Battery overcharge prevention method and device based on extended-range heavy truck and medium

Abstract

The invention discloses a battery anti-overcharge method based on an extended-range heavy truck, a controller and a medium, and is applied to the field of vehicle engineering.According to the method, when an extended-range electric vehicle is in a driving motor electric brake feedback state, the maximum rechargeable power of the current vehicle is compared with a first threshold value; controlling the range extender to return to the idling working condition from the power generation working condition based on the comparison result; or controlling the range extender to continuously work at the current power; or the sum of the generated power of the range extender and the generated power of the driving motor is controlled to be reduced to the maximum recharging power of the vehicle. The state of the current vehicle driving motor is detected in real time, and the generated power of the range extender is adjusted, so that the sum of the generated power of the range extender and the generated power of the driving motor is not larger than the maximum rechargeable power of the vehicle; on the basis that the manufacturing cost of the whole vehicle is not increased, the energy consumption of the whole vehicle is reduced, and the battery is effectively prevented from being overcharged.

Description

Technical Field

[0001] The present invention relates to the field of vehicle engineering, and in particular to a method, device and medium for preventing battery overcharging based on an extended-range heavy-duty truck. Background Art

[0002] With the increasing environmental protection requirements and restrictions on exhaust emissions of traditional fuel vehicles, new energy vehicles have become a development trend. Although pure electric heavy trucks have advantages such as zero emissions, their large-scale application is limited by limited range and insufficient charging facilities. In this context, extended-range electric heavy trucks came into being. They combine the advantages of pure electric and traditional fuel, reducing exhaust emissions and solving the range anxiety of pure electric heavy trucks.

[0003] When extended-range electric heavy trucks are operated in the actual market, due to the structure of the whole vehicle, when the vehicle is in the braking state, the drive motor is in the power generation state. At this time, if the range extender is also in the power generation mode, the battery will be under high voltage and lose driving force because the recharge current exceeds its internal setting threshold. Being in the overcharged state for a long time will also cause the battery life to decrease. In the prior art, the problem of overcharging of extended-range vehicles is solved by increasing the number of battery cells in the battery pack and restricting the size of electric brake feedback. However, increasing the size of the battery rechargeability increases the cost of the whole vehicle, and increases the size of the battery pack, which increases the difficulty of the layout of the whole vehicle. Restricting the size of the electric brake feedback so that the negative current generated by the feedback does not exceed the maximum rechargeable capacity of the battery, while protecting the battery, it correspondingly reduces the proportion of electric brake feedback, increases the energy consumption of the whole vehicle, and cannot give full play to the advantages of the extended-range vehicle over the traditional vehicle.

[0004] Therefore, there is an urgent need for a power generation control method that has low energy consumption when the extended-range electric heavy-duty truck drive motor is in power generation mode, does not increase vehicle cost and layout difficulty, reduces the vehicle's power generation at this time, prevents battery overcharging, increases the proportion of electric brake feedback power, and reduces the energy consumption of the entire vehicle. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a method and device for preventing battery overcharging based on an extended-range heavy-duty truck to solve the problem of battery overcharging of an extended-range electric heavy-duty truck. The specific scheme is as follows:

[0006] In a first aspect, the present application provides a method for preventing overcharging of a battery based on an extended-range vehicle, comprising:

[0007] When the vehicle is in the state of electric brake feedback of the driving motor, comparing the current maximum rechargeable power of the vehicle with the first threshold;

[0008] When the current maximum rechargeable power of the vehicle is less than the first threshold, controlling the range extender to return from the power generation condition to the idle condition;

[0009] If the current maximum rechargeable power of the vehicle is greater than the first threshold and the current maximum rechargeable power of the vehicle is greater than the actual power of the range extender, controlling the range extender to continue operating at the current power;

[0010] If the current maximum rechargeable power of the vehicle is greater than the first threshold and the current maximum rechargeable power of the vehicle is less than the actual power of the range extender, the power generation power of the range extender is controlled to be reduced to the difference between the maximum rechargeable power of the vehicle and the power generation power of the drive motor.

[0011] Optionally, before comparing the current maximum rechargeable power of the vehicle with the first threshold, the method further includes:

[0012] Get battery status;

[0013] Determining a battery safety factor based on a battery status;

[0014] Get the maximum rechargeable power of the battery and the current actual power of the vehicle;

[0015] The current maximum rechargeable power of the vehicle is determined based on the maximum rechargeable power of the battery, the battery safety factor and the current actual power of the vehicle.

[0016] Optionally, obtaining the maximum rechargeable power of the battery includes:

[0017] Measure the current battery bus voltage value;

[0018] Get the maximum rechargeable current of the battery pack;

[0019] The maximum rechargeable power of the battery is determined based on the current battery bus voltage value and the maximum rechargeable current of the battery pack.

[0020] Optionally, the first threshold is a minimum value of the maximum rechargeable power of the vehicle when the range extender returns to an idle condition;

[0021] The process of obtaining the minimum value of the maximum rechargeable power of the vehicle includes:

[0022] Obtaining the maximum power generation of the range extender and the battery capacity of the battery pack;

[0023] The minimum value of the maximum rechargeable power of the vehicle when the range extender returns to the idle condition is determined based on the maximum power generation power of the range extender and the battery capacity of the battery pack.

[0024] Optionally, controlling the range extender to return from the power generation condition to the idle condition includes:

[0025] Controlling the engine fuel injection amount of the range extender to decrease, wherein the engine fuel injection amount decrease value is equal to the current maximum engine fuel injection amount decrease value;

[0026] The excitation current of the generator of the range extender is controlled to decrease by a maximum decreasing amount, so as to reduce the power generation power of the generator of the range extender.

[0027] Optionally, controlling the range extender power generation to decrease to a difference between the maximum rechargeable power of the vehicle and the power generation of the drive motor includes:

[0028] Controlling the engine fuel injection amount of the range extender to be reduced by a preset stepwise gradient;

[0029] Controlling the excitation current of the generator of the range extender to decrease gradually;

[0030] The electromagnetic resistance of the generator of the range extender is controlled to increase when the rotation speed of the generator is greater than a rotation speed threshold, and the electromagnetic resistance of the generator of the range extender is controlled to decrease when the rotation speed of the generator is not greater than the rotation speed threshold.

[0031] Optionally, controlling the range extender power generation to decrease to a difference between the maximum rechargeable power of the vehicle and the power generation of the drive motor includes:

[0032] Acquire the current generated by the range extender and the current generated by the drive motor;

[0033] The sum of the current generated by the range extender and the current generated by the drive motor is controlled to be smaller than the maximum allowable recharge current of the battery.

[0034] Optional, including:

[0035] When the vehicle is in the state of electric brake feedback of the driving motor, comparing the current maximum rechargeable power of the vehicle with the second threshold;

[0036] When the current maximum rechargeable power of the vehicle is less than the second threshold, the driving motor power is controlled to decrease to the current maximum rechargeable power of the vehicle, and the second threshold is less than the first threshold.

[0037] On the second aspect, the present application provides a whole vehicle control device for realizing the power control of the vehicle, so as to realize the above-mentioned battery overcharging prevention method based on extended-range heavy-duty trucks.

[0038] In a third aspect, the present application provides a computer-readable storage medium for storing a computer program; wherein, when the computer program is executed by a processor, the above-mentioned battery overcharging prevention method based on an extended-range heavy-duty truck is implemented.

[0039] It can be seen that in this application, when the extended-range electric vehicle is in the electric braking feedback state of the drive motor, the current maximum rechargeable power of the vehicle is compared with the first threshold value; when the current maximum rechargeable power of the vehicle is less than the first threshold value, the range extender is controlled to return from the power generation condition to the idle condition; if the current maximum rechargeable power of the vehicle is greater than the first threshold value and the current maximum rechargeable power of the vehicle is greater than the actual power of the range extender, the range extender is controlled to continue operating at the current power; if the current maximum rechargeable power of the vehicle is greater than the first threshold value and the current maximum rechargeable power of the vehicle is less than the actual power of the range extender, the sum of the power generation power of the range extender and the power generation power of the drive motor is controlled to be reduced to the maximum rechargeable power of the vehicle. By real-time detection of the current state of the vehicle's drive motor, when the vehicle is in the drive motor electric brake feedback state, the current vehicle's maximum rechargeable power is compared with the first threshold and the actual power of the range extender, and the range extender's power generation power is adjusted in real time so that the sum of the range extender's power generation power and the drive motor's power generation power is not greater than the vehicle's maximum rechargeable power. Compared with the situation of increasing battery cells and reducing the proportion of electric brake feedback, the present application reduces the energy consumption of the entire vehicle without increasing the cost of the entire vehicle and effectively prevents battery overcharging, greatly improving the safety performance of the vehicle's drive motor in the electric brake feedback state. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0041] Figure 1 A flow chart of a battery overcharge prevention method based on an extended-range vehicle disclosed in the present application;

[0042] Figure 2 A structural topology diagram of an extended-range electric vehicle disclosed in this application;

[0043] Figure 3 A specific VCU workflow diagram disclosed in this application;

[0044] Figure 4 This is a flow chart of a specific method for preventing battery overcharging based on an extended-range vehicle disclosed in the present application. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions 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 are within the scope of protection of the present invention.

[0046] The present application focuses on disclosing a battery overcharge prevention method based on an extended-range vehicle.

[0047] Due to the overall structure of extended-range electric heavy-duty trucks, when the vehicle is in a braking state, the drive motor is in a power generation state. At this time, if the range extender is also in power generation mode, the battery will be under high voltage and lose driving force because the recharge current exceeds its internal set threshold. Long-term overcharge will also reduce the battery life.

[0048] Therefore, there is an urgent need for a method for controlling the power generation of an extended-range electric heavy-duty truck when the drive motor is in power generation mode, so as to reduce the power generation of the vehicle at this time, prevent battery overcharging, increase the proportion of electric brake feedback power, and reduce the energy consumption of the entire vehicle.

[0049] See also Figure 1 As shown, in order to solve the problem of battery overcharging when the driving motor of an extended-range electric heavy truck is in a power generation mode, an embodiment of the present invention discloses a battery overcharging prevention method based on an extended-range vehicle, comprising:

[0050] S11. When the vehicle is in a state of electric brake feedback of the driving motor, compare the current maximum rechargeable power of the vehicle with a first threshold.

[0051] like Figure 2 As shown in the figure, it is a structural topology diagram of an extended-range electric vehicle. According to the principle of energy conservation, the relationship between the various power components of the extended-range electric vehicle can be expressed as follows:

[0052] ;

[0053] In the formula, is the vehicle power requirement, in kilowatts (kW). >0 indicates that the vehicle is consuming electricity. <0 indicates that the vehicle is recovering energy; is the power consumption of the drive motor, in kilowatts (kW), >0 indicates that the drive motor is in electric mode. <0 indicates that the drive motor is in power generation mode; The overall power consumption of the electrical accessories, in kilowatts (kW). Since its power is small and no feedback current is generated, it has no impact on the formulation of the overcharging prevention plan and will not be considered separately in the subsequent method formulation; is the power generated by the range extender, in kilowatts (kW), >0 indicates that the range extender is in power generation state. <0 indicates that the range extender is in the startup power consumption state; is the power battery output power, in kilowatts (kW), >0 indicates that the battery is in discharge state. <0 indicates the battery is charging.

[0054] when <0 and When >0, it indicates that the vehicle is in the driving motor power generation mode, that is, the braking feedback state, and the range extender is generating electricity at this time. The vehicle starts the overcharge protection function, and the vehicle's battery management system (BMS) and vehicle control unit (VCU) work together to first calculate the current maximum rechargeable power of the vehicle.

[0055] By detecting the current of the entire vehicle, the sum of the current generated by the range extender power and the current generated by the drive motor feedback is controlled to be less than the maximum allowable recharge current of the battery.

[0056] In a specific implementation, before comparing the current maximum rechargeable power of the vehicle with the first threshold, it is also necessary to: obtain the battery status; determine the battery safety factor based on the battery status; obtain the maximum rechargeable power of the battery and the current actual power of the vehicle; wherein the current maximum rechargeable power of the vehicle is determined based on the maximum rechargeable power of the battery, the battery safety factor and the current actual power of the vehicle. After the vehicle starts driving, the BMS monitors the battery status throughout the entire process. When the vehicle enters the braking condition and prepares for electric braking feedback, the BMS immediately obtains key battery information, including temperature, battery state of charge (State of Charge, referred to as SOC) and battery internal resistance. These parameters fully reflect the current health and performance of the battery, laying a solid foundation for subsequent accurate decision-making. At the same time, the BMS cooperates with the VCU to obtain the maximum rechargeable power of the battery and the current actual power of the vehicle. The former is calculated by combining the voltage and current monitoring formula, and the latter includes comprehensive factors such as the vehicle's operating power and the energy consumption of the electrical equipment in the vehicle. The combination of the two provides necessary data for accurately judging the battery charging tolerance. The battery safety factor is calculated based on the obtained battery status parameters, and the battery safety factor fluctuates flexibly according to the battery status. Using this coefficient, the maximum rechargeable power of the battery, and the current actual power of the vehicle, the established formula is:

[0057] ;

[0058] Calculate the maximum rechargeable power of the current vehicle, where is the maximum rechargeable power of the current vehicle, α is the set battery safety factor, is the current maximum rechargeable power of the battery, The required power of the vehicle calculated by the VCU, that is, the sum of the current power of high-voltage components. In actual application, α is generally set to 0.95.

[0059] The specific methods for obtaining the maximum rechargeable power of the battery may include: measuring the current battery bus voltage value; obtaining the maximum rechargeable current of the battery pack; determining the maximum rechargeable power of the battery based on the current battery bus voltage value and the maximum rechargeable current of the battery pack. During the operation of the vehicle, the BMS continuously monitors the battery status. When the vehicle is about to enter the brake electric brake feedback stage, the BMS quickly carries out two key operations. First, accurately measure the current battery bus voltage value. The current battery bus voltage value can reflect the current electrical state of the battery and is an important basic data for subsequent calculations. Second, obtain the maximum rechargeable current of the battery pack. The maximum rechargeable current is restricted by multiple factors such as battery material characteristics, temperature, and aging degree, which limit the maximum current intensity that the battery can safely accept in the current state. Then calculate the maximum rechargeable power of the battery, the formula is as follows:

[0060] ;

[0061] in the formula is the current maximum rechargeable power of the battery, in kilowatts (kW), is the current bus voltage value of the battery pack, in volts (V), The maximum rechargeable current of the battery, in amperes (A). According to the electrical power calculation formula, power is equal to the product of voltage and current. Multiply the measured current battery bus voltage value by the obtained maximum rechargeable current of the battery pack, and the result is in watts. Since power is usually described in kilowatts in the field of vehicle engineering, it is necessary to divide the above product by 1000 to complete the unit conversion, so as to accurately calculate the maximum rechargeable power of the battery.

[0062] In this embodiment, the first threshold value is the minimum value of the maximum rechargeable power of the vehicle when the range extender returns to the idle condition; the process of obtaining the minimum value of the maximum rechargeable power of the vehicle includes: obtaining the maximum power generation power of the range extender and the battery capacity of the battery pack; and determining the minimum value of the maximum rechargeable power of the vehicle when the range extender returns to the idle condition based on the maximum power generation power of the range extender and the battery capacity of the battery pack.

[0063] The maximum power generation of the range extender reflects the maximum power that the range extender can output under ideal working conditions, which is determined by factors such as the design of the range extender itself, engine performance, and generator efficiency. At the same time, the battery capacity of the battery pack can reflect the maximum ability of the battery to store electrical energy. The first threshold is determined by these two parameters, which is based on the maximum recharge power that the battery can withstand under the most unfavorable charging conditions to avoid overcharging the battery.

[0064] S12: When the current maximum rechargeable power of the vehicle is less than a first threshold, the range extender is controlled to return from the power generation condition to the idle condition.

[0065] When it is necessary to control the range extender to return from the power generation condition to the idle condition, the VCU sends the range extender control command to the range extender generator control unit (GCU) and the range extender engine control unit (ECU), and then controls the engine and the generator through the ECU and the GCU respectively to control the range extender from the power generation condition to the idle condition.

[0066] In a specific implementation, in terms of the engine, the engine fuel injection amount of the range extender is controlled to be reduced, and the reduction value of the engine fuel injection amount is equal to the maximum reduction value of the current engine fuel injection amount. In actual use, the fuel injection amount is usually reduced by 30%-50%, so that the engine speed drops rapidly, and quickly transitions from the higher speed during power generation to an intermediate speed range. At the same time, as the engine speed decreases, appropriately increasing the ignition advance angle can make the combustion process more efficient and avoid problems such as incomplete combustion, jitter, and even flameout caused by reduced speed. In the process of returning to the idle condition, the range extender control system dynamically adjusts the ignition advance angle according to the real-time engine speed, temperature and other parameters to ensure smooth operation of the engine. In addition to fuel and ignition control, by controlling the throttle opening, the amount of air entering the engine is reduced to match the reduction in fuel injection, further reducing the engine's output power and assisting in the smooth decline of the engine speed.

[0067] In a specific implementation, in terms of the engine, the excitation current of the range extender's generator is controlled to decrease at a maximum decreasing amount to reduce the power generated by the range extender's generator. In the initial deceleration stage, the excitation current can be quickly reduced by 40%-60%, allowing the generator's power to drop rapidly and reducing the engine load.

[0068] S13: If the current maximum rechargeable power of the vehicle is greater than the first threshold and the current maximum rechargeable power of the vehicle is greater than the actual power of the range extender, control the range extender to continue operating at the current power.

[0069] When the current maximum rechargeable power of the vehicle is greater than the first threshold and the current maximum rechargeable power of the vehicle is greater than the actual power of the range extender, it means that the current generated by the range extender plus the current generated by the motor electric braking is less than the maximum rechargeable current of the battery, and the range extender can continue to maintain the current power generation. By refining the current maximum rechargeable power range of the vehicle and adopting different processing methods, compared with directly reducing the power generation of the range extender to the braking condition, frequent engine starts and stops are avoided, and it also helps the vehicle reduce the noise generated by the engine when switching conditions.

[0070] S14: If the current maximum rechargeable power of the vehicle is greater than the first threshold and the current maximum rechargeable power of the vehicle is less than the actual power of the range extender, control the power generation of the range extender to be reduced to the difference between the maximum rechargeable power of the vehicle and the power generation of the drive motor.

[0071] If the current maximum rechargeable power of the vehicle is greater than the first threshold and the current maximum rechargeable power of the vehicle is less than the actual power of the range extender, it indicates that the current generated by the range extender plus the current generated by the motor has exceeded the maximum rechargeable capacity of the battery. However, since the current maximum rechargeable power of the vehicle is greater than the first threshold, it indicates that the current maximum rechargeable power value of the vehicle can still allow the range extender to operate in the power generation mode without returning to the idle condition. At this time, it is sufficient to control the power of the range extender to be reduced to the difference between the maximum rechargeable power of the vehicle and the power generated by the drive motor.

[0072] At this time, the engine fuel injection amount of the range extender is controlled to be reduced with a segmented preset gradient, and the excitation current of the generator of the range extender is controlled to be gradually reduced; the electromagnetic resistance of the generator of the range extender is controlled to increase when the speed of the generator is greater than the speed threshold, and the electromagnetic resistance of the generator of the range extender is reduced when the speed of the generator is not greater than the speed threshold.

[0073] In a specific implementation, when it is necessary to reduce the power generation of the range extender, the engine fuel injection amount is reduced by a segmented preset gradient to achieve a smooth transition of the engine power. If the fuel injection amount is reduced suddenly, the engine speed will drop sharply, which may lead to problems such as unstable combustion and flameout. At the same time, it will also cause a large impact on the mechanical parts of the engine, affecting its service life. By reducing the fuel injection amount in segments, the engine can reduce the output power at a certain rhythm. After the engine speed slowly drops to a transition interval, subsequent adjustments are made according to the real-time working conditions to ensure that the engine always maintains a relatively stable operating state during the power reduction process. Similarly, the progressive reduction of the excitation current can, on the one hand, smoothly reduce the power generation of the generator to match the current maximum rechargeable power demand of the vehicle, and avoid the risk of overcharging the battery due to sudden changes in the power generation; on the other hand, slowly adjusting the excitation current can make the electromagnetic state of the generator change smoothly, prevent electrical shocks caused by sudden changes in electromagnetic force, protect the windings, electronic components and other components inside the generator, and ensure its reliability and stability. When the speed of the generator is greater than the speed threshold, the electromagnetic resistance is increased, which is to use electromagnetic resistance to assist the engine in slowing down. In the early stage of power generation reduction, the engine speed is high. At this time, appropriately increasing the electromagnetic resistance can speed up the engine speed reduction and make the power generation approach the target value faster. When the generator speed is not greater than the speed threshold, the electromagnetic resistance is reduced. At this time, the engine speed is close to the idle speed or lower stable operating range. If the electromagnetic resistance is maintained, it will prevent the engine from entering the idle state smoothly, and may even cause the engine to shake or stall. Therefore, reducing the electromagnetic resistance allows the engine to smoothly transition to a stable idle condition.

[0074] It is understandable that while controlling the output power of the range extender as above, the current generated by the range extender should also be controlled. The steps may include: obtaining the current generated by the range extender and the current generated by the drive motor; controlling the sum of the current generated by the range extender and the current generated by the drive motor to be less than the maximum allowable recharge current of the battery. During the operation of the extended-range vehicle, safe charging of the battery is crucial. When the vehicle is in a state such as braking electric brake feedback, and the range extender and the drive motor are simultaneously charging the battery, if the sum of the currents of the two exceeds the maximum allowable recharge current of the battery, the battery is very likely to be overcharged, thereby damaging the battery life, reducing battery performance, and even causing safety hazards. Therefore, the current generated by the range extender must be accurately controlled so that the sum of the currents generated by the range extender and the drive motor are always kept within an acceptable range for battery safety.

[0075] like Figure 3As shown in the figure, it is a VCU workflow diagram. First, the maximum power generation of the range extender and the battery capacity of the battery pack are used to determine the minimum value of the vehicle's maximum rechargeable power when the range extender returns to the idle condition. The minimum value is set as the criterion for the range extender to return to the idle condition, that is, the first threshold. Then, the required power of the vehicle is calculated, that is, the sum of the current power of the high-voltage components. Then, according to whether the vehicle is in braking mode, anti-overcharging measures are taken: the current maximum rechargeable power of the vehicle is calculated and compared with the first threshold value. When the current maximum rechargeable power of the vehicle is less than the first threshold value, the range extender is controlled to return from the power generation condition to the idle condition, and the range extender stops generating power; if the current maximum rechargeable power of the vehicle is greater than the first threshold value, the relationship between the current maximum rechargeable power of the vehicle and the actual power of the range extender is determined. When the current maximum rechargeable power of the vehicle is greater than the actual power of the range extender, the current output power of the range extender is maintained; when the current maximum rechargeable power of the vehicle is less than the actual power of the range extender, the power generation power of the range extender is controlled to be reduced to the difference between the maximum rechargeable power of the vehicle and the power generation power of the drive motor.

[0076] It can be seen that in this application, when the extended-range electric vehicle is in the electric braking feedback state of the drive motor, the current maximum rechargeable power of the vehicle is compared with the first threshold value; when the current maximum rechargeable power of the vehicle is less than the first threshold value, the range extender is controlled to return from the power generation condition to the idle condition; if the current maximum rechargeable power of the vehicle is greater than the first threshold value and the current maximum rechargeable power of the vehicle is greater than the actual power of the range extender, the range extender is controlled to continue operating at the current power; if the current maximum rechargeable power of the vehicle is greater than the first threshold value and the current maximum rechargeable power of the vehicle is less than the actual power of the range extender, the sum of the power generation power of the range extender and the power generation power of the drive motor is controlled to be reduced to the maximum rechargeable power of the vehicle. By real-time detection of the current state of the vehicle's drive motor, when the vehicle is in the drive motor electric brake feedback state, the current vehicle's maximum rechargeable power is compared with the first threshold and the actual power of the range extender, and the range extender's power generation power is adjusted in real time so that the sum of the range extender's power generation power and the drive motor's power generation power is not greater than the vehicle's maximum rechargeable power. Compared with the situation of increasing battery cells and reducing the proportion of electric brake feedback, this application reduces the energy consumption of the entire vehicle without increasing the cost of the entire vehicle and effectively prevents battery overcharging, greatly improving the safety performance of the vehicle's drive motor in the electric brake feedback state.

[0077] In order to further improve the safety of the extended-range vehicle battery, this application also discloses a specific implementation method, such as Figure 4 As shown, it may include:

[0078] S21. When the vehicle is in a state of electric brake feedback of the driving motor, compare the current maximum rechargeable power of the vehicle with a first threshold.

[0079] S22: When the current maximum rechargeable power of the vehicle is less than a first threshold, the range extender is controlled to return from the power generation condition to the idle condition.

[0080] S23: When the current maximum rechargeable power of the vehicle is less than a second threshold, control the drive motor power to decrease to the current maximum rechargeable power of the vehicle, and the second threshold is less than the first threshold.

[0081] When it is necessary to control the drive motor power to drop to the current maximum rechargeable power of the vehicle, the VCU sends the range extender control command to the vehicle drive motor control unit (Motor Control Unit, MCU for short). In a specific implementation, not only the range extender will affect the charging of the battery, but the drive motor will also recharge the battery during braking energy recovery, which may also cause overcharging problems. The second threshold is lower than the first threshold because the first threshold is set based on comprehensive factors such as the range extender returning to the idle condition to ensure that the battery is not overcharged under relatively normal conditions; the second threshold is set for the battery to be in a more sensitive and more prone to overcharge state. Once the second threshold is exceeded, the risk of battery overcharge increases sharply. When it is determined that the current maximum rechargeable power of the vehicle is less than the second threshold, the VCU quickly issues instructions to the drive motor control system to accurately reduce the drive motor power so that it matches the current fragile acceptance capacity of the battery to avoid battery overcharging.

[0082] S24: If the current maximum rechargeable power of the vehicle is greater than the first threshold and the current maximum rechargeable power of the vehicle is greater than the actual power of the range extender, control the range extender to continue operating at the current power.

[0083] S25. If the current maximum rechargeable power of the vehicle is greater than the first threshold and the current maximum rechargeable power of the vehicle is less than the actual power of the range extender, control the power generation of the range extender to be reduced to the difference between the maximum rechargeable power of the vehicle and the power generation of the drive motor.

[0084] Among them, steps S21, S22, S24, and S25 are all mentioned in the above embodiments and will not be repeated here.

[0085] It can be seen that in this embodiment, in addition to the output power of the range extender, the output power of the drive motor is also limited. The order of limiting the range extender first can reduce the energy consumption of the vehicle as much as possible and store the electrical energy converted from the mechanical energy of the drive motor. However, when limiting the output power of the range extender alone is not enough to solve the battery recharging problem, limiting the output power of the drive motor can further solve the battery recharging problem.

[0086] The present application also discloses a whole vehicle control device for realizing power control of the vehicle, so as to implement the above-mentioned battery overcharging prevention method based on extended-range heavy-duty trucks.

[0087] Furthermore, the present application also discloses a computer-readable storage medium for storing a computer program; wherein, when the computer program is executed by a processor, the battery overcharge prevention method for a range-extended heavy-duty truck disclosed above is implemented. The specific steps of the method can be referred to the corresponding contents disclosed in the above embodiments, and will not be repeated here.

[0088] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0089] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0090] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0091] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0092] The technical solution provided by the present application is introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for general technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A method for preventing battery overcharging based on an extended-range vehicle, characterized in that: include: When the vehicle is in the state of electric brake feedback of the driving motor, comparing the current maximum rechargeable power of the vehicle with the first threshold; When the current maximum rechargeable power of the vehicle is less than the first threshold, controlling the range extender to return from the power generation condition to the idle condition; If the current maximum rechargeable power of the vehicle is greater than the first threshold and the current maximum rechargeable power of the vehicle is greater than the actual power of the range extender, controlling the range extender to continue operating at the current power; If the current maximum rechargeable power of the vehicle is greater than the first threshold and the current maximum rechargeable power of the vehicle is less than the actual power of the range extender, the power generation power of the range extender is controlled to be reduced to the difference between the maximum rechargeable power of the vehicle and the power generation power of the drive motor.

2. The method for preventing overcharging of a battery of a range-extended heavy-duty truck according to claim 1, characterized in that: Before comparing the current maximum rechargeable power of the vehicle with the first threshold, the method further includes: Get battery status; Determining a battery safety factor based on a battery status; Get the maximum rechargeable power of the battery and the current actual power of the vehicle; The current maximum rechargeable power of the vehicle is determined based on the maximum rechargeable power of the battery, the battery safety factor and the current actual power of the vehicle.

3. The method for preventing overcharging of a battery of a range-extended heavy-duty truck according to claim 2, characterized in that: The obtaining of the maximum rechargeable power of the battery includes: Measure the current battery bus voltage value; Get the maximum rechargeable current of the battery pack; The maximum rechargeable power of the battery is determined based on the current battery bus voltage value and the maximum rechargeable current of the battery pack.

4. The method for preventing overcharging of a battery of an extended-range heavy-duty truck according to claim 1, characterized in that: The first threshold is the minimum value of the maximum rechargeable power of the vehicle when the range extender returns to the idle condition; The process of obtaining the minimum value of the maximum rechargeable power of the vehicle includes: Obtaining the maximum power generation of the range extender and the battery capacity of the battery pack; The minimum value of the maximum rechargeable power of the vehicle when the range extender returns to the idle condition is determined based on the maximum power generation power of the range extender and the battery capacity of the battery pack.

5. The method for preventing overcharging of a battery of a range-extended heavy-duty truck according to claim 1, characterized in that: The controlling the range extender to return from the power generation condition to the idle condition comprises: Controlling the engine fuel injection amount of the range extender to decrease, wherein the engine fuel injection amount decrease value is equal to the current maximum engine fuel injection amount decrease value; The excitation current of the generator of the range extender is controlled to decrease by a maximum decreasing amount, so as to reduce the power generation power of the generator of the range extender.

6. The method for preventing overcharging of a battery of a range-extended heavy-duty truck according to claim 1, characterized in that: The controlling the range extender power generation to be reduced to the difference between the maximum rechargeable power of the vehicle and the power generation of the drive motor includes: Controlling the engine fuel injection amount of the range extender to be reduced by a preset stepwise gradient; Controlling the excitation current of the generator of the range extender to decrease gradually; The electromagnetic resistance of the generator of the range extender is controlled to increase when the rotation speed of the generator is greater than a rotation speed threshold, and the electromagnetic resistance of the generator of the range extender is controlled to decrease when the rotation speed of the generator is not greater than the rotation speed threshold.

7. The method for preventing overcharging of a battery of a range-extended heavy-duty truck according to claim 1, characterized in that: The controlling the range extender power generation to be reduced to the difference between the maximum rechargeable power of the vehicle and the power generation of the drive motor includes: Acquire the current generated by the range extender and the current generated by the drive motor; The sum of the current generated by the range extender and the current generated by the drive motor is controlled to be smaller than the maximum allowable recharge current of the battery.

8. The method for preventing battery overcharging of a range-extended heavy-duty truck according to any one of claims 1 to 7, characterized in that: include: When the vehicle is in the state of electric brake feedback of the driving motor, comparing the current maximum rechargeable power of the vehicle with the second threshold; When the current maximum rechargeable power of the vehicle is less than the second threshold, the driving motor power is controlled to decrease to the current maximum rechargeable power of the vehicle, and the second threshold is less than the first threshold.

9. A vehicle control device, characterized in that: Used to achieve power control of the vehicle to implement the battery overcharging prevention method based on the extended-range heavy-duty truck as described in any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that: Used to store computer programs; wherein, when the computer program is executed by a processor, the battery overcharging prevention method based on an extended-range heavy-duty truck is implemented as described in any one of claims 1 to 8.

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