Thermal management control method for hybrid electric vehicle under cross-country working condition and vehicle

Abstract

The invention discloses a thermal management control method of a hybrid electric vehicle under a cross-country working condition and the hybrid electric vehicle under a cross-country heat dissipation mode. The thermal management control module CLM reads the water temperature of an engine, and the engine management system EMS controls the duty ratio of a water pump of the engine according to the numerical value of the water temperature; the thermal management control module CLM reads the water temperature of an engine, and the duty ratio of a cooling fan is controlled by the vehicle control unit HCU according to the numerical value of the water temperature; the thermal management control module CLM reads temperature signals of a rear motor and a motor controller, and the duty ratio of an electric drive water pump is controlled by a vehicle control unit HCU according to temperature values; and the highest temperature threshold value of the battery cell in the battery cooling starting condition is reduced. According to the thermal management control method for the hybrid electric vehicle under the off-road working condition, on the basis of off-road scene analysis, thermal management of the whole vehicle is adjusted from passive cooling to active cooling, related parameters of the whole vehicle are monitored from strategy logic, cooling is conducted in advance, and the thermal runaway phenomenon is prevented.

Description

Technical Field

[0001] The present invention relates to the field of hybrid vehicle thermal management, and in particular to a thermal management control method for a hybrid vehicle under off-road conditions and a vehicle. Background Art

[0002] Under the requirements of "dual carbon" indicators, all car companies are vigorously developing new energy vehicles and hybrid vehicles. In the off-road market segment, the hybrid phenomenon is more obvious in terms of power, fuel consumption and mileage.

[0003] Due to the tough shape of the "square box" off-road vehicles, this series of vehicles has a large drag coefficient, and the wheel side power demand is large under the same working conditions; and off-road vehicle scenarios are mostly concentrated in low-speed and high-torque situations, and their power and heat dissipation requirements are higher, and the thermal runaway control of the entire vehicle is more stringent and urgent.

[0004] At present, some car companies use two cooling modules and match them with cooling fans to solve the heat dissipation problem of off-road vehicles. For example, the hybrid off-road vehicle cooling system and control method disclosed in Chinese patent CN109515168A include a first cooling module and a second cooling module arranged in the engine compartment. The first cooling module includes an electric part radiator, a condenser and a motor controller cooling fan; the second cooling module includes an oil cooler, an intercooler, an engine radiator and a cooling fan directly connected to the engine. This matching method has a high weight and cost per vehicle, and is still a "passive cooling" method. Summary of the invention

[0005] The object of the present invention is to provide a thermal management control method for a hybrid electric vehicle under off-road conditions and a vehicle, so as to solve the problems raised in the above background technology.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: A thermal management control method for a hybrid electric vehicle under off-road conditions, comprising the following steps:

[0007] Determine whether the vehicle enters off-road conditions;

[0008] If so, the off-road cooling mode is automatically turned on;

[0009] In the off-road cooling mode, one or a combination of the following control steps are included;

[0010] The thermal management control module CLM reads the engine water temperature, and based on the water temperature value, the engine management system EMS controls the engine water pump duty cycle;

[0011] The thermal management control module CLM reads the engine water temperature, and the vehicle controller HCU controls the cooling fan duty cycle based on the water temperature value;

[0012] The thermal management control module CLM reads the temperature signals of the rear motor and the motor controller. According to the temperature values, the vehicle controller HCU controls the duty cycle of the electric drive water pump.

[0013] Lower the maximum temperature threshold of the battery cells in the battery cooling startup condition, manage the thermal performance of the battery in advance, and ensure that the battery operates at a "comfortable temperature".

[0014] Preferably, the vehicle monitors the engine water temperature, intake air temperature, motor temperature, MCU temperature, and battery cell temperature to determine whether to enter off-road conditions.

[0015] Preferably, when the engine water temperature is greater than or equal to a first threshold, a request is made to adjust to a first duty cycle of the engine water pump; when the engine water temperature is greater than or equal to a second threshold, a request is made to adjust to a second duty cycle of the engine water pump; when the engine water temperature is greater than or equal to a third threshold, a request is made to adjust to a third duty cycle of the engine water pump;

[0016] The first threshold, the second threshold, and the third threshold increase sequentially, and the first duty cycle of the engine water pump, the second duty cycle of the engine water pump, and the third duty cycle of the engine water pump increase sequentially.

[0017] Preferably, when the engine water temperature is greater than or equal to a first threshold, a request is made to adjust the cooling fan to a first duty cycle.

[0018] Preferably, based on the temperature of the rear motor and the motor controller as a reference value, when the reference value is a first-level value, a request is made to adjust to the first duty cycle of the electric drive water pump;

[0019] When the reference value is the second level value, it is requested to adjust to the second duty cycle of the electric drive water pump;

[0020] When the reference value is the third level value, it is requested to adjust to the third duty cycle of the electric drive water pump;

[0021] The first level value, the second level value and the third level value increase in sequence, and the first duty cycle of the electric water pump, the second duty cycle of the electric water pump and the third duty cycle of the electric water pump increase in sequence.

[0022] Preferably, the control step also includes setting a battery cooling level, and after turning on the off-road cooling mode, lowering the temperature of the turning-on condition of each cooling level to achieve early entry into the battery cooling condition.

[0023] Preferably, when the battery charge SOC is greater than value A, the off-road cooling mode is started when the maximum temperature of the battery cell is greater than or equal to value B, and the exit condition is when the maximum temperature of the battery cell is less than or equal to value C, and value C is at least 5°C lower than value B;

[0024] When the battery charge SOC is less than or equal to value A, the off-road cooling mode is enabled when the battery cell is at its highest

[0025] The temperature is greater than or equal to the D value. The exit condition is that the maximum temperature of the battery cell is less than or equal to the E value, the D value is greater than the B value, and the E value is greater than the C value.

[0026] Preferably, it also includes the step of manually opening the off-road cooling film type by setting a soft button to manually open it on the large screen of the vehicle machine;

[0027] Click the "Off-road Cooling" switch on the large screen interface, and the thermal management control module CLM receives the off-road cooling signal.

[0028] No. turns on off-road cooling mode;

[0029] Feedback the off-road cooling mode on status to the large screen;

[0030] The thermal management control module CLM sends requests according to the strategy, and each controller controls the execution of the components.

[0031] Preferably, the design structure of the front-end cooling module is also included:

[0032] Including hybrid box oil cooler, condenser, high temperature radiator, cooling fan, low temperature radiator and anti-collision beam;

[0033] The hybrid box oil cooler is located at the front end and on the upper part of the anti-collision beam. The condenser and high-temperature radiator are located on the rear side of the hybrid box oil cooler. The low-temperature radiator is located at the bottom of the condenser and the high-temperature radiator. The front side of the low-temperature radiator is unobstructed and directly in contact with the air. The cooling fan is located at the rear end.

[0034] The present invention also provides a vehicle, which is used to implement the thermal management control method of the hybrid vehicle under off-road conditions.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] The present invention provides a thermal management control method for a hybrid electric vehicle under off-road conditions. Based on off-road scenario analysis, the thermal management of the entire vehicle is adjusted from "passive cooling" to "active cooling". Starting from the strategy logic, the associated parameters of the entire vehicle are monitored, cooling is performed in advance, the thermal management performance under off-road conditions is improved, and thermal runaway is prevented. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 : Front-end cooling module layout diagram;

[0038] Figure 2 :Overall process diagram;

[0039] Figure 3 : Electric drive water pump control parameter table;

[0040] Figure 4: Battery cooling control parameter table. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] As shown in the figure, this embodiment provides a thermal management control method for a hybrid vehicle under off-road conditions and a vehicle;

[0043] In the present invention, the front-end module is designed with off-road performance in mind, and the low-temperature radiator for cooling the engine water-to-air intercooler and the hybrid module is placed at the front end of the module to ensure sufficient low-temperature air passes quickly, thus ensuring the optimal performance of the front-end cooling module from a hardware perspective. Figure 1 As shown, it includes a hybrid box oil cooler 2, a condenser 3, a high-temperature radiator 4, a cooling fan 5, a low-temperature radiator 6 and an anti-collision beam 7;

[0044] The hybrid box oil cooler 2 is located at the front end and on the upper part of the anti-collision beam 7, the condenser 3 and the high-temperature radiator 4 are located on the rear side of the hybrid box oil cooler 2, the low-temperature radiator 6 is located at the bottom of the condenser 3 and the high-temperature radiator 4, the front side of the low-temperature radiator 6 is unobstructed and directly in contact with the air 1, and the cooling fan 5 is located at the rear end.

[0045] In the present invention, an "off-road cooling" soft switch is designed under the off-road module in the large screen. Before entering the off-road mode, the soft switch is manually clicked to enter the "off-road cooling" mode.

[0046] Under off-road conditions, the power demand of the vehicle is higher and the instantaneous discharge rate of the battery will increase. To ensure that the battery can be cooled quickly, the BMS (battery management system) will send a cooling request 5°C in advance. After receiving the request, the CLM (thermal management controller) will control the battery water pump, EXV valve and compressor to ensure that the battery operates within an appropriate temperature range.

[0047] Under off-road conditions, the power demand of the vehicle is higher and the instantaneous heat generated by the hybrid module is higher. The CLM (thermal management controller) actively controls the electric drive water pump and cooling fan to increase the speed to ensure that the hybrid module operates within an appropriate temperature range.

[0048] Under off-road conditions, the power demand of the whole vehicle is higher, and the instantaneous heat generated by the engine is higher. The EMS (engine management system controller) actively controls the attack water pump speed to increase to ensure that the engine operates within an appropriate temperature range.

[0049] During the architecture development and function definition stage, the signal interaction between the related control modules has been planned to ensure that this function can be realized; in addition, the electrical balance of the entire vehicle needs to be considered to ensure that the vehicle will not run out of power under all operating conditions.

[0050] Specifically, in the off-road heat dissipation mode, one or a combination of the following control steps are included;

[0051] The thermal management control module CLM reads the engine water temperature, and based on the water temperature value, the engine management system EMS controls the engine water pump duty cycle;

[0052] When the engine water temperature is greater than or equal to the first threshold, request to adjust to the first duty cycle of the engine water pump; when the engine water temperature is greater than or equal to the second threshold, request to adjust to the second duty cycle of the engine water pump; when the engine water temperature is greater than or equal to the third threshold, request to adjust to the third duty cycle of the engine water pump;

[0053] The first threshold, the second threshold, and the third threshold increase sequentially, and the first duty cycle of the engine water pump, the second duty cycle of the engine water pump, and the third duty cycle of the engine water pump increase sequentially.

[0054] The specific steps of this embodiment are: CLM reads the engine water temperature signal, sends a water pump duty cycle signal according to the water temperature, and EMS receives and compares it to obtain the maximum value;

[0055] ① When the water temperature is less than 108℃, CLM does not send a request and is controlled by EMS;

[0056] ② When the water temperature is ≥108℃, CLM sends the engine water pump to a duty cycle of 60% (flow rate 68L / min);

[0057] ③ When the water temperature is ≥112℃, CLM sends the engine water pump to a duty cycle of 80% (flow rate 91L / min);

[0058] ④ When the water temperature is ≥115℃, CLM sends the engine water pump to a duty cycle of 98% (flow rate 114L / min).

[0059] The thermal management control module CLM reads the engine water temperature, and the vehicle controller HCU controls the cooling fan duty cycle based on the water temperature value;

[0060] The specific steps of this embodiment are: CLM reads the engine water temperature signal, sends the fan duty cycle signal according to the water temperature, and the HCU receives and compares it to obtain the maximum value;

[0061] ① When the water temperature is less than 108℃, CLM does not send a request and the HCU controls the system;

[0062] ② When the water temperature is ≥108℃, the CLM sends the fan with a duty cycle of 87%.

[0063] The thermal management control module CLM reads the temperature signals of the rear motor and the motor controller. According to the temperature value, the vehicle controller HCU controls the duty cycle of the electric drive water pump. Specifically, CLM reads the temperature signals of the rear motor controller & rear motor, sends the water pump duty cycle signal, and the HCU receives it and compares it to take the maximum value - NOK;

[0064] According to the temperature of the rear motor and the motor controller as a reference value, when the reference value is the first level value, it is requested to adjust to the first duty cycle of the electric drive water pump;

[0065] When the reference value is the second level value, it is requested to adjust to the second duty cycle of the electric drive water pump;

[0066] When the reference value is the third level value, it is requested to adjust to the third duty cycle of the electric drive water pump;

[0067] The first level value, the second level value and the third level value increase in sequence, and the first duty cycle of the electric drive water pump, the second duty cycle of the electric drive water pump and the third duty cycle of the electric drive water pump increase in sequence. Figure 3 As shown, the first level value is preferably 90°C, the second level value is preferably 91°C-100°C, and the third level value is 101°C.

[0068] Lower the maximum temperature threshold of the battery cells in the battery cooling startup condition, manage the thermal performance of the battery in advance, and ensure that the battery operates at a "comfortable temperature".

[0069] When the battery charge SOC is greater than value A, the off-road cooling mode is enabled when the maximum temperature of the battery cell is greater than or equal to value B, and is exited when the maximum temperature of the battery cell is less than or equal to value C, which is at least 5°C lower than value B.

[0070] When the battery charge SOC is less than or equal to value A, the off-road cooling mode is enabled when the maximum temperature of the battery cell is greater than or equal to value D, and the exit condition is when the maximum temperature of the battery cell is less than or equal to value E, value D is greater than value B, and value E is greater than value C. Value A can be 35%, value B can be 35°C, value C can be 30°C, value D can be 37°C, and value E can be 33°C. The control step also includes setting the battery cooling level. After the off-road cooling mode is enabled, the temperature of the enabling condition of each cooling level is lowered to achieve early entry into the battery cooling condition. For details, refer to Figure 4 As shown,

[0071] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A thermal management control method for a hybrid electric vehicle under off-road conditions, characterized in that: The steps include: Determine whether the vehicle enters off-road conditions; If so, the off-road cooling mode is automatically turned on; In the off-road cooling mode, one or a combination of the following control steps are included; The thermal management control module CLM reads the engine water temperature, and based on the water temperature value, the engine management system EMS controls the engine water pump duty cycle; The thermal management control module CLM reads the engine water temperature, and the vehicle controller HCU controls the cooling fan duty cycle based on the water temperature value; The thermal management control module CLM reads the temperature signals of the rear motor and the motor controller. According to the temperature values, the vehicle controller HCU controls the duty cycle of the electric drive water pump. Lower the maximum temperature threshold of the battery cells in the battery cooling startup condition, control the thermal performance of the battery in advance, and ensure that the battery operates at a "comfortable temperature".

2. The thermal management control method for hybrid electric vehicle under off-road conditions according to claim 1, characterized in that: The vehicle monitors the engine water temperature, intake air temperature, motor temperature, MCU temperature, and battery cell temperature to determine whether it has entered off-road conditions.

3. The thermal management control method for hybrid electric vehicle under off-road conditions according to claim 1, characterized in that: When the engine water temperature is greater than or equal to the first threshold, request to adjust to the first duty cycle of the engine water pump; when the engine water temperature is greater than or equal to the second threshold, request to adjust to the second duty cycle of the engine water pump; when the engine water temperature is greater than or equal to the third threshold, request to adjust to the third duty cycle of the engine water pump; The first threshold, the second threshold, and the third threshold increase sequentially, and the first duty cycle of the engine water pump, the second duty cycle of the engine water pump, and the third duty cycle of the engine water pump increase sequentially.

4. The thermal management control method for hybrid electric vehicle under off-road conditions according to claim 1, characterized in that: When the engine water temperature is greater than or equal to a first threshold, a request is made to adjust the cooling fan to a first duty cycle.

5. The thermal management control method for hybrid electric vehicle under off-road conditions according to claim 1, characterized in that: According to the temperature of the rear motor and the motor controller as a reference value, when the reference value is the first level value, it is requested to adjust to the first duty cycle of the electric drive water pump; When the reference value is the second level value, it is requested to adjust to the second duty cycle of the electric drive water pump; When the reference value is the third level value, it is requested to adjust to the third duty cycle of the electric drive water pump; The first level value, the second level value and the third level value increase in sequence, and the first duty cycle of the electric water pump, the second duty cycle of the electric water pump and the third duty cycle of the electric water pump increase in sequence.

6. The thermal management control method for hybrid electric vehicle under off-road conditions according to claim 1, characterized in that: The control step also includes setting the battery cooling level. After turning on the off-road cooling mode, the temperature of the opening condition of each cooling level is lowered to achieve early entry into the battery cooling condition.

7. The thermal management control method for hybrid electric vehicle under off-road conditions according to claim 6, characterized in that: When the battery charge SOC is greater than value A, the off-road cooling mode is enabled when the maximum temperature of the battery cell is greater than or equal to value B, and is exited when the maximum temperature of the battery cell is less than or equal to value C, which is at least 5°C lower than value B. When the battery charge SOC is less than or equal to value A, the off-road cooling mode is activated when the maximum temperature of the battery cell is greater than or equal to value D, and the exit condition is when the maximum temperature of the battery cell is less than or equal to value E, value D is greater than value B, and value E is greater than value C.

8. The thermal management control method for hybrid electric vehicle under off-road conditions according to claim 1, characterized in that: It also includes the steps of manually opening the off-road cooling film type, which can be manually opened on the large screen of the vehicle computer by setting a soft button; Click the "off-road cooling" switch on the large screen interface, and the thermal management control module CLM receives the off-road cooling signal to start the off-road cooling mode; Feedback the off-road cooling mode on status to the large screen; The thermal management control module CLM sends requests according to the strategy, and each controller controls the execution of the components.

9. The thermal management control method for hybrid electric vehicle under off-road conditions according to claim 1, characterized in that: It also includes the design structure of the front-end cooling module: Including hybrid box oil cooler, condenser, high temperature radiator, cooling fan, low temperature radiator and anti-collision beam; The hybrid box oil cooler is located at the front end and on the upper part of the anti-collision beam. The condenser and high-temperature radiator are located on the rear side of the hybrid box oil cooler. The low-temperature radiator is located at the bottom of the condenser and the high-temperature radiator. The front side of the low-temperature radiator is unobstructed and directly in contact with the air. The cooling fan is located at the rear end.

10. An automobile, characterized in that: The vehicle is used to implement the thermal management control method for a hybrid vehicle under off-road conditions as described in any one of claims 1-9.

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