A range-extending vehicle electric quantity control method, system and range-extending vehicle

Abstract

The application discloses a range-extending vehicle electric quantity control method and system and a range-extending vehicle, which comprises the following steps: determining the proportion k of fuel driving mileage in the total mileage A of the vehicle in the latest driving; obtaining the current residual fuel quantity Q o , the current residual electric quantity Q e and the current driving cycle mileage M of the vehicle; performing fuzzy control calculation based on k, Q o , Q e and M to obtain the probability Y of using fuel to supplement electricity of the vehicle; determining the residual electric quantity correction value SOC corr according to Y; and calculating the target residual electric quantity SOC tar by using the formula: SOC base =SOC corr + SOC tar , wherein SOC base represents the basic residual electric quantity; and starting the engine to generate electricity in response to the actual residual electric quantity being less than or equal to the target residual electric quantity SOC tar . The application can dynamically adjust the residual electric quantity threshold for triggering the engine start, improve the pure electric cruising range and improve the vehicle experience.

Description

Technical Field

[0001] This invention belongs to the field of electric power control for new energy vehicles, specifically relating to a method, system, and range-extended vehicle for electric power control. Background Technology

[0002] The typical method for controlling the battery charge in hybrid electric vehicles is as follows: when the actual remaining battery charge (i.e., actual SOC) is less than or equal to the baseline remaining battery charge, the engine is started to charge the battery. At this point, the remaining battery charge threshold that triggers engine start is equal to the baseline remaining battery charge. After the engine starts, the generator's output power is controlled based on the current actual remaining battery charge. The lower the actual remaining battery charge, the higher the output power; conversely, the higher the actual remaining battery charge, the lower the output power.

[0003] Currently, for range-extended electric vehicles (REEVs), the maximum allowable discharge power of the battery is far greater than the engine's rated power. Therefore, during actual road driving, under certain conditions (such as long uphill climbs), the remaining battery charge will inevitably decrease. When the battery charge drops, the engine generates power at high power to maintain the remaining charge, resulting in increased engine noise. Simultaneously, the maximum allowable discharge power of the battery also decreases, leading to a decline in vehicle performance. To prevent the battery charge from dropping too low during driving, the remaining charge threshold for triggering engine start is set relatively high, providing a buffer period for the vehicle to cope with different road conditions. However, this reduces the pure electric range of REEVs in daily use. Therefore, choosing an appropriate remaining charge threshold for triggering engine start in daily use is a problem that needs to be addressed for REEVs. Summary of the Invention

[0004] The purpose of this invention is to provide a method, system, and vehicle for controlling the battery power of a range-extended vehicle, so as to dynamically adjust the remaining battery power threshold that triggers engine start, thereby increasing the pure electric range and improving the user experience.

[0005] In a first aspect, the present invention provides a method for controlling the battery power of a range-extended vehicle, comprising: Determine the proportion k of fuel-powered mileage in the vehicle's most recent mileage A.

[0006] Get the current remaining fuel level Q of the vehicle o Current vehicle remaining battery power Q e And the current driving cycle vehicle has traveled a distance of M.

[0007] Based on the aforementioned percentage k and the current remaining fuel Q of the vehicle o Current vehicle remaining battery power Q eThe probability Y of the vehicle using fuel to recharge is obtained by performing fuzzy control calculations on the mileage M already traveled in the current driving cycle.

[0008] The remaining battery power correction value SOC is determined based on the probability Y. corr .

[0009] Using the formula: SOC tar = SOC base +SOC corr The target remaining power SOC is calculated. tar Among them, SOC base This indicates the basic remaining power.

[0010] Responding to when the actual remaining battery power is less than or equal to the target remaining battery power (SOC) tar (That is, the remaining battery power threshold that triggers engine start is the target remaining battery power SOC) tar ), controls the engine to start and generate electricity.

[0011] Preferably, the method for determining the proportion k of fuel-powered mileage in the vehicle's most recent mileage A includes: Determine the fuel mileage S within the vehicle's most recent mileage A. Here, fuel mileage S refers to the actual remaining battery charge being less than or equal to the target remaining battery charge SOC. tar Furthermore, the mileage traveled while the engine is running, and the target remaining state of charge (SOC). tar The initial value is equal to SOC. base That is, the first fuel-powered driving range S is calculated when the actual remaining battery power is less than or equal to the state of charge (SOC). base Furthermore, the engine start time also refers to the trigger condition when the basic remaining battery power is used as the first time the engine is started.

[0012] Using the formula k = S / A, the proportion of fuel-powered mileage (k) in the vehicle's most recent mileage (A) can be calculated.

[0013] Mileage A includes both pure electric driving mileage and fuel driving mileage. Only the proportion k of fuel driving mileage in the vehicle's most recent mileage A is considered. That is, the duty cycle k is calculated using mileage A as a sliding time window, which is more conducive to improving the accuracy of the probability Y of the vehicle using fuel to replenish electricity in the future.

[0014] Preferably, the mileage A is a preset value, which is equal to the pure electric range value corresponding to the design capacity of the power battery obtained by WLTC test, thereby helping to improve the pure electric range and reduce fuel consumption.

[0015] Preferably, the mileage A is equal to x1 × A'; where x1 represents the mileage correction coefficient, which is obtained by querying a preset table of correspondence between power battery temperature and mileage correction coefficient based on the current power battery temperature, and A' is a preset value, equal to the pure electric range value corresponding to the power battery design capacity obtained from WLTC test. Correcting A' using the current power battery temperature improves the accuracy of mileage A, thereby improving the accuracy of the percentage k.

[0016] Preferably, the basic remaining power SOC base As a preset value, SOC base This is equal to the remaining charge when starting the engine, which corresponds to the design capacity of the power battery, obtained from WLTC test conditions.

[0017] Preferably, the basic remaining power SOC base equals x2×SOC' base Where x2 represents the power correction coefficient, which is obtained by querying a preset table of the correspondence between power battery temperature and power correction coefficient based on the current power battery temperature, and SOC' base As a preset value, SOC' base This equals the remaining charge when starting the engine, corresponding to the design capacity of the power battery, obtained from WLTC testing. The SOC' is then calculated using the current power battery temperature. base The correction increased the base remaining power SOC. base This improves the accuracy of the target remaining power SOC, thereby increasing its effectiveness. tar The accuracy.

[0018] Preferably, the remaining power correction value (SOC) is determined. corr The method is as follows: Based on the probability Y of the vehicle using fuel to replenish electricity, a preset probability-remaining battery power correction table is consulted to obtain the corresponding remaining battery power correction value SOC. corr The preset probability-remaining battery power correction table is a table showing the correspondence between the probability of a vehicle using fuel to recharge and the remaining battery power correction value, obtained through calibration.

[0019] Preferably, in the preset probability-remaining battery power correction table, when the probability of the vehicle using fuel for recharging is greater than a preset probability threshold, the remaining battery power correction value is positive and increases with the increase of probability; when the probability of the vehicle using fuel for recharging is equal to the preset probability threshold, the remaining battery power correction value is 0; and when the probability of the vehicle using fuel for recharging is less than the preset probability threshold, the remaining battery power correction value is negative and decreases with the decrease of probability. When it is predicted that the vehicle does not need to use fuel for recharging (i.e., when the probability of the vehicle using fuel for recharging is less than the preset probability threshold), the remaining battery power threshold that triggers engine start is reduced (i.e., SOC).tar <SOC base When it is predicted that the vehicle will need to use fuel for extended periods to recharge (i.e., the probability of the vehicle using fuel for recharging is greater than a preset probability threshold), the remaining battery charge threshold that triggers engine startup will be increased (i.e., State of Charge (SOC)). tar >SOC base This prevents the battery from dropping too low under various complex road conditions. It further improves the pure electric range for users in daily use and the driving experience when the vehicle is being recharged with fuel.

[0020] Secondly, the present invention provides a range-extended vehicle power control system, which includes a controller configured to execute the above-described range-extended vehicle power control method.

[0021] Thirdly, the present invention provides a range-extended vehicle, which includes the above-described range-extended vehicle power control system.

[0022] The present invention has the following effects: (1) The higher the proportion k of fuel-powered mileage in the most recent mileage A, the higher the probability that the vehicle has used fuel to recharge or is currently using fuel to recharge in the short term, and the higher the probability that it will use fuel to recharge in the future; the higher the remaining battery power, the lower the probability of using fuel, and the lower the remaining fuel, the lower the probability of using fuel; after the mileage of a single driving cycle exceeds the pure electric range, the vehicle needs to use fuel to recharge, and the probability of the vehicle using fuel is high. Therefore, based on the proportion k of fuel-powered mileage in the most recent mileage A and the current remaining fuel Q of the vehicle... o Current vehicle remaining battery power Q e The system uses fuzzy control to calculate the mileage M that the vehicle has traveled in the current driving cycle, and obtains the probability Y of the vehicle using fuel to replenish electricity in the future. This comprehensive approach improves the accuracy of the prediction, ensures the accuracy of the calculation of the remaining power correction value, and thus ensures the accuracy of the target remaining power (i.e., the remaining power threshold that triggers engine start).

[0023] (2) The target remaining battery power will be dynamically adjusted according to the probability Y of the vehicle using fuel to recharge, thereby automatically adapting to different travel scenarios, improving the pure electric range and enhancing the user experience. In addition, the dynamic target remaining battery power strategy is more likely to make the engine work at a higher overall efficiency point than the fixed threshold strategy, thereby reducing the vehicle's average fuel consumption and emissions.

[0024] (3) Fuzzy control has a certain tolerance for noise and fluctuations in the input signal. Even if the acquired data has slight errors, the fuzzy rule can still give a reasonable output direction. Using fuzzy control for processing is more robust and more in line with the actual situation than simple threshold or linear rules. Furthermore, the probability of the vehicle using fuel to replenish the battery output by fuzzy control is a continuous value, which makes the remaining battery power correction value SOC more accurate. corr and target remaining power SOC tar The changes are smooth, avoiding sudden shifts in strategy and helping to improve driving smoothness. Attached Figure Description

[0025] Figure 1 This is a flowchart of the range-extended vehicle power control method in an embodiment of the present invention.

[0026] Figure 2 This is a flowchart illustrating the method for determining the proportion k of fuel-powered mileage in the most recent mileage A of a vehicle, as described in this embodiment of the invention. Detailed Implementation

[0027] To gain a more detailed understanding of the features and technical content of the embodiments of the present invention, the implementation of the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for reference and illustration only and are not intended to limit the embodiments of the present invention.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing embodiments of the invention only and is not intended to limit the invention.

[0029] In the following description, references are made to “some embodiments,” which describe a subset of all possible embodiments. However, it is understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0030] like Figure 1 As shown, the range-extended vehicle power control method in this embodiment of the invention includes the following steps: S1. Determine the proportion k of fuel-powered mileage in the vehicle's most recent mileage A, and then execute S2.

[0031] like Figure 2 As shown, in some embodiments, the method for determining the proportion k of fuel-powered mileage in the most recent mileage A of the vehicle includes: S11. Determine the fuel mileage S in the vehicle's most recent mileage A.

[0032] Mileage A includes both pure electric driving range and fuel-powered driving range. Fuel-powered driving range S refers to the actual remaining battery charge being less than or equal to the target remaining battery charge (SOC). tar Furthermore, the mileage traveled while the engine is running, and the target remaining state of charge (SOC). tar The initial value is equal to SOC. base That is, the first fuel-powered driving range S is calculated when the actual remaining battery power is less than or equal to the state of charge (SOC). base Furthermore, the engine start time also refers to the trigger condition when the basic remaining battery power is used as the first time the engine is started. The determination method in S11 is existing technology.

[0033] In some embodiments, the vehicle's most recently driven mileage A is a preset value, where A equals the pure electric driving range corresponding to the design capacity of the power battery, obtained according to WLTC testing. For example, if the power battery design capacity is 30 kWh, the mileage A = 150 km.

[0034] In some embodiments, the vehicle's most recently driven mileage A is equal to x1 × A'. Here, x1 represents the mileage correction factor, which is obtained by querying a preset table of correspondence between power battery temperature and mileage correction factor based on the current power battery temperature. A' is a preset value, which is equal to the pure electric range value corresponding to the power battery design capacity obtained from WLTC test.

[0035] S12. Using the formula: k = S / A, calculate the proportion of fuel-powered mileage (k) in the vehicle's most recent mileage (A).

[0036] As an example, if the vehicle's most recent mileage A = 150km, meaning that within the most recent 150km of the vehicle's mileage, 30km was traveled on fuel, then the proportion of fuel-powered mileage in the vehicle's most recent mileage A is k = 30 / 150 = 20%.

[0037] S2, Obtain the current remaining fuel level Q of the vehicle. o Current vehicle remaining battery power Q e And the current driving cycle vehicle has traveled a distance of M, then execute S3.

[0038] S3, the percentage of fuel-fueled mileage in the vehicle's most recent mileage A, k, and the current remaining fuel level Q. o Current vehicle remaining battery power Q e The system performs fuzzy control calculations on the mileage M already traveled by the vehicle in the current driving cycle to obtain the probability Y of the vehicle using fuel to recharge in the future, and then executes S4.

[0039] Specifically, it is calculated as follows: the percentage of fuel-fueled mileage (k) in the vehicle's most recent mileage (A) (ranging from 0 to 100%), and the current remaining fuel level (Q). o(Value range is 0 to 100%) Current vehicle remaining battery power Q e (Values ​​range from 0 to 100%) and the current driving cycle mileage M as input, with the probability Y of the vehicle using fuel to recharge (in the future) as output, a fuzzy control model is established as follows: 1) Blurring For the proportion k of fuel-powered mileage in the vehicle's most recent mileage A, the fuzzy sets are defined as "low" (B), "medium" (C), and "high" (D), and the membership function is a trigonometric function. For example, the range of "low" is 0-10%, the range of "medium" is 5%-50%, and the range of "high" is 40%-100%.

[0040] Regarding the current remaining battery power Q of the vehicle e The fuzzy sets are defined as "sufficient" (E), "moderate" (F), and "insufficient" (G), and the membership function is a trigonometric function. For example, the range of "sufficient" is 50% to 100%, the range of "moderate" is 15% to 60%, and the range of "insufficient" is 0% to 20%.

[0041] Regarding the current remaining fuel level Q of the vehicle o The fuzzy sets are defined as "Many" (H), "Medium" (I), and "Few" (J), and the membership function is a trigonometric function. For example, the range of "Many" is 45% to 100%, the range of "Medium" is 20% to 50%, and the range of "Few" is 0% to 25%.

[0042] For the current driving cycle vehicle's mileage M, the fuzzy sets are defined as "short" (K), "medium" (L), and "long" (N), with the membership function being a trigonometric function. For example, the range of "short" is 0-40 kilometers, "medium" is 35-100 kilometers, and "long" is over 90 kilometers.

[0043] For the probability Y of (future) vehicles using fuel to replenish electricity, fuzzy sets are defined as "small" (P), "medium" (R), and "large" (U), with trigonometric functions as membership functions. For example, the range of "small" is 0-15%, "medium" is 10%-50%, and "large" is 45%-100%.

[0044] 2) Establish a fuzzy rule base (see Table 1) Table 1 4) Deblurring The centroid method is used for defuzzification. Based on the designed membership function and fuzzy rules, the probability Y of (future) vehicles using fuel for recharging is calculated.

[0045] S4. Determine the remaining battery charge correction value SOC based on the probability Y of the vehicle using fuel to recharge. corr Then execute S5.

[0046] In some embodiments, the remaining battery power correction value (SOC) is determined. corr The method is as follows: Based on the probability Y of the vehicle using fuel to recharge, a preset probability-remaining battery power correction table is consulted to obtain the corresponding remaining battery power correction value SOC. corr The preset probability-remaining battery power correction table is a table showing the correspondence between the probability of a vehicle using fuel to recharge and the remaining battery power correction value, obtained through calibration.

[0047] As an example, in the preset probability-remaining battery power correction value table, when the probability of the vehicle using fuel to recharge is greater than the preset probability threshold, the remaining battery power correction value is positive and increases as the probability increases; when the probability of the vehicle using fuel to recharge is equal to the preset probability threshold, the remaining battery power correction value is 0; and when the probability of the vehicle using fuel to recharge is less than the preset probability threshold, the remaining battery power correction value is negative and decreases as the probability decreases.

[0048] S5. Using the formula: SOC tar = SOC base +SOC corr The target remaining power SOC is calculated. tar Then execute S6. Wherein, SOC... base This indicates the basic remaining power.

[0049] In some embodiments, the base remaining power SOC base As a preset value, SOC base This is equal to the remaining charge when starting the engine, which corresponds to the design capacity of the power battery, obtained from WLTC test conditions.

[0050] In some embodiments, the base remaining power SOC base equals x2×SOC' base Where x2 represents the power correction coefficient, which is obtained by querying a preset table of the correspondence between power battery temperature and power correction coefficient based on the current power battery temperature. SOC' base As a preset value, SOC' base This is equal to the remaining charge when starting the engine, which corresponds to the design capacity of the power battery, obtained from WLTC test conditions.

[0051] S6. Determine whether the (current) actual remaining battery power is less than or equal to the target remaining battery power SOC. tar If yes, then execute S7; otherwise, return to execute S1.

[0052] S7. Control the engine to start generating electricity, then stop.

[0053] In addition, embodiments of the present invention also provide a range-extended vehicle power control system, which includes a controller configured to execute the above-described range-extended vehicle power control method.

[0054] In addition, embodiments of the present invention also provide a range-extended vehicle, which includes the above-described range-extended vehicle power control system.

[0055] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for controlling the battery power of a range-extended vehicle, characterized in that, include: Determine the proportion k of fuel-powered mileage in the vehicle's most recent mileage A; Get the current remaining fuel level Q of the vehicle o Current vehicle remaining battery power Q e And the current driving cycle vehicle has traveled a distance of M; Based on the aforementioned percentage k and the current remaining fuel Q of the vehicle o Current vehicle remaining battery power Q e The probability Y of the vehicle using fuel to recharge is obtained by performing fuzzy control calculations on the mileage M already traveled in the current driving cycle. The remaining battery power correction value SOC is determined based on the probability Y. corr ; Using the formula: SOC tar = SOC base +SOC corr The target remaining power SOC is calculated. tar SOC base Indicates the basic remaining power; Responding to when the actual remaining battery power is less than or equal to the target remaining battery power (SOC) tar Control the engine to start and generate electricity; Among them, the remaining power correction value SOC is determined. corr The method is as follows: Based on the probability Y of the vehicle using fuel to replenish electricity, a preset probability-remaining battery power correction table is consulted to obtain the corresponding remaining battery power correction value SOC. corr The preset probability-remaining battery power correction table is a table showing the correspondence between the probability of a vehicle using fuel to recharge and the remaining battery power correction value, obtained through calibration. The fuzzy control model used in the fuzzy control calculation includes: the proportion k of the fuel-fueled mileage in the vehicle's most recent mileage A, and the current remaining fuel Q of the vehicle. o Current vehicle remaining battery power Q e And define the fuzzy set and membership function for the mileage M that the vehicle has traveled in the current driving cycle; establish a fuzzy rule base; During defuzzification, the centroid method is used. Based on the designed membership function and fuzzy rules, the probability Y of the vehicle using fuel to replenish electricity is calculated.

2. The range-extended vehicle power control method according to claim 1, characterized in that, Methods for determining the proportion k of fuel-powered mileage in the vehicle's most recent mileage A include: Determine the fuel mileage S within the vehicle's most recent mileage A; where fuel mileage S refers to the actual remaining battery power being less than or equal to the target remaining battery power SOC. tar Furthermore, the mileage traveled while the engine is running, and the target remaining state of charge (SOC). tar The initial value is equal to SOC. base ; The proportion k can be calculated using the formula: k = S / A.

3. The range-extended vehicle power control method according to claim 1, characterized in that, The mileage A is a preset value, which is equal to the pure electric range value corresponding to the design capacity of the power battery obtained according to the WLTC test.

4. The range-extended vehicle power control method according to claim 1, characterized in that, The mileage A is equal to x1 × A'; where x1 represents the mileage correction coefficient, which is obtained by querying a preset table of the correspondence between the current power battery temperature and the mileage correction coefficient, and A' is a preset value, which is equal to the pure electric range value corresponding to the design capacity of the power battery obtained by WLTC test.

5. The range-extended vehicle power control method according to claim 1, characterized in that, The basic remaining power SOC base As a preset value, SOC base This is equal to the remaining charge when starting the engine, which corresponds to the design capacity of the power battery, obtained from WLTC test conditions.

6. The range-extended vehicle power control method according to claim 1, characterized in that, The basic remaining power SOC base equals x2×SOC' base Where x2 represents the power correction coefficient, which is obtained by querying a preset table of the correspondence between power battery temperature and power correction coefficient based on the current power battery temperature, and SOC' base As a preset value, SOC' base This is equal to the remaining charge when starting the engine, which corresponds to the design capacity of the power battery, obtained from WLTC test conditions.

7. The range-extended vehicle power control method according to any one of claims 1 to 6, characterized in that: In the preset probability-remaining battery power correction table, when the probability of the vehicle using fuel to recharge is greater than the preset probability threshold, the remaining battery power correction value is positive and increases as the probability increases; when the probability of the vehicle using fuel to recharge is equal to the preset probability threshold, the remaining battery power correction value is 0; and when the probability of the vehicle using fuel to recharge is less than the preset probability threshold, the remaining battery power correction value is negative and decreases as the probability decreases.

8. A range-extended vehicle power control system, comprising a controller, characterized in that: The controller is configured to perform the range-extended vehicle power control method as described in any one of claims 1 to 7.

9. A range-extended vehicle, characterized in that: Including the range-extended vehicle power control system as described in claim 8.

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