Hybrid vehicle power system predictive thermal protection and power distribution method and system

Abstract

The application discloses a hybrid vehicle power system predictive thermal protection and power distribution method and system, which constructs a component temperature prediction model coupled with multiple boundary conditions through a closed loop process of driving condition perception, power system mode decision, component temperature prediction, power limitation and mode optimization, executes graded engine power limitation and active motor torque limitation based on the prediction results, and optimizes the power system series-parallel mode, electric drive torque distribution and electric quantity strategy; the system corresponds to a perception module, a prediction module, a limitation control module and an optimization module, and realizes collaborative control of the cooling system and the power system. The application realizes early prediction and active intervention of over-temperature risk, minimizes power attenuation under the premise of guaranteeing thermal safety of the power system, improves driving smoothness, slows down component thermal aging, and enhances adaptability of the vehicle in extreme conditions.

Description

Technical Field

[0001] This invention relates to the field of thermal management and power control technology for hybrid vehicles, specifically to a predictive thermal protection and power distribution method and system for a hybrid vehicle powertrain. Background Technology

[0002] Hybrid vehicles are widely promoted due to their advantages in balancing energy conservation and emission reduction with power performance. Their power systems consist of core components such as engines, drive motors, and power batteries. Thermal management of the power system under complex operating conditions has become a core technological bottleneck in the industry. Under extreme conditions of high load, such as climbing hills at high altitudes, continuous high-speed overtaking, and driving under full load, the heat generation power of various components in the power system increases sharply. However, the cooling system is limited by physical boundaries such as radiator size, fan power, water pump flow rate, and overall vehicle layout, and its heat exchange capacity has an inherent upper limit. This can easily lead to a contradiction where the heat dissipation rate lags behind the heat generation rate, causing the temperature of core components to rise rapidly and triggering the over-temperature protection mechanism.

[0003] Currently, the industry generally adopts a passive thermal protection and power torque limiting control scheme based on temperature threshold. The core of this scheme is a "post-event remediation" type control logic. It collects the power system temperature signal in real time through sensors. When the temperature reaches the preset safety threshold, the controller forcibly reduces the engine power and motor torque by a fixed ratio until the temperature drops back to the safe range. The cooling system only acts as a passive heat dissipation unit and does not participate in active regulation.

[0004] The existing solution has several technical flaws: First, it is only passively triggered based on real-time temperature thresholds without predicting over-temperature risks, resulting in a delayed control response. Second, it uses a fixed ratio to forcibly limit torque after over-temperature, without dynamically distributing power based on operating conditions and cooling system margin, leading to severe power attenuation and poor driving smoothness. Third, it cannot suppress the heat accumulation effect, causing the power system to repeatedly experience a "over-temperature-torque-temperature recovery" cycle, which exacerbates component thermal aging and reduces the overall vehicle lifespan. Fourth, the cooling system and power distribution strategy lack closed-loop coordination, making it impossible to maximize the use of heat dissipation margin and achieve a balance between thermal safety and power performance.

[0005] Therefore, there is an urgent need for a predictive thermal protection and intelligent power distribution scheme that can predict overheating risks in advance, dynamically adjust power output, and achieve synergy between cooling and power systems, in order to solve the technical pain points of existing passive strategies. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide a...

[0007] To achieve the above-mentioned technical effects, the present invention adopts the following technical solution:

[0008] According to a first aspect of the present invention, a predictive thermal protection and power distribution method for a hybrid vehicle powertrain system is provided, comprising the following steps:

[0009] Step 1: Driving condition perception. The system collects vehicle operating condition parameters, environmental parameters, and powertrain status parameters through sensors and detection units, and transmits them to the vehicle controller.

[0010] Step 2: Powertrain mode decision-making. The vehicle controller determines the initial operating mode of the powertrain based on the collected parameters, including series-parallel mode, drive type allocation mode, and power management mode.

[0011] Step 3: Component temperature prediction. Based on a temperature prediction model coupled with multiple boundary conditions, combined with the cooling system capacity boundary, vehicle operating condition boundary, ambient temperature boundary and power system temperature rise characteristics, the model predicts the changing trends of engine coolant temperature and motor winding temperature, and judges the risk of overheating by combining preset engine coolant temperature and motor winding temperature thresholds.

[0012] Step 4: Power limiting and mode optimization. Based on the temperature prediction results, implement graded engine power limiting and active motor torque limiting, and perform forward-looking optimization of the power system operation mode to form closed-loop dynamic control.

[0013] The graded engine power limiting is achieved by: based on the engine coolant temperature prediction threshold, combined with real-time vehicle speed and real-time ambient temperature, retrieving a preset corresponding engine allowable output power matching table, and performing differentiated, graded power limiting; the active motor torque limiting is achieved by: based on the motor winding temperature prediction threshold, performing step-by-step peak torque limiting based on the motor efficiency MAP; different winding temperature thresholds correspond to different torque limiting intensities, achieving smooth torque limiting; the power system mode optimization includes: switching between series and parallel modes based on the efficiency status after engine power limiting to optimize the energy flow path; adjusting the torque output ratio of the front and rear motors based on the front and rear motor temperature prediction results to balance the thermal load; and switching between power preservation mode and power consumption mode based on the engine coolant temperature prediction results to reserve power for high-load conditions;

[0014] In step 1, the vehicle operating condition parameters include vehicle speed, actual wheel-side output power, and real-time motor operating condition point; the environmental parameters include real-time ambient temperature; and the power system status parameters include remaining battery charge, motor efficiency MAP, motor cooling system flow rate, motor inlet water temperature, and real-time engine operating power.

[0015] Optionally, in step 3, the engine coolant temperature prediction is based on the engine operating power, the heat exchange capacity of the cooling system, the vehicle speed and the ambient temperature, and the predicted coolant temperature value is calculated through the engine temperature rise characteristic model; the motor winding temperature prediction is based on the cooling flow rate, the motor inlet coolant temperature, the motor operating point and the motor efficiency MAP, and the predicted winding temperature value is calculated through the motor temperature rise characteristic model.

[0016] Optionally, after step 4 is executed, operating conditions and temperature parameters are continuously collected, temperature predictions are updated in real time, and limiting and optimization strategies are dynamically adjusted; power output is smoothly restored after the temperature drops back to the safe range.

[0017] According to a second aspect of the present invention, a predictive thermal protection and intelligent power distribution system for a hybrid vehicle powertrain is provided for implementing the above-described method, comprising:

[0018] The sensing module is used to collect vehicle operating condition parameters, environmental parameters, and powertrain status parameters, and output them after preprocessing.

[0019] The prediction module has a built-in component temperature prediction model coupled with multiple boundary conditions, which is used to predict engine water temperature, motor winding temperature and over-temperature risk in a forward-looking manner.

[0020] The limiting module is used to generate and issue graded engine power limiting commands and active motor torque limiting commands based on temperature prediction results;

[0021] The optimization module is used to generate commands for series-parallel mode switching, electric drive torque distribution, and power strategy optimization based on the control results and temperature prediction results.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. Improve driving experience and avoid sudden power drop-off: Through forward-looking temperature prediction and graded power limiting control, a smooth transition of power output is achieved, effectively solving the problem of sudden and significant power drop-off after overheating in existing passive strategies, and improving the smoothness of vehicle driving and user confidence in handling.

[0024] 2. Reduce component thermal aging and improve vehicle thermal robustness: By actively intervening in advance to suppress the thermal accumulation effect of the power system, avoid repeated cycles of "overheating-torque limiting-temperature recovery", reduce the thermal aging of core components such as engine, motor, and power battery, extend the service life of components, and improve the operational reliability of the whole vehicle throughout its entire life cycle.

[0025] 3. Achieve a precise balance between thermal safety and power performance: Based on a dynamic and hierarchical limit control strategy with multi-dimensional boundary conditions, the power output is precisely adjusted according to the actual degree of thermal risk, so as to retain the vehicle's power performance to the maximum extent while ensuring thermal safety and avoiding unnecessary power loss.

[0026] 4. Improve energy utilization efficiency and optimize range performance: Through forward-looking optimization of the power system mode, energy flow path is planned in advance, heat load is balanced, and power capacity is reserved to avoid energy waste caused by passive torque limiting, effectively improving the overall energy efficiency and power battery range performance of hybrid vehicles.

[0027] 5. Enhanced adaptability to extreme operating conditions: The closed-loop control architecture provided by this invention can adapt to extreme operating conditions where the cooling system is overloaded. It maintains stable power output and thermal safety in scenarios such as high-altitude climbing, high-temperature high-speed driving, and fully loaded driving, significantly improving the vehicle's adaptability to complex driving environments. Attached Figure Description

[0028] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0029] Figure 1 This is a spatial layout simulation diagram of the method described in the first embodiment;

[0030] Figure 2 The image shows a simulation of the engine coolant temperature using the method described in the first embodiment.

[0031] Figure 3 This is a flowchart of the technical solution of the method described in the first embodiment. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0033] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0034] It should be noted that similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, all directional indications (such as up, down, left, right, front, back, bottom, etc.) in this application are only used to explain the relative positional relationships and movements between components in a specific orientation (as shown in the figures). If the specific orientation changes, the directional indication will also change accordingly. Furthermore, descriptions involving "first," "second," etc., in this application are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated.

[0035] This embodiment provides a predictive thermal protection and power distribution method for a hybrid vehicle powertrain. Through a closed-loop control logic of "prediction-limitation-optimization," and through the coordinated cooperation of the sensing module and the execution module, predictive thermal protection and intelligent power distribution of the powertrain are achieved. By considering boundary conditions such as the vehicle cooling system boundary, the actual driving conditions of the customer, and the ambient temperature, the method predicts the temperature performance of the core components of the powertrain (such as engine coolant temperature, motor intake air temperature, and motor winding temperature). Based on the prediction results, the method intelligently allocates power demand and optimizes the vehicle operating mode, minimizing the limitation of the powertrain under heavy load conditions.

[0036] like Figure 1 As shown, the technical solution flow of this embodiment includes: driving condition perception → power system mode decision → component temperature prediction → power limitation and mode optimization, specifically:

[0037] Step 1: Driving Condition Perception

[0038] By deploying various sensors and detection units throughout the vehicle and powertrain, real-time acquisition of all-dimensional operating parameters is achieved. The collected parameters cover three major categories: vehicle operating condition parameters, environmental parameters, and powertrain status parameters. This provides complete and accurate basic data support for subsequent mode decisions and temperature prediction. The specific data collected and their sources are as follows:

[0039] Vehicle operating parameters: Real-time vehicle speed is collected through vehicle speed sensor, actual output power of wheel side is collected through wheel side power detection unit, and real-time operating points of motor (speed and torque matching value) are collected through motor controller (MCU).

[0040] Environmental parameters: Real-time ambient temperature is collected via an external ambient temperature sensor;

[0041] Power system status parameters: The remaining power of the power battery is collected through the battery management system (BMS), the pre-calibrated motor efficiency MAP is retrieved through the MCU, the real-time flow of the motor cooling system is collected through the cooling pipe flow sensor, the motor inlet water temperature is collected through the cooling pipe temperature sensor, and the real-time operating power of the engine is collected through the engine electronic control unit (ECU).

[0042] All the above-mentioned collected parameters are transmitted to the vehicle controller (VCU) in real time via the vehicle's CAN bus. The collection frequency is adapted to the changes in the vehicle's operating conditions to ensure the real-time performance and validity of the parameters, without the need for additional testing equipment.

[0043] Step 2: Dynamics System Mode Decision

[0044] Based on the real-time parameters collected in step 1, the vehicle controller (VCU) determines the initial operating mode of the power system in accordance with the core principles of vehicle power demand and energy utilization efficiency. The mode decision covers three major dimensions: series and parallel mode, drive form allocation mode, and power management mode.

[0045] Step 3: Component Temperature Prediction

[0046] A component temperature prediction model coupled with multiple boundary conditions is constructed, specifically including an engine temperature rise characteristic model and a motor temperature rise characteristic model. All real-time parameters collected in step 1 are input into this model. This model integrates the cooling system capacity boundary (radiator heat exchange capacity, fan power, water pump flow rate), the vehicle operating condition boundary (vehicle speed, wheel-side power, motor operating point), the ambient temperature boundary (real-time ambient temperature), and the coupled temperature rise characteristics of multiple components in the powertrain. Through the coupled calculation of multi-dimensional parameters, it proactively predicts the temperature change trend of core components in the powertrain. The core prediction objects are engine coolant temperature and motor winding temperature, while also considering the prediction of related temperature parameters such as electric drive coolant temperature. The specific prediction logic is as follows:

[0047] Engine coolant temperature prediction: Based on the engine's real-time operating power, cooling system heat exchange capacity, real-time vehicle speed and ambient temperature, the engine coolant temperature prediction value is calculated and output under different operating conditions through a preset engine temperature rise characteristic model. At the same time, it is determined whether the preset temperature threshold is exceeded. If it is exceeded, an over-temperature warning is triggered.

[0048] Motor winding temperature prediction: Based on the motor cooling system flow rate, motor inlet water temperature, and real-time motor operating conditions, the motor efficiency MAP is retrieved to calculate the real-time heat generation of the motor. Combined with the preset motor temperature rise characteristic model, the predicted temperature of the motor winding body is calculated, and it is determined whether it exceeds the preset temperature threshold. If it does, an over-temperature warning is triggered.

[0049] The core of this step is forward-looking prediction. Unlike existing technologies that rely solely on passive sensing through real-time temperature acquisition, this step uses coupled calculations of multiple boundary conditions to predict over-temperature risks before the core component temperature reaches a safe threshold, providing a basis for decision-making regarding subsequent power limiting and mode optimization.

[0050] Step 4: Power Limiting and Mode Optimization

[0051] Based on the core component temperature prediction results from step 3, if an overheating risk is anticipated, the Vehicle Control Unit (VCU) immediately activates power limiting and powertrain mode optimization strategies. First, it suppresses core component temperature rise at the source through tiered power / torque limiting. Then, it further balances thermal load and optimizes energy flow paths through mode optimization. While ensuring powertrain thermal safety, it minimizes power loss and improves driving smoothness. Specifically:

[0052] 4.1 Power Limitation Strategy Based on Engine Coolant Temperature Prediction Results

[0053] Based on the engine coolant temperature prediction value output in step 3, when it is predicted that the coolant temperature will reach a preset threshold (108℃ or 113℃ in this embodiment), the vehicle control unit (VCU) matches the corresponding allowable engine output power according to the real-time vehicle speed and real-time ambient temperature, and executes dynamic graded power limiting. The specific execution logic is as follows:

[0054] A coupled model of the Amesim powertrain and thermal management system is established, inputting vehicle boundary conditions such as vehicle speed, ambient temperature, and vehicle weight. By adjusting different vehicle weights (e.g., trailer or fully loaded), frontal area, drag coefficient, and rolling resistance coefficient, the engine power and engine coolant temperature under different vehicle load conditions (i.e., different engine power) are calculated. The simulation calculation formulas for the operating conditions in this embodiment are as follows:

[0055] (1) Overall vehicle resistance: ;

[0056] (2) Climbing resistance: ;

[0057] (3) Wind resistance: ;

[0058] (4) Rolling resistance: ;

[0059] (5) Wind resistance:

[0060] (6) Heat exchange correlation:

[0061]

[0062]

[0063] Where Fres is the total vehicle resistance; Fcl is the climbing resistance; Faero is the air resistance; Froll is the rolling resistance; gain is the gain coefficient of rolling resistance; mass is the vehicle mass; g is the acceleration due to gravity; α is the road gradient; ρair is the air density; Sx is the vehicle's frontal area; Cx is the drag coefficient; v is the vehicle speed; vwind is the wind speed; f is the basic rolling resistance coefficient; k is the velocity coefficient of the first term of rolling resistance; wind is the velocity coefficient of the square term of rolling resistance; ΔP is the pressure loss; K is the local resistance coefficient; ρ is the fluid density; Xareaint is the internal flow cross-sectional area; Q is the volumetric flow rate; Φ is the total heat exchange; ϵi is the efficiency of the i-th heat exchanger; Φmax,i is the theoretical maximum heat exchange of the i-th heat exchanger; Cmin,i is the smaller of the heat capacity flow rates; Tint,in,i is the internal fluid inlet temperature; and Tint,in,i is the external fluid inlet temperature.

[0064] Using the above simulation model, the following is performed: Figure 1 The simulation shown depicts a three-stage cooling system arranged from left to right: first, two low-temperature radiators, one large and one small, are arranged side-by-side to cool the electric drive circuit and engine intake; in the middle is the condenser, which handles air conditioning and battery pack cooling; and finally, the high-temperature radiator is used for controlling the engine coolant temperature.

[0069] The above simulation process yields the following results: Figure 2 The engine coolant temperature simulation diagram shown below is illustrated in Tables 1 and 2. In the table, the orange line represents engine power, the blue line represents vehicle speed, and the red line represents engine coolant temperature. Based on the engine coolant temperature simulation diagram, the allowable output power matching table is obtained.

[0070] When the engine coolant temperature is predicted to reach 108℃, the vehicle control unit (VCU) retrieves the preset engine allowable output power matching table (as shown in Table 1 below) based on the current real-time vehicle speed (10km / h~170km / h) and real-time ambient temperature (25℃, 38℃, 43℃, 49℃). The maximum output power of the engine is limited according to the values ​​in the table. The matching allowable output power is adjusted differently depending on the vehicle speed and ambient temperature to avoid excessive power loss caused by fixed proportional power limiting.

[0071] Table 1. Permissible engine output power (kW) at a water temperature of 108℃

[0072] To facilitate understanding of the data in the table, the following example illustrates the situation: When the engine coolant temperature is predicted to reach 108℃, the vehicle speed is 90km / h, and the actual ambient temperature is 25℃, the maximum output power of the engine will be limited to 72kW to avoid unnecessary power loss.

[0073] When the engine coolant temperature is predicted to reach 113℃, the engine's allowable output power matching standard is further adjusted based on the power limit of 108℃. The corresponding preset matching table is retrieved (as shown in Table 2 below), and a stricter power limit is implemented according to the values ​​in the table to enhance the engine temperature rise suppression effect and ensure engine thermal safety.

[0074] Table 2. Allowable engine output power (kW) at a water temperature of 113℃

[0075] To facilitate understanding of the data in the table, the following example illustrates the situation: When the engine coolant temperature is predicted to reach 113℃, the vehicle speed is 90km / h, and the actual ambient temperature is 25℃, the maximum output power of the engine will be limited to 103kW to avoid unnecessary power loss.

[0076] The core of this strategy is differentiated and graded power limiting. Based on the dynamic changes in water temperature prediction threshold, vehicle speed, and ambient temperature, the allowable output power of the engine is adjusted in real time, rather than the fixed proportional forced power limiting of existing technologies. While suppressing water temperature rise, it maximizes the preservation of the engine's power output capability and adapts to the power requirements of different operating conditions.

[0077] 4.2 Torque Limiting Strategy Based on Motor Winding Temperature Prediction Results

[0078] Based on the predicted motor winding temperature output in step 3, when the winding temperature is predicted to reach a preset threshold (130℃ or 140℃), the vehicle control unit (VCU) performs active, step-by-step torque limiting based on the motor cooling system parameters and the motor's real-time operating conditions. This reduces heat generation from the source by weakening the motor's peak torque, thus suppressing the winding temperature rise. The specific execution logic is as follows:

[0079] When it is predicted that the winding temperature will reach 130℃ after the motor has been running continuously, the vehicle controller (VCU) retrieves the preset motor efficiency MAP and limits the peak torque of the motor step by step according to the preset grading rules of the MAP. The torque limit range is adapted to the motor operating point to avoid sudden and large reduction in torque and achieve smooth torque limiting.

[0080] When it is predicted that the winding temperature will reach 140℃ after continuous operation of the motor, the torque limit standard is further tightened on the basis of the 130℃ torque limit, the peak torque reduction is increased, the motor temperature rise suppression effect is strengthened, the motor winding temperature is kept within a safe range, and the long-term reliability of the motor is guaranteed.

[0081] This strategy is an active, pre-emptive torque limiting mechanism, which differs from the passive, forced torque limiting mechanism that is triggered only after overheating in existing technologies. It intervenes in advance before the winding temperature reaches the safety threshold, thus avoiding the risk of overheating and achieving smooth torque adjustment, thereby improving driving smoothness.

[0082] 4.3 Dynamic System Model Optimization Strategy Based on Predicted Temperature

[0083] After implementing the engine power and motor torque limits, the vehicle control unit (VCU) further optimizes the initial operating mode of the powertrain based on the predicted temperatures of core components. Through three dimensions—series-parallel mode switching, electric drive torque distribution, and power strategy optimization—it achieves a deep balance between thermal safety and power performance, maximizing the utilization of cooling system capacity and powertrain efficiency. The specific optimization logic is as follows:

[0084] Series-Parallel Mode Switching: The Vehicle Control Unit (VCU) switches the power system's series-parallel mode in advance based on the engine's torque characteristics after power limiting and the real-time efficiency of the electric drive system. If the engine operates in an inefficient range after power limiting, it immediately switches from parallel mode to series mode, where the engine only drives the generator to generate electricity, and the electric motor drives the vehicle alone, optimizing the energy flow path and reducing ineffective heat generation from the engine. If the engine is still in an efficient range after power limiting, it maintains parallel mode, with the engine and electric motor working together to ensure power demand.

[0085] Electric drive torque distribution: The vehicle control unit (VCU) adjusts the torque output ratio of the front and rear motors in real time based on the predicted temperature of the front and rear motor windings. If it is predicted that a certain motor is at risk of overheating, it immediately reduces the torque output ratio of that motor and increases the torque output ratio of the other motor to avoid excessive heat load on a single motor, achieve a balanced distribution of heat load between the front and rear motors, and make full use of the overall cooling capacity of the electric drive system.

[0086] Power strategy optimization: The vehicle control unit (VCU) adjusts the power battery power management strategy in advance based on the predicted engine coolant temperature. If it is predicted that the engine will be in a power-limited state for a long time, it immediately switches from the normal power consumption mode to the power-preserving mode. The power battery power is maintained within the preset range by the engine driving the generator, reserving power space for subsequent high-load conditions (such as continuous climbing and high-speed overtaking), ensuring the continuous power output of the motor and avoiding power attenuation due to insufficient power. If it is predicted that the engine power limitation is a short-term condition, the power consumption mode is maintained, and the power of the motor is used first to improve energy utilization efficiency.

[0087] After the above power limiting and mode optimization strategies are implemented, the vehicle control unit (VCU) will continuously collect vehicle operating parameters and core component temperature parameters, update temperature prediction results in real time, and dynamically adjust the power limiting range and mode optimization strategies according to the prediction results to form a closed-loop dynamic control. When the predicted temperature value of the core component falls back to the safe range, the engine power and motor torque will be gradually released to restore the normal output of the power system. The recovery process is adapted to the vehicle operating requirements to achieve a smooth power recovery.

[0088] In this embodiment, through the complete process of driving condition perception, power system mode decision-making, component temperature prediction, and power limiting and mode optimization, the hybrid vehicle successfully achieved early prediction and proactive intervention of the risk of overheating of core power system components under high temperature, high altitude, and high load conditions. This not only avoids the overheating problem of the engine and motor, but also controls the power attenuation within a reasonable range through graded power / torque limiting and forward-looking mode optimization. This effectively solves the problem of precipitous power attenuation in existing passive thermal protection strategies, while suppressing the thermal accumulation effect of the power system, slowing down the thermal aging of core components, and achieving the optimal technical balance between thermal safety and power performance under overload conditions of the cooling system.

[0089] The technical solution of this embodiment can be directly integrated into the vehicle controller (VCU) or power domain controller of existing hybrid vehicles without the need for additional hardware. It is fully compatible with the perception and execution architecture of existing hybrid vehicles, has low modification costs, strong applicability, and can be widely used in high-load thermal management and power control of various hybrid vehicles.

[0090] Example 2

[0091] This embodiment provides a predictive thermal protection and power distribution system for a hybrid vehicle powertrain, used to implement the method described in Embodiment 1. The system is built on the existing hardware architecture of hybrid vehicles, requiring no additional dedicated equipment. It consists of a sensing module, a prediction module, a limiting control module, and an optimization module connected in sequence. The specific structure and functions are as follows:

[0092] The perception module consists of the vehicle's existing speed sensor, ambient temperature sensor, cooling pipe flow / temperature sensor, wheel-side power detection unit, and data acquisition modules that are compatible with the engine ECU, motor MCU, and battery BMS. Its core function is to collect the full-dimensional operating parameters in step 1 of Example 1 in real time, and after completing filtering and noise reduction preprocessing, transmit them to the prediction module via the CAN bus to provide accurate and real-time basic data for subsequent control.

[0093] Prediction Module: A software function module integrated into the VCU / power domain controller. It has a built-in component temperature prediction model with multiple boundary conditions coupled. It is used to receive preprocessed data from the sensing module and predict the changing trends and over-temperature risks of engine water temperature and motor winding temperature in advance, according to the logic of step 3 in Example 1. The prediction results are transmitted to the limiting and control module in real time.

[0094] Limiting module: It is used to receive the temperature prediction results from the prediction module, generate graded power / torque limiting commands according to the rules in step 4 of Example 1, issue the engine allowable output power command to the ECU, issue the generator peak torque limiting command to the MCU, and feed back the command execution results to the optimization module.

[0095] The optimization module includes sub-modules for series-parallel mode switching, electric drive torque distribution, and power strategy optimization. It establishes signal interaction channels with the ECU, MCU, and BMS to receive the execution results of the limiting control module. Combined with the temperature prediction results, it generates power system mode optimization instructions according to the logic of step 4 in Example 1. It sends series-parallel mode switching instructions to the ECU / MCU, four-wheel drive torque distribution adjustment instructions to the MCU, and power-saving / power-consuming mode switching instructions to the BMS to achieve thermal load balancing and energy flow optimization.

[0096] The specific embodiments of the present invention have been described above. Based on the above description, those skilled in the art can make various changes and modifications without departing from the technical concept of the present invention.

Claims

1. A predictive thermal protection and power distribution method for a hybrid vehicle powertrain system, characterized in that, Includes the following steps: Step 1: Driving condition perception. The system collects vehicle operating condition parameters, environmental parameters, and powertrain status parameters through sensors and detection units, and transmits them to the vehicle controller. Step 2: Powertrain mode decision-making. The vehicle controller determines the initial operating mode of the powertrain based on the collected parameters, including series-parallel mode, drive type allocation mode, and power management mode. Step 3: Component temperature prediction. Based on a temperature prediction model coupled with multiple boundary conditions, combined with the cooling system capacity boundary, vehicle operating condition boundary, ambient temperature boundary and power system temperature rise characteristics, the model predicts the changing trends of engine coolant temperature and motor winding temperature, and judges the risk of overheating by combining preset engine coolant temperature and motor winding temperature thresholds. Step 4: Power limiting and mode optimization. Based on the temperature prediction results, implement graded engine power limiting and active motor torque limiting, and perform forward-looking optimization of the power system operation mode to form closed-loop dynamic control. The graded engine power limiting is achieved by: based on the engine coolant temperature prediction threshold, combined with real-time vehicle speed and real-time ambient temperature, retrieving a preset corresponding engine allowable output power matching table, and performing differentiated, graded power limiting; the active motor torque limiting is achieved by: based on the motor winding temperature prediction threshold, performing step-by-step peak torque limiting based on the motor efficiency MAP; different winding temperature thresholds correspond to different torque limiting intensities, achieving smooth torque limiting; the power system mode optimization includes: switching between series and parallel modes based on the efficiency status after engine power limiting to optimize the energy flow path; adjusting the torque output ratio of the front and rear motors based on the front and rear motor temperature prediction results to balance the thermal load; and switching between power preservation mode and power consumption mode based on the engine coolant temperature prediction results to reserve power for high-load conditions; In step 1, the vehicle operating condition parameters include vehicle speed, actual wheel-side output power, and real-time motor operating condition point; the environmental parameters include real-time ambient temperature; and the power system status parameters include remaining battery charge, motor efficiency MAP, motor cooling system flow rate, motor inlet water temperature, and real-time engine operating power.

2. The method according to claim 1, characterized in that, In step 3, the engine coolant temperature prediction is based on the engine operating power, the heat exchange capacity of the cooling system, the vehicle speed and the ambient temperature, and the predicted coolant temperature value is calculated through the engine temperature rise characteristic model; the motor winding temperature prediction is based on the cooling flow rate, the motor inlet coolant temperature, the motor operating point and the motor efficiency MAP, and the predicted winding temperature value is calculated through the motor temperature rise characteristic model.

3. The method according to claim 1, characterized in that, After step 4 is executed, operating conditions and temperature parameters are continuously collected, temperature predictions are updated in real time, and limiting and optimization strategies are dynamically adjusted; power output is smoothly restored after the temperature drops back to the safe range.

4. A predictive thermal protection and intelligent power distribution system for a hybrid vehicle powertrain, used to implement the method described in any one of claims 1-3, characterized in that, include: The sensing module is used to collect vehicle operating condition parameters, environmental parameters, and powertrain status parameters, and output them after preprocessing. The prediction module has a built-in component temperature prediction model coupled with multiple boundary conditions, which is used to predict engine water temperature, motor winding temperature and over-temperature risk in a forward-looking manner. The limiting module is used to generate and issue graded engine power limiting commands and active motor torque limiting commands based on temperature prediction results; The optimization module is used to generate commands for series-parallel mode switching, electric drive torque distribution, and power strategy optimization based on the control results and temperature prediction results.

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