A torque grading protection method, system medium and hybrid vehicle in series mode of a hybrid vehicle

Abstract

The application discloses a torque grading protection method and system in a series mode of a hybrid vehicle, a medium and the hybrid vehicle, and the method comprises the following steps: collecting engine operation parameters and generator operation parameters; determining a target power generation torque issued by a whole vehicle according to the engine operation parameters, and calculating an actual power generation torque according to the generator operation parameters; judging whether the hybrid vehicle is in a steady state working condition; if the hybrid vehicle is in the steady state working condition, calculating a torque deviation between the target power generation torque and the actual power generation torque; and executing a corresponding grading torque protection strategy according to the torque deviation.

Description

Technical Field

[0001] This invention relates to the field of new energy vehicle technology, and in particular to a torque classification protection method, system medium, and hybrid vehicle in series mode of a hybrid vehicle. Background Technology

[0002] In series hybrid vehicles, the engine does not directly drive the wheels but instead powers a generator to produce electricity. This electricity is used to charge the battery or power the drive motor, which then propels the vehicle. In this mode, stable vehicle operation relies on the coordinated control of various controllers. Typically, the vehicle control unit (VCU) requests the target torque from the engine control unit (ECU) based on battery charge and vehicle power requirements, and then adjusts the torque output of the generator control unit (GCU) to achieve closed-loop speed control.

[0003] In actual operation, the actual generated torque calculated by the generator controller (GCU) may deviate from the target generated torque requested by the vehicle controller (VCU).

[0004] In existing technologies, the conventional way to address deviations is to rely on PID closed-loop regulation for correction, or to directly trigger a fault alarm and limit power output when the deviation exceeds a single safety threshold. However, these solutions have significant drawbacks: the adjustment precision is insufficient for minor deviations, making it difficult to cope with continuous disturbances under complex operating conditions; while intervention is too abrupt for severe deviations, affecting driving smoothness.

[0005] Therefore, the urgent technical problem to be solved is that the torque deviation control strategy in the series mode of existing hybrid vehicles is difficult to meet the requirements of stable vehicle operation under complex driving conditions. Summary of the Invention

[0006] To address or partially address the technical problem that existing torque deviation control strategies in series hybrid vehicles struggle to meet the demands of stable vehicle operation under complex driving conditions, this invention provides a torque grading protection method and system for series hybrid vehicles. By synchronously collecting engine and generator operating parameters, the method accurately calculates the target and actual generated torque. It first performs steady-state condition determination to filter out transient fluctuations in engine speed and vehicle speed, then calculates the torque deviation and executes grading protection strategies. This effectively avoids misjudgments of torque deviation, improves the accuracy of torque matching and condition determination, achieves grading adaptive control of torque deviation, and balances vehicle power smoothness, generator system stability, and driving safety, adapting to stable vehicle operation under complex conditions.

[0007] To address the aforementioned technical problems, a first aspect of the present invention discloses a torque grading protection method for hybrid vehicles in series mode, the method comprising: Collect engine operating parameters and generator operating parameters; The target power generation torque of the whole vehicle is determined based on the engine operating parameters, and the actual power generation torque is calculated based on the generator operating parameters. Determine whether the hybrid vehicle is in a steady-state operating condition; If the hybrid vehicle is in the steady-state condition, calculate the torque deviation between the target generated torque and the actual generated torque; The corresponding graded torque protection strategy is executed based on the torque deviation.

[0008] Optionally, determining the target power generation torque of the vehicle based on the engine operating parameters specifically includes: The initial power generation torque is determined based on the actual operating conditions of the hybrid vehicle. The maximum available torque of the engine is determined based on the engine operating parameters. Using the engine's maximum available torque as a constraint, and combining it with the initial power generation torque, a target power generation torque is determined so that the target power generation torque does not exceed the engine's maximum available torque.

[0009] Optionally, determining the maximum available torque of the engine based on the engine operating parameters specifically includes: Based on the engine operating parameters, the corresponding compensation coefficient is obtained by looking up the table; the compensation coefficient is multiplied by the engine's theoretical maximum usable torque to obtain the engine's maximum usable torque.

[0010] Optionally, determining the maximum available torque of the engine based on the engine operating parameters specifically includes: Determine the maximum torque corresponding to the preset parameter combination in the engine operating parameters; combine the maximum torque corresponding to the preset parameter combination and the engine's theoretical maximum usable torque, and take the minimum value between them as the engine's maximum usable torque.

[0011] Optionally, calculating the actual generated torque based on the generator operating parameters specifically includes: Calculate the generator output power based on the generator operating parameters; The reference power generation efficiency of the generator at the current speed is obtained by looking up a table, and the actual conversion efficiency is obtained by combining the generator temperature correction coefficient. Divide the generator output power by the actual conversion efficiency to obtain the equivalent mechanical power. The actual generated torque is obtained by substituting the equivalent mechanical power into the relationship between mechanical power and rotational speed.

[0012] Optionally, determining whether the hybrid vehicle is in a steady-state operating condition specifically includes: Real-time acquisition of generator speed data is used to calculate generator speed fluctuation value; wherein, the generator speed fluctuation value is obtained by the difference between the maximum generator speed and the minimum generator speed in a preset number of continuously acquired generator speed data; Vehicle speed is collected in real time to calculate the vehicle speed fluctuation value; wherein, the vehicle speed fluctuation value is obtained by the difference between the maximum and minimum vehicle speed values ​​in the preset number of continuously collected vehicle speed data; Determine whether the generator speed fluctuation value is less than a first fluctuation threshold, whether the speed fluctuation value is less than a second fluctuation threshold, and whether the duration for which the generator speed fluctuation value and the vehicle speed fluctuation value simultaneously meet the corresponding thresholds reaches a first preset duration. If so, it indicates that the hybrid vehicle is in the steady-state operating condition.

[0013] Optionally, the torque deviation is obtained by subtracting the target power generation torque from the actual power generation torque and taking the absolute value; the execution of the corresponding graded torque protection strategy based on the torque deviation specifically includes: If the torque deviation is less than or equal to the first threshold, maintain the current vehicle control state; If the torque deviation exceeds the first threshold and is less than or equal to the second threshold, and continues for a second preset duration, the corresponding level of torque protection strategy is executed: increase the engine target speed while reducing the target generated torque; If the torque deviation exceeds the second threshold and is less than or equal to the third threshold, and continues for a third preset duration, the corresponding level of torque protection strategy is executed: limiting the drive motor power, limiting the maximum vehicle speed, and illuminating one or more of the following combinations of instrument panel fault indicator lights.

[0014] A second aspect of the present invention discloses a torque grading protection system in series mode for hybrid vehicles, the system comprising: The data acquisition module is used to collect engine operating parameters and generator operating parameters; The processing module is used to determine the target power generation torque of the whole vehicle based on the engine operating parameters, and to calculate the actual power generation torque based on the generator operating parameters. The judgment module is used to determine whether the hybrid vehicle is in a steady-state operating condition; The calculation module is used to calculate the torque deviation between the target power generation torque and the actual power generation torque if the hybrid vehicle is in the steady-state operating condition. The execution module is used to execute the corresponding graded torque protection strategy according to the torque deviation.

[0015] A third aspect of the present invention discloses a computer-readable storage medium having a computer program stored thereon that, when executed by a processor, implements the steps of the above-described method.

[0016] A fourth aspect of the present invention discloses a hybrid vehicle, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of the above-described method.

[0017] Through one or more technical solutions of the present invention, the present invention has the following beneficial effects or advantages: The technical solution of this invention, by simultaneously collecting engine operating parameters and generator operating parameters, accurately calculates the target generated torque and the actual generated torque respectively. It first determines the steady-state operating condition of the hybrid vehicle, eliminates transient operating condition fluctuations, and then calculates the torque deviation. Based on the torque deviation, it executes corresponding graded torque protection strategies. This effectively avoids misjudgments of torque deviation caused by complex operating conditions such as transient fluctuations in engine speed and vehicle speed, improves the accuracy of generated torque matching and operating condition determination, and achieves graded adaptive control under various torque deviation conditions. It can balance the smoothness of vehicle power, the stability of the power generation system, and the reliability of driving safety, meeting the stable operation requirements of the vehicle under complex driving conditions.

[0018] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0019] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A flowchart of a torque grading protection method for a hybrid vehicle in series mode according to an embodiment of the present invention is shown; Figure 2 A schematic diagram of a torque grading protection system in series mode for a hybrid vehicle according to an embodiment of the present invention is shown. Detailed Implementation

[0020] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0021] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0022] Firstly, the present invention provides a torque classification protection method for hybrid vehicles in series mode. This invention integrates the vehicle controller (VCU), generator controller (GCU), and engine controller (ECU) onto a single main control chip, eliminating the hardware isolation barriers of traditional multi-controller layouts. This achieves unified scheduling of hardware resources and deep coupling of control logic for vehicle control, generator control, and engine control, eliminating issues such as CAN bus communication delays, signal loss, and timing misalignments between controllers at the hardware level. This provides hardware architecture support for subsequent accurate acquisition of multi-source operating parameters, real-time calculation of target and actual generator torque, accurate identification of steady-state operating conditions, and torque deviation classification protection. It also facilitates unified scheduling of hardware resources and coordinated execution of the protection method of this invention.

[0023] like Figure 1 As shown in the figure, an embodiment of the present invention provides a torque grading protection method in series mode for hybrid vehicles, comprising the following steps: S101 collects engine operating parameters and generator operating parameters.

[0024] The engine operating parameters include, but are not limited to: engine intake air temperature, engine coolant temperature, engine running time after starting, engine initial coolant temperature at start-up, and engine real-time speed.

[0025] The generator operating parameters include, but are not limited to: DC bus current, DC bus voltage, generator body temperature, and generator real-time speed.

[0026] Specifically, the engine controller relies on its own deployed sensors to collect and upload various engine operating parameters in real time; the generator controller, through its built-in sampling circuit, temperature sensor, and speed sensor, synchronously collects bus electrical parameters, generator body temperature, and generator real-time speed and reports them upwards, realizing the synchronous collection and unified storage of multi-source operating parameters of the entire vehicle.

[0027] S102, determine the target power generation torque of the whole vehicle based on the engine operating parameters, and calculate the actual power generation torque based on the generator operating parameters.

[0028] In this embodiment, the system consists of two parallel logic branches: On the one hand, the target power generation torque of the entire vehicle is calculated based on the engine operating parameters, and the parameters are progressively adjusted from the vehicle's energy demand and operating condition requirements to the engine's operating condition constraints, outputting a reasonable power generation torque that meets the engine's load-bearing capacity. On the other hand, the actual power generation torque of the generator is calculated based on the generator operating parameters, taking into full account power generation efficiency, temperature loss, and energy conversion loss, to restore the true mechanical torque output level of the generator input from the engine.

[0029] The two branches operate synchronously and refresh periodically, providing a precise torque benchmark for subsequent steady-state determination, torque deviation calculation, and graded protection.

[0030] In determining the target generated torque of the vehicle based on the engine operating parameters, the following steps are performed: S201 determines the initial power generation torque based on the actual operating conditions of the hybrid vehicle.

[0031] The actual operating conditions of the vehicle include the vehicle's drive power requirements, vehicle speed, battery state of charge (SOC), and vehicle driving mode. Specifically, the vehicle controller collects and analyzes accelerator pedal signals, brake pedal signals, drive motor operating status signals, vehicle speed signals, power battery SOC signals, and driving mode gear signals in real time to identify the current operating conditions of the hybrid vehicle. Then, it combines the vehicle's preset energy management control strategy, vehicle energy consumption calibration MAP, and battery balancing control logic to perform multi-dimensional logical operations and lookup table interpolation to accurately match the initial power generation torque. This initial torque is used as the basis for obtaining the target power generation torque after subsequent correction by the engine's maximum available torque constraint, ensuring that the initial power generation torque meets the vehicle's driving and battery management requirements.

[0032] S202 determines the maximum available torque of the engine based on the engine operating parameters.

[0033] Among them, the maximum usable torque of the engine is the upper limit of the torque that the engine can safely output under the current operating conditions, which is constrained by multiple parameters such as the current intake air temperature, coolant temperature, starting conditions, and real-time speed. It is used to strictly limit the torque output boundary of the engine and prevent the engine from overloading, deteriorating combustion, vibrating and making abnormal noises, and fatigue wear of parts due to excessive target generated torque.

[0034] The maximum available torque of an engine is not a fixed value; it is affected by the engine's operating parameters and changes dynamically in real time with the engine's operating conditions. Therefore, this embodiment will correct the engine's theoretical maximum torque in real time to obtain the maximum available torque that best fits the current operating conditions.

[0035] Specifically, the maximum available torque of an engine is determined as follows: Based on the engine operating parameters, the corresponding compensation coefficient is obtained by looking up a table; the compensation coefficient is then multiplied by the engine's theoretical maximum usable torque to obtain the engine's maximum usable torque; or... Determine the maximum torque corresponding to the preset parameter combination in the engine operating parameters; combine the maximum torque corresponding to the preset parameter combination and the engine's theoretical maximum usable torque, and take the minimum value between them as the engine's maximum usable torque.

[0036] In one optional example, during the process of determining the compensation coefficient by looking up the table, the engine's various operating parameters, such as intake air temperature, coolant temperature, running time after starting, initial coolant temperature at startup, and real-time speed, are calibrated in advance through engine bench performance calibration, environmental chamber high and low temperature calibration, and full vehicle road testing. This involves multi-dimensional, full-condition range calibration of various operating parameters, including start-up air temperature, coolant temperature, running time after starting, initial coolant temperature at startup, and real-time speed. Different operating condition ranges are then defined, and corresponding torque attenuation compensation coefficients are calibrated for each range, establishing a complete one-to-one mapping relationship between parameter combinations and torque compensation coefficients. Once the engine operating parameters are obtained, the mapping relationship can be looked up to match the corresponding compensation coefficient. Furthermore, the compensation coefficient is multiplied by the engine's theoretical maximum usable torque to obtain the engine's maximum usable torque. For example, if the engine's theoretical maximum usable torque is 200 Nm and the compensation coefficient is 0.9, then the engine's maximum usable torque is 180 Nm.

[0037] In one optional example, the preset parameter combinations include: a combination of engine start-up running time and engine start-up initial coolant temperature, a combination of engine real-time speed and engine coolant temperature, and a basic combination with engine real-time speed as the independent variable; for each preset parameter combination, the torque limit under each operating condition constraint is obtained by looking up a table through the calibration pulse spectrum; then, the torque limit under each operating condition constraint and the engine's theoretical maximum usable torque are combined and the minimum value is taken as the engine's maximum usable torque under the current operating condition.

[0038] S203, using the engine's maximum available torque as a constraint, and combining the initial power generation torque to determine the target power generation torque, so that the target power generation torque does not exceed the engine's maximum available torque.

[0039] Specifically, the initial generated torque is compared with the engine's maximum available torque. When the initial generated torque is less than or equal to the engine's maximum available torque, the initial generated torque is directly used as the target generated torque. When the initial generated torque is greater than the engine's maximum available torque, the engine's maximum available torque is used as the target generated torque, thereby ensuring that the target generated torque is always within the safe output boundary allowed by the engine's current operating conditions.

[0040] In the process of calculating the actual generated torque based on the generator operating parameters, the following steps are performed: S301, Calculate the generator output power based on the generator operating parameters.

[0041] Specifically, the generator output power is obtained by multiplying the real-time collected DC bus voltage and DC bus current.

[0042] S302, the reference power generation efficiency of the generator at the current speed is obtained by looking up the table, and the actual conversion efficiency is obtained by combining the generator temperature correction coefficient.

[0043] Specifically, using the generator's current real-time speed and real-time load conditions as independent variables, the benchmark power generation efficiency under the current operating conditions is obtained by looking up a table using the benchmark power generation efficiency pulse spectrum calibrated by bench testing; at the same time, based on the generator's current temperature, the temperature correction coefficient corresponding to the generator's current temperature is obtained by looking up a table using the temperature correction coefficient pulse spectrum; the benchmark power generation efficiency is multiplied by the temperature correction coefficient to obtain the actual conversion efficiency under the current operating conditions.

[0044] S303, divide the output electrical power of the generator by the actual conversion efficiency to obtain the equivalent mechanical power.

[0045] Specifically, based on the energy transfer relationship between the mechanical energy of the generator and the electrical energy, the measured output power of the generator is divided by the actual conversion efficiency to calculate the equivalent mechanical power at the generator shaft end, so as to restore the true mechanical power level input from the engine to the generator.

[0046] S304, by substituting the equivalent mechanical power into the relationship between mechanical power and rotational speed, the actual generated torque is obtained.

[0047] Specifically, the equivalent mechanical power is uniformly converted to the standard unit of kilowatts, and then substituted into the relationship between mechanical power, speed, and torque. .in, T This represents the actual generated torque. P mech For equivalent mechanical power, n Given the real-time rotational speed of the generator, the actual generating torque at the generator shaft end is calculated.

[0048] The above describes the relevant logic for calculating the target generated torque and the actual generated torque. In order to accurately identify the steady-state power generation condition of hybrid vehicles, avoid misjudgment of torque deviation caused by transient fluctuations, and ensure that the torque graded protection strategy is reliably effective under stable operating conditions, it is necessary to monitor the deviation between the target generated torque and the actual generated torque under steady-state conditions and implement graded control and progressive protection.

[0049] S103, determine whether the hybrid vehicle is in a steady-state condition.

[0050] If the hybrid vehicle is in a steady-state condition, execute S104. If the hybrid vehicle is not in a steady-state condition, return to S101.

[0051] In the specific implementation process, generator speed data is collected in real time to calculate the generator speed fluctuation value. The generator speed fluctuation value is obtained by the difference between the maximum and minimum generator speed values ​​from a preset number of continuously collected generator speed data points.

[0052] Vehicle speed is collected in real time to calculate the vehicle speed fluctuation value. The vehicle speed fluctuation value is obtained by the difference between the maximum and minimum vehicle speed values ​​among the preset number of continuously collected vehicle speed data. Determine whether the generator speed fluctuation value is less than a first fluctuation threshold, whether the speed fluctuation value is less than a second fluctuation threshold, and whether the duration for which the generator speed fluctuation value and the vehicle speed fluctuation value simultaneously meet the corresponding thresholds reaches a first preset duration.

[0053] If so, it indicates that the hybrid vehicle is in the steady-state operating condition.

[0054] For example, when the generator speed fluctuation value is in [-30rpm, 30rpm] and the vehicle speed fluctuation value is in [0, 5km / h], and this lasts for 5 seconds, the hybrid vehicle is determined to be in the steady-state operating condition.

[0055] S104, if the hybrid vehicle is in the steady-state condition, calculate the torque deviation between the target power generation torque and the actual power generation torque.

[0056] The torque deviation is obtained by subtracting the target power generation torque from the actual power generation torque and taking the absolute value, which characterizes the degree of deviation between the two.

[0057] S105, execute the corresponding graded torque protection strategy according to the torque deviation.

[0058] In the graded torque protection strategy, if the torque deviation is lower than the first threshold, it indicates that the actual generated torque of the generator matches the target generated torque well, the system is operating normally, and the current vehicle control state is maintained.

[0059] If the torque deviation exceeds the first threshold but is less than or equal to the second threshold, and persists for a second preset duration, it is determined to be a moderate torque deviation condition, triggering the secondary torque protection logic and executing the corresponding torque protection strategy. Specifically, the secondary torque protection logic involves increasing the engine target speed while simultaneously reducing the target generator torque. Increasing the engine target speed raises the operating range of the engine-generator set, improving the unit's load-carrying capacity, generator response margin, and steady-state output stability. Simultaneously reducing the target generator torque moderately lowers the generator demand command within the engine's maximum available torque constraint boundary, reducing the deviation between the target generator torque and the current actual generator torque, preventing further widening of the torque deviation. Combined with the increase in the engine target speed, this allows the actual generator torque to gradually converge towards the target generator torque, achieving smooth self-correction and adaptive matching under moderate torque deviation conditions.

[0060] If the torque deviation exceeds the second threshold and is less than or equal to the third threshold, and continues for a third preset duration, the corresponding level of torque protection strategy (first-level torque protection logic) is executed: limiting the drive motor power, limiting the maximum vehicle speed, and illuminating one or more of the following combinations of instrument panel fault indicator lights.

[0061] Specifically, limiting the output power of the drive motor can reduce the vehicle's power load demand, decrease the generator set's power generation load pressure, and alleviate the torque mismatch between the engine and generator; limiting the vehicle's maximum speed can constrain the vehicle's operating range, preventing the torque deviation from worsening under high-speed, high-load conditions and ensuring vehicle stability; illuminating the instrument panel fault indicator light allows for real-time feedback to the driver on abnormal torque matching in the power generation system, reminding the driver to pay attention to the vehicle's operating condition, achieving early fault warning and graded vehicle safety protection. In practical applications, one or a combination of the above protective actions can be executed according to the fault level.

[0062] The above describes the implementation logic of torque grading protection in the series mode of hybrid vehicles in this technical solution. By synchronously collecting engine operating parameters and generator operating parameters, the target generated torque and the actual generated torque are accurately calculated respectively. The hybrid vehicle is first judged for steady-state operation, and the torque deviation is calculated after eliminating transient operation fluctuations. Then, the corresponding graded torque protection strategy is executed according to the torque deviation. This can effectively avoid misjudgment of torque deviation caused by transient fluctuations in speed and vehicle speed, greatly improve the accuracy of generating torque matching and steady-state operation judgment, realize graded adaptive control under different torque deviations, take into account the smoothness of vehicle power, the working stability of the power generation system and the reliability of driving safety, and meet the stable operation requirements of the vehicle under complex driving conditions.

[0063] Furthermore, this technical solution also adopts a graded intervention strategy. Under moderate torque deviation conditions, through energy management feedforward adjustment, it uses control logic to increase the target engine speed while appropriately reducing the target generated torque to maintain the dynamic balance of the vehicle's power battery charge, effectively avoiding false protection and false alarm faults caused by transient disturbances. When there is a severe torque deviation and the previous adjustment fails, the vehicle's functional safety mechanism is triggered in a timely manner. This is done by limiting the drive motor power, limiting the vehicle's maximum speed, and illuminating the instrument panel fault indicator light to provide fallback protection. This forms a progressive graded protection system from precision self-correction adjustment to mandatory functional safety intervention, ensuring the stable balance of the vehicle's battery charge while also taking into account vehicle driving safety and overall driving smoothness.

[0064] Secondly, based on the same inventive concept as the torque grading protection method for hybrid vehicles in series mode provided in the first aspect embodiment, this embodiment of the invention also provides a torque grading protection system for hybrid vehicles in series mode, see below. Figure 2 The system includes: The acquisition module 201 is used to acquire engine operating parameters and generator operating parameters; Processing module 202 is used to determine the target power generation torque of the whole vehicle based on the engine operating parameters, and to calculate the actual power generation torque based on the generator operating parameters. The judgment module 203 is used to determine whether the hybrid vehicle is in a steady-state operating condition; Calculation module 204 is used to calculate the torque deviation between the target power generation torque and the actual power generation torque if the hybrid vehicle is in the steady-state operating condition; The execution module 205 is used to execute a corresponding graded torque protection strategy based on the torque deviation.

[0065] It should be noted that the specific operation of each module in the torque classification protection system of the hybrid vehicle in series mode provided in the embodiments of the present invention has been described in detail in the method embodiments provided in the first aspect above. The specific implementation process can be referred to the method embodiments provided in the first aspect above, and will not be described in detail here.

[0066] Thirdly, based on the same inventive concept as the torque grading protection method in the series mode of hybrid vehicles provided in the first aspect embodiment, the present invention also discloses a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of any of the methods described above.

[0067] Fourthly, based on the same inventive concept as the torque grading protection method in series mode for hybrid vehicles provided in the first aspect embodiment, this embodiment of the invention also discloses a hybrid vehicle, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of any of the methods described above.

[0068] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0069] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A torque grading protection method for hybrid vehicles in series mode, characterized in that, The method includes: Collect engine operating parameters and generator operating parameters; The target power generation torque of the whole vehicle is determined based on the engine operating parameters, and the actual power generation torque is calculated based on the generator operating parameters. Determine whether the hybrid vehicle is in a steady-state operating condition; If the hybrid vehicle is in the steady-state condition, calculate the torque deviation between the target generated torque and the actual generated torque; The corresponding graded torque protection strategy is executed based on the torque deviation.

2. The method as described in claim 1, characterized in that, The step of determining the target power generation torque of the vehicle based on the engine operating parameters specifically includes: The initial power generation torque is determined based on the actual operating conditions of the hybrid vehicle. The maximum available torque of the engine is determined based on the engine operating parameters. Using the engine's maximum available torque as a constraint, and combining it with the initial power generation torque, a target power generation torque is determined so that the target power generation torque does not exceed the engine's maximum available torque.

3. The method as described in claim 2, characterized in that, The step of determining the maximum available torque of the engine based on the engine operating parameters specifically includes: Based on the engine operating parameters, the corresponding compensation coefficient is obtained by looking up the table; the compensation coefficient is multiplied by the engine's theoretical maximum usable torque to obtain the engine's maximum usable torque.

4. The method as described in claim 2, characterized in that, The step of determining the maximum available torque of the engine based on the engine operating parameters specifically includes: Determine the maximum torque corresponding to the preset parameter combination in the engine operating parameters; combine the maximum torque corresponding to the preset parameter combination and the engine's theoretical maximum usable torque, and take the minimum value between them as the engine's maximum usable torque.

5. The method as described in claim 1, characterized in that, The calculation of the actual generated torque based on the generator operating parameters specifically includes: Calculate the generator output power based on the generator operating parameters; The reference power generation efficiency of the generator at the current speed is obtained by looking up a table, and the actual conversion efficiency is obtained by combining the generator temperature correction coefficient. Divide the generator output power by the actual conversion efficiency to obtain the equivalent mechanical power. The actual generated torque is obtained by substituting the equivalent mechanical power into the relationship between mechanical power and rotational speed.

6. The method as described in claim 1, characterized in that, The determination of whether the hybrid vehicle is in a steady-state operating condition specifically includes: Real-time acquisition of generator speed data is used to calculate generator speed fluctuation value; wherein, the generator speed fluctuation value is obtained by the difference between the maximum generator speed and the minimum generator speed in a preset number of continuously acquired generator speed data; Vehicle speed is collected in real time to calculate the vehicle speed fluctuation value; wherein, the vehicle speed fluctuation value is obtained by the difference between the maximum and minimum vehicle speed values ​​in the preset number of continuously collected vehicle speed data; Determine whether the generator speed fluctuation value is less than a first fluctuation threshold, whether the speed fluctuation value is less than a second fluctuation threshold, and whether the duration for which the generator speed fluctuation value and the vehicle speed fluctuation value simultaneously meet the corresponding thresholds reaches a first preset duration. If so, it indicates that the hybrid vehicle is in the steady-state operating condition.

7. The method as described in claim 1, characterized in that, The torque deviation is obtained by subtracting the target power generation torque from the actual power generation torque and taking the absolute value; the execution of the corresponding graded torque protection strategy based on the torque deviation specifically includes: If the torque deviation is less than or equal to the first threshold, maintain the current vehicle control state; If the torque deviation exceeds the first threshold and is less than or equal to the second threshold, and continues for a second preset duration, the corresponding level of torque protection strategy is executed: increase the engine target speed while reducing the target generated torque; If the torque deviation exceeds the second threshold and is less than or equal to the third threshold, and continues for a third preset duration, the corresponding level of torque protection strategy is executed: limiting the drive motor power, limiting the maximum vehicle speed, and illuminating one or more of the following combinations of instrument panel fault indicator lights.

8. A torque grading protection system in series mode for hybrid vehicles, characterized in that, The system includes: The data acquisition module is used to collect engine operating parameters and generator operating parameters; The processing module is used to determine the target power generation torque of the whole vehicle based on the engine operating parameters, and to calculate the actual power generation torque based on the generator operating parameters. The judgment module is used to determine whether the hybrid vehicle is in a steady-state operating condition; The calculation module is used to calculate the torque deviation between the target power generation torque and the actual power generation torque if the hybrid vehicle is in the steady-state operating condition. The execution module is used to execute the corresponding graded torque protection strategy according to the torque deviation.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the program implements the steps of the method according to any one of claims 1-7.

10. A hybrid vehicle, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps of the method according to any one of claims 1-7.

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