The computer-readable storage medium may be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. The computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination thereof. Alternatively, the computer-readable storage medium may be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0121] Optionally, embodiments of the present invention also provide a vehicle, including a controller and a power system; the power system includes an engine, a clutch, a drive motor, and a power battery; the controller is used to execute the power battery charge retention method in the vehicle provided in any embodiment of the present invention. Therefore, the vehicle provided in the embodiments of the present invention includes the technical features of the power battery charge retention method in the vehicle provided in any embodiment of the present invention, and can achieve the beneficial effects of the power battery charge retention method in the vehicle provided in any embodiment of the present invention. Similarities can be referred to the above description of the power battery charge retention method in the vehicle provided in the embodiments of the present invention, and will not be repeated here.

[0122] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0123] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for maintaining the charge of a power battery in a vehicle, wherein the vehicle's power system includes an engine, a clutch, a drive motor, and a power battery, characterized in that, include: When the vehicle is in power consumption mode, the trigger signal of energy preservation mode is acquired in real time; When the trigger signal is received, the vehicle's operating condition information is obtained; The operating condition information includes: the driving capability of the drive motor, the power generation capability of the drive motor, the charging capability of the power battery, the discharging capability of the power battery, the fault status information of the engine, and the fault status information of the clutch. The system determines whether the triggering conditions for the energy retention mode are met based on the operating condition information. The triggering conditions include: the driving capability of the drive motor is greater than the preset driving capability; the power generation capability of the drive motor is greater than the preset power generation capability; the discharge capability of the power battery is greater than the preset discharge capability; the charging capability of the power battery is greater than the preset charging capability; and the engine and clutch are fault-free. If so, then the energy preservation mode is triggered; When the vehicle is in the energy-saving mode, the required torque of the powertrain is acquired in real time; When the engine is stopped, the engine is started when the required torque is greater than the engine's starting torque threshold; After the engine is started, the engine is stopped when the required torque is less than the engine's shutdown torque threshold. The real-time acquisition of the required torque of the power system includes: The system acquires real-time information on accelerator pedal opening, vehicle speed, the speed ratio from the drive motor to the wheel, high-voltage accessory power, power battery balance charging power, and drive motor rotation speed. Based on the correspondence between the accelerator pedal opening information, the vehicle speed information, and the desired torque, the desired torque corresponding to the current accelerator pedal opening information and the vehicle speed information is determined. Based on the desired torque, the end speed ratio from the drive motor to the wheel, the power of the high-voltage accessory, the balance charging power of the power battery, and the rotational speed of the drive motor, the required torque of the power system is determined using a fourth formula; the fourth formula is: Tsys=Tdriver / Igear+(Pacc-SOCblcPwr)*9550 / Ntm; Wherein, Tsys is the required torque of the power system, Tdriver is the desired torque, Igear is the end speed ratio from the drive motor to the wheel, Pacc is the power of the high-voltage accessory, SOCblcPw r is the balance charging power of the power battery, and Ntm is the rotational speed of the drive motor.

2. The method for maintaining the charge of a power battery in a vehicle according to claim 1, characterized in that, Also includes: When the vehicle is in the energy retention mode, the remaining power, power parameters and preset retention power of the power battery are acquired in real time. The engine is started or stopped based on the remaining charge of the power battery, the charge parameters, and the preset charge level.

3. The method for maintaining the charge of a power battery in a vehicle according to claim 2, characterized in that, Controlling engine start or stop based on the remaining charge of the power battery, the charge parameters, and the preset charge holding level includes: Based on the remaining charge of the power battery, the charge parameters, and the preset hold charge, the start-up charge threshold and the shutdown charge threshold of the power battery in the charge hold mode are determined. The engine is started based on the remaining charge of the power battery and the starting charge threshold of the power battery; After the engine starts, the engine is stopped based on the remaining charge of the power battery and the shutdown charge threshold of the power battery.

4. The method for maintaining the charge of a power battery in a vehicle according to claim 3, characterized in that, The power battery's power parameters include: the power battery's maximum available power SOCmax, the power battery's maximum power offset SOCgapmax, the power battery's default median power SOCmid auto, the power battery's startup power offset SOCgapst, and the power battery's shutdown power offset SOCgapsp. Based on the remaining charge of the power battery, the charge parameters, and the preset hold-up charge, determine the start-up charge threshold and the shutdown charge threshold of the power battery in the charge hold-up mode, including: Based on the maximum available capacity (SOCmax), maximum capacity offset (SOC gapmax), default median capacity (SOCmidauto), and the SOC of the power battery when entering the capacity retention mode, a first formula is used to determine the median capacity (SOCmid) of the power battery in the current capacity retention mode; the first formula is: SOCmid=min{SOCmax-SOCgapmax,max{SOC,SOCmidauto}}; Based on the median battery capacity SOCmid in the current battery capacity retention mode and the starting battery capacity offset SOCgapst of the power battery, the starting battery capacity threshold SOCengst of the power battery is determined using a second formula; the second formula is: SOCengst = SOCmid - SOCgapst; Based on the median battery capacity SOCmid in the current battery capacity retention mode and the battery shutdown capacity offset SOCgapsp, the battery shutdown capacity threshold SOCengsp is determined using a third formula; the third formula is: SOCengsp = SOCmid + SOCgapsp.

5. The method for maintaining the charge of a power battery in a vehicle according to claim 4, characterized in that, Controlling engine starting based on the remaining charge of the power battery and the starting charge threshold of the power battery includes: When the charge of the power battery is lower than the starting charge threshold of the power battery, the engine is controlled to start; After the engine starts, the engine is controlled to stop based on the remaining charge of the power battery and the power battery's shutdown charge threshold, including: When the charge of the power battery is higher than the shutdown charge threshold of the power battery, the engine is controlled to stop.

6. The method for maintaining the charge of a power battery in a vehicle according to claim 3, characterized in that, After controlling the engine start based on the remaining charge of the power battery and the starting charge threshold of the power battery, the method further includes: The relationship between the required torque and the economic torque of the power system can be obtained in real time. The engine output torque is controlled according to the relationship between the required torque and the economical torque.

7. A power battery charge retention device for a vehicle, wherein the vehicle's power system includes an engine, a clutch, a drive motor, and a power battery, characterized in that, include: The trigger signal acquisition module is used to acquire the trigger signal of the energy preservation mode in real time when the vehicle is in the power consumption mode; The operating condition information acquisition module is used to acquire the operating condition information of the vehicle when the trigger signal is received; The operating condition information includes: the operating parameters of the drive motor, the operating parameters of the power battery, the fault status information of the engine, and the fault status information of the clutch; The triggering judgment module is used to determine whether the triggering conditions of the energy preservation mode are met based on the operating condition information. An energy retention mode triggering module is used to trigger the energy retention mode when the triggering judgment module determines, based on the operating condition information, that the triggering conditions of the energy retention mode are met. The torque demand acquisition module is used to acquire the torque demand of the power system in real time when the vehicle is in the energy-saving mode. An engine start control module is used to control the engine to start when the required torque is greater than the engine's start torque threshold when the engine is stopped. An engine shutdown control module is used to control the engine to shut down after the engine starts, when the required torque is less than the engine's shutdown torque threshold. The required torque acquisition module includes: a torque information acquisition unit, used to acquire in real time the accelerator pedal opening information, vehicle speed information, the end speed ratio from the drive motor to the wheel, the power of the high-voltage accessory, the balance charging power of the power battery, and the rotational speed of the drive motor; a desired torque determination unit, used to determine the desired torque corresponding to the current accelerator pedal opening information and vehicle speed information based on the correspondence between the accelerator pedal opening information, the vehicle speed information, and the desired torque; and a required torque determination unit, used to determine the required torque of the power system using a fourth formula based on the desired torque, the end speed ratio from the drive motor to the wheel, the power of the high-voltage accessory, the balance charging power of the power battery, and the rotational speed of the drive motor; the fourth formula is: Tsys=Tdriver / Igear+(Pacc-SOCblcPwr)*9550 / Ntm; Wherein, Tsys is the required torque of the power system, Tdriver is the desired torque, Igear is the end speed ratio from the drive motor to the wheel, Pacc is the power of the high-voltage accessory, SOCblcPw r is the balance charging power of the power battery, and Ntm is the rotational speed of the drive motor.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that, when executed by a processor, implement the method for maintaining the charge of a power battery in a vehicle as described in any one of claims 1 to 6.

9. A vehicle, characterized in that, Including controllers and power systems; The power system includes an engine, a clutch, a drive motor, and a power battery; the controller is used to execute the power battery charge retention method in the vehicle according to any one of claims 1 to 6.

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