Hybrid electric vehicle level balance control method and system

Abstract

The application discloses a kind of hybrid electric vehicle electric balance control method and system, it is related to vehicle technical field, the method includes: the state of charge is divided into high charge level, normal charge level, and according to the threshold value of entering high charge level dynamically calibrated by speed;When in high-speed range, control engine charges power battery to enter high charge level, pure electric mode operation, high-speed range is 70km / h~100km / h;In pure electric mode, when the state of charge drops to normal charge level, if the speed of hybrid electric vehicle enters ultra-high speed range, restart engine and prohibit shutdown, after power battery is charged to preset threshold value by engine, enter high charge level, with direct drive mode operation, ultra-high speed is 100km / h~135km / h;When decelerating in ultra-high speed range, the state of charge is improved to electric balance point by energy recovery, the present application can solve the technical problems that the driving behavior of driver directly affects the electric balance test results of WLTC in prior art, leading to test failure.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and specifically to a method and system for electric balance control of hybrid electric vehicles. Background Technology

[0002] With increasing environmental awareness and the development of new energy vehicle technology, hybrid vehicles have become a major trend in the modern automotive market. Hybrid vehicles combine the advantages of traditional and electric vehicles, offering better fuel economy and lower emissions.

[0003] Currently, hybrid vehicles control the engine start-stop based on vehicle speed and throttle position. In order to meet the electrical balance requirements of the Worldwide Harsh Trial Cycle (WLTC), the timing and percentage of the driver's accelerator pedal press are very important. The driver's driving behavior directly affects the engine's start-up or shutdown, and thus directly affects the WLTC electrical balance test results. Because it is difficult to ensure that the driving behavior of the same driver at different times or different drivers is consistent, it is difficult to ensure the electrical balance at the start and end, thus making the test invalid. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a hybrid electric vehicle electric balance control method and system, which addresses the technical problem in the prior art where the driver's driving behavior directly affects the electric balance test results of WLTC, leading to test failure.

[0005] The present invention provides a method for electric balance control of a hybrid electric vehicle, the method comprising:

[0006] The state of charge is divided into high charge level, hysteresis range and normal charge level, and the threshold for entering the high charge level is dynamically calibrated according to vehicle speed.

[0007] When the hybrid vehicle is in the high-speed range, if the state of charge has not reached the high charge level, the engine is controlled to charge the power battery to the first high charge threshold, enter the high charge level, and maintain pure electric mode operation. The high-speed range is 70km / h to 100km / h.

[0008] In pure electric mode, when the state of charge drops to the normal state of charge level, if the speed of the hybrid vehicle enters the ultra-high speed range, the engine is restarted and shutdown is prohibited. The engine charges the power battery to a preset threshold and then enters the high state of charge level. The engine is controlled to run in direct drive mode so that the state of charge is maintained within the second high state of charge threshold. The ultra-high speed is 100km / h to 135km / h.

[0009] When decelerating within the ultra-high speed range, energy recovery is used to raise the state of charge to a preset electrical balance point, thereby achieving electrical balance control.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows: By dividing the state of charge of the vehicle speed in the high-speed range and the ultra-high-speed range and dynamically calibrating the threshold for entering the high charge level, the electric balance control method of the hybrid electric vehicle (WLTC) can be precisely controlled in the high-speed range and the ultra-high-speed range, which greatly reduces the impact of driver behavior on the WLTC test. As long as the driver meets the speed range requirements of the WLTC, electric balance can be achieved and the best fuel consumption effect can be guaranteed. This solves the technical problem in the prior art that the driver's driving behavior directly affects the electric balance test results of the WLTC, leading to test failure.

[0011] According to one aspect of the above technical solution, the method further includes:

[0012] When the speed of a hybrid vehicle decreases from the high-speed range to the low-speed range, if the state of charge reaches the third high-charge threshold, it is determined that the state of charge has entered the high-charge level, and the engine is shut down to switch to pure electric mode. The low-speed range is 30km / h to 40km / h.

[0013] According to one aspect of the above technical solution, the step of dynamically calibrating the threshold for entering a high charge level based on vehicle speed specifically includes:

[0014] When the vehicle speed range is 0-20km / h, 50km / h-100km / h, and above 140km / h, the threshold for high charge level is the first high charge threshold.

[0015] When the vehicle speed range is 30km / h to 40km / h, the threshold for high charge level is the third high charge threshold.

[0016] When the vehicle speed range is 105km / h to 135km / h, the threshold for high charge level is the second high charge threshold.

[0017] The first high charge threshold is greater than the third high charge threshold, which is greater than the second high charge threshold.

[0018] According to one aspect of the above technical solution, the normal charge level is:

[0019] When the vehicle speed range is 30km / h to 40km / h, the threshold for normal charge level is the first normal charge threshold.

[0020] When the vehicle speed range is 50km / h to 135km / h, the threshold for normal charge level is the second normal charge threshold.

[0021] Other speed ranges are preset electrical balance points, which are greater than a first normal charge threshold and a second normal charge threshold.

[0022] According to one aspect of the above technical solution, the preset electrical balance point is greater than the second high charge threshold and less than the third high charge threshold.

[0023] According to one aspect of the above technical solution, the hysteresis range is between the high charge level and the normal charge level.

[0024] According to one aspect of the above technical solution, the preset electrical balance point and the energy recovered can be dynamically adjusted according to the actual working conditions.

[0025] According to one aspect of the above technical solution, the preset threshold is 0.1% larger than the second high charge threshold.

[0026] According to one aspect of the above technical solution, in the engine's direct drive mode, the engine output power is equal to the sum of the wheel-end drive power and the accessory power, and the power battery is in a state of neither charging nor discharging.

[0027] Another aspect of the present invention provides a hybrid electric vehicle electric balance control system, the system being used to implement the above-mentioned hybrid electric vehicle electric balance control method, the system comprising:

[0028] The state of charge classification module is used to classify the state of charge into high charge level, hysteresis range and normal charge level, and dynamically calibrate the threshold for entering the high charge level according to the vehicle speed.

[0029] The high-speed charge control module is used to control the engine to charge the power battery to the first high charge threshold when the state of charge has not reached the high charge level when the hybrid vehicle is in the high-speed range. This allows the vehicle to enter the high charge level and maintain pure electric mode operation. The high-speed range is 70km / h to 100km / h.

[0030] The ultra-high speed charge control module is used to restart the engine and prevent it from stopping when the state of charge drops to the normal charge level in pure electric mode. If the speed of the hybrid vehicle enters the ultra-high speed range, the engine is restarted and the power battery is charged to a preset threshold by the engine. Then, the vehicle enters a high charge level and the engine is controlled to run in direct drive mode so that the state of charge is maintained within the second high charge threshold. The ultra-high speed is 100km / h to 135km / h.

[0031] The deceleration and charge control module is used to raise the state of charge to a preset electrical balance point through energy recovery when decelerating in the ultra-high speed range, thereby achieving electrical balance control. Attached Figure Description

[0032] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0033] Figure 1 This is a flowchart illustrating the electric balance control method for hybrid electric vehicles in Embodiment 1 of the present invention.

[0034] Figure 2 This is a schematic diagram illustrating the relationship between the state of charge and vehicle speed in Embodiment 1 of the present invention;

[0035] Figure 3 This is a structural block diagram of the hybrid electric vehicle electric balance control system in Embodiment 2 of the present invention;

[0036] Component symbol explanation in the attached diagram:

[0037] Charge state division module 100, high-speed charge control module 200, ultra-high-speed charge control module 300, deceleration charge control module 400;

[0038] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0039] To make the objectives, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Several embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of the present invention will be more thorough and complete.

[0040] Example 1

[0041] Please see Figures 1-2 The first embodiment of the present invention provides a hybrid electric vehicle electric balance control method, the method comprising steps S10-S13:

[0042] Step S10: Divide the state of charge into high charge level, hysteresis range and normal charge level, and dynamically calibrate the threshold for entering the high charge level according to the vehicle speed.

[0043] In order to reduce the impact of driver behavior on the WLTC electrical balance test, it is necessary to classify the state of charge of vehicle speeds in the high-speed and ultra-high-speed ranges, dynamically calibrate the threshold for entering the high charge level, and effectively control the start and stop of the engine. As long as the driver meets the WLTC speed deviation requirements, electrical balance can be achieved regardless of who is driving, and optimal fuel consumption can be guaranteed.

[0044] Furthermore, the hysteresis range lies between the high charge level and the normal charge level.

[0045] Specifically, the steps for dynamically calibrating the threshold for entering a high charge level based on vehicle speed include:

[0046] When the vehicle speed range is 0-20km / h, 50km / h-100km / h, and above 140km / h, the threshold for high charge level is the first high charge threshold.

[0047] When the vehicle speed range is 30km / h to 40km / h, the threshold for high charge level is the third high charge threshold.

[0048] When the vehicle speed range is 105km / h to 135km / h, the threshold for high charge level is the second high charge threshold.

[0049] The first high charge threshold is greater than the third high charge threshold, which is greater than the second high charge threshold.

[0050] The normal charge level is:

[0051] When the vehicle speed range is 30km / h to 40km / h, the threshold for normal charge level is the first normal charge threshold.

[0052] When the vehicle speed range is 50km / h to 135km / h, the threshold for normal charge level is the second normal charge threshold.

[0053] Other speed ranges are preset electrical balance points, which are greater than a first normal charge threshold and a second normal charge threshold.

[0054] Furthermore, the preset electrical balance point is greater than the second high charge threshold and less than the third high charge threshold.

[0055] Examples, not limitations, such as Figure 2 As shown, the first high charge threshold is greater than 20.6%, the third high charge threshold is greater than 19.5%, and the second high charge threshold is greater than 18.6%. The first normal charge threshold is less than or equal to 18.8%, the second normal charge threshold is less than or equal to 18.1%, and the preset balance point is 19%.

[0056] Step S11: When the hybrid vehicle is in the high-speed range, if the state of charge has not reached the high charge level, control the engine to charge the state of charge of the power battery to the first high charge threshold, enter the high charge level, and maintain pure electric mode operation. The high-speed range is 70km / h to 100km / h.

[0057] In addition, in order to ensure that the hybrid vehicle enters a high charge level within the high-speed range, it is considered that the vehicle speed will decrease to a low-speed range within the high-speed range. If the state of charge reaches the third high charge threshold, it is determined that the state of charge has entered a high charge level and the engine will be shut down.

[0058] Specifically, when the speed of the hybrid vehicle decreases from the high-speed range to the low-speed range, if the state of charge reaches the third high-charge threshold, it is determined that the state of charge has entered the high-charge level, and the engine is controlled to shut down, switching to pure electric mode. The low-speed range is 30km / h to 40km / h.

[0059] Step S12: In pure electric mode, when the state of charge drops to the normal state of charge level, if the speed of the hybrid vehicle enters the ultra-high speed range, the engine is restarted and shutdown is prohibited. After the power battery is charged to the preset threshold by the engine, it enters the high state of charge level and controls the engine to run in direct drive mode so that the state of charge is maintained within the second high state of charge threshold. The ultra-high speed is 100km / h to 135km / h.

[0060] In pure electric mode, the state of charge begins to decrease, and the vehicle continues to drive in the early stages of high-speed and ultra-high-speed ranges. When the state of charge drops to 18.1%, it returns to the normal state of charge. If the hybrid vehicle's speed enters the ultra-high-speed range, the engine is restarted and shutting down is prohibited. The engine charges the power battery to a preset threshold.

[0061] Furthermore, the preset threshold is 0.1% larger than the second high charge threshold, i.e., 18.7%, because when entering the high charge level and controlling the engine to start direct drive mode, the state of charge will drop by 0.1%, so the second high charge threshold is 18.6%.

[0062] In addition, in the engine's direct drive mode, the engine output power is equal to the sum of the wheel-end drive power and the accessory power, and the power battery is in a state of neither charging nor discharging.

[0063] Step S13: When decelerating within the ultra-high speed range, the state of charge is raised to a preset electrical balance point through energy recovery to achieve electrical balance control.

[0064] The preset electrical balance point and the energy recovered can be dynamically adjusted according to the actual working conditions.

[0065] As an example, not a limitation, generally 0.4% to 0.5% of the energy recovered can guarantee the preset electrical balance point of 19%.

[0066] Furthermore, in the vehicle speed range of 105km / h to 135km / h, the threshold for the high charge level is the second high charge threshold; the second high charge threshold can be adjusted up or down to ensure that the energy in the cycle process reaches electrical balance, or is properly charged, or properly discharged.

[0067] Compared with existing technologies, the hybrid electric vehicle (WLTC) electric balance control method shown in this embodiment divides the vehicle speed into charge states in the high-speed and ultra-high-speed ranges and dynamically calibrates the threshold for entering a high charge level. This allows for precise control of the high-speed and ultra-high-speed ranges of the WLTC, greatly reducing the impact of driver behavior on the WLTC test. As long as the driver meets the WLTC speed range requirements, electric balance can be achieved, ensuring optimal fuel consumption. This solves the technical problem in existing technologies where driver behavior directly affects the WLTC electric balance test results, leading to test failure.

[0068] Example 2

[0069] Please see Figure 3 The image shows a hybrid electric vehicle electric balance control system provided in a second embodiment of the present invention, the system comprising:

[0070] The state of charge classification module 100 is used to classify the state of charge into high charge level, hysteresis range and normal charge level, and dynamically calibrate the threshold for entering the high charge level according to the vehicle speed.

[0071] The high-speed charge control module 200 is used to control the engine to charge the power battery to the first high charge threshold when the state of charge of the hybrid vehicle is in the high-speed range and the state of charge has not reached the high charge level, so as to enter the high charge level and maintain pure electric mode operation. The high-speed range is 70km / h to 100km / h.

[0072] The ultra-high speed charge control module 300 is used to restart the engine and prevent it from stopping when the state of charge drops to the normal charge level in pure electric mode, if the speed of the hybrid vehicle enters the ultra-high speed range. After the engine charges the power battery to a preset threshold, it enters the high charge level and controls the engine to run in direct drive mode so that the state of charge is maintained within the second high charge threshold. The ultra-high speed is 100km / h to 135km / h.

[0073] The deceleration charge control module 400 is used to raise the state of charge to a preset electrical balance point through energy recovery when decelerating in the ultra-high speed range, thereby achieving electrical balance control.

[0074] Compared with existing technologies, the hybrid electric vehicle electric balance control system shown in this embodiment divides the vehicle speed into high-speed and ultra-high-speed ranges through a state-of-charge (SOC) division module and dynamically calibrates the threshold for entering a high SOC level. This allows for precise control of the high-speed and ultra-high-speed ranges of the WLTC, significantly reducing the impact of driver behavior on the WLTC test. As long as the driver meets the WLTC speed range requirements, electric balance can be achieved, ensuring optimal fuel consumption. This solves the technical problem in existing technologies where driver behavior directly affects the WLTC electric balance test results, leading to test failure.

[0075] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0076] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0077] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A method for electric balance control of a hybrid electric vehicle, characterized in that, The method includes: The state of charge is divided into high charge level, hysteresis range, and normal charge level, and the threshold for entering the high charge level is dynamically calibrated according to vehicle speed, including: The high charge level threshold is defined as follows: First high charge threshold for vehicle speeds of 0-20 km / h, 50-100 km / h, and above 140 km / h; third high charge threshold for vehicle speeds of 30-40 km / h; and second high charge threshold for vehicle speeds of 105-135 km / h. The first high charge threshold is greater than the third high charge threshold, which in turn is greater than the second high charge threshold. The normal charge level is defined as follows: when the vehicle speed range is 30km / h to 40km / h, the threshold value of the normal charge level is the first normal charge threshold value; when the vehicle speed range is 50km / h to 135km / h, the threshold value of the normal charge level is the second normal charge threshold value; and other vehicle speed ranges are defined as preset balance points. The preset balance points are greater than the first normal charge threshold value and greater than the second normal charge threshold value. When the hybrid vehicle is in the high-speed range, if the state of charge has not reached the high charge level, the engine is controlled to charge the power battery to the first high charge threshold, enter the high charge level, and maintain pure electric mode operation. The high-speed range is 70km / h~100km / h. In pure electric mode, when the state of charge drops to the normal state of charge level, if the speed of the hybrid vehicle enters the ultra-high speed range, the engine is restarted and shutdown is prohibited. The engine charges the power battery to a preset threshold and then enters the high state of charge level. The engine is controlled to run in direct drive mode so that the state of charge is maintained within the second high state of charge threshold. The ultra-high speed is 100km / h~135km / h. When decelerating in the ultra-high speed range, energy recovery is used to raise the state of charge to a preset electrical balance point to achieve electrical balance control; The method further includes: When the speed of a hybrid vehicle decreases from the high-speed range to the low-speed range, if the state of charge reaches the third high-charge threshold, it is determined that the state of charge has entered the high-charge level, and the engine is shut down to switch to pure electric mode. The low-speed range is 30km / h to 40km / h.

2. The hybrid electric vehicle electric balance control method according to claim 1, characterized in that, The preset electrical balance point is greater than the second high charge threshold and less than the third high charge threshold.

3. The hybrid electric vehicle electric balance control method according to claim 1, characterized in that, The hysteresis range lies between the high charge level and the normal charge level.

4. The hybrid electric vehicle electric balance control method according to claim 1, characterized in that, The preset electrical balance point and the energy recovered can be dynamically adjusted according to actual working conditions.

5. The hybrid electric vehicle electric balance control method according to claim 4, characterized in that, The preset threshold is 0.1% greater than the second high charge threshold.

6. The electric balance control method for hybrid electric vehicles according to claim 1, characterized in that, In the engine's direct drive mode, the engine output power equals the sum of the wheel-end drive power and the accessory power, and the power battery is in a state of neither charging nor discharging.

7. A hybrid electric vehicle electric balance control system, characterized in that, The system is used to implement the hybrid electric vehicle electric balance control method according to any one of claims 1 to 6, and the system comprises: The state of charge classification module is used to classify the state of charge into high charge level, hysteresis range and normal charge level, and dynamically calibrate the threshold for entering the high charge level according to the vehicle speed. The high-speed charge control module is used to control the engine to charge the power battery to the first high charge threshold when the state of charge has not reached the high charge level when the hybrid vehicle is in the high-speed range. This allows the vehicle to enter the high charge level and maintain pure electric mode operation. The high-speed range is 70km / h~100km / h. The ultra-high-speed charge control module is used to restart the engine and prevent it from stopping when the state of charge drops to the normal charge level in pure electric mode. If the speed of the hybrid vehicle enters the ultra-high-speed range, the engine is restarted and the power battery is charged to a preset threshold by the engine. Then, the vehicle enters a high charge level and the engine is controlled to run in direct drive mode so that the state of charge is maintained within the second high charge threshold. The ultra-high speed is 100km / h~135km / h. The deceleration and charge control module is used to raise the state of charge to a preset electrical balance point through energy recovery when decelerating in the ultra-high speed range, thereby achieving electrical balance control.

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