Vehicle control method, vehicle, and computer-readable storage medium

Abstract

This application discloses a vehicle control method, a vehicle, and a computer-readable storage medium. The method includes: acquiring generator temperature, inverter temperature, and vehicle operating parameters, wherein the vehicle operating parameters include motor water pump duty cycle, cooling fan duty cycle, generator output torque, engine status, and vehicle drive mode; the engine status includes running state and stopped state; and the vehicle drive mode includes parallel drive mode and pure electric drive mode; determining a generator fault level based on the generator temperature, inverter temperature, and a preset temperature threshold, wherein the generator fault level is used to determine the degree of generator over-temperature; determining an over-temperature protection strategy based on the generator fault level and vehicle operating parameters; and performing over-temperature protection on the generator based on the over-temperature protection strategy. This application solves the technical problems of incomplete protection, unreasonable limp-out strategies, and low system reliability in related technologies when performing generator over-temperature protection.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and more specifically, to a vehicle control method, a vehicle, and a computer-readable storage medium. Background Technology

[0002] In hybrid vehicles, the generator serves the dual function of starting the engine and generating electricity. Under high loads or extreme conditions, it is prone to overheating due to heat accumulation from copper and iron losses, threatening system safety. Related technologies generally employ power derating strategies based on individual unit temperature thresholds, passively protecting the system by limiting motor torque or output power, resulting in a localized perspective and incomplete protection. Furthermore, these technologies do not differentiate between different fault modes such as short-term overload and cooling failure, leading to rigid control strategies. Additionally, under extreme conditions, the secondary overheating of the inverter caused by weak magnetic current cannot be suppressed, easily inducing cascading failures, posing significant safety risks and severely insufficient reliability.

[0003] There is currently no effective solution to the above problems. Summary of the Invention

[0004] This application provides a vehicle control method, a vehicle, and a computer-readable storage medium to at least solve the technical problems of incomplete protection, unreasonable limp-riding strategy, and low system reliability in related technologies when performing generator over-temperature protection.

[0005] According to one aspect of the embodiments of this application, a vehicle control method is provided, comprising: acquiring generator temperature, inverter temperature, and vehicle operating parameters, wherein the vehicle operating parameters include motor water pump duty cycle, cooling fan duty cycle, generator output torque, engine status, and vehicle drive mode; the motor water pump duty cycle is used to represent the proportion of time during which the electronic control signal driving the motor water pump is in the on state in the current cycle; the cooling fan duty cycle is used to represent the proportion of time during which the electronic control signal driving the cooling fan is in the on state in the current cycle; the engine status includes a running state and a stopped state; and the vehicle drive mode includes a parallel drive mode and a pure electric drive mode; determining a generator fault level based on the generator temperature, inverter temperature, and a preset temperature threshold, wherein the generator fault level is used to determine the degree of generator over-temperature; determining an over-temperature protection strategy based on the generator fault level and the vehicle operating parameters; and performing over-temperature protection on the generator based on the over-temperature protection strategy.

[0006] Further, based on the generator temperature, inverter temperature, and preset temperature thresholds, the generator fault level is determined as follows: In response to the generator temperature being less than or equal to a first temperature threshold, or the inverter temperature being less than or equal to a first temperature threshold, the generator fault level is determined to be a slight overheating level; or, in response to the generator temperature being greater than or equal to a second temperature threshold, or the inverter temperature being greater than or equal to a third temperature threshold, the generator fault level is determined to be a mild overheating level, wherein the second temperature threshold is greater than the first temperature threshold and the third temperature threshold is greater than the second temperature threshold; or, in response to the generator temperature being greater than or equal to a fourth temperature threshold, or the inverter temperature being greater than or equal to a fifth temperature threshold, the generator fault level is determined to be a moderate overheating level, wherein the fourth temperature threshold is greater than the second temperature threshold, the fourth temperature threshold is less than the third temperature threshold, and the fifth temperature threshold is greater than the third temperature threshold; or, in response to the generator temperature being greater than or equal to a sixth temperature threshold, or the inverter temperature being greater than or equal to a seventh temperature threshold, the generator fault level is determined to be a severe overheating level, wherein the sixth temperature threshold is greater than the fourth temperature threshold, the sixth temperature threshold is less than the fifth temperature threshold, and the seventh temperature threshold is greater than the fifth temperature threshold.

[0007] Furthermore, the generator fault level includes: slight overtemperature level. The vehicle operating parameters also include: power battery charge, generator rated torque, and generator safe torque. Based on the generator fault level and vehicle operating parameters, the overtemperature protection strategy is determined as follows: in response to the generator fault level being slight overtemperature level, the motor water pump duty cycle and cooling fan duty cycle are controlled to be preset duty cycles, and the generator output torque is less than or equal to a first torque threshold. When the power battery charge is less than a preset charge threshold, the vehicle drive mode is controlled to be parallel drive mode. The first torque threshold is determined based on the generator rated torque, a first temperature coefficient, and the generator safe torque. The first temperature coefficient is determined based on the generator temperature. The parallel drive mode is used to indicate that the engine and drive motor provide driving force to the vehicle.

[0008] Furthermore, the generator fault level includes a mild overtemperature level, and the vehicle operating parameters also include the generator rated torque and the generator safe torque. Based on the generator fault level and vehicle operating parameters, the overtemperature protection strategy is determined as follows: in response to the generator fault level being a mild overtemperature level and the engine being in an operating state, the motor water pump duty cycle and the cooling fan duty cycle are controlled to a preset duty cycle, the generator output torque is less than or equal to a second torque threshold, the vehicle drive mode is a parallel drive mode, and the engine state is controlled to maintain the operating state. The second torque threshold is based on the generator rated torque, a second temperature coefficient, and the generator... The safe torque is determined, and the second temperature coefficient is less than the first temperature coefficient; or, in response to the generator fault level being a slight overheating level and the engine state being a stopped state, the duty cycle of the motor water pump and the duty cycle of the cooling fan are controlled to a preset duty cycle, and the engine state is controlled to switch from a stopped state to a running state; in response to the engine state successfully switching from a stopped state to a running state, the vehicle drive mode is controlled to a parallel drive mode; or, in response to the engine state failing to successfully switch from a stopped state to a running state, the vehicle drive mode is controlled to a pure electric drive mode, wherein the pure electric drive mode is used to indicate that the drive motor provides driving force to the vehicle.

[0009] Furthermore, the generator fault level includes: moderate overtemperature level. Based on the generator fault level and vehicle operating parameters, the overtemperature protection strategy is determined as follows: In response to the generator fault level being moderate overtemperature level and the vehicle driving mode being parallel drive mode, the motor water pump duty cycle is controlled to a preset duty cycle, the cooling fan duty cycle is controlled to a preset duty cycle, the engine status is running, the generator output torque is controlled to a preset output torque, and the vehicle driving mode is controlled to maintain parallel drive mode; or, in response to the generator fault level being moderate overtemperature level and the vehicle driving mode not being parallel drive mode, the motor water pump duty cycle is controlled to a preset duty cycle, the cooling fan duty cycle is controlled to a preset duty cycle, the engine status is stopped, the generator output torque is controlled to a preset output torque, and the vehicle driving mode is controlled to switch to pure electric drive mode.

[0010] Furthermore, the generator fault level includes a severe overtemperature level, and the vehicle operating parameters also include a target vehicle speed. Based on the generator fault level and the vehicle operating parameters, the overtemperature protection strategy is determined as follows: In response to the generator fault level being a severe overtemperature level and the vehicle driving mode being a parallel drive mode, the duty cycle of the motor water pump, the duty cycle of the cooling fan, the generator output torque, and the engine status are all set to a preset duty cycle, the vehicle driving mode is maintained in parallel drive mode, and the target vehicle speed is controlled to be less than a preset speed threshold; or, in response to the generator fault level being a severe overtemperature level and the vehicle driving mode not being a parallel drive mode, the duty cycle of the motor water pump, the duty cycle of the cooling fan, the generator output torque, and the engine status are all set to a preset duty cycle, the engine status is set to a stopped state, and the vehicle driving mode is switched to pure electric drive mode.

[0011] Furthermore, the vehicle control method also includes: acquiring the motor cooling water temperature and cooling demand; determining that the generator temperature is in a normal state in response to the motor cooling water temperature being less than or equal to an eighth temperature threshold, wherein the eighth temperature threshold is less than a first temperature threshold; or, determining that the generator temperature is in a normal state in response to the generator temperature being less than or equal to an eighth temperature threshold; or, determining that the generator temperature is in a normal state in response to the inverter temperature being less than or equal to a ninth temperature threshold, wherein the ninth temperature threshold is less than the eighth temperature threshold; and performing over-temperature protection on the generator based on the cooling demand.

[0012] According to another aspect of the embodiments of this application, a vehicle control device is also provided, comprising: a first acquisition module, configured to acquire generator temperature, inverter temperature, and vehicle operating parameters, wherein the vehicle operating parameters include motor water pump duty cycle, cooling fan duty cycle, generator output torque, engine status, and vehicle drive mode; the motor water pump duty cycle is used to represent the proportion of time during which the electronic control signal driving the motor water pump is in the on state in the current cycle; the cooling fan duty cycle is used to represent the proportion of time during which the electronic control signal driving the cooling fan is in the on state in the current cycle; the engine status includes a running state and a stopped state; and the vehicle drive mode includes a parallel drive mode and a pure electric drive mode; a first determination module, configured to determine a generator fault level based on the generator temperature, inverter temperature, and a preset temperature threshold, wherein the generator fault level is used to determine the degree of generator over-temperature; a second determination module, configured to determine an over-temperature protection strategy based on the generator fault level and the vehicle operating parameters; and a first protection module, configured to perform over-temperature protection on the generator based on the over-temperature protection strategy.

[0013] Furthermore, the first determining module is also configured to: determine the generator fault level as a slight overtemperature level in response to the generator temperature being less than or equal to a first temperature threshold, or the inverter temperature being less than or equal to the first temperature threshold; or, determine the generator fault level as a mild overtemperature level in response to the generator temperature being greater than or equal to a second temperature threshold, or the inverter temperature being greater than or equal to a third temperature threshold, wherein the second temperature threshold is greater than the first temperature threshold and the third temperature threshold is greater than the second temperature threshold; or, determine the generator fault level as a moderate overtemperature level in response to the generator temperature being greater than or equal to a fourth temperature threshold, or the inverter temperature being greater than or equal to a fifth temperature threshold, wherein the fourth temperature threshold is greater than the second temperature threshold, the fourth temperature threshold is less than the third temperature threshold, and the fifth temperature threshold is greater than the third temperature threshold; or, determine the generator fault level as a severe overtemperature level in response to the generator temperature being greater than or equal to a sixth temperature threshold, or the inverter temperature being greater than or equal to a seventh temperature threshold, wherein the sixth temperature threshold is greater than the fourth temperature threshold, the sixth temperature threshold is less than the fifth temperature threshold, and the seventh temperature threshold is greater than the fifth temperature threshold.

[0014] Furthermore, the generator fault level includes: a slight over-temperature level. The vehicle operating parameters also include: the power battery charge, the generator rated torque, and the generator safe torque. The second determining module is also used to: in response to the generator fault level being a slight over-temperature level, control the motor water pump duty cycle to a preset duty cycle, the cooling fan duty cycle to a preset duty cycle, and the generator output torque to be less than or equal to a first torque threshold. When the power battery charge is less than a preset charge threshold, control the vehicle drive mode to a parallel drive mode. The first torque threshold is determined based on the generator rated torque, the first temperature coefficient, and the generator safe torque. The first temperature coefficient is determined based on the generator temperature. The parallel drive mode is used to indicate that the engine and the drive motor provide driving force to the vehicle.

[0015] Furthermore, the generator fault level includes a slight overtemperature level, and the vehicle operating parameters also include the generator rated torque and the generator safe torque. The second determining module is further configured to: in response to the generator fault level being a slight overtemperature level and the engine state being in operation, control the motor water pump duty cycle to a preset duty cycle, the cooling fan duty cycle to a preset duty cycle, the generator output torque being less than or equal to a second torque threshold, the vehicle drive mode being a parallel drive mode, and control the engine state to maintain the operating state, wherein the second torque threshold is determined based on the generator rated torque, the second temperature coefficient, and the generator safe torque. The second temperature coefficient is less than the first temperature coefficient; or, in response to the generator fault level being a slight overheating level and the engine state being a stopped state, the duty cycle of the motor water pump and the duty cycle of the cooling fan are controlled to a preset duty cycle, and the engine state is controlled to switch from a stopped state to a running state; in response to the engine state successfully switching from a stopped state to a running state, the vehicle drive mode is controlled to a parallel drive mode; or, in response to the engine state failing to successfully switch from a stopped state to a running state, the vehicle drive mode is controlled to a pure electric drive mode, wherein the pure electric drive mode is used to indicate that the drive motor provides driving force to the vehicle.

[0016] Furthermore, the generator fault level includes: a moderate overtemperature level. The second determining module is also configured to: in response to the generator fault level being a moderate overtemperature level and the vehicle driving mode being a parallel driving mode, control the motor water pump duty cycle to a preset duty cycle, the cooling fan duty cycle to a preset duty cycle, the engine status to a running state, the generator output torque to a preset output torque, and control the vehicle driving mode to maintain the parallel driving mode; or, in response to the generator fault level being a moderate overtemperature level and the vehicle driving mode not being a parallel driving mode, control the motor water pump duty cycle to a preset duty cycle, the cooling fan duty cycle to a preset duty cycle, the engine status to a stopped state, the generator output torque to a preset output torque, and control the vehicle driving mode to switch to a pure electric driving mode.

[0017] Furthermore, the generator fault level includes: severe overtemperature level, and the vehicle operating parameters also include: target vehicle speed. The second determining module is further configured to: in response to the generator fault level being severe overtemperature level and the vehicle driving mode being parallel drive mode, control the motor water pump duty cycle to a preset duty cycle, the cooling fan duty cycle to a preset duty cycle, the generator output torque to a preset output torque, the engine status to be running, maintain the vehicle driving mode in parallel drive mode, and control the target vehicle speed to be less than a preset speed threshold; or, in response to the generator fault level being severe overtemperature level and the vehicle driving mode not being parallel drive mode, control the motor water pump duty cycle to a preset duty cycle, the cooling fan duty cycle to a preset duty cycle, the generator output torque to a preset output torque, the engine status to be stopped, and control the vehicle driving mode to switch to pure electric drive mode.

[0018] Furthermore, the vehicle control device also includes: a second acquisition module for acquiring the motor cooling water temperature and cooling demand; a third determination module for: determining that the generator temperature is in a normal state in response to the motor cooling water temperature being less than or equal to an eighth temperature threshold, wherein the eighth temperature threshold is less than a first temperature threshold; or, determining that the generator temperature is in a normal state in response to the generator temperature being less than or equal to an eighth temperature threshold; or, determining that the generator temperature is in a normal state in response to the inverter temperature being less than or equal to a ninth temperature threshold, wherein the ninth temperature threshold is less than the eighth temperature threshold; and a second protection module for performing over-temperature protection on the generator based on the cooling demand.

[0019] According to another aspect of the embodiments of this application, a vehicle is also provided, including: a processor; a memory for storing processor-executable instructions; wherein the processor is configured to execute instructions to implement the vehicle control methods in various embodiments of this application.

[0020] According to another aspect of the embodiments of this application, a computer-readable storage medium is also provided, the computer-readable storage medium including a stored executable program, wherein, when the executable program is running, it controls the device where the computer-readable storage medium is located to execute the vehicle control method of various embodiments of this application.

[0021] According to another aspect of the embodiments of this application, a computer program product is also provided, including computer instructions that, when executed by a processor, implement the methods in various embodiments of this application.

[0022] In this embodiment, a graded over-temperature identification and vehicle-wide coordinated control approach is adopted. This involves first acquiring the generator temperature, inverter temperature, and vehicle operating parameters. These parameters include the motor water pump duty cycle, cooling fan duty cycle, generator output torque, engine status, and vehicle drive mode. The motor water pump duty cycle represents the proportion of time the electronic control signal driving the motor water pump is on within the current cycle. The cooling fan duty cycle represents the proportion of time the electronic control signal driving the cooling fan is on within the current cycle. The engine status includes both running and stopped states. The vehicle drive mode includes parallel drive mode and pure electric mode. The system operates in drive mode, and then determines the generator fault level based on generator temperature, inverter temperature, and preset temperature thresholds. The generator fault level is used to determine the degree of generator over-temperature. Then, based on the generator fault level and vehicle operating parameters, an over-temperature protection strategy is determined. Finally, based on the over-temperature protection strategy, the generator is protected against over-temperature. This achieves the goal of accurately matching protection actions under different over-temperature scenarios, thereby improving the comprehensiveness of system protection, robustness in dealing with complex faults, and reliability. This solves the technical problems of incomplete protection, unreasonable limp-out strategies, and low system reliability in related technologies when performing generator over-temperature protection. Attached Figure Description

[0023] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0024] Figure 1 This is a schematic diagram of a hybrid power system based on related technologies;

[0025] Figure 2 This is a flowchart of an optional vehicle control method according to an embodiment of this application;

[0026] Figure 3 This is a schematic diagram of an optional vehicle control method according to an embodiment of this application;

[0027] Figure 4 This is a schematic diagram of another optional vehicle control method according to an embodiment of this application;

[0028] Figure 5 This is a structural block diagram of an optional vehicle control device according to an embodiment of this application. Detailed Implementation

[0029] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0030] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0031] In hybrid vehicles, the generator, as a core component at the crankshaft end of the engine, performs both starting and power generation functions. Under high loads or extreme conditions, it is prone to overheating due to heat accumulation from losses. Related technologies mainly employ power limiting strategies based on temperature thresholds, achieving passive protection by detecting motor temperature and linearly reducing output torque or power. While some solutions introduce power variation gradients to alleviate driving vibrations or implement shutdown protection for internal controller components such as Insulated Gate Bipolar Transistors (IGBTs), these are all limited to the local response of a single assembly, failing to distinguish the functional differences between the generator and the drive motor, and lacking a systematic protection mechanism from the perspective of overall vehicle energy flow and powertrain coordination. Moreover, these methods lack the ability to identify overheating causes; regardless of whether the fault originates from a brief period of high load or cooling system failure, similar derating strategies are used, failing to effectively curb continuous temperature rise under severe conditions. Meanwhile, the limp-riding control strategy fails to incorporate battery charge balancing and redundant power sources, leading to a sharp drop in vehicle range and power interruption under critical faults. It can even trigger a chain reaction of overheating due to inverter weak magnetic current. The overall protection system exhibits a crude response and poor adaptability, making it difficult to guarantee safety and reliability under complex operating conditions. In summary, the relevant technologies still suffer from incomplete protection, unreasonable limp-riding strategies, and low system reliability when performing generator over-temperature protection.

[0032] Figure 1 This is a schematic diagram of a hybrid power system based on related technologies, such as... Figure 1 As shown, the system mainly consists of an engine, generator, motor, battery, clutch, and reduction gear. The engine is mechanically connected to the generator via gear pairs, enabling the generator to convert its mechanical energy into electrical energy while the engine is running. This electrical energy is used to charge the battery or directly power the motor. When the clutch is disengaged, the engine does not directly drive the vehicle; energy conversion is achieved solely through the generator. When the clutch is engaged, the engine torque is transmitted to the wheels through the clutch and reduction gear, achieving parallel drive mode with the motor. The engine, generator, and motor drive the wheels through a transmission mechanism to achieve various operating modes. The battery, as the core of energy storage and release, is monitored and managed by a Battery Management System (BMS). The motor and generator are precisely controlled in terms of torque and speed by their respective motor controllers, namely Motor Control Unit 1 (MCU1, i.e., the drive motor controller) and Motor Control Unit 2 (MCU2, i.e., the generator controller). The engine is regulated by the Engine Management System (EMS). In addition, each controller communicates in real time with the hybrid power management system (HCU) via the Controller Area Network (CAN) bus. The HCU, as the central control unit of the vehicle, comprehensively collects the status and fault information of each component, coordinates the switching of power sources, energy distribution, cooling control and fault limp strategy, so as to realize the safe, efficient and reliable operation of the hybrid power system under normal and fault conditions.

[0033] According to an embodiment of this application, a method embodiment for vehicle control is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0034] Figure 2 This is a flowchart of an optional vehicle control method according to an embodiment of this application, such as... Figure 2 As shown, the method includes the following steps:

[0035] Step S202: Obtain generator temperature, inverter temperature, and vehicle operating parameters. The vehicle operating parameters include motor water pump duty cycle, cooling fan duty cycle, generator output torque, engine status, and vehicle drive mode. The motor water pump duty cycle represents the proportion of time the electronic control signal driving the motor water pump is in the on state during the current cycle. The cooling fan duty cycle represents the proportion of time the electronic control signal driving the cooling fan is in the on state during the current cycle. The engine status includes running state and stopped state. The vehicle drive mode includes parallel drive mode and pure electric drive mode.

[0036] Step S204: Based on the generator temperature, inverter temperature and preset temperature threshold, determine the generator fault level, wherein the generator fault level is used to determine the degree of generator overheating.

[0037] Step S206: Determine the over-temperature protection strategy based on the generator fault level and vehicle operating parameters;

[0038] Step S208: Based on the over-temperature protection strategy, perform over-temperature protection on the generator.

[0039] The generator temperature mentioned above represents the real-time thermodynamic temperature of the coil windings and iron core measured by a temperature sensor installed inside the generator body. It is used to reflect the degree of internal temperature rise caused by the accumulation of copper and iron losses in the generator.

[0040] The inverter temperature mentioned above represents the thermal conductivity temperature of the semiconductor power device region collected by the temperature sensing element arranged near the heat dissipation structure of the generator power inverter module. It is used to characterize the local overheating state caused by switching losses and conduction losses during the alternating conversion of electrical energy.

[0041] The above-mentioned motor-water pump duty cycle represents the proportion of time that the electronic control signal of the drive motor-water pump is in the on state within the current cycle. It quantifies the circulation intensity of the coolant in the generator cooling circuit and is used to characterize the supply level of active heat dissipation capability.

[0042] The aforementioned cooling fan duty cycle refers to the proportion of time during which the electronic control signal driving the cooling fan is in the on state within the current cycle. It reflects the intensity of forced convection cooling of external air flowing through the radiator and is used to characterize the dynamic adjustment degree of the environment's heat dissipation capacity.

[0043] The generator output torque mentioned above represents the actual rotational mechanical torque output by the generator in power generation mode. It reflects the amount of mechanical power consumption borne by the generator as a load device and can indirectly indicate the generator's heat generation rate.

[0044] The engine status mentioned above indicates the current state of the engine, which can be either running or stopped. The engine status information is used to determine whether the power source participates in the energy supply path.

[0045] The aforementioned vehicle drive mode represents the current operating mode of the hybrid system, which can be either parallel drive mode or pure electric drive mode. The vehicle drive mode is determined by the clutch engagement state and the power distribution logic, and is used to characterize the power coupling relationship between the engine and the drive motor.

[0046] The generator temperature, inverter temperature, motor water pump duty cycle, cooling fan duty cycle, generator output torque, engine status, and vehicle drive mode mentioned above together constitute a multi-dimensional state input set used to implement generator over-temperature protection decisions.

[0047] The aforementioned preset temperature thresholds represent multiple temperature judgment benchmark values ​​pre-set in this embodiment of the application, including a first temperature threshold, a second temperature threshold, a third temperature threshold, a fourth temperature threshold, a fifth temperature threshold, a sixth temperature threshold, and a seventh temperature threshold. These thresholds correspond to triggering conditions for different fault levels and are used to distinguish multiple state ranges of the generator from normal operation to severe overheating.

[0048] The generator fault levels described above represent the fault state categories classified after comparing the generator temperature and inverter temperature with preset temperature thresholds at multiple levels. Specifically, these include normal level, minor over-temperature level, mild over-temperature level, moderate over-temperature level, and severe over-temperature level. These levels are used to quantify the current severity of generator over-temperature and serve as the sole basis for selecting subsequent protection strategies.

[0049] The aforementioned over-temperature protection strategy represents a set of preset control commands corresponding to the generator fault level. It is a dynamic response mechanism that is hierarchical, scenario-based, and multi-dimensionally coordinated. The input is the generator fault level, and the output is the specific action to be executed, thereby ensuring that the protection behavior is precisely matched to the severity of the fault. The specific actions may include cooling system control, generator output torque limiting, engine status maintenance, and coordination with vehicle drive mode.

[0050] When determining the generator fault level based on the generator fault level and vehicle operating parameters, the HCU synchronously reads the generator temperature and inverter temperature, and compares them hierarchically with multiple preset temperature thresholds. Based on whether either exceeds the corresponding threshold, the fault level of the generator is determined. The fault level is a composite judgment result integrating the generator and inverter temperatures, thus accurately mapping the actual degree of generator overheating and avoiding misjudgments caused by fluctuations at a single temperature point or sensor errors.

[0051] During the over-temperature protection process for the generator, the HCU, after acquiring the generator fault level, automatically triggers protective actions such as cooling system power regulation, generator torque limiting, engine start-stop control, and vehicle speed limiting according to a predefined over-temperature protection strategy that corresponds one-to-one with the fault level. This protection process does not rely on manual intervention or employ a single derating mode. Instead, it implements differentiated and structured protection responses based on the cause of the over-temperature and the system state, ensuring that the protection behavior is highly consistent with the actual fault risk level.

[0052] Based on steps S202 to S208 above, this embodiment of the application adopts a graded over-temperature identification and vehicle-wide coordinated control approach. This involves first acquiring generator temperature, inverter temperature, and vehicle operating parameters. The vehicle operating parameters include the motor water pump duty cycle, cooling fan duty cycle, generator output torque, engine status, and vehicle drive mode. The motor water pump duty cycle represents the proportion of time the electronic control signal driving the motor water pump is on within the current cycle. The cooling fan duty cycle represents the proportion of time the electronic control signal driving the cooling fan is on within the current cycle. The engine status includes running and stopped states. The vehicle drive mode includes parallel operation. The system employs both drive mode and pure electric drive mode, and determines the generator fault level based on generator temperature, inverter temperature, and preset temperature thresholds. The generator fault level is used to determine the degree of generator over-temperature. Then, based on the generator fault level and vehicle operating parameters, an over-temperature protection strategy is determined. Finally, based on the over-temperature protection strategy, the generator is protected against over-temperature. This achieves the goal of accurately matching protection actions under different over-temperature scenarios, thereby improving the comprehensiveness of system protection, robustness in dealing with complex faults, and reliability. This solves the technical problems of incomplete protection, unreasonable limp-out strategies, and low system reliability in related technologies when performing generator over-temperature protection.

[0053] Optionally, determining the generator fault level based on the generator temperature, inverter temperature, and preset temperature thresholds includes: determining the generator fault level as a slight overtemperature level in response to the generator temperature being less than or equal to a first temperature threshold, or the inverter temperature being less than or equal to a first temperature threshold; or, determining the generator fault level as a mild overtemperature level in response to the generator temperature being greater than or equal to a second temperature threshold, or the inverter temperature being greater than or equal to a third temperature threshold, wherein the second temperature threshold is greater than the first temperature threshold and the third temperature threshold is greater than the second temperature threshold; or, determining the generator fault level as a moderate overtemperature level in response to the generator temperature being greater than or equal to a fourth temperature threshold, or the inverter temperature being greater than or equal to a fifth temperature threshold, wherein the fourth temperature threshold is greater than the second temperature threshold, the fourth temperature threshold is less than the third temperature threshold, and the fifth temperature threshold is greater than the third temperature threshold; or, determining the generator fault level as a severe overtemperature level in response to the generator temperature being greater than or equal to a sixth temperature threshold, or the inverter temperature being greater than or equal to a seventh temperature threshold, wherein the sixth temperature threshold is greater than the fourth temperature threshold, the sixth temperature threshold is less than the fifth temperature threshold, and the seventh temperature threshold is greater than the fifth temperature threshold.

[0054] Specifically, when determining the generator fault level based on generator temperature, inverter temperature, and preset temperature thresholds, the HCU collects generator and inverter temperatures in real time and compares them hierarchically with the preset temperature thresholds. When any temperature parameter meets the triggering condition for a certain level, the corresponding fault level is determined. This judgment logic employs asymmetric, cross-overlapping threshold settings to ensure accurate fault level identification even when the generator and inverter temperatures are not synchronized, avoiding protection failure due to single sensor failure or misjudgment of localized temperature rise.

[0055] Table 1 below illustrates the fault level classification strategy of this application embodiment, as shown in Table 1:

[0056] Table 1

[0057]

[0058] The specific fault level judgment conditions and thresholds are set as follows: First, when the generator temperature is less than or equal to the first temperature threshold, or the inverter temperature is less than or equal to the first temperature threshold, the generator fault level is determined to be a slight over-temperature level. The first temperature threshold can be 110℃.

[0059] Second, when the generator temperature is greater than or equal to the second temperature threshold, or the inverter temperature is greater than or equal to the third temperature threshold, the generator fault level is determined to be a mild overheating level. The second temperature threshold can be 125℃, and the third temperature threshold can be 150℃, that is, the second temperature threshold is greater than the first temperature threshold, and the third temperature threshold is greater than the second temperature threshold.

[0060] Third, when the generator temperature is greater than or equal to the fourth temperature threshold, or the inverter temperature is greater than or equal to the fifth temperature threshold, the generator fault level is determined to be the moderate over-temperature level. The fourth temperature threshold can be 140℃, and the fifth temperature threshold can be 155℃. That is, the fourth temperature threshold is greater than the second temperature threshold and less than the third temperature threshold, and the fifth temperature threshold is greater than the third temperature threshold.

[0061] Fourth, when the generator temperature is greater than or equal to the sixth temperature threshold, or the inverter temperature is greater than or equal to the seventh temperature threshold, the generator fault level is determined to be a severe overtemperature level. The sixth temperature threshold can be 145℃, and the seventh temperature threshold can be 170℃. That is, the sixth temperature threshold is greater than the fourth temperature threshold, and the sixth temperature threshold is less than the fifth temperature threshold, while the seventh temperature threshold is greater than the fifth temperature threshold.

[0062] Based on the above optional embodiments, the embodiments of this application realize refined, asymmetric, and multi-dimensional classification of generator over-temperature state, so that the determination of fault level no longer depends on a single temperature point or linear range, but accurately identifies the abnormal coupling relationship between the generator body and the inverter thermal state through cross-nesting and non-monotonic increasing threshold combinations, significantly improving the robustness, accuracy and anti-interference ability of over-temperature fault identification, and providing a unique, stable and reproducible decision input for the reliable execution of subsequent differentiated protection strategies.

[0063] Optionally, the generator fault level includes a slight over-temperature level, and the vehicle operating parameters also include the power battery charge, the generator rated torque, and the generator safe torque. Based on the generator fault level and the vehicle operating parameters, the over-temperature protection strategy is determined as follows: in response to the generator fault level being a slight over-temperature level, the motor water pump duty cycle and the cooling fan duty cycle are controlled to be preset duty cycles, and the generator output torque is less than or equal to a first torque threshold. When the power battery charge is less than a preset charge threshold, the vehicle drive mode is controlled to be a parallel drive mode. The first torque threshold is determined based on the generator rated torque, a first temperature coefficient, and the generator safe torque. The first temperature coefficient is determined based on the generator temperature. The parallel drive mode is used to indicate that the engine and the drive motor provide driving force to the vehicle.

[0064] The above-mentioned slight overtemperature level is the lowest level in the fault level, corresponding to the generator body temperature being less than or equal to the first temperature threshold of 110°C, or the inverter temperature being less than or equal to the first temperature threshold of 110°C. This indicates that the generator is in a state of slight heat accumulation, the generator torque capacity is limited, and there is a possibility of insufficient power generation, but it has not yet posed a substantial threat to the operation of the system.

[0065] The above-mentioned power battery charge represents the percentage of the power battery's current remaining electrical energy relative to its rated capacity, and is used to assess the overall vehicle's energy reserve level.

[0066] The rated torque of the generator mentioned above represents the maximum rotational torque that the generator can stably output over a long period of time under rated operating conditions, and serves as the benchmark performance parameter for system design.

[0067] The aforementioned generator safety torque represents the maximum permissible output torque calculated based on a thermodynamic model under current temperature and operating conditions, ensuring that the generator will not experience insulation degradation or material deterioration. Furthermore, the generator safety torque is dynamically corrected by the temperature-torque mapping relationship, and its value does not exceed the generator's rated torque.

[0068] The aforementioned first torque threshold represents the upper limit of output torque set to limit the rate of heat generation of the generator under a slight overtemperature level. The first torque threshold is determined by the minimum value among the generator rated torque, the first temperature coefficient, and the generator safe torque. The first temperature coefficient is a normalized derating coefficient calculated based on a preset temperature-coefficient mapping relationship or function curve, with a value ranging from 0.5 to 0.7, and gradually decreasing as the temperature increases. It is used to dynamically adjust the torque limiting intensity.

[0069] The aforementioned preset duty cycle represents the fixed maximum output value of the motor water pump duty cycle and the cooling fan duty cycle set to enhance cooling capacity. It is usually 100% to ensure that the cooling system operates at maximum capacity.

[0070] The parallel drive mode described above indicates a hybrid operating state in which the engine and drive motor participate in driving the vehicle simultaneously. At this time, the clutch is engaged, the engine outputs torque to the wheels through mechanical coupling, and the generator can assist in generating electricity to maintain the balance of the power battery.

[0071] When the generator fault level is classified as minor overtemperature, the specific steps for determining the overtemperature protection strategy based on the generator fault level and vehicle operating parameters are as follows: Upon the HCU determining the generator fault level to be minor overtemperature, the first-level protection action is immediately initiated. This involves adjusting the duty cycles of both the motor water pump and the cooling fan to preset duty cycles to enhance heat dissipation, while simultaneously limiting the generator output torque to no more than a first torque threshold. This first torque threshold is determined by the minimum value among the generator's rated torque, a first temperature coefficient, and the generator's safe torque, ensuring that the torque limitation both meets thermal safety boundaries and possesses temperature adaptability. Simultaneously, if the power battery charge falls below a preset charge threshold, the control unit will actively switch the vehicle's drive mode to parallel drive mode, causing the engine to start and participate in driving. This allows the drive motor to take on the power generation task, actively replenishing the power battery charge and preventing further temperature increases due to continuous high-load generator operation.

[0072] Based on the above optional embodiments, the embodiments of this application realize precise, coordinated, and adaptive protection under slight over-temperature conditions. Specifically, it enhances cooling capacity by setting a preset duty cycle and achieves temperature-related torque derating by dynamically calculating a first torque threshold to avoid excessive limitation of power performance. At the same time, it actively switches to parallel drive mode when the battery is insufficient, using the engine's driving capability to replace the generator's power generation load, thereby alleviating the generator's thermal load at the system level. This achieves the goal of maintaining the vehicle's power continuity and energy balance to the greatest extent possible while ensuring power generation safety.

[0073] Optionally, the generator fault level includes a mild overtemperature level, and the vehicle operating parameters also include the generator rated torque and the generator safe torque. Based on the generator fault level and vehicle operating parameters, the overtemperature protection strategy includes: in response to the generator fault level being a mild overtemperature level and the engine being in an operating state, controlling the motor water pump duty cycle and the cooling fan duty cycle to a preset duty cycle, the generator output torque being less than or equal to a second torque threshold, the vehicle driving mode being a parallel drive mode, and controlling the engine to maintain the operating state. The second torque threshold is based on the generator rated torque, a second temperature coefficient, and the generator... The safe torque is determined, and the second temperature coefficient is less than the first temperature coefficient; or, in response to the generator fault level being a slight overheating level and the engine state being a stopped state, the duty cycle of the motor water pump and the duty cycle of the cooling fan are controlled to a preset duty cycle, and the engine state is controlled to switch from a stopped state to a running state; in response to the engine state successfully switching from a stopped state to a running state, the vehicle drive mode is controlled to a parallel drive mode; or, in response to the engine state failing to successfully switch from a stopped state to a running state, the vehicle drive mode is controlled to a pure electric drive mode, wherein the pure electric drive mode is used to indicate that the drive motor provides driving force to the vehicle.

[0074] The above-mentioned mild overheating level is the second level in the fault level, which corresponds to the generator body temperature being greater than or equal to the second temperature threshold of 125°C, or the inverter temperature being greater than or equal to the third temperature threshold of 150°C. This indicates that the generator is in a state of moderate heat accumulation, the generator torque capacity is limited, there is a risk of start-up failure, and there is a risk of start-up failure or severely limited power generation capacity.

[0075] The rated torque of the generator mentioned above represents the maximum rotational torque that the generator can stably output over a long period of time under rated operating conditions, and serves as the benchmark performance parameter for system design.

[0076] The aforementioned second torque threshold represents the upper limit of output torque set to limit the rate of heat generation of the generator under the mild overtemperature level. The second torque threshold is determined by the minimum value among the generator rated torque, the second temperature coefficient, and the generator safe torque. The second temperature coefficient is a normalized derating coefficient calculated based on a preset temperature-coefficient mapping relationship or function curve. It gradually decreases as the temperature increases and its value is less than the first temperature coefficient. It can be 0.2 to 0.4, indicating that the system's torque limitation intensity is higher than that under the mild overtemperature level, so as to more strictly suppress heat accumulation.

[0077] The pure electric drive mode mentioned above refers to the operating state in which only the drive motor outputs driving force and the engine completely stops participating in power output. At this time, the clutch is in the disengaged state, the generator does not participate in power generation, and the power battery supplies power to the drive motor.

[0078] When the generator fault level is a mild overtemperature level, the specific steps for determining the overtemperature protection strategy based on the generator fault level and vehicle operating parameters are as follows: When the HCU determines that the generator fault level is a mild overtemperature level, if the engine is currently running, the engine will continue to run, the vehicle drive mode will be kept in parallel drive mode, the duty cycle of the motor water pump and the duty cycle of the cooling fan will be set to the preset duty cycle, and the generator output torque will be limited to not exceeding the second torque threshold. The second torque threshold is further reduced from the mild overtemperature level because the second temperature coefficient is less than the first temperature coefficient, reflecting a more stringent protection for higher risks.

[0079] If the engine is currently stopped, the engine start-up logic is immediately activated to switch the engine from a stopped state to a running state, establishing a parallel drive path so that the drive motor can take over the power generation task, thereby reducing the load on the generator. If the engine starts successfully, the vehicle drive mode is switched to parallel drive mode, allowing the vehicle's energy flow to enter a stable and coordinated state. If the engine fails to start, a forced switch to pure electric drive mode is initiated, completely cutting off the generator's participation in energy supply to prevent it from continuing to bear the power generation load under high heat risk, and to prevent the fault from escalating to moderate overheating or equipment damage.

[0080] Based on the above optional embodiments, the embodiments of this application realize differentiated and scenario-based protection responses based on engine status under mild overheating levels. That is, when the engine is available, it actively maintains the parallel mode and strengthens torque limiting protection. When the engine is unavailable, it prioritizes trying to restore the power source coordination capability. If it fails, it completely isolates the generator to ensure that it is disconnected from the power generation load. In this way, while ensuring that the vehicle continues to drive, it minimizes the risk of generator thermal damage and improves the fault tolerance and protection reliability of the system under complex operating conditions.

[0081] Optionally, the generator fault level includes: a moderate overtemperature level. Based on the generator fault level and vehicle operating parameters, the overtemperature protection strategy is determined as follows: in response to the generator fault level being a moderate overtemperature level and the vehicle driving mode being a parallel drive mode, the motor water pump duty cycle is controlled to a preset duty cycle, the cooling fan duty cycle is controlled to a preset duty cycle, the engine status is set to an operating state, the generator output torque is set to a preset output torque, and the vehicle driving mode is controlled to maintain the parallel drive mode; or, in response to the generator fault level being a moderate overtemperature level and the vehicle driving mode not being a parallel drive mode, the motor water pump duty cycle is controlled to a preset duty cycle, the cooling fan duty cycle is controlled to a preset duty cycle, the engine status is set to a stopped state, the generator output torque is set to a preset output torque, and the vehicle driving mode is controlled to switch to a pure electric drive mode.

[0082] The above-mentioned moderate overheating level is the third level in the fault level, which corresponds to the generator body temperature being greater than or equal to the fourth temperature threshold of 140°C, or the inverter temperature being greater than or equal to the fifth temperature threshold of 155°C. This indicates that the generator is in a state of severe heat accumulation, the generator torque capacity is zero, and it cannot start or generate electricity. Moreover, continuing to generate electricity will significantly increase the risk of insulation failure, coil degradation, or cascading damage to the inverter.

[0083] The aforementioned preset output torque represents the zero torque output value forcibly set under the moderate overheating level, that is, the generator output torque is limited to 0 Newton-meters (N·m) to completely cut off its power generation function and prevent further heat generation.

[0084] When the generator fault level is moderate overheating, the specific steps for determining the overheat protection strategy based on the generator fault level and vehicle operating parameters are as follows: When the HCU determines that the generator fault level is moderate overheating, if the vehicle is currently in parallel drive mode, the generator output torque is immediately set to the preset output torque, i.e., zero torque, to keep the engine running and ensure that the drive motor continues to undertake all drive tasks. At the same time, the duty cycle of the motor water pump and cooling fan is increased to the preset duty cycle to enhance heat dissipation and prevent the generator from experiencing a temperature rebound due to residual induced current or mechanical back drag. Meanwhile, the parallel drive mode is maintained to avoid power interruption caused by mode switching.

[0085] If the vehicle is currently in a non-parallel drive mode, i.e., pure electric drive or stopped, the engine will be stopped immediately, the generator output torque will be set to the preset output torque, i.e., zero torque, and the vehicle drive mode will be switched to pure electric drive mode, with the power battery directly driving the drive motor. This completely isolates the generator from the power system, preventing it from generating additional heat due to unexpected power generation loads or external reverse drag, thus ensuring its thermal safety.

[0086] Based on the above optional embodiments, the embodiments of this application realize a precise and adaptive protection response based on the current driving mode under moderate overheating levels. That is, in parallel mode, the system power continuity is maintained and the generator is driven to stop to reduce the heat source. In non-parallel mode, the generator participation is completely cut off and the system is switched to pure electric drive to ensure that it is completely removed from the heat generation path. Thus, while ensuring the vehicle's continuous driving capability, the causes of generator thermal damage are eliminated to the greatest extent, significantly improving the system's response safety and protection effectiveness to moderate overheating faults.

[0087] Optionally, the generator fault level includes a severe overtemperature level, and the vehicle operating parameters also include a target vehicle speed. Based on the generator fault level and the vehicle operating parameters, the overtemperature protection strategy is determined as follows: In response to the generator fault level being a severe overtemperature level and the vehicle driving mode being a parallel drive mode, the duty cycle of the motor water pump is controlled to a preset duty cycle, the duty cycle of the cooling fan is controlled to a preset duty cycle, the generator output torque is controlled to a preset output torque, the engine status is set to running, the vehicle driving mode is maintained in parallel drive mode, and the target vehicle speed is controlled to be less than a preset speed threshold; or, in response to the generator fault level being a severe overtemperature level and the vehicle driving mode not being a parallel drive mode, the duty cycle of the motor water pump is controlled to a preset duty cycle, the duty cycle of the cooling fan is controlled to a preset duty cycle, the generator output torque is controlled to a preset output torque, the engine status is set to a stopped state, and the vehicle driving mode is controlled to switch to pure electric drive mode.

[0088] The above-mentioned severe overtemperature level is the highest level in the fault level, corresponding to a generator body temperature greater than or equal to the sixth temperature threshold of 145°C, or an inverter temperature greater than or equal to the seventh temperature threshold of 170°C. This indicates that the generator and its inverter are in an extreme heat accumulation state, the generator torque capability is zero, the reverse-drive generator speed is limited, and there is a high risk of insulation breakdown, power device damage and complete failure of the cooling system. Ultimate protection measures must be taken.

[0089] The target vehicle speed mentioned above represents the maximum permissible driving speed limit set by the HCU to ensure system safety. The value of the target vehicle speed is calculated based on the mapping relationship between the power battery voltage, generator speed, and vehicle speed, and is used to prevent secondary temperature rise of the inverter caused by weak magnetic current.

[0090] The aforementioned preset speed thresholds represent the maximum vehicle speed limit set under severe overheating conditions to prevent the inverter's temperature from continuously rising due to weak magnetic current. These values ​​are calculated based on the battery voltage, gear ratio, and tire radius. For example, a battery voltage of 200V corresponds to 90km / h, while 300V and above correspond to 120km / h. These thresholds are non-linear and do not dynamically adjust with vehicle speed feedback; rather, they are rigidly limited by the control unit. Different generators have slightly different gear ratios, tire radii, and other parameters, as shown in Table 2 below, which illustrates the preset speed thresholds for a single generator under different battery voltages.

[0091] Table 2

[0092]

[0093] In actual limp control, in addition to protecting the generator, the user experience of limping the vehicle must also be taken into account. Therefore, the preset speed threshold is optimized as shown in Table 3 below:

[0094] Table 3

[0095]

[0096] When the generator fault level is severe overtemperature, the specific steps for determining the overtemperature protection strategy based on the generator fault level and vehicle operating parameters are as follows: When the HCU determines that the generator fault level is severe overtemperature, if the vehicle is currently in parallel drive mode, the generator output torque is immediately set to the preset output torque, i.e., zero torque, to keep the engine running and ensure that the drive motor continues to undertake the drive task. At the same time, the duty cycle of the motor water pump and cooling fan is increased to the preset duty cycle to maximize heat dissipation, and the target vehicle speed is limited to not exceed the preset speed threshold to prevent secondary temperature rise caused by excessive vehicle speed leading to generator speed exceeding the limit and inverter generating weak magnetic current.

[0097] If the vehicle is currently in a non-parallel drive mode, i.e., pure electric drive or stopped, the engine will be immediately stopped, and the generator output torque will be set to the preset output torque, i.e., zero torque. The duty cycle of the motor, water pump and cooling fan will be increased to the preset duty cycle. At the same time, the vehicle drive mode will be switched to pure electric drive mode, completely cutting off the electrical and mechanical coupling between the generator and the power system, ensuring that the vehicle is in an absolutely safe state with no load, no reverse towing and no power generation.

[0098] Based on the above optional embodiments, the embodiments of this application achieve ultimate safety protection based on drive mode and vehicle speed constraints under severe overheating levels. That is, in parallel mode, the inverter is prevented from overheating due to secondary overheating caused by weak magnetic current by forced speed limiting, and in non-parallel mode, the generator is completely isolated to ensure that it is out of all heat generation paths. Thus, while ensuring that the vehicle has low-speed limp-walking capability, the irreversible damage to the core three-electric system caused by chain reaction is avoided to the greatest extent, and the survivability and safety of the system under extreme thermal failure scenarios are significantly improved.

[0099] Optionally, the vehicle control method further includes: acquiring the motor cooling water temperature and cooling demand; determining that the generator temperature is in a normal state in response to the motor cooling water temperature being less than or equal to an eighth temperature threshold, wherein the eighth temperature threshold is less than a first temperature threshold; or, determining that the generator temperature is in a normal state in response to the generator temperature being less than or equal to an eighth temperature threshold; or, determining that the generator temperature is in a normal state in response to the inverter temperature being less than or equal to a ninth temperature threshold, wherein the ninth temperature threshold is less than the eighth temperature threshold; and performing over-temperature protection on the generator based on the cooling demand.

[0100] The aforementioned motor cooling water temperature represents the real-time temperature of the cooling medium collected by a temperature sensor installed in the generator coolant circulation loop, which reflects the actual heat dissipation capability of the cooling system for the generator body.

[0101] The cooling requirements mentioned above represent the required output capacity level of the cooling system, calculated based on a comprehensive assessment of motor cooling water temperature, ambient temperature, vehicle speed, generator operating status, and historical heat load trends. This is used to dynamically adjust the operating intensity of the motor water pump and cooling fan.

[0102] The aforementioned eighth temperature threshold represents the upper limit benchmark value of the cooling water temperature used to determine whether the generator temperature is in a normal state. The value of the eighth temperature threshold is set to be less than the first temperature threshold by 110°C, for example, set to 100°C. The aforementioned eighth temperature threshold is lower than the starting point of slight overheating to ensure that preventive cooling is initiated in the early stage of temperature rise and to avoid entering the overheating zone.

[0103] The aforementioned ninth temperature threshold represents the upper limit reference value of the inverter temperature used to determine whether the generator temperature is in a normal state. The value of the ninth temperature threshold is set to be lower than the eighth temperature threshold, for example, set to 55℃. The aforementioned ninth temperature threshold is much lower than the upper limit of the inverter's normal operating temperature range, and is used to prioritize the identification of local abnormal temperature rises in the inverter, thereby achieving pre-protection of the power module.

[0104] The above-mentioned normal state is the normal level in the generator fault level. In the process of determining whether the generator temperature is in a normal state, the HCU continuously collects the motor cooling water temperature, generator body temperature and inverter temperature, and compares them with the eighth temperature threshold and the ninth temperature threshold respectively. When the motor cooling water temperature does not exceed 100℃, or the generator body temperature does not exceed 100℃, or the inverter temperature does not exceed 55℃, the generator temperature is determined to be in a normal state, indicating that the system is in a safe operating range and there is no need to activate over-temperature protection actions such as derating or mode switching.

[0105] When the generator temperature is under normal conditions, and the generator is over-temperature protected based on cooling demand, the system will actively control the motor water pump and cooling fan to operate in accordance with the duty cycle based on the real-time assessment results of the cooling demand. For example, the output of the water pump and fan will be increased under high ambient temperature or low speed driving conditions to achieve forward adjustment of the generator's heat load. This will establish an effective heat dissipation barrier before the temperature reaches the threshold, and prevent the temperature from exceeding the first temperature threshold due to the lag in cooling response.

[0106] Based on the above optional embodiments, the embodiments of this application realize multi-dimensional, low-threshold, and proactive cooling intervention before the generator temperature reaches the over-temperature level. That is, by setting an eighth temperature threshold and a ninth temperature threshold that are lower than the over-temperature start threshold, an earlier temperature normal state judgment boundary is constructed, and the heat dissipation capacity is dynamically adjusted in combination with cooling demand, so that the cooling system changes from passive response to active prevention, which significantly improves the system's buffering capacity for temperature rise and the response lead of thermal management, and effectively reduces the probability of over-temperature caused by cooling lag.

[0107] In one optional embodiment, the data transmission between the HCU and the motor controller 2 (MCU2) via the CAN bus may be interrupted or abnormal. Specifically, this may manifest as a checksum error, a livecounter error, or a communication timeout. Such interruptions or abnormalities will prevent the HCU from obtaining key status information such as generator body temperature, inverter temperature, and torque feedback in real time, causing the over-temperature protection logic to lose its sensing basis.

[0108] For example, when MCU2 detects an interruption in communication with HCU, to ensure system safety, it adopts the most conservative protection strategy, that is, it executes the processing logic according to the generator overheating level, including controlling the duty cycle of the motor water pump and the cooling fan to the preset duty cycle, controlling the generator output torque to the preset output torque (i.e., zero torque), deciding whether to maintain parallel drive or switch to pure electric drive according to the vehicle drive mode, and limiting the target vehicle speed to no more than the preset speed threshold in parallel mode, so as to avoid the risk of thermal runaway caused by information loss to the greatest extent.

[0109] Figure 3 This is a schematic diagram of an optional vehicle control method according to an embodiment of this application, such as... Figure 3 As shown, this method uses the HCU as its core and integrates a motor coolant temperature sensor, motor controller 1 (drive motor controller), motor controller 2 (generator controller), battery management system, engine management system, fan, water pump, clutch, and other assembly controllers. Each of these assembly controllers monitors and identifies its own fault status in real time and sends this information to the HCU via the CAN bus. The HCU receives relevant component and fault information from the engine, drive motor, generator, battery, and other controllers, identifies the clutch and its own status and faults, and sends control commands to the relevant controllers to coordinate the orderly operation of all components, achieving hybrid drive and regenerative braking functions, and ensuring the vehicle operates safely and reliably according to the driver's needs in the event of a fault.

[0110] Figure 4 This is a schematic diagram of another optional vehicle control method according to an embodiment of this application, such as... Figure 4 As shown, a generator over-temperature protection strategy according to an embodiment of this application is specifically illustrated. This embodiment uses the HCU as the decision-making center and performs over-temperature protection based on the over-temperature level. Specifically, it classifies the over-temperature into five fault levels based on the generator body temperature, inverter temperature, and coolant temperature: normal, slight over-temperature, mild over-temperature, moderate over-temperature, and severe over-temperature, each corresponding to a different combination of control actions.

[0111] Specifically, when the generator is at normal operating temperature, the HCU dynamically adjusts the duty cycle of the motor water pump and cooling fan based on the motor cooling water temperature, ambient temperature, and vehicle speed, i.e., it controls the fan and water pump to ensure cooling requirements.

[0112] When a slight overheating is detected, the HCU will increase the duty cycle of the motor water pump and cooling fan to the maximum, i.e., the maximum cooling, and limit the generator output torque to no more than 50% to 70% of the rated torque, while other controls remain normal. At the same time, when the power battery charge is lower than the set threshold, the engine will be started to enter the parallel drive mode to maintain the power balance.

[0113] When a slight overheating is detected, the HCU will also force the cooling system to run at full load, i.e., maximum cooling, and further limit the generator output torque to 20% to 40% of the rated torque. If the engine is already running, it will prevent shutdown and maintain parallel mode. If the engine is not running, it will attempt to start. If successful, it will maintain parallel mode drive; if it fails, it will switch to pure electric drive.

[0114] When the temperature is determined to be moderately high, the HCU controls the generator output torque to zero, i.e., the generator has zero torque, and the cooling system maintains maximum output. If the vehicle is in parallel mode, the engine is prohibited from stopping to maintain power output. If it is in non-parallel mode, the engine is driven to stop and the vehicle is switched to pure electric mode.

[0115] When the overheating is determined to be severe, the HCU will, while performing zero torque output and full-load operation of the cooling system, forcibly limit the target vehicle speed to no more than the preset speed threshold if the vehicle is in parallel mode, in order to prevent the inverter from overheating again due to the weak magnetic current and maintain parallel drive. If it is in non-parallel mode, it will drive the engine to stop and switch to pure electric drive.

[0116] The above strategy, through a combination of progressively increasing temperature threshold determination, differentiated torque limitation, active intervention of the cooling system, coordinated power source mode and rigid vehicle speed constraints, achieves full-scenario coverage from minor temperature rise warning to extreme thermal failure fallback. It ensures that the generator can obtain the optimal protection response matching its risk level under different fault severity conditions, significantly improving the thermal safety resilience and operational reliability of the system under complex operating conditions.

[0117] Figure 5 This is a structural block diagram of an optional vehicle control device according to an embodiment of this application, such as... Figure 5 As shown, the device includes: a first acquisition module 501, used to acquire generator temperature, inverter temperature, and vehicle operating parameters, wherein the vehicle operating parameters include motor water pump duty cycle, cooling fan duty cycle, generator output torque, engine status, and vehicle drive mode; the motor water pump duty cycle is used to represent the proportion of time the electronic control signal driving the motor water pump is in the on state within the current cycle; the cooling fan duty cycle is used to represent the proportion of time the electronic control signal driving the cooling fan is in the on state within the current cycle; the engine status includes running state and stopped state; and the vehicle drive mode includes parallel drive mode and pure electric drive mode; a first determination module 502, used to determine the generator fault level based on generator temperature, inverter temperature, and a preset temperature threshold, wherein the generator fault level is used to determine the degree of generator over-temperature; a second determination module 503, used to determine an over-temperature protection strategy based on the generator fault level and vehicle operating parameters; and a first protection module 504, used to perform over-temperature protection on the generator based on the over-temperature protection strategy.

[0118] Furthermore, the first determining module 502 is also configured to: determine the generator fault level as a slight overtemperature level in response to the generator temperature being less than or equal to a first temperature threshold, or the inverter temperature being less than or equal to the first temperature threshold; or, determine the generator fault level as a mild overtemperature level in response to the generator temperature being greater than or equal to a second temperature threshold, or the inverter temperature being greater than or equal to a third temperature threshold, wherein the second temperature threshold is greater than the first temperature threshold and the third temperature threshold is greater than the second temperature threshold; or, determine the generator fault level as a moderate overtemperature level in response to the generator temperature being greater than or equal to a fourth temperature threshold, or the inverter temperature being greater than or equal to a fifth temperature threshold, wherein the fourth temperature threshold is greater than the second temperature threshold, the fourth temperature threshold is less than the third temperature threshold, and the fifth temperature threshold is greater than the third temperature threshold; or, determine the generator fault level as a severe overtemperature level in response to the generator temperature being greater than or equal to a sixth temperature threshold, or the inverter temperature being greater than or equal to a seventh temperature threshold, wherein the sixth temperature threshold is greater than the fourth temperature threshold, the sixth temperature threshold is less than the fifth temperature threshold, and the seventh temperature threshold is greater than the fifth temperature threshold.

[0119] Furthermore, the generator fault level includes: a slight over-temperature level, and the vehicle operating parameters also include: power battery charge, generator rated torque, and generator safe torque. The second determining module 503 is also used to: in response to the generator fault level being a slight over-temperature level, control the motor water pump duty cycle to a preset duty cycle, the cooling fan duty cycle to a preset duty cycle, and the generator output torque to be less than or equal to a first torque threshold, and when the power battery charge is less than a preset charge threshold, control the vehicle drive mode to a parallel drive mode, wherein the first torque threshold is determined based on the generator rated torque, a first temperature coefficient, and the generator safe torque, the first temperature coefficient is determined based on the generator temperature, and the parallel drive mode is used to indicate that the engine and drive motor provide driving force for the vehicle.

[0120] Furthermore, the generator fault level includes a slight overtemperature level, and the vehicle operating parameters also include the generator rated torque and the generator safe torque. The second determining module 503 is further configured to: in response to the generator fault level being a slight overtemperature level and the engine being in an operating state, control the motor water pump duty cycle to a preset duty cycle, the cooling fan duty cycle to a preset duty cycle, the generator output torque being less than or equal to a second torque threshold, the vehicle driving mode being a parallel drive mode, and control the engine to maintain the operating state, wherein the second torque threshold is determined based on the generator rated torque, the second temperature coefficient, and the generator safe torque. The second temperature coefficient is less than the first temperature coefficient; or, in response to the generator fault level being a slight overheating level and the engine state being a stopped state, the duty cycle of the motor water pump and the duty cycle of the cooling fan are controlled to a preset duty cycle, and the engine state is controlled to switch from a stopped state to a running state; in response to the engine state successfully switching from a stopped state to a running state, the vehicle drive mode is controlled to a parallel drive mode; or, in response to the engine state failing to successfully switch from a stopped state to a running state, the vehicle drive mode is controlled to a pure electric drive mode, wherein the pure electric drive mode is used to indicate that the drive motor provides driving force to the vehicle.

[0121] Furthermore, the generator fault level includes: a moderate overtemperature level. The second determining module 503 is also configured to: in response to the generator fault level being a moderate overtemperature level and the vehicle driving mode being a parallel driving mode, control the motor water pump duty cycle to a preset duty cycle, the cooling fan duty cycle to a preset duty cycle, the engine status to a running state, the generator output torque to a preset output torque, and control the vehicle driving mode to maintain the parallel driving mode; or, in response to the generator fault level being a moderate overtemperature level and the vehicle driving mode not being a parallel driving mode, control the motor water pump duty cycle to a preset duty cycle, the cooling fan duty cycle to a preset duty cycle, the engine status to a stopped state, the generator output torque to a preset output torque, and control the vehicle driving mode to switch to a pure electric driving mode.

[0122] Furthermore, the generator fault level includes: severe overtemperature level, and the vehicle operating parameters also include: target vehicle speed. The second determining module 503 is also used to: in response to the generator fault level being severe overtemperature level and the vehicle driving mode being parallel driving mode, control the motor water pump duty cycle to a preset duty cycle, the cooling fan duty cycle to a preset duty cycle, the generator output torque to a preset output torque, the engine status to be running, the vehicle driving mode to maintain parallel driving mode, and control the target vehicle speed to be less than a preset speed threshold; or, in response to the generator fault level being severe overtemperature level and the vehicle driving mode not being parallel driving mode, control the motor water pump duty cycle to a preset duty cycle, the cooling fan duty cycle to a preset duty cycle, the generator output torque to a preset output torque, the engine status to be stopped, and control the vehicle driving mode to switch to pure electric driving mode.

[0123] Furthermore, the vehicle control device also includes: a second acquisition module 505, used to acquire the motor cooling water temperature and cooling demand; a third determination module 506, used to: determine that the generator temperature is in a normal state in response to the motor cooling water temperature being less than or equal to an eighth temperature threshold, wherein the eighth temperature threshold is less than a first temperature threshold; or, determine that the generator temperature is in a normal state in response to the generator temperature being less than or equal to an eighth temperature threshold; or, determine that the generator temperature is in a normal state in response to the inverter temperature being less than or equal to a ninth temperature threshold, wherein the ninth temperature threshold is less than the eighth temperature threshold; and a second protection module 507, used to perform over-temperature protection on the generator based on the cooling demand.

[0124] According to another aspect of the embodiments of this application, a vehicle is also provided, including: a processor; a memory for storing processor-executable instructions; wherein the processor is configured to execute instructions to implement the vehicle control methods in various embodiments of this application.

[0125] According to another aspect of the embodiments of this application, a computer-readable storage medium is also provided, the computer-readable storage medium including a stored executable program, wherein, when the executable program is running, it controls the device where the computer-readable storage medium is located to execute the vehicle control method of various embodiments of this application.

[0126] According to another aspect of the embodiments of this application, a computer program product is also provided, including computer instructions that, when executed by a processor, implement the methods in various embodiments of this application.

[0127] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0128] In the above embodiments of this application, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0129] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0130] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0131] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0132] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, read-only memory (ROM), random access memory (RAM), portable hard drive, magnetic disk, or optical disk.

[0133] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A vehicle control method, characterized in that, include: The system acquires generator temperature, inverter temperature, and vehicle operating parameters. The vehicle operating parameters include motor water pump duty cycle, cooling fan duty cycle, generator output torque, engine status, and vehicle drive mode. The motor water pump duty cycle represents the proportion of time the electronic control signal driving the motor water pump is on in the current cycle. The cooling fan duty cycle represents the proportion of time the electronic control signal driving the cooling fan is on in the current cycle. The engine status includes running and stopped states. The vehicle drive mode includes parallel drive mode and pure electric drive mode. Based on the generator temperature, the inverter temperature, and a preset temperature threshold, the generator fault level is determined, wherein the generator fault level is used to determine the degree of generator overheating; Based on the generator fault level and the vehicle operating parameters, determine the over-temperature protection strategy; Based on the aforementioned over-temperature protection strategy, the generator is protected against over-temperature.

2. The vehicle control method according to claim 1, characterized in that, The determination of the generator fault level based on the generator temperature, the inverter temperature, and a preset temperature threshold includes: In response to the generator temperature being less than or equal to a first temperature threshold, or the inverter temperature being less than or equal to the first temperature threshold, the generator fault level is determined to be a minor overtemperature level; or, In response to the generator temperature being greater than or equal to a second temperature threshold, or the inverter temperature being greater than or equal to a third temperature threshold, the generator fault level is determined to be a mild overtemperature level, wherein the second temperature threshold is greater than the first temperature threshold, and the third temperature threshold is greater than the second temperature threshold; or, In response to the generator temperature being greater than or equal to a fourth temperature threshold, or the inverter temperature being greater than or equal to a fifth temperature threshold, the generator fault level is determined to be a moderate overtemperature level, wherein the fourth temperature threshold is greater than the second temperature threshold, the fourth temperature threshold is less than the third temperature threshold, and the fifth temperature threshold is greater than the third temperature threshold; or, In response to the generator temperature being greater than or equal to a sixth temperature threshold, or the inverter temperature being greater than or equal to a seventh temperature threshold, the generator fault level is determined to be a severe overtemperature level, wherein the sixth temperature threshold is greater than the fourth temperature threshold, the sixth temperature threshold is less than the fifth temperature threshold, and the seventh temperature threshold is greater than the fifth temperature threshold.

3. The vehicle control method according to claim 1, characterized in that, The generator fault level includes: minor overtemperature level. The vehicle operating parameters also include: power battery charge, generator rated torque, and generator safe torque. The overtemperature protection strategy determined based on the generator fault level and vehicle operating parameters includes: In response to the generator fault level being the slight overtemperature level, the duty cycle of the motor water pump and the cooling fan are controlled to be the preset duty cycle, and the generator output torque is less than or equal to a first torque threshold. When the power battery charge is less than a preset charge threshold, the vehicle drive mode is controlled to be the parallel drive mode. The first torque threshold is determined based on the generator rated torque, a first temperature coefficient, and the generator safe torque. The first temperature coefficient is determined based on the generator temperature. The parallel drive mode indicates that the engine and drive motor provide driving force to the vehicle.

4. The vehicle control method according to claim 1, characterized in that, The generator fault level includes a slight overtemperature level, and the vehicle operating parameters also include the generator rated torque and the generator safe torque. The determination of the overtemperature protection strategy based on the generator fault level and the vehicle operating parameters includes: In response to the generator fault level being the slight overtemperature level and the engine state being the operating state, the system controls the motor water pump duty cycle to a preset duty cycle, the cooling fan duty cycle to the preset duty cycle, the generator output torque to be less than or equal to a second torque threshold, the vehicle drive mode to the parallel drive mode, and controls the engine state to maintain the operating state, wherein the second torque threshold is determined based on the generator rated torque, a second temperature coefficient, and the generator safe torque, and the second temperature coefficient is less than a first temperature coefficient; or, In response to the generator fault level being the slight overtemperature level and the engine state being the stopped state, the duty cycle of the motor water pump and the duty cycle of the cooling fan are controlled to be the preset duty cycle, and the engine state is controlled to switch from the stopped state to the running state. In response to the engine successfully switching from the stopped state to the running state, the vehicle drive mode is controlled to the parallel drive mode; or, In response to the engine state failing to switch from the stopped state to the running state, the vehicle drive mode is controlled to the pure electric drive mode, wherein the pure electric drive mode is used to indicate that the drive motor provides driving force to the vehicle.

5. The vehicle control method according to claim 1, characterized in that, The generator fault level includes: moderate overheating level. The determination of the overheating protection strategy based on the generator fault level and the vehicle operating parameters includes: In response to the generator fault level being the moderate overtemperature level and the vehicle drive mode being the parallel drive mode, the system controls the motor water pump duty cycle to a preset duty cycle, the cooling fan duty cycle to the preset duty cycle, the engine status to the operating status, the generator output torque to a preset output torque, and controls the vehicle drive mode to maintain the parallel drive mode; or, In response to the generator fault level being the moderate overheat level and the vehicle driving mode not being the parallel drive mode, the system controls the motor water pump duty cycle to the preset duty cycle, the cooling fan duty cycle to the preset duty cycle, the engine state to the stopped state, the generator output torque to the preset output torque, and controls the vehicle driving mode to switch to the pure electric drive mode.

6. The vehicle control method according to claim 1, characterized in that, The generator fault level includes: severe overtemperature level, and the vehicle operating parameters also include: target vehicle speed. The determination of the overtemperature protection strategy based on the generator fault level and the vehicle operating parameters includes: In response to the generator fault level being the severe overtemperature level and the vehicle drive mode being the parallel drive mode, the following controls are implemented: the motor water pump duty cycle is set to a preset duty cycle, the cooling fan duty cycle is set to the preset duty cycle, the generator output torque is set to a preset output torque, the engine status is set to the operating status, the vehicle drive mode is maintained as the parallel drive mode, and the target vehicle speed is controlled to be less than a preset speed threshold; or, In response to the generator fault level being the severe overtemperature level and the vehicle drive mode not being the parallel drive mode, the system controls the motor water pump duty cycle to the preset duty cycle, the cooling fan duty cycle to the preset duty cycle, the generator output torque to the preset output torque, the engine status to the stopped state, and controls the vehicle drive mode to switch to the pure electric drive mode.

7. The vehicle control method according to claim 2, characterized in that, The method further includes: Obtain the motor cooling water temperature and cooling requirements; In response to the motor cooling water temperature being less than or equal to an eighth temperature threshold, it is determined that the generator temperature is in a normal state, wherein the eighth temperature threshold is less than the first temperature threshold; or, In response to the generator temperature being less than or equal to the eighth temperature threshold, it is determined that the generator temperature is in a normal state; or, In response to the inverter temperature being less than or equal to a ninth temperature threshold, it is determined that the generator temperature is in a normal state, wherein the ninth temperature threshold is less than the eighth temperature threshold; Based on the aforementioned cooling requirements, the generator is equipped with over-temperature protection.

8. A vehicle, characterized in that, include: processor; Memory used to store the processor's executable instructions; The processor is configured to execute the instructions to implement the vehicle control method according to any one of claims 1 to 7.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored executable program, wherein, when the executable program is executed, it controls the device on which the storage medium is located to perform the vehicle control method according to any one of claims 1 to 7.

10. A computer program product, characterized in that, The computer program product includes computer instructions that, when executed by a processor, implement the vehicle control method as described in any one of claims 1 to 7.

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