A large electric quantity extended-range electric vehicle calibration method

Abstract

The application discloses a large-electricity range-extender electric vehicle calibration method, and the overall calibration architecture comprises drive mode calibration, energy management calibration, battery low-temperature protection calibration, battery discharge limitation calibration and electric drive external characteristic limitation calibration. The application is adapted to the mode management and energy management and other functional modules of the large-electricity range-extender electric commercial vehicle, so that the vehicle only discharges the battery in most working conditions, reasonably allocates the consumption proportion of electricity and oil, simultaneously exerts the system configuration advantage, as far as possible, guarantees the power performance of the vehicle, simultaneously takes into account the overcharge protection of the battery, maximizes the user vehicle benefit, creates greater value for the customer, and protects the core components; the VCU dynamically and real-timely adjusts the APU allowed power generation power according to the available charging power of the battery, so that the battery also will not appear overcharge in the dynamic working condition, which guarantees the brake efficiency and brake performance, reduces the wear of the mechanical brake, and protects the battery.

Description

Technical Field

[0001] This invention relates to the field of new energy vehicle technology, and more specifically, to a calibration method for a large-capacity range-extended electric vehicle. Background Technology

[0002] Range-extended electric commercial vehicles equipped with high-capacity batteries have higher battery capacity, which can support a longer pure electric driving range. Therefore, under the control framework of traditional range-extended electric vehicles, the vehicle should be driven by discharging the battery as much as possible in different driving modes to power the electric drive, while the APU (Automatic Power Unit) assists in operation to minimize fuel consumption and improve user benefits.

[0003] Existing technologies for high-capacity range-extended electric commercial vehicles have many problems with mode management and energy management calibration compared to low-capacity range-extended electric commercial vehicles. The ratio of fuel and electricity usage in the vehicle is not adaptively adjusted, resulting in increased fuel consumption for users and reduced user benefits. Summary of the Invention

[0004] This invention provides a calibration method for a high-capacity range-extended electric vehicle, which adaptively adjusts the ratio of fuel and electricity usage in the vehicle to avoid increasing fuel consumption and improve user benefits.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a calibration method for a high-capacity range-extended electric vehicle, wherein the overall calibration architecture includes drive mode calibration, energy management calibration, battery low-temperature protection calibration, battery discharge limit calibration, and electric drive external characteristic limit calibration;

[0006] The specific calibration method is as follows:

[0007] Step S1, drive mode calibration: When there is a heating request in different drive modes, the VCU will control the engine to start to provide a heat source for the passenger compartment. The actual drive mode changes due to the intervention of the heating request. However, in order to avoid confusion for the driver regarding the driving mode, when entering heating in different modes, the drive mode before entering heating is maintained. Furthermore, when entering heating, clicking the drive mode switch will not switch to the target drive mode.

[0008] Step S2, energy management calibration: The full load weight of the extended range with a large charge is greater than that with a low charge, and the drive power requirement of the drive end is also greater. For the basic battery power protection map, the power protection power needs to be increased adaptively. For the battery power protection map of coasting and neutral, it should be increased by 5~10kW to replenish the battery faster and meet the power consumption of the large drive power requirement.

[0009] Step S3, battery low temperature protection calibration, for extended electric vehicles, due to the presence of APU, when the battery temperature is low in winter cold state, the battery charging capacity is low or not allowed to charge, when the driver releases the throttle to make the vehicle slide or steps on the brake to recover energy, due to the slow power reduction of APU, the energy recovery power is established, and the APU power is not quickly reduced, resulting in overcharge of the battery, therefore, when the battery temperature is lower than 10℃ and the battery charging capacity is lower than 5kW, the battery low temperature protection strategy is entered;

[0010] Step S4, battery discharge limit calibration, in order to protect the battery life, the lower limit of battery discharge is set according to EV mode and SHEV mode, and the lower limit of EV mode discharge is further lowered;

[0011] Step S5, electric drive external characteristic limit calibration, in order to ensure the low speed climbing power of the vehicle, the peak torque capacity of the motor constant torque interval needs to be released, when the motor approaches the base speed, the motor enters the constant power interval, and the external characteristic torque capacity of the motor is gradually limited to limit the maximum drive power output of the motor.

[0012] Preferably, the step S1, drive mode calibration, the specific steps are:

[0013] Step S1.1, judge whether there is a heating request, if yes, proceed to step S1.2, if not, proceed to step S1.3;

[0014] Step S1.2, keep the external drive mode before heating;

[0015] Step S1.3, keep the drive mode before heating after the heating request is exited, and allow the user to freely switch the drive mode;

[0016] Step S1.4, judge whether the driver presses the drive mode switch, if yes, proceed to step S1.5, if not, repeat this step;

[0017] Step S1.5, keep the drive mode before heating.

[0018] Preferably, the specific content of step S1.3 is:

[0019] Step S1.31, judge whether SOC in EV mode is lower than 16% or in SHEV mode is lower than 18%, or whether the battery discharge capacity is lower than 35kW, if yes, proceed to step S1.32, if not, proceed to step S1.33;

[0020] Step S1.32, VCU controls engine start;

[0021] Step S1.33, judge if the battery continuous charging ability is higher than 60kw, if yes, go to step S1.34, if no, go to step S1.35;

[0022] Step S1.34, allow to enter REV mode;

[0023] Step S1.35, judge if the continuous charging ability is lower than 55kw, if yes, go to step S1.36, if no, go to step S1.37;

[0024] Step S1.36, prohibit to enter REV mode;

[0025] Step S1.37, keep the driving mode unchanged.

[0026] Preferably, the step S2, energy management calibration, the specific steps are:

[0027] Step S2.1, judge if the driving mode is REV or EV mode with heating request, if yes, go to step S2.2, if no, go to step S2.3;

[0028] Step S2.2, user selects power generation;

[0029] Step S2.21, judge if the battery SOC is greater than or equal to 98%, if yes, go to step S2.22, if no, go to step S2.23;

[0030] Step S2.24, request the power generation to be zero;

[0031] Step S2.25, execute power generation according to the user selected power generation;

[0032] Step S2.3, judge if the driving mode is Auto, if yes, go to step S2.4;

[0033] Step S2.4, judge if the battery SOC is higher than 30%, if yes, go to step S2.5, if no, go to step S2.6;

[0034] Step S2.5, keep the battery discharging, prohibit to start APU power generation;

[0035] Step S2.6, judge if the battery SOC is lower than 25%, if yes, go to step S2.7, if no, repeat this step;

[0036] Step S2.7, APU power follow-up control;

[0037] Step S2.8, the whole battery protection basis map of coasting and braking is adaptively calibrated by 5~10KW;

[0038] Step S2.9, the battery power protection basic map of the driving condition is adapted by 10~20kW.

[0039] Preferably, the step S3, the battery low temperature protection calibration, the specific content is:

[0040] Step S3.1, judge whether the battery allows continuous charging capacity is lower than 5kw, and the minimum temperature of the battery is lower than-10℃, if yes, then proceed to step S3.2, if not, then proceed to step S3.3;

[0041] Step S3.2, the battery low temperature protection;

[0042] Step S3.21, judge whether the REV mode or other mode is started APU, if yes, then proceed to step S3.22, if not, then repeat this step;

[0043] Step S3.23, execute the battery low temperature protection;

[0044] Step S3.24, VCU constant request APU power generation 5kW;

[0045] Step S3.3, judge whether the battery allows continuous charging capacity is higher than 10kW, or the minimum temperature of the battery is higher than-8C, if yes, then proceed to step S3.4, if not, then repeat this step;

[0046] Step S3.4, do not execute the battery low temperature protection.

[0047] Preferably, the step S4, the battery discharge limit calibration, the specific content is:

[0048] Step S4.1, judge whether the driving mode is EV, if yes, then proceed to step S4.2, if not, then proceed to step S4.3;

[0049] Step S4.2, S0C is lower than 16% to start linear gradient to reduce the available power of the battery, 10% to 0;

[0050] Step S4.3, the driving mode is SHEV;

[0051] Step S4.4, S0C is lower than 18% to start linear gradient to reduce the available power of the battery, 12% to 0.

[0052] Preferably, the step S5, the electric drive external characteristic limit calibration, the specific content is:

[0053] Step S5.1, the driving mode is ECO;

[0054] Step S5.11, judge whether the speed is lower than the base speed, if yes, then proceed to step S5.12. If not, then proceed to step S5.13;

[0055] Step S5.12, no external characteristic restriction is performed below the motor base speed;

[0056] Step S5.13, the external characteristic torque restriction makes the drive power output less than or equal to 90KW;

[0057] Step S5.2, the driving mode is Normal;

[0058] Step S5.21, it is judged whether the rotating speed is lower than the base speed, if yes, step S5.22 is performed, if not, step S5.23 is performed;

[0059] Step S5.22, no external characteristic restriction is performed below the motor base speed;

[0060] Step S5.23, the external characteristic torque restriction makes the drive power output less than or equal to 110KW.

[0061] The beneficial effects of the above technical solutions are:

[0062] 1. The application is adapted to the mode management and energy management of the extended-range electric commercial vehicle with large power, so that the vehicle is discharged by the battery in most working conditions, the consumption proportion of electricity and oil is reasonably distributed, the system configuration advantage is exerted, the power performance of the vehicle is ensured as much as possible, the overcharge protection of the battery is considered, the user's vehicle benefit is maximized, greater value is created for customers, and the core components are protected.

[0063] 2. The VCU dynamically adjusts the APU allowed power generation according to the available charging power of the battery, so that the battery will not be overcharged in dynamic working conditions, the braking efficiency and braking performance are ensured, the mechanical braking wear is reduced, and the battery is protected. BRIEF DESCRIPTION OF DRAWINGS

[0064] Figure 1 It is a general calibration architecture of the application;

[0065] Figure 2 It is a mode management calibration flowchart of the application;

[0066] Figure 3 It is an energy management calibration flowchart of the application;

[0067] Figure 4 It is a low-temperature protection calibration flowchart of the application;

[0068] Figure 5 It is an external characteristic restriction calibration flowchart of the application;

[0069] Figure 6 It is a battery discharge restriction calibration flowchart of the application. DETAILED DESCRIPTION

[0070] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, in order to help those skilled in the art to have a more complete, accurate and in-depth understanding of the concept and technical solutions of the present invention, and to facilitate its implementation.

[0071] like Figures 1 to 6 As shown, this invention is a calibration method for a high-capacity range-extended electric vehicle, which adaptively adjusts the ratio of fuel and electricity usage in the vehicle to avoid increasing fuel consumption for users and improve their vehicle usage benefits.

[0072] Specifically, such as Figures 1 to 6 As shown, the overall calibration architecture includes drive mode calibration, energy management calibration, battery low temperature protection calibration, battery discharge limit calibration, and electric drive external characteristic limit calibration.

[0073] The specific calibration method is as follows:

[0074] Step S1, drive mode calibration: When there is a heating request in different drive modes, the VCU will control the engine to start to provide a heat source for the passenger compartment. The actual drive mode changes due to the intervention of the heating request. However, in order to avoid confusion for the driver regarding the driving mode, when entering heating in different modes, the drive mode before entering heating is maintained. Furthermore, when entering heating, clicking the drive mode switch will not switch to the target drive mode.

[0075] Step S2, energy management calibration: The full load weight of the extended range with a large charge is greater than that with a low charge, and the drive power requirement of the drive end is also greater. For the basic battery power protection map, the power protection power needs to be increased adaptively. For the battery power protection map of coasting and neutral, it should be increased by 5~10kW to replenish the battery faster and meet the power consumption of the large drive power requirement.

[0076] Step S3, battery low temperature protection calibration. For range-extended electric vehicles, due to the presence of the APU, when the battery temperature is low or the battery charging capacity is low or charging is not allowed in the cold winter state, when the driver releases the accelerator to coast the vehicle or applies the brake to perform energy recovery, the APU's power reduction is slow, so after the energy recovery power is built up, the superimposed APU power generation power that has not decreased rapidly may cause the battery to overcharge. Therefore, the battery temperature is calibrated to be below 10°C and the battery charging capacity is below 5kW, and the battery low temperature protection strategy is entered.

[0077] Step S4, battery discharge limit calibration. In order to protect battery life, the lower limit of battery discharge is set differently according to EV mode and SHEV mode, with the lower limit of EV mode being further lowered.

[0078] Step S5, electric drive external characteristic limit calibration, in order to ensure the low-speed climbing power of the whole vehicle, the peak torque capacity of the motor constant torque interval needs to be fully released, and when approaching the motor base speed, the motor enters the constant power interval, and the external characteristic torque capacity of the motor is gradually limited to limit the maximum drive power output of the motor.

[0079] Step S1, drive mode calibration, the specific steps are:

[0080] Step S1.1, judge whether there is a heating request, if yes, proceed to step S1.2, if not, proceed to step S1.3;

[0081] Step S1.2, the external drive mode keeps the pre-heating drive mode;

[0082] Step S1.3, after the heating request exits, keep the drive mode before heating, and allow the user to freely switch the drive mode;

[0083] Step S1.4, judge whether the driver presses the drive mode switch, if yes, proceed to step S1.5, if not, repeat this step;

[0084] Step S1.5, the drive mode keeps the pre-heating drive mode.

[0085] The specific content of step S1.3 is:

[0086] Step S1.31, judge whether SOC is lower than 16% in EV mode or lower than 18% in SHEV mode, or whether the battery discharge capacity is lower than 35kW, if yes, proceed to step S1.32, if not, proceed to step S1.33;

[0087] Step S1.32, VCU controls engine start;

[0088] Step S1.33, judge whether the battery continuous charging capacity is higher than 60kw, if yes, proceed to step S1.34, if not, proceed to step S1.35;

[0089] Step S1.34, allow entering REV mode;

[0090] Step S1.35, judge whether the continuous charging capacity is lower than 55kw, if yes, proceed to step S1.36, if not, proceed to step S1.37;

[0091] Step S1.36, prohibit entering REV mode;

[0092] Step S1.37, keep the drive mode unchanged.

[0093] Step S2, energy management calibration, the specific steps are:

[0094] Step S2.1, judge whether the driving mode is REV or EV mode with heating request, if yes, proceed to step S2.2, if not, proceed to step S2.3;

[0095] Step S2.2, user selects the power generation power;

[0096] Step S2.21, judge whether the battery SOC is greater than or equal to 98%, if yes, proceed to step S2.22, if not, proceed to step S2.23;

[0097] Step S2.24, request the power generation power to be zero;

[0098] Step S2.25, execute power generation according to the user-selected power generation power;

[0099] Step S2.3, judge whether the driving mode is Auto, if yes, proceed to step S2.4;

[0100] Step S2.4, judge whether the battery SOC is higher than 30%, if yes, proceed to step S2.5, if not, proceed to step S2.6;

[0101] Step S2.5, keep the battery discharge, and prohibit starting the APU to generate power;

[0102] Step S2.6, judge whether the battery SOC is lower than 25%, if yes, proceed to step S2.7, if not, repeat this step;

[0103] Step S2.7, APU power follow-up control;

[0104] Step S2.8, the battery protection basis map of coasting and braking is adaptively marked by 5~10KW;

[0105] Step S2.9, the battery protection basis map of driving working condition is adaptively marked by 10~20kW.

[0106] Step S3, battery low temperature protection calibration, the specific content is:

[0107] Step S3.1, judge whether the battery allowed continuous charging capacity is lower than 5kw, and whether the battery minimum temperature is lower than-10℃, if yes, proceed to step S3.2, if not, proceed to step S3.3;

[0108] Step S3.2, battery low temperature protection;

[0109] Step S3.21, judge whether the APU is started in REV mode or other mode, if yes, proceed to step S3.22, if not, repeat this step;

[0110] Step S3.23, execute battery low temperature protection;

[0111] Step S3.24, VCU constant request APU power generation 5kW;

[0112] Step S3.3, judge whether the battery allows continuous charging capacity is higher than 10kW, or the battery minimum temperature is higher than -8C, if yes, proceed to step S3.4, if not, repeat this step;

[0113] Step S3.4, no battery low temperature protection is performed.

[0114] Step S4, battery discharge limit calibration, the specific content is:

[0115] Step S4.1, judge whether the driving mode is EV, if yes, proceed to step S4.2, if not, proceed to step S4.3;

[0116] Step S4.2, S0C is lower than 16% to start linear gradient to reduce the available power of the battery, 10% to 0;

[0117] Step S4.3, the driving mode is SHEV;

[0118] Step S4.4, S0C is lower than 18% to start linear gradient to reduce the available power of the battery, 12% to 0.

[0119] Step S5, the specific content of the external characteristic limit calibration is:

[0120] Step S5.1, the driving mode is ECO;

[0121] Step S5.11, judge whether the speed is lower than the base speed, if yes, proceed to step S5.12. If not, proceed to step S5.13;

[0122] Step S5.12, no external characteristic limit is performed below the base speed of the motor;

[0123] Step S5.13, the external characteristic torque limit makes the driving power output less than or equal to 90KW;

[0124] Step S5.2, the driving mode is Normal;

[0125] Step S5.21, judge whether the speed is lower than the base speed, if yes, proceed to step S5.22. If not, proceed to step S5.23;

[0126] Step S5.22, no external characteristic limit is performed below the base speed of the motor;

[0127] Step S5.23, the external characteristic torque limit makes the driving power output less than or equal to 110KW.

[0128] It needs to be explained that when the ambient temperature is low in winter and the driver has a heating request and presses the heating switch, the air conditioning control panel CLM will forward the heating request to the vehicle control unit (hereinafter referred to as "VCU") of the EVCAN through the central gateway TBOX. After the VCU receives the CLM heating request forwarded by the TBOX, the intervention driving mode cannot enter the pure electric EV mode, the mode management module judges that the engine needs to be started, and the VCU sends a start engine instruction to the range extender (hereinafter referred to as "APU") control unit GCU. The GCU interacts with the engine control unit (hereinafter referred to as "EMS") to control the engine start. After the engine starts running, the cooling water temperature increases to provide heating for the passenger compartment;

[0129] In different driving modes, different control strategies are adopted for APU power generation control after the engine is started by the heating request. If the engine is started by the heating request in the EV mode or the range extending mode (hereinafter referred to as "REV"), the control strategy of user's free selection of APU power generation power is adopted for APU power generation control. The default power generation power only supports the power consumption of high-voltage accessories (initial calibration 1kW). In this way, if the battery power is high, the engine is only used to provide a heat source for the vehicle heating, and the small power generation ensures that the engine does not consume much fuel, and the engine in the power generation state also does not consume electricity.

[0130] The reason why APU small power generation is adopted instead of APU idle running is that when the engine is in idle running, the engine output torque is zero, and the generator needs to consume a part of the electric energy in order to maintain the speed control with the synchronous speed. Therefore, APU small power generation is needed to meet the passenger compartment heating demand without increasing excessive fuel consumption and consuming battery power.

[0131] If the engine is started by the heating request in the intelligent mode (hereinafter referred to as "Auto"), the VCU will calculate the APU power generation power request after the engine is started according to the definition of the intelligent mode. When the battery power is high, the default small power generation strategy is adopted to fully discharge the battery. When the battery SOC is lower than 25%, in order to ensure the power performance of the vehicle and the balance of the power, the APU enters the power following control, that is, the APU power generation power follows the discharge demand power of the driving end, the power consumption of the high-voltage accessories, and the battery power compensation demand power.

[0132] It should be noted that when there is a heating request in different driving modes, VCU will control the engine to start to provide warm air heat source for the passenger compartment. The actual driving mode changes due to the intervention of the heating request, but in order to avoid the driver's doubts about the driving mode, the driving mode before entering the heating is kept when entering the heating in different modes, and the target driving mode cannot be switched by clicking the driving mode switch during heating. After the heating request is exited, the driving mode before heating is kept, and the user is allowed to freely switch the driving mode.

[0133] If there is no heating request for the whole vehicle, the lower limit of the battery SOC for mode conversion needs to be further lowered for EV mode. The lower limit of the discharge for EV mode is set to 16%. When the battery SOC is lower than 16%, the vehicle will exit the EV mode and enter the SHEV mode. In SHEV mode, VCU will control the engine to start, and APU will generate power according to the energy management strategy of VCU.

[0134] When APU starts to generate power, the battery SOC will gradually rise. When the battery SOC is higher than 18%, the vehicle will enter EV mode again, which aims to keep the battery power at a reasonable level, neither too low to cause power out of control or affect the vehicle's power, nor too high to cause fuel consumption to rise and affect the user's vehicle economy.

[0135] For REV mode, the user selects the energy management strategy of generating power independently, and the power required for APU power generation is appropriately limited to prevent battery overcharging, excessive NVH noise, etc. For some battery platform products, the driving charging map is consistent with the plug-in charging map, which aims to ensure that the battery can be fully charged. The problem is that the charging capacity of the battery management unit BMS is still greater than zero at 100% SOC. For VCU energy management control, the required APU power generation power is set to zero when the SOC is above 98% to avoid the problem of battery overcharging when the battery is fully charged.

[0136] For Auto mode, when the battery SOC is higher than 30%, the actual EV mode driving is maintained, i.e. when the battery power is high, the battery is allowed to discharge independently in Auto mode, and the engine is prohibited from intervention to avoid consuming fuel and increasing the user's vehicle cost. The battery remaining power threshold obtained by looking up the table according to the vehicle speed and SOC is set to -1000, so that the available remaining power of the battery above 30% SOC is always less than the EV conversion threshold, so that the engine will not start when the SOC is higher than the threshold of 30% in Auto mode.

[0137] When the calibrated battery SOC is lower than 25%, the engine is started in time according to the driving power demand and the SOC state. If the driving power demand is higher than the battery discharge capacity or the SOC in the Auto mode is lower than the calibrated threshold, the VCU sends a starting instruction to the GCU, and the APU starts to generate power for driving and power supply of the vehicle.

[0138] In the Auto mode, when the calibrated battery SOC is higher than 20% and the driving power demand is lower than the threshold, the EV mode is maintained. When the calibrated battery SOC is lower than 18%, the EV mode is exited and the SHEV mode is entered.

[0139] The full-load mass of the large-capacity range extension is larger than that of the low-capacity range extension, and the driving power demand of the driving end is also larger. For the basic battery power preservation map, the power preservation power needs to be adaptively marked larger. For the battery power preservation map of coasting and neutral, the power is adaptively marked larger by 5-10 kW to charge the battery faster and meet the large driving power demand. For the basic battery power preservation map in the driving state, the power is adaptively marked larger by 10-20 kW to charge the battery faster and meet the large driving power demand. The increment of the battery power preservation map of coasting and neutral is smaller than that of the battery power preservation map in the driving state, so as to balance the vehicle NVH. When coasting or in N gear, the wind noise is small, and there is no driving power demand, so the APU power generation power does not need to be too large. When driving, the demand for driving power is large, so the battery needs to be charged faster to balance the battery power;

[0140] For the range-extended electric vehicle, when the battery temperature is low and the battery charging capacity is low or not allowed to charge in the winter cold state due to the presence of the APU,

[0141] When the driver releases the accelerator to coast or steps on the brake to recover energy, the APU power decreases slowly, and the energy recovery power is established, and the APU power does not decrease quickly, which may cause the battery to be overcharged. Therefore, when the calibrated battery temperature is lower than 10℃ and the battery charging capacity is lower than 5kW, the battery low-temperature protection strategy is entered. After entering, the default APU power generation power is 5kW, which meets the basic high-voltage accessory power demand and the battery heating mode power demand. When the calibrated battery temperature is higher than -8℃ or the battery charging capacity is higher than 10kW, the battery low-temperature protection strategy is exited.

[0142] In order to protect the battery life, the lower limit of discharge of the battery is set differently according to the EV mode and the SHEV mode, the lower limit of discharge of the EV mode is further lowered, the calibration battery SOC 10% is completely not allowed to discharge to protect the battery, the calibration linearly reduces the battery allowed discharge power from 16%, and for the SHEV mode, the calibration limits the discharge power of the battery from SOC 18%, and the battery discharge power is reduced to 0 at 12% to protect the battery;

[0143] For the economy of the whole vehicle, the external characteristics of the motor need to be adaptively limited, under the premise of guaranteeing the power demand covering most of the normal user driving conditions, the external characteristics of the motor are appropriately limited to improve the economy of the whole vehicle and maximize the user's benefit.

[0144] For the external characteristic limitation of the motor, the power of the whole vehicle needs to be guaranteed in the constant torque interval, and the power of the whole vehicle in extreme conditions such as heavy load and steep slope climbing can meet the vehicle climbing demand, and above the motor inflection point, the external characteristics of the motor need to be gradually limited to ensure that the driving power demand of the motor is generally lower than the upper limit of the power limit allowed by the electric drive.

[0145] The external characteristic power limit of the calibration ECO mode is 90kW, and the external characteristic power limit of the calibration Normal mode is 110kW, the ECO mode is economical, and the Normal mode is powerful, in order to guarantee the low-speed climbing power of the whole vehicle, the peak torque capacity of the motor constant torque interval needs to be fully released, when approaching the motor base speed, the motor enters the constant power interval, and the external characteristic torque capacity of the motor is gradually limited to limit the maximum driving power output of the motor;

[0146] When the battery temperature is extremely low in winter, the battery charging capacity is weak or even zero in the cold start state, at this time, in order to save the battery power and ensure that the whole vehicle has more available power to the electric drive system for vehicle driving, the VCU will control the start of the APU to generate power, the calibration energy recovery is given priority, the APU power generation is second, when the electric braking power is improved, the VCU dynamically adjusts the APU allowed power generation power according to the available charging power of the battery, to ensure that the battery does not overcharge in dynamic conditions, which guarantees the braking efficiency and braking performance, reduces the wear of mechanical braking, and protects the battery.

[0147] For the REV mode, since it allows users to freely select the power generation, when the winter ambient temperature is low, the battery charging capacity is greatly reduced, the REV mode is prohibited, and the battery charging capacity boundary is prevented from being approached by the power generation selected by the user in the REV mode. When the battery charging capacity is lower than 55kW, the REV mode is prohibited. When the battery charging capacity is higher than 60kW, the REV mode is allowed to let the user freely select the power generation. The upper and lower limit values of the threshold are set according to the charging map capacity of the large-capacity battery and the driving end power consumption.

[0148] When the winter ambient temperature is low, the battery discharge capacity will also decrease due to physical characteristics. If the ambient temperature is extremely low, the battery discharge capacity is very low after the vehicle is started in the cold state, and the vehicle power will be greatly reduced. When the battery discharge capacity is lower than 35kW, the VCU will immediately control the APU to start and generate power to provide more available discharge power for the electric drive to improve the vehicle power.

[0149] The application is described above with reference to the drawings, and it is obvious that the specific implementation of the application is not limited to the above manner. Any non-essential improvement made by using the method concept and technical solution of the application, or directly applying the above concept and technical solution of the application to other occasions without improvement, is within the protection scope of the application.

Claims

1. A calibration method for a high-capacity range-extended electric vehicle, characterized in that: The overall calibration architecture includes drive mode calibration, energy management calibration, battery low temperature protection calibration, battery discharge limit calibration, and electric drive external characteristic limit calibration. The specific calibration method is as follows: Step S1, Drive Mode Calibration: When there is a heating request, maintain the drive mode before heating. During heating, drive mode switching is prohibited. After the heating request is cancelled, free switching is allowed. When the SOC is below 16% in EV mode, below 18% in SHEV mode, or the battery discharge capacity is below 35kW, the VCU controls the engine to start. When the battery's continuous charging capacity is above 60kW, entering REV mode is allowed. When it is below 55kW, entering REV mode is prohibited. Step S2, Energy Management Calibration: The battery power preservation map adaptability calibration for coasting and neutral is increased by 5~10kW, and the battery power preservation base map adaptability calibration for driving conditions is increased by 10~20kW; in Auto mode, when the battery SOC is higher than 30%, the battery discharge is maintained and APU power generation is prohibited; when the SOC is lower than 25%, the APU performs power following control; in REV mode or EV mode, when there is a heating request, if the battery SOC is ≥98%, the APU requests zero power generation. Step S3, battery low temperature protection calibration: when the battery's lowest temperature is ≤-10℃ and the allowable continuous charging capacity is ≤5kW, the low temperature protection strategy is entered, and the VCU constantly requests the APU's power generation to be 5kW; when the battery's lowest temperature is ≥-8℃ or the allowable continuous charging capacity is ≥10kW, the protection strategy is exited. Step S4, Battery discharge limit calibration: In EV mode, the battery's usable power begins to decrease linearly when the SOC is below 16%, and the power is zero when the SOC drops to 10%; in SHEV mode, the battery's usable power begins to decrease linearly when the SOC is below 18%, and the power is zero when the SOC drops to 12%. Step S5, Electric drive external characteristic limit calibration: In ECO mode, there is no limit to the external characteristics below the motor base speed, and the torque limit above the base speed ensures that the drive power is ≤90kW; in Normal mode, there is no limit to the external characteristics below the motor base speed, and the torque limit above the base speed ensures that the drive power is ≤110kW.

2. The calibration method for a high-capacity range-extended electric vehicle according to claim 1, characterized in that: Step S1, drive mode calibration, specifically involves the following steps: Step S1.1: Determine if there is a heating request. If yes, proceed to step S1.2; otherwise, proceed to step S1.

3. Step S1.2: The external drive mode remains the pre-heating drive mode; Step S1.3: After the heating request is exited, the driving mode before heating is maintained, and the user is allowed to freely switch the driving mode. Step S1.4: Determine whether the driver has pressed the drive mode switching switch. If yes, proceed to step S1.5; otherwise, repeat this step. Step S1.5: Maintain the pre-heating drive mode.

3. The calibration method for a high-capacity range-extended electric vehicle according to claim 2, characterized in that: The specific content of step S1.3 is as follows: Step S1.31: Determine whether the SOC is below 16% in EV mode or below 18% in SHEV mode, or whether the battery discharge capacity is below 35kW. If yes, proceed to step S1.32; otherwise, proceed to step S1.

33. Step S1.32, VCU controls engine start; Step S1.33: Determine whether the battery's continuous charging capability is higher than 60kW. If yes, proceed to step S1.34; otherwise, proceed to step S1.

35. Step S1.34: Allow entry into REV mode; Step S1.35: Determine whether the continuous charging capability is less than 55kW. If yes, proceed to step S1.36; otherwise, proceed to step S1.

37. Step S1.36: Prevent entry into REV mode; Step S1.37: Keep the drive mode unchanged.

4. The calibration method for a high-capacity range-extended electric vehicle according to claim 1, characterized in that: Step S2, energy management calibration, specifically involves the following steps: Step S2.1: Determine whether there is a heating request in REV or EV mode. If yes, proceed to step S2.

2. Otherwise, proceed to step S2.

3. Step S2.2: The user selects the power generation capacity; Step S2.21: Determine whether the battery SOC is greater than or equal to 98%. If yes, proceed to step S2.22; otherwise, proceed to step S2.

23. Step S2.24, request that the power generation capacity be zero; Step S2.25: Execute power generation according to the power generation capacity selected by the user; Step S2.3: Determine if the driving mode is Auto; if so, proceed to step S2.

4. Step S2.4: Determine if the battery SOC is higher than 30%. If yes, proceed to step S2.5; otherwise, proceed to step S2.

6. Step S2.5: Keep the battery discharging and prevent the APU from generating power; Step S2.6: Determine if the battery SOC is below 25%. If yes, proceed to step S2.7; otherwise, repeat this step. Step S2.7, APU power follower control; Step S2.8, the battery power preservation base map for coasting and braking is fully adaptable to a capacity of 5~10KW; Step S2.9, the battery power preservation basic map adaptability standard for driving conditions is increased by 10~20kW.

5. The calibration method for a high-capacity range-extended electric vehicle according to claim 1, characterized in that: Step S3, battery low-temperature protection calibration, specifically includes: Step S3.1: Determine whether the battery's allowable continuous charging capacity is less than 5kW and whether the battery's minimum temperature is less than -10℃. If yes, proceed to step S3.2; otherwise, proceed to step S3.

3. Step S3.2, battery low temperature protection; Step S3.21: Determine whether the APU has been started in REV mode or other modes. If yes, proceed to step S3.22; otherwise, repeat this step. Step S3.23: Execute battery low-temperature protection; Step S3.24, VCU constantly requests APU power generation of 5kW; Step S3.3: Determine whether the battery's allowable continuous charging capacity is higher than 10kW, or whether the battery's minimum temperature is higher than -8C. If yes, proceed to step S3.4; otherwise, repeat this step. Step S3.4: Do not perform battery low-temperature protection.

6. The calibration method for a high-capacity range-extended electric vehicle according to claim 1, characterized in that: Step S4, battery discharge limit calibration, specifically includes: Step S4.1: Determine if the drive mode is EV. If yes, proceed to step S4.2; otherwise, proceed to step S4.

3. Step S4.2: When SOC is below 16%, the available battery power begins to decrease linearly, dropping to 0 when it reaches 10%. Step S4.3, drive mode is SHEV; In step S4.4, when the SOC is below 18%, the available battery power is reduced linearly by gradient, dropping to 0 when it is below 12%.

7. The calibration method for a high-capacity range-extended electric vehicle according to claim 1, characterized in that: Step S5, calibration of the external characteristic limits of the electric drive, specifically includes: Step S5.1, drive mode is ECO; Step S5.11: Determine if the rotational speed is lower than the base speed. If yes, proceed to step S5.

12. Otherwise, proceed to step S5.

13. Step S5.12: No external characteristic limitation is applied below the motor base speed; Step S5.13, the external characteristic torque limit makes the drive power output less than or equal to 90KW; Step S5.2, driving mode is set to Normal; Step S5.21: Determine whether the rotational speed is lower than the base speed. If yes, proceed to step S5.

22. Otherwise, proceed to step S5.

23. Step S5.22: No external characteristic limitation is applied below the motor base speed; Step S5.23, the external characteristic torque limit makes the drive power output less than or equal to 110KW.

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