Thermal management control method for hybrid electric vehicle under off-road conditions and vehicle

Abstract

This invention discloses a thermal management control method and vehicle for hybrid electric vehicles under off-road conditions. In off-road cooling mode, the thermal management control module (CLM) reads the engine coolant temperature and, based on the temperature value, the engine management system (EMS) controls the duty cycle of the engine water pump; the thermal management control module (CLM) reads the engine coolant temperature and, based on the temperature value, the vehicle controller (HCU) controls the duty cycle of the cooling fan; the thermal management control module (CLM) reads the temperature signals of the rear motor and its controller and, based on the temperature values, the vehicle controller (HCU) controls the duty cycle of the electric water pump; and the maximum cell temperature threshold in the battery cooling activation conditions is reduced. This invention provides a thermal management control method for hybrid electric vehicles under off-road conditions. Based on off-road scenario analysis, it adjusts the vehicle's thermal management from "passive cooling" to "active cooling." Starting from the strategy logic, it monitors the vehicle's related parameters and performs cooling in advance to prevent thermal runaway.

Description

Technical Field

[0001] This invention relates to the field of thermal management of hybrid vehicles, specifically to a thermal management control method and vehicle for hybrid vehicles under off-road conditions. Background Technology

[0002] Under the "dual carbon" requirements, automakers are vigorously developing new energy vehicles and hybrid vehicles. In the off-road segment, the hybrid trend is even more pronounced, considering factors such as power, fuel consumption, and range.

[0003] Due to the rugged design of the "boxy" off-road vehicle, this series of models has a high drag coefficient and a large wheel-side power requirement under the same working conditions; moreover, off-road vehicle scenarios are mostly concentrated in low-speed, high-torque situations, which require even higher power and heat dissipation, making the control of thermal runaway of the whole vehicle more stringent and urgent.

[0004] Currently, some automakers are using two cooling modules, each equipped with a cooling fan, to address the heat dissipation issues of off-road vehicles. For example, Chinese patent CN109515168A discloses a hybrid off-road vehicle cooling system and its control method, which includes a first cooling module and a second cooling module located in the engine compartment. The first cooling module includes an electric component radiator, a condenser, and a motor controller cooling fan; the second cooling module includes an oil cooler, an intercooler, an engine radiator, and an engine-direct-drive cooling fan. This matching method results in higher vehicle weight and cost, and is still considered a "passive cooling" method. Summary of the Invention

[0005] The purpose of this invention is to provide a thermal management control method and vehicle for hybrid electric vehicles under off-road conditions, so as to solve the problems mentioned in the background art.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a thermal management control method for a hybrid electric vehicle under off-road conditions, comprising the following steps:

[0007] Determine if the vehicle has entered off-road conditions;

[0008] If so, then actively activate the off-road cooling mode;

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

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

[0011] The thermal management control module (CLM) reads the engine coolant temperature and, based on the temperature value, the vehicle control unit (HCU) controls the duty cycle of the cooling fan.

[0012] The thermal management control module (CLM) reads the temperature signals of the rear motor and motor controller, and controls the duty cycle of the electric water pump by the vehicle controller (HCU) based on the temperature values.

[0013] Lowering the maximum cell temperature threshold in the battery cooling activation conditions allows for proactive thermal performance management of the battery, ensuring it operates at a "comfortable temperature."

[0014] Preferably, the vehicle determines whether it has entered off-road conditions by monitoring engine coolant temperature, intake air temperature, motor temperature, MCU temperature, and battery cell temperature.

[0015] Preferably, when the engine coolant temperature is greater than or equal to the first threshold, the engine water pump is requested to be adjusted to the first duty cycle; when the engine coolant temperature is greater than or equal to the second threshold, the engine water pump is requested to be adjusted to the second duty cycle; and when the engine coolant temperature is greater than or equal to the third threshold, the engine water pump is requested to be adjusted to the third duty cycle.

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

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

[0018] Preferably, the temperature of the rear motor and the motor controller is used 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 water pump.

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

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

[0021] The values ​​at the first, second, and third levels increase sequentially, as do the first, second, and third duty cycles of the electric water pump.

[0022] Preferably, the control steps also include setting the battery cooling level, and after activating the off-road cooling mode, reducing the temperature of the activation condition for each cooling level to achieve early battery cooling conditions.

[0023] Preferably, when the battery charge SOC is greater than value A, the off-road cooling mode is activated when the highest cell temperature is greater than or equal to value B, and deactivated when the highest cell temperature is less than or equal to value C, where value C is at least 5°C lower than value B.

[0024] When the battery's State of Charge (SOC) is less than or equal to value A, the off-road cooling mode is activated when the cell's highest charge level is reached.

[0025] If the temperature is greater than or equal to the D value, the exit condition is that the highest temperature of the 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 a step of manually opening the off-road cooling film, which can be manually opened on the vehicle's large screen via a soft button;

[0027] Clicking the "Off-road Cooling" switch on the large screen interface triggers the thermal management control module (CLM) to receive the off-road cooling signal.

[0028] The vehicle activates off-road cooling mode;

[0029] The system displays feedback on the activation status of the off-road cooling mode on the large screen.

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

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

[0032] This includes the hybrid gearbox oil cooler, condenser, high-temperature radiator, cooling fan, low-temperature radiator, and anti-collision beam;

[0033] The hybrid gearbox oil cooler is located at the very front and above the anti-collision beam. The condenser and high-temperature radiator are located behind the hybrid gearbox oil cooler. The low-temperature radiator is located at the bottom of the condenser and high-temperature radiator. The front of the low-temperature radiator is unobstructed and directly exposed to the air. The cooling fan is located at the very rear.

[0034] The present invention also proposes a vehicle for implementing the above-mentioned thermal management control method for a hybrid vehicle under off-road conditions.

[0035] Compared with the prior art, the beneficial effects of the present invention are:

[0036] This invention provides a thermal management control method for hybrid electric vehicles under off-road conditions. Based on off-road scenario analysis, the method adjusts the vehicle's thermal management from "passive cooling" to "active cooling". Starting from the strategy logic, it monitors the vehicle's related parameters and performs cooling in advance to improve the thermal management performance under off-road conditions and prevent thermal runaway. Attached Figure Description

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

[0038] Figure 2 Overall process diagram;

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

[0040] Figure 4Battery cooling control parameter table. Detailed Implementation

[0041] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0042] Please refer to the figure. This embodiment provides a thermal management control method and vehicle for a hybrid electric vehicle under off-road conditions.

[0043] In this invention, the front-end module is designed with off-road performance in mind. The low-temperature radiator, which cools the engine's water-to-air intercooler and the hybrid module, is placed at the very front of the module, ensuring sufficient and rapid passage of low-temperature air and guaranteeing optimal performance of the front-end cooling module from a hardware perspective. (Refer to...) Figure 1 As shown, it includes a hybrid gearbox oil cooler 2, a condenser 3, a high-temperature radiator 4, a cooling fan 5, a low-temperature radiator 6, and a crash beam 7.

[0044] The hybrid gearbox oil cooler 2 is located at the front end and above the anti-collision beam 7. The condenser 3 and the high-temperature radiator 4 are located behind the hybrid gearbox 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 of the low-temperature radiator 6 is unobstructed and directly contacts the air 1. The cooling fan 5 is located at the rear end.

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

[0046] Under off-road conditions, the vehicle's power demand is high, 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 a suitable temperature range.

[0047] Under off-road conditions, the vehicle has high power requirements and the hybrid module generates a lot of heat instantaneously. The CLM (thermal management controller) actively controls the electric water pump and cooling fan to increase their speed to ensure that the hybrid module operates within a suitable temperature range.

[0048] Under off-road conditions, the vehicle has high power requirements and the engine generates a lot of heat. The EMS (Engine Management System Controller) actively controls the engine to increase the speed of the water pump to ensure that the engine operates within a suitable temperature range.

[0049] During the architecture development and function definition phase, the signal interaction between various related control modules has been planned to ensure that this function can be realized; in addition, the vehicle's electrical balance also needs to be considered to ensure that the vehicle will not lose power under various operating conditions.

[0050] Specifically, in off-road cooling mode, one or more of the following control steps are included;

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

[0052] When the engine coolant 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 coolant 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 coolant 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, as do the first duty cycle, the second duty cycle, and the third duty cycle of the engine water pump.

[0054] The specific steps in this embodiment are as follows: The CLM reads the engine coolant temperature signal, sends the water pump duty cycle signal according to the coolant temperature, and the EMS receives and compares the maximum value.

[0055] ①If the water temperature is <108℃, the CLM will not send a request and the EMS will control it.

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

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

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

[0059] The thermal management control module (CLM) reads the engine coolant temperature and, based on the temperature value, the vehicle control unit (HCU) controls the duty cycle of the cooling fan.

[0060] The specific steps in this embodiment are as follows: The CLM reads the engine coolant temperature signal and sends the fan duty cycle signal according to the coolant temperature. The HCU receives the signal and compares the values ​​to obtain the maximum value.

[0061] ① When the water temperature is <108℃, the CLM will not send a request, and the HCU will control it.

[0062] ② Water temperature ≥ 108℃, CLM fan duty cycle 87%.

[0063] The thermal management control module (CLM) reads the temperature signals of the rear motor and motor controller. Based on the temperature values, the vehicle control unit (HCU) controls the duty cycle of the electric water pump. Specifically, the CLM reads the temperature signals of the rear motor controller and rear motor, sends the water pump duty cycle signal, and the HCU receives it and compares the maximum value with NOK.

[0064] Based on the temperature of the rear motor and 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 water pump.

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

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

[0067] The values ​​for the first, second, and third levels increase sequentially, as do the first, second, and third duty cycles of the electric water pump. For specific values, please refer to... Figure 3 As shown, the preferred value for the first level is 90℃, the preferred value for the second level is 91℃-100℃, and the preferred value for the third level is 101℃.

[0068] Lowering the maximum cell temperature threshold in the battery cooling activation conditions allows for proactive thermal performance management of the battery, ensuring it operates at a "comfortable temperature."

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

[0070] When the battery's State of Charge (SOC) is less than or equal to value A, the off-road cooling mode is activated when the highest cell temperature is greater than or equal to value D, and deactivated when the highest cell temperature 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 selected as 35%, value B as 35℃, value C as 30℃, value D as 37℃, and value E as 33℃. The control steps also include setting the battery cooling level. After activating the off-road cooling mode, the activation temperature of each cooling level is lowered to achieve earlier battery cooling conditions. See details below. Figure 4 As shown,

[0071] While 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 these embodiments without departing from the principles and spirit of the invention, and that the scope of the 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: Includes the following steps: Determine if the vehicle has entered off-road conditions; If so, then actively activate the off-road cooling mode; In off-road cooling mode, the following control steps are included: Lower the maximum cell temperature threshold in the battery cooling activation conditions, and manage the battery's thermal performance in advance to ensure that the battery operates at a comfortable temperature. It also includes setting battery cooling levels, and after activating the off-road cooling mode, reducing the temperature of the activation conditions for each cooling level, so as to achieve battery cooling conditions earlier. When the battery charge SOC is greater than value A, the off-road cooling mode is activated when the highest cell temperature is greater than or equal to value B, and deactivated when the highest cell temperature is less than or equal to value C, and value C is at least 5°C lower than value B. When the battery's State of Charge (SOC) is less than or equal to value A, the off-road cooling mode is activated under the following conditions: The cell's highest temperature is greater than or equal to value D. The exit condition is that the cell's highest temperature is less than or equal to value E, value D is greater than value B, and value E is greater than value C.

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

3. The thermal management control method for a hybrid electric vehicle under off-road conditions according to claim 1, characterized in that: The thermal management control module (CLM) reads the engine coolant temperature and, based on the temperature value, the engine management system (EMS) controls the engine water pump duty cycle. Specifically, this includes: when the engine coolant temperature is greater than or equal to the first threshold, requesting adjustment to the first duty cycle of the engine water pump; when the engine coolant temperature is greater than or equal to the second threshold, requesting adjustment to the second duty cycle of the engine water pump; and when the engine coolant temperature is greater than or equal to the third threshold, requesting adjustment to the third duty cycle of the engine water pump. The first threshold, the second threshold, and the third threshold increase sequentially, as do the first duty cycle, the second duty cycle, and the third duty cycle of the engine water pump.

4. The thermal management control method for a hybrid electric vehicle under off-road conditions according to claim 1, characterized in that: The thermal management control module (CLM) reads the engine coolant temperature and, based on the temperature value, the vehicle control unit (HCU) controls the duty cycle of the cooling fan. Specifically, this includes: when the engine coolant temperature is greater than or equal to the first threshold, requesting adjustment to the first duty cycle of the cooling fan.

5. The thermal management control method for a hybrid electric vehicle under off-road conditions according to claim 1, characterized in that: The thermal management control module (CLM) reads the temperature signals of the rear motor and motor controller, and controls the duty cycle of the electric water pump by the vehicle controller (HCU) based on the temperature values. Specifically, this includes: using the temperature of the rear motor and motor controller as a reference value, when the reference value is the first level value, requesting adjustment to the first duty cycle of the electric water pump; When the reference value is the second level value, please adjust to the second duty cycle of the electric water pump; When the reference value is at the third level, please adjust it to the third duty cycle of the electric water pump; The values ​​at the first, second, and third levels increase sequentially, as do the first, second, and third duty cycles of the electric water pump.

6. The thermal management control method for a hybrid electric vehicle under off-road conditions according to claim 1, characterized in that: It also includes the step of manually opening the off-road cooling membrane, which can be manually opened on the vehicle's large screen via a soft button. Clicking the "Off-road Cooling" switch on the large screen interface will trigger the thermal management control module (CLM) to receive the off-road cooling signal and activate the off-road cooling mode. The system displays feedback on the activation status of the off-road cooling mode on the large screen. The thermal management control module (CLM) sends requests according to the strategy, and each controller controls the execution of actions.

7. The thermal management control method for a 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: This includes the hybrid gearbox oil cooler, condenser, high-temperature radiator, cooling fan, low-temperature radiator, and anti-collision beam; The hybrid gearbox oil cooler is located at the very front and above the anti-collision beam. The condenser and high-temperature radiator are located behind the hybrid gearbox oil cooler. The low-temperature radiator is located at the bottom of the condenser and high-temperature radiator. The front of the low-temperature radiator is unobstructed and directly exposed to the air. The cooling fan is located at the very rear.

8. A car, characterized in that: The vehicle is used to implement the thermal management control method for off-road conditions of a hybrid electric vehicle as described in any one of claims 1-7.

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