Control method and system for maximum allowable service power of power battery and extended-range hybrid vehicle

Abstract

The invention discloses a control method and system for the maximum allowable service power of a power battery and an extended-range hybrid vehicle, and the control method comprises the steps: calculating the first allowable service power P1 of the power battery according to the current SOC value SOC0 of the power battery, the current minimum available SOC value SOCmin of the power battery and the current maximum discharge power Pmax of the power battery; if the vehicle is in the starting working condition or the transient acceleration working condition, second allowable service power P2 of the power battery is obtained according to the current vehicle speed and the current accelerator pedal opening degree look-up table, and the current maximum allowable service power Pen of the power battery is made to be equal to min (max (P2, P1), Pmax); otherwise, enabling the maximum allowable service power Pen of the current power battery to be equal to P1. By adopting the method, the electric quantity reduction rate of the power battery can be slowed down under the condition of low electric quantity, the electric quantity maintaining capability of the vehicle is improved, and meanwhile, the problem that the power response is severely slowed down during starting or transient acceleration of the vehicle is avoided.

Description

Technical Field

[0001] The present invention belongs to the field of power batteries, and in particular relates to a control method and system for the maximum allowable power of a power battery and an extended-range hybrid vehicle. Background Art

[0002] At present, the power sources of extended-range hybrid vehicles (i.e., extended-range hybrid new energy vehicles) are power batteries and engines. During the driving process of the vehicle, the power battery supplies power to the drive motor, and the engine output power is supplied to the drive motor and power battery after being generated by the generator. In general, the maximum discharge power of the power battery is much greater than the maximum output power of the engine, and there is a certain lag in the engine power output. When the vehicle accelerates suddenly, the power demand is high, and the vehicle's drive motor will first use the available discharge power of the power battery. Therefore, under certain working conditions, especially during long-distance uphill driving, when the vehicle frequently accelerates suddenly, even if the engine is in operation, the power of the power battery will gradually decrease until it drops to 0.

[0003] To prevent the power battery from dropping to 0 and causing the vehicle to break down, the battery management system of a range-extended hybrid vehicle usually limits the (allowed) discharge power of the power battery when the power drops to a certain value. When the discharge power of the power battery is limited to a lower value, the power required by the drive motor during acceleration is provided by the engine output power after the generator generates electricity. However, since the engine has a low output power and a slow response at low speeds, the vehicle's power response will become slower, and may even cause the vehicle to be unable to start on a slope or under certain road conditions.

[0004] When the power battery is low in power, how to control the maximum allowable power of the power battery, use the discharge power of the power battery within the maximum allowable power range of the power battery (corresponding to the discharge power of the power battery that can be used is less than or equal to the maximum allowable power of the power battery), avoid further rapid reduction of power, and avoid a major impact on the vehicle's starting and acceleration power response, is an urgent problem that needs to be solved. Summary of the invention

[0005] The purpose of the present invention is to provide a control method and system for the maximum allowable power of a power battery and an extended-range hybrid vehicle, so as to slow down the rate of power battery decline under low power conditions, improve the vehicle's power maintenance capability, and avoid the problem of severe slowdown in power response when the vehicle starts or accelerates transiently.

[0006] In a first aspect, the method for controlling the maximum allowable power of a power battery according to the present invention comprises: According to the current power battery SOC value SOC0, the current power battery minimum available SOC value SOC min and the current maximum discharge power of the power battery Pmax , calculate the first allowable power P1 of the power battery.

[0007] If the vehicle is in a starting condition or a transient acceleration condition, the preset second allowable power table of the power battery is queried according to the current vehicle speed and the current accelerator pedal opening to obtain the second allowable power P2 of the power battery, so that the current maximum allowable power P of the power battery is en = min(max(P2, P1) , P max ), that is, min(max(P2, P1), P max ) is assigned to P en Otherwise (i.e. the vehicle is neither in the starting condition nor in the transient acceleration condition; it also means the vehicle is in other conditions except starting and transient acceleration), the current maximum allowable power of the power battery is P en = P1, that is, the first allowable power P1 of the power battery is assigned to P en .

[0008] Among them, max(P2, P1) means taking the maximum value of P2 and P1, min(max(P2, P1) , P max ) means taking max(P2, P1) and P max The preset second allowable power table of the power battery is a correspondence table of the vehicle speed, the accelerator pedal opening and the second allowable power of the power battery obtained through calibration.

[0009] Preferably, in consideration of the road slope, after obtaining the second allowable power P2 of the power battery, the following steps are performed: Using the formula: P'2=k* P2, P2 is corrected to obtain the corrected second allowable power P'2 of the power battery.

[0010] The maximum allowable power of the current power battery is P en = min(max(P'2, P1) , P max ). max(P'2, P1) means taking the maximum value of P'2 and P1, min(max(P'2, P1) , P max ) means taking max(P'2, P1) and P max The minimum value in .

[0011] Among them, k represents the current power correction coefficient, k≥1, k is obtained by querying a preset power correction coefficient table according to the current road slope and the current vehicle speed, and the preset power correction coefficient table is a correspondence table of road slope, vehicle speed and power correction coefficient obtained through calibration.

[0012] Preferably, the first allowable power P1 of the power battery is calculated as follows: Get the current power battery SOC value SOC0 and the current power battery maximum discharge power P max .

[0013] According to the current power battery temperature, query the preset power battery temperature and the power battery minimum available SOC value corresponding relationship table to obtain the current power battery minimum available SOC value SOC min .

[0014] Use the formula: ΔSOC= SOC0-SOC min , calculate the current SOC difference ΔSOC.

[0015] According to the current SOC difference ΔSOC, a preset correspondence table between the SOC difference and the power limit coefficient is queried to obtain the current power limit coefficient η; wherein 0≤η≤1.

[0016] Using the formula: P1 = η*P max , calculate and obtain the first allowable power P1 of the power battery.

[0017] Preferably, in the correspondence table between the preset SOC difference and the limited power coefficient, when the SOC difference is greater than or equal to the first preset SOC threshold, the limited power coefficient is 1; when the SOC difference is greater than 0 and less than the first preset SOC threshold, the limited power coefficient decreases as the SOC difference decreases; when the SOC difference is equal to 0, the limited power coefficient is 0.

[0018] Preferably, if conditions 1a to 1d are met at the same time, the vehicle is determined to be in a starting condition; wherein, condition 1a: the vehicle gear is in D gear or R gear; condition 1b: the current vehicle speed is less than a preset vehicle speed threshold; condition 1c: the driver's original required torque T is greater than the first preset torque threshold; condition 1d: the starting flag changes from 0 to 1.

[0019] Preferably, if conditions 2a to 2e are met at the same time, the vehicle is determined to be in a transient acceleration condition; wherein, condition 2a: the vehicle gear is in D gear; condition 2b: the current vehicle speed is greater than the preset vehicle speed threshold; condition 2c: the driver's original required torque T is greater than the first preset torque threshold; condition 2d: the difference between the driver's original required torque T and the filtered driver's required torque T' is greater than x*T; condition 2e: the transient acceleration flag changes from 0 to 1.

[0020] According to the current accelerator pedal opening, a preset correspondence table between the accelerator pedal opening and the driver's original demand torque is queried to obtain the driver's original demand torque T. The driver's original demand torque T is first-order filtered to obtain the filtered driver demand torque T'; x represents a preset torque coefficient, 0<x<0.5.

[0021] Preferably, the first preset torque threshold is the vehicle creep torque, and the preset torque coefficient x=0.1.

[0022] Preferably, if both condition 3a and condition 3b are satisfied, it is determined that the vehicle has completed starting. Wherein, condition 3a: the current vehicle speed is greater than the preset vehicle speed threshold; condition 3b: the starting flag changes from 1 to 0. If both condition 4a and condition 4b are satisfied, it is determined that the vehicle has completed transient acceleration. Wherein, condition 4a: the difference between the driver's original required torque T and the filtered driver's required torque T' is less than x*T; condition 4b: the transient acceleration flag changes from 1 to 0.

[0023] Preferably, after the vehicle starts or after the vehicle completes transient acceleration, a first-order filtering method is used to make the current maximum allowable power of the power battery P en By min(max(P2, P1) , P max ) or min(max(P'2, P1) , P max ) gradually transitions to P1.

[0024] In a second aspect, the control system of the maximum allowable power usage of a power battery described in the present invention includes a controller, and the controller is configured to execute the control method of the maximum allowable power usage of the power battery described above.

[0025] In a third aspect, the extended-range hybrid vehicle described in the present invention includes the above-mentioned control system for the maximum allowable power usage of the power battery.

[0026] The present invention has the following effects: (1) According to SOC0, SOC min and P max , calculate the first allowable power P1 of the power battery. When the vehicle is neither in the starting condition nor in the transient acceleration condition, the discharge power of the power battery (i.e., the low-battery time-limited power) is used within the first allowable power range of the power battery (i.e., less than or equal to the P1 range). This reduces the discharge power of the power battery during low-battery uniform acceleration and uniform speed driving, slows down the rate of power battery charge reduction, and improves the vehicle's ability to maintain power.

[0027] (2) Determine the second allowable power P2 of the power battery according to the current vehicle speed and the current accelerator pedal opening. When the vehicle is in the starting condition or transient acceleration condition, the second allowable power P2 of the power battery is determined in the range of min(max(P2, P1), P max ) range (i.e. less than or equal to min(max(P2, P1) , P max ) range), which not only slows down the rate at which the power battery power decreases, but also avoids the problem of severe slowdown in power response when the vehicle starts or undergoes transient acceleration. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The present invention is a flowchart of a method for controlling the maximum allowable power of a power battery in an embodiment of the present invention.

[0029] Figure 2 The present invention is a flowchart of another method for controlling the maximum allowable power of a power battery in an embodiment of the present invention.

[0030] Figure 3 This is a flow chart for calculating the first allowable power P1 of the power battery in an embodiment of the present invention. DETAILED DESCRIPTION

[0031] In order to enable a more detailed understanding of the features and technical contents of the embodiments of the present invention, the implementation of the embodiments of the present invention is described in detail below in conjunction with the accompanying drawings. The attached drawings are for reference only and are not intended to limit the embodiments of the present invention.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein are only for the purpose of describing the embodiments of the present invention and are not intended to limit the present invention.

[0033] In the following description, reference is made to “some embodiments”, which describe a subset of all possible embodiments, but it will be 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.

[0034] Signals involved in the embodiment of the present invention: current power battery temperature, current power battery SOC value SOC0 and current power battery maximum discharge power P max The current vehicle speed, the current accelerator pedal opening and the current road slope are obtained from the vehicle body control system. The acquisition methods are all related to the prior art.

[0035] like Figure 1 As shown, a method for controlling the maximum allowable power of a power battery in an embodiment of the present invention includes: Step 1: According to the current power battery SOC value SOC0 and the current power battery minimum available SOC value SOC min and the current maximum discharge power of the power battery P max , calculate the first allowable power P1 of the power battery, and then execute step 2.

[0036] Step 2: Determine whether the vehicle is in the starting condition. If so, execute step 5; otherwise, execute step 3.

[0037] Step 3: Determine whether the vehicle is in a transient acceleration condition. If yes, execute step 7; otherwise, execute step 4.

[0038] Step 4: Set the current maximum allowable power of the power battery to P en = P1, that is, the first allowable power P1 of the power battery is assigned to P en , then return to step 1.

[0039] Step 5: According to the current vehicle speed and the current accelerator pedal opening, query the preset second allowable power table of the power battery to obtain the second allowable power P2 of the power battery, so that the current maximum allowable power P of the power battery en = min(max(P2, P1) , P max ), that is, min(max(P2, P1), P max ) is assigned to P en , and then proceed to step 6. Where max(P2, P1) means taking the maximum value of P2 and P1, min(max(P2, P1) , P max ) means taking max(P2, P1) and P max The preset second allowable power table of the power battery is a correspondence table of the vehicle speed, the accelerator pedal opening and the second allowable power of the power battery obtained through calibration.

[0040] The second allowable power P2 of the power battery satisfies the discharge power required for transient acceleration and starting of the vehicle. First, take the larger of P2 and P1, and then add P max The smaller of P is taken as the maximum allowable power of the power battery under the starting condition or transient acceleration condition of the vehicle, which avoids the unreasonable situation that the maximum allowable power of the power battery under the starting condition or transient acceleration condition is smaller than the maximum allowable power of the power battery under other conditions, and also ensures that the maximum allowable power of the power battery under any condition will be less than or equal to P max .

[0041] Step 6: Determine whether the start is completed. If yes, proceed to step 9, otherwise continue to step 6.

[0042] Step 7: According to the current vehicle speed and the current accelerator pedal opening, query the preset second allowable power table of the power battery to obtain the second allowable power P2 of the power battery, so that the current maximum allowable power P of the power battery en = min(max(P2, P1) , P max ), that is, min(max(P2, P1), P max ) is assigned to P en , and then proceed to step eight.

[0043] Step 8: Determine whether the transient acceleration is completed. If yes, execute step 9; otherwise, continue to execute step 8.

[0044] Step 9: Use the first-order filtering method to make the current maximum allowable power of the power battery P en By min(max(P2,P1) , P max ) gradually transitions to P1, and then returns to execute step 1. The filter coefficient of the first-order filter here is a preset value calibrated according to the driving performance of the whole vehicle, and the first-order filtering method belongs to the existing conventional technology.

[0045] like Figure 2 As shown, another method for controlling the maximum allowable power of a power battery in an embodiment of the present invention includes: Step 1: According to the current power battery SOC value SOC0 and the current power battery minimum available SOC value SOC min and the current maximum discharge power of the power battery P max , calculate the first allowable power P1 of the power battery, and then execute step 2.

[0046] Step 2: Determine whether the vehicle is in the starting condition. If so, execute step 5; otherwise, execute step 3.

[0047] Step 3: Determine whether the vehicle is in a transient acceleration condition. If yes, execute step 9; otherwise, execute step 4.

[0048] Step 4: Set the current maximum allowable power of the power battery to P en = P1, that is, the first allowable power P1 of the power battery is assigned to P en , then return to step 1.

[0049] Step 5: According to the current vehicle speed and the current accelerator pedal opening, query the preset second allowable power table of the power battery to obtain the second allowable power P2 of the power battery, and then execute step 6.

[0050] Step 6: Use the formula: P'2=k* P2 to correct P2 and obtain the corrected second allowable power of the power battery P'2, and then execute step 7. Wherein, k represents the current power correction coefficient, k≥1, and k is obtained by querying the preset power correction coefficient table according to the current road slope and the current vehicle speed. The preset power correction coefficient table is a correspondence table of the road slope, vehicle speed and power correction coefficient obtained through calibration. In the preset power correction coefficient table, at the same vehicle speed, the greater the road slope, the greater the power correction coefficient.

[0051] Step 7: Set the current maximum allowable power of the power battery to P en = min(max(P'2, P1) , P max ), and then execute step 8. Where max(P'2, P1) means taking the maximum value of P'2 and P1, min(max(P'2, P1) , P max ) means taking max(P'2, P1) and P max The preset second allowable power table of the power battery is a correspondence table of the vehicle speed, the accelerator pedal opening and the second allowable power of the power battery obtained through calibration.

[0052] Step 8: Determine whether the start is completed. If yes, proceed to step 13; otherwise, continue to step 8.

[0053] Step 9: According to the current vehicle speed and the current accelerator pedal opening, query the preset second allowable power table of the power battery to obtain the second allowable power P2 of the power battery, and then execute step 10.

[0054] Step 10: Use the formula: P'2=k* P2 to correct P2, obtain the corrected second allowable power P'2 of the power battery, and then execute step 11.

[0055] Step 11: Set the current maximum allowable power of the power battery to P en = min(max(P'2, P1) , P max ), and then proceed to step twelve.

[0056] Step 12: determine whether transient acceleration is completed, if yes, execute step 13, otherwise continue to execute step 12.

[0057] Step 13: Use the first-order filtering method to make the current maximum allowable power of the power battery P en By min(max(P'2, P1) , P max) gradually transitions to P1, and then returns to execute step 1. The filter coefficient of the first-order filter here is a preset value calibrated according to the driving performance of the whole vehicle, and the first-order filtering method belongs to the existing conventional technology.

[0058] Normally, the maximum discharge power of the power battery of an extended-range hybrid vehicle is much greater than the maximum power of the engine. Therefore, the power of the extended-range hybrid vehicle will continue to decrease under certain operating conditions (such as during continuous climbing). In order to prevent the power battery from decreasing too quickly or even decreasing to 0 during use, as the power decreases, on the one hand, it is necessary to limit the discharge power of the power battery, and on the other hand, it is necessary to reserve some power and not allow it to be used. The reserved power is the minimum available SOC value of the power battery. The minimum available SOC value of the power battery is related to the temperature of the power battery.

[0059] In some embodiments, Figure 3 As shown, the method for calculating the first allowable power P1 of the power battery is: The first step is to obtain the current power battery SOC value SOC0 and the current power battery maximum discharge power P max .

[0060] Step 2: According to the current power battery temperature, query the corresponding relationship table between the preset power battery temperature and the minimum available SOC value of the power battery to obtain the current minimum available SOC value of the power battery SOC min In the preset corresponding relationship table between the power battery temperature and the minimum available SOC value of the power battery (obtained through calibration), the higher the power battery temperature, the smaller the minimum available SOC value of the power battery, and the lower the power battery temperature, the larger the minimum available SOC value of the power battery. As an example, the minimum available SOC value of the power battery is usually in the range of 3% to 5%. For example, when the power battery temperature is 20°C, the SOC min =3%, when the power battery temperature is -20℃, SOC min =5%, when the power battery temperature is between -20℃ and 20℃, the minimum available SOC value of the power battery is between 3% and 5% according to the corresponding relationship between the power battery temperature and the minimum available SOC value of the power battery.

[0061] Step 3: Use the formula: ΔSOC = SOC0-SOC min , calculate the current SOC difference ΔSOC.

[0062] Step 4: According to the current SOC difference ΔSOC, query the preset SOC difference and power limit coefficient correspondence table to obtain the current power limit coefficient η; wherein 0≤η≤1. In the preset SOC difference and power limit coefficient correspondence table (obtained by calibration), when the SOC difference is greater than or equal to the first preset SOC threshold, the power limit coefficient is 1, when the SOC difference is greater than 0 and less than the first preset SOC threshold (indicating low battery), the power limit coefficient decreases as the SOC difference decreases, and when the SOC difference is equal to 0, the power limit coefficient is 0. As an example, the first preset SOC threshold is 20%.

[0063] Step 5: Use the formula: P1 = η*P max , calculate and obtain the first allowable power P1 of the power battery.

[0064] In some embodiments, if conditions 1a to 1d are met at the same time, it is determined that the vehicle is in a starting condition, and if conditions 3a and 3b are met at the same time, it is determined that the vehicle has completed starting. Among them, condition 1a: the vehicle gear is D gear or R gear; condition 1b: the current vehicle speed is less than the preset vehicle speed threshold; condition 1c: the driver's original required torque T is greater than the first preset torque threshold; condition 1d: the starting flag changes from 0 to 1; condition 3a: the current vehicle speed is greater than the preset vehicle speed threshold; condition 3b: the starting flag changes from 1 to 0.

[0065] In some embodiments, if conditions 2a to 2e are met at the same time, it is determined that the vehicle is in a transient acceleration state, and if conditions 4a and 4b are met at the same time, it is determined that the vehicle has completed transient acceleration. Among them, condition 2a: the vehicle gear is D gear; condition 2b: the current vehicle speed is greater than the preset vehicle speed threshold; condition 2c: the driver's original demand torque T is greater than the first preset torque threshold; condition 2d: the difference between the driver's original demand torque T and the filtered driver's demand torque T' is greater than x*T; condition 2e: the transient acceleration flag is changed from 0 to 1; condition 4a: the difference between the driver's original demand torque T and the filtered driver's demand torque T' is less than x*T; condition 4b: the transient acceleration flag is changed from 1 to 0.

[0066] Among them, according to the current accelerator pedal opening, the corresponding relationship table between the preset accelerator pedal opening and the driver's original demand torque is queried to obtain the driver's original demand torque T; the driver's original demand torque T is first-order filtered (the filtering rate is a preset value) to obtain the filtered driver demand torque T'; x represents the preset torque coefficient, 0<x<0.5. As an example, the first preset torque threshold is the vehicle creep torque (such as 10N.m), and the preset torque coefficient x=0.1. As an example, the preset vehicle speed threshold is 5km / h.

[0067] In the above-mentioned transient acceleration identification method, the judgment is made by the difference between the driver's original required torque T and the filtered driver required torque T'. On the one hand, it avoids the problem of frequent changes in the judgment state caused by frequent changes in the accelerator pedal opening when judging by the accelerator pedal opening, and misjudgment caused by small changes in the accelerator pedal opening; on the other hand, the accurate identification of transient acceleration is achieved through the judgment of torque changes, and the frequent changes in transient acceleration state are avoided. That is, the problem of frequent changes in the judgment state caused by torque fluctuations is solved by filtering. At the same time, the difference between T and T' is required to be less than x*T, thereby achieving accurate identification of transient acceleration.

[0068] In addition, when the filtered driver demand torque T' reaches 90% of the driver's original demand torque, the vehicle is considered to have completed transient acceleration. The moment of completion of transient acceleration is determined by the difference between the driver's original demand torque and the filtered driver demand torque, which accurately realizes the judgment of the moment of completion of transient acceleration and avoids the problem of inaccurate recognition of the moment of completion of transient acceleration caused by judging by the accelerator pedal opening or the time of pressing the accelerator pedal.

[0069] The embodiment of the present invention accurately identifies the starting and transient acceleration conditions of the vehicle. In the case of low battery, on the one hand, within the precise transient acceleration and starting time, the maximum allowable power of the power battery is equal to min(max(P2, P1), P max ) or min(max(P'2, P1) , P max ), which reduces the time and discharge power of high-power battery discharge during transient acceleration and starting of the vehicle, slows down the rate of power battery charge decline, improves the vehicle's ability to maintain power, and avoids the problem of serious slowdown in power response during starting or transient acceleration of the vehicle. On the other hand, after the vehicle completes starting or transient acceleration, it returns to the first allowable power range of the power battery and uses the discharge power of the power battery, reducing the available power of the power battery. Most of the power required for uniform acceleration and uniform speed driving of the vehicle is provided by the engine, further reducing the discharge power of the power battery during uniform acceleration and uniform speed driving, further reducing the rate of power battery charge decline, and improving the vehicle's ability to maintain power.

[0070] In addition, an embodiment of the present invention further provides a control system for the maximum allowable power usage of a power battery, which includes a controller configured to execute the above-mentioned control method for the maximum allowable power usage of a power battery.

[0071] In addition, an embodiment of the present invention further provides an extended-range hybrid vehicle, which includes the above-mentioned control system for the maximum allowable power usage of the power battery.

[0072] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for controlling the maximum allowable power of a power battery, characterized in that: include: According to the current power battery SOC value SOC0, the current power battery minimum available SOC value SOC min and the current maximum discharge power of the power battery P max , calculate the first allowable power P1 of the power battery; If the vehicle is in a starting condition or a transient acceleration condition, the preset second allowable power table of the power battery is queried according to the current vehicle speed and the current accelerator pedal opening to obtain the second allowable power P2 of the power battery, so that the current maximum allowable power P of the power battery is en = min(max(P2 , P1) , P max ); otherwise, the maximum allowable power of the current power battery is P en = P1; Among them, max(P2, P1) means taking the maximum value of P2 and P1, min(max(P2, P1), P max ) means taking max(P2, P1) and P max The preset second allowable power table of the power battery is a correspondence table of the vehicle speed, the accelerator pedal opening and the second allowable power of the power battery obtained through calibration.

2. The method for controlling the maximum allowable power of a power battery according to claim 1, characterized in that: After obtaining the second allowable power P2 of the power battery, perform the following steps: Use the formula: P'2=k* P2 to correct P2 and obtain the corrected second allowable power P'2 of the power battery; The maximum allowable power of the current power battery is P en = min(max(P'2 , P1) , P max ); Among them, k represents the current power correction coefficient, k≥1, k is obtained by querying a preset power correction coefficient table according to the current road slope and the current vehicle speed, and the preset power correction coefficient table is a correspondence table of road slope, vehicle speed and power correction coefficient obtained through calibration.

3. The method for controlling the maximum allowable power of a power battery according to claim 1 or 2, characterized in that: The method for calculating the first allowable power P1 of the power battery is: Get the current power battery SOC value SOC0 and the current power battery maximum discharge power P max ; According to the current power battery temperature, query the preset power battery temperature and the power battery minimum available SOC value corresponding relationship table to obtain the current power battery minimum available SOC value SOC min ; Use the formula: ΔSOC= SOC0-SOC min , calculate the current SOC difference ΔSOC; According to the current SOC difference ΔSOC, a preset correspondence table between the SOC difference and the power limit coefficient is queried to obtain the current power limit coefficient η; wherein 0≤η≤1; Using the formula: P1 = η*P max , calculate and obtain the first allowable power P1 of the power battery.

4. The method for controlling the maximum allowable power of a power battery according to claim 3, characterized in that: In the correspondence table between the preset SOC difference and the limited power coefficient, when the SOC difference is greater than or equal to the first preset SOC threshold, the limited power coefficient is 1; when the SOC difference is greater than 0 and less than the first preset SOC threshold, the limited power coefficient decreases as the SOC difference decreases; when the SOC difference is equal to 0, the limited power coefficient is 0.

5. The method for controlling the maximum allowable power of a power battery according to claim 1 or 2, characterized in that: If conditions 1a to 1d are met at the same time, the vehicle is determined to be in the starting condition; wherein condition 1a: the vehicle gear is in D gear or R gear; condition 1b: the current vehicle speed is less than the preset vehicle speed threshold; condition 1c: the driver's original required torque T is greater than the first preset torque threshold; condition 1d: the starting flag changes from 0 to 1; If conditions 2a to 2e are met at the same time, it is determined that the vehicle is in a transient acceleration condition; wherein condition 2a: the vehicle gear is in D gear; condition 2b: the current vehicle speed is greater than a preset vehicle speed threshold; condition 2c: the driver's original required torque T is greater than a first preset torque threshold; condition 2d: the difference between the driver's original required torque T and the filtered driver's required torque T' is greater than x*T; condition 2e: the transient acceleration flag changes from 0 to 1; Among them, according to the current accelerator pedal opening, the preset correspondence table between the accelerator pedal opening and the driver's original required torque is queried to obtain the driver's original required torque T; the driver's original required torque T is first-order filtered to obtain the filtered driver's required torque T'; x represents the preset torque coefficient, 0<x<0.

5.

6. The method for controlling the maximum allowable power of a power battery according to claim 5, characterized in that: The first preset torque threshold is the vehicle creep torque, and the preset torque coefficient x=0.

1.

7. The method for controlling the maximum allowable power of a power battery according to claim 5, characterized in that: If both conditions 3a and 3b are met, it is determined that the vehicle has completed starting; wherein condition 3a: the current vehicle speed is greater than the preset vehicle speed threshold; condition 3b: the starting flag changes from 1 to 0; If conditions 4a and 4b are met at the same time, it is determined that the vehicle has completed transient acceleration; wherein, condition 4a: the difference between the driver's original required torque T and the filtered driver's required torque T' is less than x*T; condition 4b: the transient acceleration flag changes from 1 to 0.

8. The method for controlling the maximum allowable power of a power battery according to claim 7, characterized in that: After the vehicle starts or completes transient acceleration, the first-order filtering method is used to make the current maximum allowable power of the power battery P en By min(max(P2, P1), P max ) or min(max(P'2 , P1) , P max ) gradually transitions to P1.

9. A control system for the maximum allowable power of a power battery, comprising a controller, characterized in that: The controller is configured to execute the method for controlling the maximum allowable power of a power battery as claimed in any one of claims 1 to 8.

10. An extended-range hybrid vehicle, characterized in that: A control system for the maximum allowable power usage of a power battery as claimed in claim 9.

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