Hybrid electric vehicle electric balance control method and system

Abstract

The invention discloses an electric balance control method and system for a hybrid electric vehicle, and relates to the technical field of vehicles, and the method comprises the steps: dividing the charge state into a high charge level and a normal charge level, and dynamically calibrating a threshold value entering the high charge level according to the vehicle speed; when the power battery is in the high-speed range, the engine is controlled to charge the power battery until the power battery enters a high charge level and runs in a pure electric mode, and the high-speed range is 70 km / h-100 km / h; in the pure electric mode, when the state of charge drops to the normal charge level, if the speed of the hybrid electric vehicle enters the ultra-high speed range, restarting the engine and forbidding shutdown, and after the power battery is charged to a preset threshold value through the engine, entering the high charge level, running in a direct drive mode and having the ultra-high speed of 100 km / h-135 km / h; and when speed reduction is carried out in an ultra-high-speed range, the charge state is improved to an electric balance point through energy recovery, and the technical problem that in the prior art, the driving behavior of a driver directly affects the electric balance test result of the WLTC, and consequently test failure is caused can be solved.

Description

Technical Field

[0001] The present invention relates to the field of vehicle technology, and in particular to a hybrid electric vehicle electric balance control method and system. Background Art

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

[0003] Currently, hybrid vehicles all control engine start and stop based on vehicle speed and throttle pedal. To meet the electrical balance requirements of the Worldwide Light Vehicle Test Cycle (WLTC), strict requirements are placed on the timing and percentage of the driver's accelerator pedal application. The driver's driving behavior directly affects the engine's start or stop, which in turn directly affects the WLTC electrical balance test results. Because it is difficult to ensure consistent driving behavior at different times for the same driver or for different drivers, it is difficult to ensure electrical balance at the start and end, resulting in invalid testing. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a hybrid electric vehicle electric balance control method and system, aiming to solve the technical problem in the existing technology that the driver's driving behavior directly affects the WLTC electric balance test results, resulting in test failure.

[0005] One aspect of the present invention is to provide a hybrid electric vehicle electric balance control method, 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 a high-speed range, and the state of charge has not reached a high charge level, the engine is controlled to charge the power battery to a first high charge threshold, enter the high charge level, and maintain pure electric mode operation. The high-speed range is 70 km / h to 100 km / h.

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

[0009] When decelerating in the ultra-high-speed range, the state of charge is raised to the preset electrical balance point through energy recovery to achieve electrical balance control.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows: through the hybrid vehicle electric balance control method provided by the present invention, the charge state is divided into the high-speed range and the ultra-high-speed range by the vehicle speed, and the threshold for entering the high charge level is dynamically calibrated, so that the high-speed range and the ultra-high-speed range of WLTC are accurately controlled, which greatly reduces the impact of the driver's driving behavior on the WLTC test. As long as the driver meets the WLTC speed range requirements, electric balance can be achieved and the optimal fuel consumption effect can be guaranteed, thereby solving the technical problem in the prior art that the driver's driving behavior directly affects the WLTC electric balance test results, resulting in test failure.

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

[0012] When the speed of the hybrid vehicle drops from the high speed range to the low speed range, if the state of charge reaches the third highest charge threshold, it is determined that the state of charge enters the high charge level, and the engine is controlled to be shut down and switched 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 the high charge level according to the vehicle speed specifically includes:

[0014] When the vehicle speed ranges are: 0-20km / h, 50km / h-100km / h, and above 140km / h, the high charge level threshold is the first high charge threshold;

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

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

[0017] The first high charge threshold is greater than the third high charge threshold and 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 of the normal charge level is the first normal charge threshold;

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

[0021] The other vehicle speed intervals are preset electrical balance points, and the preset electrical balance point is greater than the first normal charge threshold and greater than the 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 interval 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 actual working conditions.

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

[0026] According to one aspect of the above technical solution, in the direct drive mode of the engine, 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 non-charging and non-discharging state.

[0027] Another aspect of the present invention is to provide a hybrid electric vehicle electric balance control system, wherein the hybrid electric vehicle electric balance control system is used to implement the hybrid electric vehicle electric balance control method described above, and the system comprises:

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

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

[0030] The ultra-high-speed charge control module is used to restart the engine and prohibit shutdown when the state of charge drops to the normal charge level in pure electric mode and the hybrid vehicle's speed enters the ultra-high-speed range. After the engine charges the power battery to a preset threshold, the vehicle enters the high charge level and controls the engine to operate in direct drive mode so that the state of charge is maintained within the second high charge threshold. The ultra-high speed range is 100 km / h to 135 km / h.

[0031] The deceleration charge control module is used to increase the charge state to a preset electrical balance point through energy recovery when decelerating in the ultra-high speed range, thereby achieving electrical balance control. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0033] Figure 1 Schematic diagram of the flow of the hybrid electric vehicle electric balance control method in the first embodiment of the present invention;

[0034] Figure 2 Schematic diagram of the relationship between state of charge and vehicle speed in the first embodiment of the present invention;

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

[0036] Component symbol description in the attached figure:

[0037] State of charge classification module 100, high-speed charging control module 200, ultra-high-speed charging control module 300, deceleration charging control module 400;

[0038] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0039] To make the objectives, features, and advantages of the present invention more readily apparent, the following detailed description of specific embodiments of the present invention is provided in conjunction with the accompanying drawings. The accompanying drawings illustrate several embodiments of the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the present invention.

[0040] Example 1

[0041] See also Figure 1-Figure 2 , which shows a hybrid electric vehicle electric balance control method provided by the first embodiment of the present invention, the method includes steps S10 to S13:

[0042] Step S10, classifying the state of charge into a high charge level, a hysteresis range, and a normal charge level, and dynamically calibrating a threshold for entering the high charge level according to vehicle speed;

[0043] To mitigate the impact of driver behavior on the WLTC electrical balance test, it is necessary to divide the vehicle speed into the high-speed range and the ultra-high-speed range into charge states, 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 interval is between the high charge level and the normal charge level.

[0045] Specifically, the steps of dynamically calibrating the threshold for entering the high charge level according to the vehicle speed include:

[0046] When the vehicle speed ranges are: 0-20km / h, 50km / h-100km / h, and above 140km / h, the high charge level threshold is the first high charge threshold;

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

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

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

[0050] The normal charge levels are:

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

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

[0053] The other vehicle speed intervals are preset electrical balance points, and the preset electrical balance point is greater than the first normal charge threshold and greater than the 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] By way of example and not limitation, 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 electric vehicle is in a high-speed range and the state of charge has not reached a high charge level, controlling the engine to charge the power battery to a first high charge threshold, entering a high charge level, and maintaining pure electric mode operation. The high-speed range is 70 km / h to 100 km / 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 drops to a low-speed range within the high-speed range. If the charge state reaches the third highest charge threshold, it is determined that the charge state enters a high charge level, and the engine is controlled to be shut down.

[0058] Specifically, when the speed of the hybrid vehicle drops from the high-speed range to the low-speed range, if the state of charge reaches the third highest charge threshold, the state of charge is determined to have entered the high charge level, and the engine is controlled to be shut down and switched 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 a normal charge level, if the hybrid vehicle's speed enters an ultra-high speed range, the engine is restarted and shutdown is prohibited. After the power battery is charged to a preset threshold by the engine, the vehicle enters a high charge level and the engine is controlled to operate in a direct drive mode so that the state of charge is maintained within a second high charge threshold. The ultra-high speed range is 100 km / h to 135 km / h.

[0060] Among them, in pure electric mode, the state of charge begins to decline, and the early driving in the high-speed range and ultra-high-speed range continues. When the state of charge drops to 18.1%, it returns to the normal state of charge. If the speed of the hybrid vehicle enters the ultra-high-speed range, the engine is restarted and shutdown is prohibited. The power battery is charged to the preset threshold through the engine.

[0061] Furthermore, the preset threshold is 0.1% greater than the second high charge threshold, ie, 18.7%. Because entering the high charge level and controlling the engine to start the direct drive mode, the charge state will drop by 0.1%, so the second high charge threshold is 18.6%.

[0062] In addition, in the direct drive mode of the engine, 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 non-charging and non-discharging state.

[0063] Step S13: When decelerating in 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 amount of energy recovered can be dynamically adjusted according to actual working conditions.

[0065] For example and not limitation, generally, the energy recovered is 0.4% to 0.5%, which can ensure the preset electrical balance point of 19%.

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

[0067] Compared with the prior art, the hybrid vehicle electrical balance control method shown in this embodiment divides the vehicle speed into a high-speed range and an ultra-high-speed range into charge states, and dynamically calibrates the threshold for entering a high charge level. This allows precise control of the high-speed and ultra-high-speed ranges of the WLTC, greatly reducing the impact of the driver's driving behavior on the WLTC test. As long as the driver meets the WLTC speed range requirements, electrical balance can be achieved and optimal fuel consumption can be guaranteed. This solves the technical problem in the prior art where the driver's driving behavior directly affects the WLTC electrical balance test results, resulting in test failure.

[0068] Example 2

[0069] See also Figure 3 , which shows a hybrid electric vehicle electric balance control system provided by a second embodiment of the present invention, the system includes:

[0070] The state of charge classification module 100 is used to classify the state of charge into a high charge level, a hysteresis range, and a 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 a first high charge threshold when the state of charge has not reached a high charge level when the hybrid vehicle is in a high-speed range, thereby entering a high charge level and maintaining pure electric mode operation. The high-speed range is 70 km / h to 100 km / h.

[0072] The ultra-high-speed charge control module 300 is configured to, in pure electric mode, restart the engine and prohibit shutdown when the state of charge drops to a normal charge level if the hybrid vehicle's speed enters an ultra-high speed range. After the engine charges the power battery to a preset threshold, the vehicle enters a high charge level and controls the engine to operate in a direct drive mode, maintaining the state of charge within a second high charge threshold. The ultra-high speed range is 100 km / h to 135 km / h.

[0073] The deceleration charge control module 400 is used to increase 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 the prior art, the hybrid vehicle electric balance control system shown in this embodiment divides the state of charge into the high-speed range and the ultra-high-speed range through the state of charge classification module, and dynamically calibrates the threshold for entering the high charge level, thereby accurately controlling the high-speed range and the ultra-high-speed range of WLTC. This greatly reduces the impact of the driver's driving behavior on the WLTC test. As long as the driver meets the WLTC speed range requirements, electric balance can be achieved and optimal fuel consumption can be guaranteed. This solves the technical problem in the prior art that the driver's driving behavior directly affects the WLTC electric balance test results, resulting in test failure.

[0075] The technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, 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] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations 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 any one or more embodiments or examples.

[0077] The above-described embodiments merely illustrate several implementations of the present invention. 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 a person skilled in the art would be able to make numerous modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A hybrid electric vehicle electric balance control method, characterized in that: The method comprises: 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; When the hybrid vehicle is in a high-speed range, and the state of charge has not reached a high charge level, the engine is controlled to charge the power battery to a first high charge threshold, enter the high charge level, and maintain pure electric mode operation. The high-speed range is 70 km / h to 100 km / h. In pure electric mode, when the state of charge drops to the normal charge level, if the hybrid vehicle's speed enters the ultra-high speed range, the engine is restarted and shutdown is prohibited. After the power battery is charged to a preset threshold by the engine, the vehicle enters the high charge level and controls the engine to operate in direct drive mode so that the state of charge is maintained within the second high charge threshold. The ultra-high speed range is 100 km / h to 135 km / h. When decelerating in the ultra-high-speed range, the state of charge is raised to the preset electrical balance point through energy recovery to achieve electrical balance control.

2. The hybrid vehicle electric balance control method according to claim 1, characterized in that: The method further comprises: When the speed of the hybrid vehicle drops from the high speed range to the low speed range, if the state of charge reaches the third highest charge threshold, it is determined that the state of charge enters the high charge level, and the engine is controlled to be shut down and switched to pure electric mode. The low speed range is 30km / h to 40km / h.

3. The hybrid vehicle electric balance control method according to claim 2, characterized in that: The steps of dynamically calibrating the threshold for entering a high charge level according to vehicle speed specifically include: When the vehicle speed ranges are: 0-20km / h, 50km / h-100km / h, and above 140km / h, the high charge level threshold is the first high charge threshold; When the vehicle speed range is 30km / h to 40km / h, the high charge level threshold is the third high charge threshold; When the vehicle speed range is 105km / h to 135km / h, the high charge level threshold is the second highest charge threshold; The first high charge threshold is greater than the third high charge threshold and greater than the second high charge threshold.

4. The hybrid vehicle electric balance control method according to claim 3, characterized in that: The normal charge levels are: When the vehicle speed range is 30km / h to 40km / h, the threshold of the normal charge level is the first normal charge threshold; When the vehicle speed range is 50km / h to 135km / h, the threshold of the normal charge level is the second normal charge threshold; The other vehicle speed intervals are preset electrical balance points, and the preset electrical balance point is greater than the first normal charge threshold and greater than the second normal charge threshold.

5. The hybrid electric vehicle electric balance control method according to claim 4, characterized in that: The preset electrical balance point is greater than the second high charge threshold and less than the third high charge threshold.

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

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

8. The hybrid vehicle electric balance control method according to claim 7, characterized in that: The preset threshold is 0.1% greater than the second high charge threshold.

9. The hybrid electric vehicle electric balance control method according to claim 1, characterized in that: In the direct drive mode of the engine, 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 non-charging and non-discharging state.

10. 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 9, and the system includes: The state-of-charge classification module is used to classify the state of charge into a high charge level, a hysteresis range, and a normal charge level, and dynamically calibrate the threshold for entering the high charge level based on vehicle speed; A high-speed charge control module is used to control the engine to charge the power battery to a first high charge threshold when the state of charge has not reached a high charge level when the hybrid vehicle is in a high-speed range, thereby entering a high charge level and maintaining pure electric mode operation. The high-speed range is 70 km / h to 100 km / h. The ultra-high-speed charge control module is used to restart the engine and prohibit shutdown when the state of charge drops to the normal charge level in pure electric mode and the hybrid vehicle's speed enters the ultra-high-speed range. After the engine charges the power battery to a preset threshold, the vehicle enters the high charge level and controls the engine to operate in direct drive mode so that the state of charge is maintained within the second high charge threshold. The ultra-high speed range is 100 km / h to 135 km / h. The deceleration charge control module is used to increase the charge state 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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