A temperature protection method for an electric drive system of a four-wheel drive electric vehicle and related equipment

Abstract

The application belongs to the technical field of electric vehicles, and discloses a four-wheel drive electric vehicle electric drive system temperature protection method and related equipment. The method dynamically adjusts the water pump gear of the cooling system based on the real-time temperature of the first driving device and the second driving device, realizes the accuracy and intelligence of cooling control, effectively avoids unnecessary high-power operation of the cooling water pump, reduces the vehicle energy consumption and the maintenance cost of the water pump, and can select and execute a torque distribution strategy according to the current temperature after the water pump gear is switched to a high gear, so that the four-wheel drive electric vehicle will not be directly cut off power when the motor is overheated, but the running state is maintained by adjusting the output torque of the driving device, thereby greatly improving the safety and reliability of the electric vehicle, reducing the risk of traffic accidents caused by sudden loss of power, and better protecting the safety of the electric drive system, the whole vehicle and the passengers.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electric vehicles, and particularly relates to a four-wheel drive electric vehicle electric drive system temperature protection method and related equipment. BACKGROUND

[0002] With the continuous progress of electric vehicle technology, consumers' requirements for vehicle performance and safety are increasing. Four-wheel drive electric vehicles, with their excellent power performance, handling stability and passing ability on complex road conditions, are gradually favored by the market.

[0003] However, compared with traditional two-wheel drive electric vehicles, common single-motor arrangements such as front drive or rear drive, four-wheel drive electric vehicles use double-motor drive, and their electric drive system structure is more complex, making thermal management significantly more difficult. At present, the application of four-wheel double-electric drive solutions in electric vehicles is relatively small, and the corresponding electric drive temperature protection strategy is not comprehensive enough, which is specifically manifested in that: when the existing four-wheel double-electric drive system electric vehicle has a temperature fault, the vehicle usually directly cuts off the power; this processing method can avoid serious damage caused by overheating of the electric drive system to a certain extent, but it does not analyze the temperature warning or fault in more detail and take corresponding actions, and cannot use a safe and effective driving strategy to protect the electric drive system, the vehicle and the passengers. In the actual driving process, sudden power cut-off may cause the vehicle to lose power support, causing rear-end collisions and other traffic accidents, and threatening the safety of the driver and passengers. The traditional temperature protection strategy often lacks precision and intelligence when controlling the cooling system. For example, the cooling water pump may continue to run at high power unnecessarily, which not only increases the power consumption of the water pump, causing the energy consumption of the vehicle to rise, but also reduces the reliability of the water pump due to long-term high-load operation, increasing the maintenance cost and failure risk of the vehicle.

[0004] Therefore, the temperature protection measures of the existing four-wheel drive electric vehicle usually use the method of directly cutting off the power when the motor is overheated, which causes the electric vehicle to be unable to run safely and reliably. SUMMARY

[0005] The application provides a four-wheel drive electric vehicle electric drive system temperature protection method and related equipment to solve the technical problem that the temperature protection measures of the existing four-wheel drive electric vehicle usually use the method of directly cutting off the power when the motor is overheated, which causes the electric vehicle to be unable to run safely and reliably.

[0006] In order to achieve the above purpose, the application adopts the following technical scheme:

[0007] A four-wheel drive electric vehicle electric drive system temperature protection method, comprising:

[0008] Switch the water pump gear of the cooling system based on the real-time temperature of the first driving device and the real-time temperature of the second driving device;

[0009] After the water pump gear is switched to the high water pump gear, select and execute a torque distribution strategy based on the current temperature of the first driving device and the current temperature of the second driving device; the torque distribution strategy is used to control the output torque of the first driving device or / and the second driving device, so that the four-wheel drive electric vehicle is always in an operating state.

[0010] Further, before the water pump gear of the cooling system is switched based on the real-time temperature of the first driving device and the real-time temperature of the second driving device, the method further comprises:

[0011] According to the received vehicle start signal, control the water pump and the fan of the cooling system to be in the off state;

[0012] Monitor the real-time temperature reported by the first driving device and the second driving device.

[0013] Further, the water pump gear of the cooling system is switched based on the real-time temperature of the first driving device and the real-time temperature of the second driving device, which comprises:

[0014] Collect the real-time temperature reported by the first driving device and the second driving device, and judge the real-time temperature of the first driving device and the real-time temperature of the second driving device;

[0015] If the real-time temperature of the first driving device or / and the real-time temperature of the second driving device is in the first temperature interval, the water pump gear is switched to the low water pump gear;

[0016] If the real-time temperature of the first driving device or / and the real-time temperature of the second driving device is in the second temperature interval, the water pump gear is switched to the medium water pump gear;

[0017] If the real-time temperature of the first driving device or / and the real-time temperature of the second driving device is in the third temperature interval, the water pump gear is switched to the high water pump gear.

[0018] Further,

[0019] When the water pump gear is switched to the medium water pump gear, control the fan to start the low speed mode;

[0020] When the water pump gear is switched to the high water pump gear, control the fan to start the high speed mode.

[0021] Further,

[0022] When the water pump gear is switched to the low water pump gear, control the corresponding straight-through valve of the first driving device or / and the second driving device to be opened;

[0023] When the water pump gear is switched to the water pump middle gear, the first driving device or / and the second driving device is controlled to adjust the corresponding straight-through valve to a half-open state;

[0024] When the water pump gear is switched to the water pump high gear, the straight-through valve is controlled to adjust to a fully open state.

[0025] Further, the real-time temperature of the first driving device is the highest temperature among the first vehicle-mounted power supply and charger two-in-one temperature, the first motor controller temperature and the first reduction device temperature; the real-time temperature of the second driving device is the highest temperature among the second vehicle-mounted power supply and charger two-in-one temperature, the second motor controller temperature and the second reduction device temperature.

[0026] Further, after the water pump gear is switched to the water pump high gear of the cooling system, based on the current temperature of the first driving device and the current temperature of the second driving device, a torque distribution strategy is selected and executed, including:

[0027] After the water pump gear is switched to the water pump high gear of the cooling system, the current temperature of the first driving device and the current temperature of the second driving device are continuously monitored;

[0028] The current temperature of the first driving device and the current temperature of the second driving device are judged;

[0029] If the current temperature of the first driving device is greater than the over-temperature threshold and the current temperature of the second driving device is less than the over-temperature threshold, a first torque distribution strategy is selected and executed;

[0030] If the current temperature of the first driving device is less than the over-temperature threshold and the current temperature of the second driving device is greater than the over-temperature threshold, a second torque distribution strategy is selected and executed;

[0031] If the current temperature of the first driving device and the current temperature of the second driving device are both greater than the over-temperature threshold, a third torque distribution strategy is selected and executed;

[0032] The torque distribution strategy includes the first torque distribution strategy, the second torque distribution strategy and the third torque distribution strategy.

[0033] The first torque distribution strategy is to limit the output torque of the first driving device to a preset safety limit, and the second driving device compensates for power;

[0034] The second torque distribution strategy is to limit the output torque of the second driving device to a preset safety limit, and the first driving device compensates for power;

[0035] The third torque distribution strategy is to synchronously reduce the output torque of the first driving device and the output torque of the second driving device, so that the electric vehicle is switched to a limp mode.

[0036] A temperature protection system for an electric drive system of a four-wheel drive electric vehicle, comprising:

[0037] A water pump gear switching module for switching the water pump gear of the cooling system based on the real-time temperature of the first drive device and the real-time temperature of the second drive device;

[0038] A distribution strategy execution module for selecting and executing a torque distribution strategy based on the current temperature of the first drive device and the current temperature of the second drive device after the water pump gear is switched to the high gear, the torque distribution strategy being used to control the output torque of the first drive device or / and the second drive device so that the four-wheel drive electric vehicle is always in an operating state.

[0039] An apparatus, comprising:

[0040] A memory for storing a computer program;

[0041] A processor for implementing the steps of the temperature protection method for the electric drive system of the four-wheel drive electric vehicle when executing the computer program.

[0042] A computer readable storage medium storing a computer program, the computer program being used to implement the steps of the temperature protection method for the electric drive system of the four-wheel drive electric vehicle when executed by a processor.

[0043] Compared with the prior art, the present application has the following beneficial effects:

[0044] The present application provides a temperature protection method for the electric drive system of a four-wheel drive electric vehicle, which not only dynamically adjusts the water pump gear of the cooling system based on the real-time temperature of the first drive device and the real-time temperature of the second drive device, but also realizes the precision and intelligence of cooling control, effectively avoids unnecessary high-power operation of the cooling water pump, and reduces the energy consumption of the vehicle and the maintenance cost of the water pump.

[0045] Preferably, in the present application, the water pump and the fan of the cooling system are initialized and controlled when the vehicle starts, and the real-time temperature of the drive device is monitored, which provides a basis for the subsequent temperature protection strategy and ensures that the cooling system can respond quickly when necessary, thereby improving the response speed and efficiency of the system.

[0046] Preferably, in the present application, by judging the real-time temperature of the driving device and switching the water pump gear accordingly, fine management of the cooling system is achieved, ensuring cooling effect and avoiding unnecessary energy consumption, improving system energy efficiency.

[0047] Preferably, in the present application, the opening mode and speed of the fan are controlled according to the switching of the water pump gear, further enhancing the flexibility and response speed of the cooling system, ensuring effective cooling effect under different temperature conditions.

[0048] Preferably, in the present application, the flow of cooling liquid is controlled by adjusting the opening state of the straight-through valve, further refining the control strategy of the cooling system, improving cooling efficiency and system stability.

[0049] Preferably, in the present application, the real-time temperature of the driving device is defined as the highest temperature among the temperatures of multiple key components, ensuring the accuracy and comprehensiveness of temperature monitoring, providing reliable data support for subsequent temperature protection strategies.

[0050] Preferably, in the present application, after the water pump gear is switched to high gear, different torque distribution strategies are selected and executed according to the current temperatures of the two driving devices, ensuring that the electric vehicle can continue to run when the motor is overheated, while avoiding power loss due to single motor overheating, improving the driving safety and stability of the electric vehicle. In addition, by limiting the output torque of the overheated motor and compensating power by other motors, or simultaneously reducing the output torque of both motors to switch to limp mode, the method also provides multiple strategies to deal with motor overheating, enhancing the flexibility and adaptability of the system. BRIEF DESCRIPTION OF DRAWINGS

[0051] Figure 1 The temperature arrangement information schematic diagram of the driving device for the embodiment of the present application is provided;

[0052] Figure 2 The cooling system schematic diagram of the whole vehicle driving device for the embodiment of the present application is provided;

[0053] Figure 3 The flowchart of a four-wheel drive electric vehicle electric drive system temperature protection method for the embodiment of the present application is provided;

[0054] Figure 4 The flowchart of a four-wheel drive electric vehicle electric drive system temperature protection method for the present application is provided;

[0055] Figure 5 The structural schematic diagram of a four-wheel drive electric vehicle electric drive system temperature protection system for the present application is provided. DETAILED DESCRIPTION

[0056] To further understand the content of this invention, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments are merely illustrative and not limiting of the invention.

[0057] The technical terms involved in this invention are explained below:

[0058] DCDC / OBC: A combined on-board power supply and charger device. DCDC (Direct Current - Direct Current) is a DC-DC converter that transforms a fixed DC voltage into a variable DC voltage. In electric vehicles, it is commonly used to convert the voltage of the high-voltage battery into low-voltage DC suitable for the vehicle's electronic equipment. OBC (On-Board Charger) is an on-board charger used to convert AC power from the grid into DC power to charge the electric vehicle's battery. "DCDC / OBC" indicates that these two functions are integrated into one device.

[0059] MCU: Motor Control Unit. It is the core control component of an electric vehicle's electric drive system, responsible for controlling the driving motor's speed, torque, and steering. By receiving commands from the vehicle controller and feedback signals from the motor, the MCU precisely adjusts the motor's input voltage, current, and frequency to meet the needs of different driving conditions.

[0060] MOT: Motor. In electric vehicles, the drive motor is a key component that converts electrical energy into mechanical energy, providing power for the vehicle's movement. It operates according to control signals from the motor controller, propelling the vehicle forward, backward, or accelerating.

[0061] REDUT: Reduction Gear Unit. Since drive motors typically operate at high speeds but have relatively low output torque, and vehicles require appropriate torque and speed for operation, the reduction gear unit's function is to reduce the drive motor's speed while increasing the output torque to meet the vehicle's power demands under different driving conditions.

[0062] As described in the background section, when a temperature fault occurs in an existing four-wheel drive dual-electric drive system electric vehicle, the usual procedure is to directly cut off the power. There is no corresponding action taken to address the temperature warning or fault, nor is there a safe and effective driving strategy to ensure the safety of the electric drive system, the vehicle, and the occupants.

[0063] Example 1

[0064] In order to solve the above problems, the embodiment provides a four-wheel drive electric vehicle electric drive system temperature protection method, which adopts the temperature alarm or temperature fault phenomenon of the front drive device or the rear drive device in the four-wheel drive to dynamically adjust the performance output of the front drive device or the rear drive device; at the same time, the scheme also provides a scheme for ensuring vehicle driving, and proposes a problem of power cut-off in vehicle driving due to temperature fault, thereby improving the safety of the vehicle.

[0065] The embodiment provides a four-wheel drive electric vehicle electric drive system temperature protection method, which comprises the following steps:

[0066] Switching the water pump gear position of the cooling system based on the real-time temperature of the first drive device and the real-time temperature of the second drive device;

[0067] After the water pump gear position is switched to the high gear position of the water pump, selecting and executing a torque distribution strategy based on the current temperature of the first drive device and the current temperature of the second drive device; the torque distribution strategy is used to control the output torque of the first drive device or / and the second drive device, so that the four-wheel drive electric vehicle is always in a running state.

[0068] The control method provided by the embodiment is further explained and described below in combination with the accompanying drawings:

[0069] The core technology based on the embodiment is that:

[0070] First, the integrated drive device: the vehicle-mounted power supply (DCDC / OBC), the motor controller (MCU), the driving motor (MOT) and the reduction device (REDUT) are integrated in a single module, the temperatures of each sub-component are collected in real time, and the highest temperature is taken as the over-temperature judgment basis, as shown in Figure 1 The real-time temperature of the first drive device is the highest temperature of the first vehicle-mounted power supply and charger two-in-one (DCDC / OBC1) temperature, the first motor controller (MCU1) temperature and the first reduction device (REDUT1) temperature; the real-time temperature of the second drive device is the highest temperature of the second vehicle-mounted power supply and charger two-in-one (DCDC / OBC2) temperature, the second motor controller (MCU2) temperature and the second reduction device (REDUT2) temperature.

[0071] Second, the hierarchical cooling control: dynamically adjusting the water pump power and the fan start-stop according to the temperature threshold interval (low temperature, medium temperature and high temperature), optimizing the cooling liquid flow and reducing the energy consumption.

[0072] Third, dynamic torque distribution: when one drive device is over-temperature, the output torque of the drive device is limited and the power of the other drive device is improved to maintain the power of the vehicle and avoid driving interruption.

[0073] For example, Figure 2As shown, the cooling system of the driving device includes a cooling fan, a water pump, a first straight-through valve, and a second straight-through valve. The first driving device includes a DCDC / OBC1 (first vehicle-mounted power supply and charger two-in-one), a MCU1 (first motor controller), a MOT1 (first driving motor), and a REDUT1 (first reduction device); the second driving device includes a DCDC / OBC2 (second vehicle-mounted power supply and charger two-in-one), a MCU2 (second motor controller), a MOT2 (second driving motor), and a REDUT2 (second reduction device); the cooling liquid flows through the DCDC / OBC→MCU→MOT in sequence to achieve efficient cooling.

[0074] The first driving device and the second driving device independently operate and report temperature data in real time.

[0075] The embodiment provides a temperature protection method for an electric drive system of a four-wheel drive electric vehicle, including the following steps:

[0076] Starting phase: when the vehicle enters a Ready state, the water pump and the fan remain closed, and the cooling liquid is not circulated.

[0077] Temperature monitoring: the driving device 1 and the driving device 2 report the temperature of each subcomponent in real time, and the highest temperature is taken as a judgment reference.

[0078] Graded cooling control:

[0079] Low-temperature range (T < T1): the water pump operates at a low gear, the straight-through valve is closed, and the cooling liquid only maintains basic circulation.

[0080] Medium-temperature range (T1≤T < T2): the water pump operates at a medium gear, the fan is started at a low-speed mode, and the cooling liquid flow is improved.

[0081] High-temperature range (T≥T2): the water pump operates at a high gear, the fan is switched to a high-speed mode, the straight-through valve is fully opened, and the cooling liquid flow is maximized.

[0082] Dynamic torque distribution:

[0083] Single driving device over-temperature (T≥T2): the output torque of the over-temperature device is limited to a safety limit, and the other driving device compensates for power.

[0084] Double driving device over-temperature (T≥T2): the torques of the two driving devices are simultaneously reduced, and the vehicle is switched to a “limp mode” to ensure safe driving at low speed.

[0085] As shown in the figure, as a further preferred scheme of the embodiment, the specific implementation steps are as follows: Figure 3

[0086] ​Start and initial state: when the vehicle starts, neither the water pump nor the fan is turned on. After the vehicle runs for a period of time, the driving device 1 and the driving device 2 respectively report the temperature of their sub-components in real time.

[0087] Cooling system control strategy: according to the temperature rise interval of the highest temperature reported by the first driving device and the second driving device, the corresponding action is executed. When the temperature is in the low temperature zone (i.e. T1≤ first driving device temperature < T2 or T1≤ second driving device temperature < T2), the water pump is turned on; as the temperature rises, when T2≤ first driving device temperature < T3 or T2≤ second driving device temperature < T3, the water pump middle gear is turned on, and the fan low gear is turned on; when T3≤ first driving device temperature or T3≤ second driving device temperature, the water pump high gear is turned on.

[0088] Torque distribution strategy: after executing the water pump high gear opening, the torque distribution strategy is entered. At this time, it is determined that the temperature of the first driving device is greater than T3 and the temperature of the second driving device is less than T3. If the condition is met, the first driving device enters the first torque distribution strategy, which is the temperature protection output limit outer characteristic of the first driving device;

[0089] If the condition is not met, it is determined that the temperature of the second driving device is greater than T3 and the temperature of the first driving device is less than T3. When the condition is met, the second driving device enters the second torque distribution strategy, which is the temperature protection output limit outer characteristic of the second driving device;

[0090] If the above conditions are not met, the first driving device and the second driving device enter the third torque distribution strategy, which is the lowest protection strategy that meets the safe driving according to the temperature fault strategy of the first driving device and the second driving device, ensuring that the vehicle can normally drive and will not continue to appear temperature protection, reaching the temperature natural balance limit of the first driving device and the second driving device. Of course, the execution order of the above three steps can be interchanged or performed simultaneously.

[0091] Example 2

[0092] The embodiment provides a temperature protection method for a four-wheel drive electric vehicle electric drive system, which is used for temperature protection under normal driving conditions on urban roads, and the specific implementation process is as follows:

[0093] Vehicle start-up phase: assuming that the vehicle starts in an urban road environment, at this time the vehicle is in a ready state. According to the temperature protection method of the application, the water pump is not turned on, the fan is not turned on, and the first straight-through valve and the second straight-through valve in the cooling water circuit are not turned on. The vehicle starts to drive, and the first driving device and the second driving device start to work and report the temperature of their sub-components in real time.

[0094] Temperature rise and cooling system start: During normal driving on urban roads, the temperature of the first drive device and the second drive device gradually rises due to frequent acceleration and deceleration. When the temperature of the first drive device reaches T1 (assuming T1 = 40°C) and satisfies T1 ≤ first drive device temperature < T2 (assuming T2 = 50°C), and the temperature of the second drive device is still lower than T1, according to the protection strategy, the water pump is started. At this time, the water pump runs at low power, and the cooling liquid starts to circulate in the cooling water circuit to cool the first drive device. As the vehicle continues to drive, the temperature of the first drive device and the second drive device continues to rise. When the temperature of the first drive device reaches T2 (50°C) and the temperature of the second drive device also reaches T2 (assuming the temperature of the second drive device at this time is 50°C), and satisfies T2 ≤ first drive device temperature < T3 (assuming T3 = 60°C) or T2 ≤ second drive device temperature < T3, the water pump is started at medium power and the fan is started at low power. At this time, the cooling capacity of the cooling system is further enhanced, and the cooling flow of the first drive device and the second drive device is increased, effectively controlling the temperature rise speed.

[0095] Temperature close to the upper limit and torque distribution strategy: If the vehicle drives for a long time in a congested road section, the temperature of the first drive device continues to rise to T3 (60°C), and the temperature of the second drive device is 55°C, which satisfies T3 ≤ first drive device temperature and second drive device temperature < T3. At this time, the water pump is started at high power and enters the torque distribution strategy. According to the strategy, the first drive device enters torque distribution strategy 1, that is, the first drive device adjusts the torque output according to its temperature protection output limit characteristic. At this time, the first drive device will appropriately reduce the torque output to reduce its heat generation, while ensuring that the vehicle can still maintain a certain driving speed in the urban road environment. In this process, the second drive device continues to work normally to maintain the balance of the vehicle's power output and ensure the safe driving of the vehicle.

[0096] Example 3

[0097] This embodiment provides a temperature protection method for a four-wheel electric vehicle electric drive system, which is used for temperature protection in high-speed driving conditions, and the specific implementation process is as follows:

[0098] High-speed driving initial stage: the vehicle drives at a high speed on the highway, and the water pump, fan and straight-through valve are not started at this stage. As the driving time increases, the temperature of the first drive device and the second drive device rapidly rises under high-speed operation. When the temperature of the first drive device and the second drive device reaches T1 (40°C) at the same time, the water pump is started to run at low power to preliminarily cool the drive device.

[0099] Temperature rapid rise and cooling system strengthening: Due to the large load of the motor during high-speed driving, the temperature of the first driving device and the second driving device rises rapidly. Soon, the temperature of both driving devices reaches T2 (50°C), at which time the water pump is opened at medium speed and the fan is opened at low speed, increasing the cooling flow. However, the vehicle continues to drive at high speed, and the temperature of the first driving device reaches T3 (60°C) first, and then the temperature of the second driving device also reaches T3 (60°C). At this time, the water pump is opened at high speed, and the torque distribution strategy is entered.

[0100] Torque distribution and safe driving of the vehicle: Because the temperature of the first driving device and the second driving device is greater than T3, the first driving device and the second driving device enter torque distribution strategy 3. Under torque distribution strategy 3, the first driving device and the second driving device adjust the torque according to the minimum protection strategy for safe driving formulated by the temperature fault strategy. Both driving devices simultaneously reduce the torque output, but maintain a certain power output level, so that the vehicle can safely drive at a relatively low speed on the highway, avoiding serious failures caused by excessive temperature, and also preventing safety accidents caused by sudden power cut-off. During this process, the speed of the vehicle may be reduced from the original 120 km / h to about 80 km / h, but the vehicle can still safely drive on the highway until the vehicle reaches a service area or the temperature decreases to a safe range.

[0101] As can be seen, in actual application, different vehicle driving conditions (such as climbing, sudden acceleration, sudden deceleration, etc.) will cause the temperature of the driving device to change differently. The temperature protection method of the embodiment can accurately control the cooling system and adjust the torque output of the driving device according to the real-time temperature, ensuring the safe and stable operation of the four-wheel drive electric vehicle electric drive system under various complex conditions, effectively improving the performance and safety of the vehicle. At the same time, by reasonably controlling the operation of the water pump and the fan, the energy consumption of the vehicle is reduced, the reliability of the related components is improved, and strong technical support is provided for the development of four-wheel drive electric vehicles.

[0102] Embodiment 4

[0103] As shown in Figure 4 , the embodiment provides a temperature protection method for a four-wheel drive electric vehicle electric drive system, comprising the following steps:

[0104] Based on the real-time temperature of the first driving device and the real-time temperature of the second driving device, the water pump gear position of the cooling system is switched;

[0105] When the water pump gear is switched to the high gear, a torque distribution strategy is selected and executed based on the current temperature of the first driving device and the current temperature of the second driving device, the torque distribution strategy being used to control the output torque of the first driving device or / and the second driving device, so that the four-wheel drive electric vehicle is always in an operating state.

[0106] In the embodiment, before the water pump gear of the cooling system is switched based on the real-time temperature of the first driving device and the real-time temperature of the second driving device, the following steps are further included:

[0107] According to the received vehicle starting signal, the water pump and the fan of the cooling system are controlled to be in the off state.

[0108] The real-time temperatures reported by the first driving device and the second driving device are monitored.

[0109] In the embodiment, the water pump gear of the cooling system is switched based on the real-time temperature of the first driving device and the real-time temperature of the second driving device, including:

[0110] The real-time temperatures reported by the first driving device and the second driving device are collected, and the real-time temperature of the first driving device and the real-time temperature of the second driving device are judged.

[0111] If the real-time temperature of the first driving device or / and the real-time temperature of the second driving device is in the first temperature interval, the water pump gear is switched to the low gear.

[0112] If the real-time temperature of the first driving device or / and the real-time temperature of the second driving device is in the second temperature interval, the water pump gear is switched to the middle gear.

[0113] If the real-time temperature of the first driving device or / and the real-time temperature of the second driving device is in the third temperature interval, the water pump gear is switched to the high gear.

[0114] In the embodiment, when the water pump gear is switched to the middle gear, the fan is controlled to start the low-speed mode.

[0115] When the water pump gear is switched to the high gear, the fan is controlled to start the high-speed mode.

[0116] In the embodiment, when the water pump gear is switched to the low gear, the straight-through valve corresponding to the first driving device or / and the second driving device is controlled to be opened.

[0117] When the water pump gear is switched to the middle gear, the straight-through valve corresponding to the first driving device or / and the second driving device is controlled to be adjusted to the half-open state.

[0118] When the water pump gear is switched to the high gear, the straight-through valve is controlled to be adjusted to the fully open state.

[0119] In the embodiment, the real-time temperature of the first driving device is the highest temperature among the first vehicle-mounted power supply and charger two-in-one temperature, the first motor controller temperature and the first reduction device temperature; and the real-time temperature of the second driving device is the highest temperature among the second vehicle-mounted power supply and charger two-in-one temperature, the second motor controller temperature and the second reduction device temperature.

[0120] In the embodiment, after the water pump gear is switched to the high gear of the water pump of the cooling system, based on the current temperature of the first driving device and the current temperature of the second driving device, a torque distribution strategy is selected and executed, including:

[0121] After the water pump gear is switched to the high gear of the water pump of the cooling system, the current temperature of the first driving device and the current temperature of the second driving device are continuously monitored;

[0122] The current temperature of the first driving device and the current temperature of the second driving device are judged;

[0123] If the current temperature of the first driving device is greater than the over-temperature threshold and the current temperature of the second driving device is less than the over-temperature threshold, a first torque distribution strategy is selected and executed;

[0124] If the current temperature of the first driving device is less than the over-temperature threshold and the current temperature of the second driving device is greater than the over-temperature threshold, a second torque distribution strategy is selected and executed;

[0125] If the current temperature of the first driving device and the current temperature of the second driving device are both greater than the over-temperature threshold, a third torque distribution strategy is selected and executed;

[0126] The torque distribution strategy includes the first torque distribution strategy, the second torque distribution strategy and the third torque distribution strategy.

[0127] The first torque distribution strategy is to limit the output torque of the first driving device to a preset safety limit value, and the second driving device compensates for power;

[0128] The second torque distribution strategy is to limit the output torque of the second driving device to a preset safety limit value, and the first driving device compensates for power;

[0129] The third torque distribution strategy is to synchronously reduce the output torque of the first driving device and the output torque of the second driving device, so that the electric vehicle is switched to a limp mode.

[0130] As Figure 5As shown, the embodiment also provides a temperature protection system for an electric drive system of a four-wheel drive electric vehicle, comprising: a water pump gear switching module, configured to switch a water pump gear of a cooling system based on a real-time temperature of a first drive device and a real-time temperature of a second drive device; and a distribution strategy execution module, configured to select and execute a torque distribution strategy based on a current temperature of the first drive device and a current temperature of the second drive device after the water pump gear is switched to a high gear, wherein the torque distribution strategy is used to control an output torque of the first drive device or / and the second drive device, so that the four-wheel drive electric vehicle is always in a running state.

[0131] The present application also provides a device, comprising: a memory for storing a computer program; and a processor for executing the computer program to implement the steps of the temperature protection method for an electric drive system of a four-wheel drive electric vehicle.

[0132] The processor executes the computer program to implement the steps of the temperature protection method for an electric drive system of a four-wheel drive electric vehicle, for example: switching a water pump gear of a cooling system based on a real-time temperature of a first drive device and a real-time temperature of a second drive device; and selecting and executing a torque distribution strategy based on a current temperature of the first drive device and a current temperature of the second drive device after the water pump gear is switched to a high gear, wherein the torque distribution strategy is used to control an output torque of the first drive device or / and the second drive device, so that the four-wheel drive electric vehicle is always in a running state.

[0133] Alternatively, the processor executes the computer program to implement the functions of the modules in the system, for example: a water pump gear switching module, configured to switch a water pump gear of a cooling system based on a real-time temperature of a first drive device and a real-time temperature of a second drive device; and a distribution strategy execution module, configured to select and execute a torque distribution strategy based on a current temperature of the first drive device and a current temperature of the second drive device after the water pump gear is switched to a high gear, wherein the torque distribution strategy is used to control an output torque of the first drive device or / and the second drive device, so that the four-wheel drive electric vehicle is always in a running state.

[0134] Exemplarily, the computer program can be divided into one or more modules / units stored in the memory and executed by the processor to accomplish the present application. The one or more modules / units can be a series of computer program instruction segments capable of accomplishing preset functions, and the instruction segments are used to describe the execution process of the computer program in the temperature protection device for the electric drive system of the four-wheel drive electric vehicle. For example, the computer program can be divided into a water pump gear switching module and a distribution strategy execution module; the specific functions of each module are as follows: the water pump gear switching module is used to switch the water pump gear of the cooling system based on the real-time temperature of the first driving device and the real-time temperature of the second driving device; the distribution strategy execution module is used to select and execute a torque distribution strategy based on the current temperature of the first driving device and the current temperature of the second driving device after the water pump gear is switched to the high gear of the water pump; the torque distribution strategy is used to control the output torque of the first driving device or / and the second driving device, so that the four-wheel drive electric vehicle is always in a running state.

[0135] The temperature protection device for the electric drive system of the four-wheel drive electric vehicle can be a desktop computer, a notebook computer, a palm computer, a cloud server, and the like. The temperature protection device for the electric drive system of the four-wheel drive electric vehicle can include, but is not limited to, a processor and a memory. Those skilled in the art can understand that the above is an example of the temperature protection device for the electric drive system of the four-wheel drive electric vehicle, and does not constitute a limitation on the temperature protection device for the electric drive system of the four-wheel drive electric vehicle, which can include more components than the above, or combine certain components, or different components, for example, the temperature protection device for the electric drive system of the four-wheel drive electric vehicle can also include an input / output device, a network access device, a bus, and the like.

[0136] The processor can be a central processing unit (CPU), and can also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs) or other programmable logic devices, discrete gates or transistor logic, discrete hardware components, or the like. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor or the like. The processor is the control center of the temperature protection device for the electric drive system of the four-wheel drive electric vehicle, and connects each part of the temperature protection device for the electric drive system of the four-wheel drive electric vehicle through various interfaces and lines.

[0137] The memory can be used to store the computer program and / or modules, and the processor realizes various functions of the four-wheel drive electric vehicle electric drive system temperature protection device by running or executing the computer program and / or modules stored in the memory, and calling the data stored in the memory.

[0138] The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, at least one application required by a function (such as a sound playing function, an image playing function, etc.), and the like; and the data storage area can store data created according to the use of the mobile phone (such as audio data, a phone book, etc.), and the like. In addition, the memory can include a high-speed random access memory, and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0139] The application further provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to realize the steps of the four-wheel drive electric vehicle electric drive system temperature protection method.

[0140] The modules / units of the four-wheel drive electric vehicle electric drive system temperature protection system integrated as a form of software function units and sold or used as independent products can be stored in a computer readable storage medium.

[0141] Based on such understanding, the application realizes all or part of the processes of the four-wheel drive electric vehicle electric drive system temperature protection method, and can also be completed by a computer program instructing related hardware, the computer program can be stored in a computer readable storage medium, and the computer program can realize the steps of the four-wheel drive electric vehicle electric drive system temperature protection method when executed by a processor. The computer program includes computer program codes, and the computer program codes can be in a form of source code, object code, an executable file or a preset intermediate form, etc.

[0142] The computer readable storage medium can include any entity or device, a recording medium, a U disk, a mobile hard disk, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier wave signal, a telecommunication signal and a software distribution medium, etc. that can carry the computer program codes.

[0143] It should be noted that the contents contained in the computer readable storage medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction, for example, in some jurisdictions, according to legislation and patent practice, the computer readable storage medium does not include electrical carrier signals and telecommunication signals.

[0144] The application provides a four-wheel drive electric vehicle electric drive system temperature protection method, which has the following advantages:

[0145] First, safety is improved: compared with the way of directly cutting off power when the traditional motor is overheated, the application can ensure the safe and reliable operation of the vehicle when the electric drive system has temperature abnormalities by dynamically adjusting the performance output of the fan, water pump and double drive device. According to different temperature fault conditions, the torque output of the drive device is reasonably adjusted to avoid safety accidents caused by sudden loss of power, and a safer driving environment is provided for the driver and passengers.

[0146] Second, the logic is clear and the risk is reduced: the protection method of the application has clear logic and simple strategy, which greatly reduces the risk of the vehicle losing power or other safety hazards due to temperature warnings or failures of the drive device. Through clear temperature interval judgment and corresponding action execution, the temperature problem of the electric drive system can be quickly and accurately addressed to ensure that the vehicle is always in a safe operating state.

[0147] Third, energy consumption is reduced and reliability is improved: the protection method of the application greatly reduces the power consumption of the water pump and the energy consumption of the vehicle by precisely controlling the operating power of the water pump. At the same time, due to the reduction of water pump power consumption, the working load of the water pump is reduced, which improves the reliability of the water pump to a certain extent, reduces the maintenance cost and failure probability of the vehicle, and improves the overall performance of the vehicle.

[0148] The above embodiments are only one of the implementation manners of the technical solutions of the application, and the scope of protection of the application is not limited to the above embodiments, but also includes any changes, substitutions and other implementation manners easily thought of by those skilled in the art within the technical scope disclosed by the application.

[0149] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the application and not to limit them, although the application has been described in detail with reference to the above embodiments, those skilled in the art should understand that the specific embodiments of the application can be modified or replaced, without departing from the spirit and scope of the application. Any modification or equivalent replacement, which does not depart from the spirit and scope of the application, should be covered within the protection scope of the claims of the application.

Claims

1. A temperature protection method for a four-wheel drive electric vehicle electric drive system, characterized in that, The method comprises the following steps: Switching the water pump gear of the cooling system based on the real-time temperature of the first driving device and the real-time temperature of the second driving device; After the water pump gear is switched to the high gear of the water pump of the cooling system, selecting and executing a torque distribution strategy based on the current temperature of the first driving device and the current temperature of the second driving device; The torque distribution strategy is used to control the output torque of the first driving device or / and the second driving device, so that the four-wheel drive electric vehicle is always in an operating state; After the water pump gear is switched to the high gear of the water pump of the cooling system, selecting and executing a torque distribution strategy based on the current temperature of the first driving device and the current temperature of the second driving device, comprising: After the water pump gear is switched to the high gear of the water pump of the cooling system, continuing to monitor the current temperature of the first driving device and the current temperature of the second driving device; Judging the current temperature of the first driving device and the current temperature of the second driving device; If the current temperature of the first driving device is greater than the over-temperature threshold and the current temperature of the second driving device is less than the over-temperature threshold, selecting and executing a first torque distribution strategy; If the current temperature of the first driving device is less than the over-temperature threshold and the current temperature of the second driving device is greater than the over-temperature threshold, selecting and executing a second torque distribution strategy; If the current temperature of the first driving device and the current temperature of the second driving device are both greater than the over-temperature threshold, selecting and executing a third torque distribution strategy; The torque distribution strategy comprises the first torque distribution strategy, the second torque distribution strategy and the third torque distribution strategy; The first torque distribution strategy is to limit the output torque of the first driving device to a preset safety limit, and the second driving device compensates for the power; The second torque distribution strategy is to limit the output torque of the second driving device to a preset safety limit, and the first driving device compensates for the power; The third torque distribution strategy is to synchronously reduce the output torque of the first driving device and the output torque of the second driving device, so that the electric vehicle is switched to a limp mode.

2. The temperature protection method for the electric drive system of the four-wheel drive electric vehicle according to claim 1, characterized in that, Before switching the water pump gear of the cooling system based on the real-time temperature of the first driving device and the real-time temperature of the second driving device, the method further comprises the following steps: According to the received vehicle starting signal, controlling the water pump and the fan of the cooling system to be in an off state; Monitoring the real-time temperature reported by the first driving device and the second driving device.

3. The temperature protection method for the electric drive system of the four-wheel drive electric vehicle according to claim 1, characterized in that, Switching the water pump gear of the cooling system based on the real-time temperature of the first driving device and the real-time temperature of the second driving device, comprising: Collecting the real-time temperature reported by the first driving device and the second driving device, and judging the real-time temperature of the first driving device and the real-time temperature of the second driving device; If the real-time temperature of the first driving device or / and the real-time temperature of the second driving device is in a first temperature interval, the water pump gear is switched to a low gear of the water pump; If the real-time temperature of the first driving device or / and the real-time temperature of the second driving device is in a second temperature interval, the water pump gear is switched to a middle gear of the water pump; If the real-time temperature of the first driving device or / and the real-time temperature of the second driving device is in a third temperature interval, the water pump gear is switched to a high gear of the water pump.

4. The temperature protection method for the electric drive system of the four-wheel drive electric vehicle according to claim 3, wherein When the water pump gear is switched to the middle gear, the fan is controlled to start the low-speed mode; When the water pump gear is switched to the high gear, the fan is controlled to start the high-speed mode.

5. The temperature protection method of the four-wheel drive electric vehicle electric drive system according to claim 3, characterized in that, When the water pump gear is switched to the low gear, the corresponding straight-through valve of the first drive device or / and the second drive device is controlled to open; When the water pump gear is switched to the middle gear, the corresponding straight-through valve of the first drive device or / and the second drive device is controlled to adjust to the half-open state; When the water pump gear is switched to the high gear, the straight-through valve is controlled to adjust to the fully open state.

6. The temperature protection method for the electric drive system of the four-wheel drive electric vehicle according to claim 1, characterized in that, The real-time temperature of the first drive device is the highest temperature among the first vehicle-mounted power supply and charger two-in-one temperature, the first motor controller temperature and the first reduction device temperature; the real-time temperature of the second drive device is the highest temperature among the second vehicle-mounted power supply and charger two-in-one temperature, the second motor controller temperature and the second reduction device temperature.

7. A temperature protection system for a four-wheel drive electric vehicle electric drive system, for implementing the steps of the temperature protection method for a four-wheel drive electric vehicle electric drive system according to any one of claims 1-6, characterized in that, It comprises: a water pump gear switching module for switching the water pump gear of the cooling system based on the real-time temperature of the first drive device and the real-time temperature of the second drive device; a distribution strategy execution module for selecting and executing the torque distribution strategy based on the current temperature of the first drive device and the current temperature of the second drive device after the water pump gear is switched to the high gear; The torque distribution strategy is used to control the output torque of the first drive device or / and the second drive device, so that the four-wheel drive electric vehicle is always in the running state.

8. A temperature protection device for an electric drive system of a four-wheel drive electric vehicle, characterized by, It comprises: a memory for storing a computer program; a processor for executing the computer program to realize the steps of the temperature protection method of the four-wheel drive electric vehicle electric drive system according to any one of claims 1-6.

9. A computer-readable storage medium storing a computer program, the computer program comprising instructions that, when executed by a computer, cause the computer to perform the method of any one of claims 1 to 8. The computer program is executed by the processor to realize the steps of the temperature protection method of the four-wheel drive electric vehicle electric drive system according to any one of claims 1-6.

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