Plug-in hybrid vehicle parking regeneration engine control method and parking regeneration method

Abstract

The application discloses a kind of plug-in hybrid vehicle parking regenerative engine control method and parking regenerative method, comprising: obtaining current battery power in parking regenerative process;Based on the mapping of the difference between the set target battery power and current battery power and the maximum allowed charging power, the maximum allowed charging power corresponding to the current power is obtained;According to the maximum allowed charging power corresponding to the current power obtained, the engine is controlled, so that the parking regeneration of hybrid vehicle is quickly carried out and maintained until regeneration is completed.The application obtains the maximum charging power by adjusting the target power, and then affects the net torque sent by VCU to EMS, thereby controlling the engine, avoiding the unstable state of the engine caused by different power, and realizing the quick parking regeneration of hybrid vehicle and maintaining until regeneration is completed by controlling various uncertain factors.

Description

Technical Field

[0001] This invention relates to the field of parking regeneration, and particularly to a parking regeneration engine control method and parking regeneration method for plug-in hybrid vehicles. Background Technology

[0002] In response to the national call for energy conservation and emission reduction, particulate filters have come into the public eye. After a period of vehicle use, the particulate filter will become clogged, leading to increased fuel consumption and reduced engine output power. When the carbon load reaches a certain level, passive regeneration and on-the-go active regeneration cannot effectively remove the particulate matter deposited in the filter, and it is necessary to go to a repair shop for regeneration, thereby effectively reducing particulate matter emissions. Furthermore, the purpose of regeneration is achieved by oxidizing and burning the particles in the filter.

[0003] Existing technologies generally control the regeneration process through carbon loading, GPF inlet temperature, target air-fuel ratio, and ignition angle efficiency. However, for parking regeneration in plug-in hybrid vehicles, when the battery charge is in different states, the engine may start immediately and idle, remain stationary, or stop after starting for a period of time after pressing the vehicle start button. The parking regeneration process involves many uncertainties, making it impossible for the regeneration of hybrid vehicles to be completed stably and quickly. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the technical problem to be solved by the present invention is to provide a plug-in hybrid vehicle parking regeneration engine control method and parking regeneration method that enables the parking regeneration of hybrid vehicles to proceed as quickly as possible and maintain it until the regeneration is completed.

[0005] To solve the above-mentioned technical problems, one technical solution adopted by the present invention is: to provide a method for controlling a parking regenerative engine in a plug-in hybrid vehicle, comprising the following steps:

[0006] Obtain the current battery charge C during the parking regeneration process. bat ;

[0007] Based on the set target battery capacity C target With current battery level C bat The difference C delta With the maximum allowable charging power P max The mapping yields the current battery level C. bat The corresponding maximum allowable charging power P max ;

[0008] Based on the obtained current battery level C bat The corresponding maximum allowable charging power P max The engine is controlled to enable the hybrid vehicle's parking regeneration to proceed quickly and be maintained until regeneration is complete.

[0009] Furthermore, based on the obtained current battery level C bat The corresponding maximum allowable charging power P max The steps for controlling the engine include the following sub-steps:

[0010] Based on the current power C bat The corresponding maximum allowable charging power P max To obtain the engine's indicated torque T ind ;

[0011] Based on engine indicated torque T ind The target throttle opening α is obtained;

[0012] The engine throttle opening is controlled according to the target throttle opening α to enable the engine to generate more combustion energy.

[0013] Furthermore, based on the current power level C bat The corresponding maximum allowable charging power P max To obtain the engine's indicated torque T ind The steps include the following sub-steps:

[0014] Based on the current power C bat The corresponding maximum allowable charging power P max Calculate the engine's net torque T net ;

[0015] Based on the engine's net torque T net Calculate the total combustion torque T at engine idle speed tot ;

[0016] Based on the engine's total combustion torque T tot Obtain the indicated torque T of the engine ind .

[0017] Furthermore, the engine net torque T net It is obtained through the following formula:

[0018]

[0019] In equation (1), P max Indicates the maximum allowed charging power; N represents the current engine speed; η charge Indicates generator efficiency; T safe This indicates the reserved safety margin torque;

[0020] Total combustion torque T at engine idle speed tot It is obtained through the following formula:

[0021] T tot =T friction +Tnet +T pid (two)

[0022] In formula (two), T friction represents engine self-friction torque, T pid represents engine idle speed PID control torque;

[0023] and / or

[0024] The indicated torque T ind is obtained by the following formula:

[0025]

[0026] In formula (three), η ign represents ignition angle efficiency, η lam represents air-fuel ratio efficiency.

[0027] Further, the engine idle speed PID control torque T pid is obtained by the following formula:

[0028] T pid = (N-N target ) × f p + (N-N target ) × f i (four)

[0029] In formula (four), f p is a proportional term control coefficient, f i is an integral term control coefficient, N is the current engine speed, N target is the target engine speed.

[0030] Further, the ignition angle efficiency η ign corresponds to the ignition angle ω ign is obtained by the following formula:

[0031] ω ign = ω bas - lookup(curve(η ign ), η ign ) (five)

[0032] In formula (five), ω bas is the basic ignition angle, η ign is the ignition angle efficiency, and curve(η ign ) is the ignition angle offset.

[0033] Further, based on the difference C target between the set target battery capacity C bat and the current battery capacity C delta and the allowed maximum charging power Pmax a mapping of the current battery power C bat a corresponding allowed maximum charging power P max After the step of the mapping of the current battery power C

[0034] requesting to turn on the vehicle electrical load to reasonably consume the battery power.

[0035] Further, the electrical load includes a stable load and a non-stable load, and in the step of controlling to turn on the vehicle electrical load, the following sub-steps are included:

[0036] based on the obtained current battery power C bat , determining whether the current battery power C bat is less than a first threshold value, and if less than the first threshold value, not responding to the request to turn on the vehicle electrical load;

[0037] if greater than or equal to the first threshold value, determining whether the current battery power C bat is less than a second threshold value, and if less than the second threshold value, turning on the vehicle stable load based on the request to turn on the vehicle electrical load;

[0038] if greater than or equal to the second threshold value and less than a set target battery power C target , then turning on all vehicle electrical loads based on the request to turn on the vehicle electrical load.

[0039] Further, the stable load includes a high beam, interior lighting, fog lamp, night light and / or double flash light, and the non-stable load includes an air conditioning system, seat heating and / or air purification system.

[0040] To solve the above technical problems, another technical solution adopted by the present application is to provide a plug-in hybrid vehicle parking regeneration method, comprising the following steps: obtaining a parking regeneration trigger signal;

[0041] based on the parking regeneration trigger signal, determining whether the vehicle state meets the parking regeneration enabling condition;

[0042] if the vehicle meets the parking regeneration enabling condition, then pulling up the engine speed to a target speed, setting a target air-fuel ratio and an ignition angle efficiency;

[0043] controlling the engine according to the above plug-in hybrid vehicle parking regeneration engine control method to maintain the rapid parking regeneration;

[0044] determining whether the parking regeneration progress K is greater than or equal to a third threshold value; if greater than or equal to the third threshold value, it is considered that the parking regeneration is completed.

[0045] The plug-in hybrid vehicle parking regeneration engine control method and parking regeneration method of the present invention have at least the following beneficial effects: The present invention obtains the maximum charging power by adjusting the target battery level, thereby affecting the net torque sent by the VCU to the EMS, thus controlling the engine and avoiding the instability of the engine state caused by different battery levels; reserving a safety redundancy torque can avoid battery overcharging caused by torque instability during engine operation; the PID controller can meet the dual requirements of simultaneously charging the battery and controlling idle speed. The present invention can enable the parking regeneration of the hybrid vehicle to proceed quickly and be maintained until regeneration is completed. Attached Figure Description

[0046] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0047] Figure 1 This is a flowchart of one embodiment of the plug-in hybrid vehicle parking regenerative engine control method of the present invention.

[0048] Figure 2 for Figure 1 The flowchart for step S413.

[0049] Figure 3 for Figure 2 Flowchart of step S4131.

[0050] Figure 4 This is a flowchart of one embodiment of the plug-in hybrid vehicle parking regenerative engine control method of the present invention.

[0051] Figure 5 for Figure 4 Flowchart of step S423.

[0052] Figure 6 This is a flowchart of one embodiment of the plug-in hybrid vehicle parking regeneration method of the present invention. Detailed Implementation

[0053] The invention will now be further described with reference to the accompanying drawings.

[0054] Please see Figure 1 This is a flowchart of one embodiment of the plug-in hybrid vehicle parking regenerative engine control method of the present invention. This embodiment specifically includes the following steps:

[0055] S411. Obtain the current battery charge C during the parking regeneration process. bat .

[0056] When the start button of a hybrid vehicle is pressed, a service regeneration signal is triggered via the diagnostic tool (sent to the EMS). The EMS first determines whether the vehicle status meets the GPF service regeneration (parking regeneration) enabling conditions. These conditions include, but are not limited to: whether the gear is in neutral or park, whether the accelerator pedal opening is 0%, whether the brake pedal opening is 0%, whether the vehicle speed is 0, and whether the fuel tank level is greater than a set safety value (e.g., greater than 15L). Other enabling conditions may include whether the engine speed is within a set allowable range, whether the coolant temperature is within a set safety range, and whether the GPF center temperature is within a safe range. Once the EMS determines that the vehicle status meets the parking regeneration enabling conditions, it puts the engine into operation to perform parking regeneration.

[0057] S412, Based on the set target battery level C target With current battery level C bat The difference C delta With the maximum allowable charging power P max The mapping yields the current battery level C. bat The corresponding maximum allowable charging power P max .

[0058] The target battery capacity C bat It can be set to a maximum safe charge of 80%, when the target battery charge C bat When set to 80%, C can be obtained. delta =80%-C bat The difference C delta With the maximum allowable charging power P max The mapping can be found in Table 1 below:

[0059] C delta (%)]] 0 0.5 2 5 10 20 30 40 60 P max (kw)]]> 0 1 4 6 8 8 8 8 8

[0060] Table 1

[0061] The current power C bat The corresponding maximum allowable charging power P max The value can be obtained by looking up the above mapping table: P max =lookup(P max C delta ).

[0062] To illustrate with a specific example, let's assume the current battery level is C. bat It is 30%, which is consistent with the set target power C. target The difference between 80% and 50% is 50%. The current battery level C can be obtained by looking up the value in the table above. bat With target power C target The maximum power corresponding to the difference (50%) is 8kW.

[0063] S413、According to the current power C bat The corresponding maximum allowed charging power P max , the engine is controlled so that the hybrid vehicle parking regeneration is quickly performed and maintained until the regeneration is completed.

[0064] Please refer to Figure 2 , this step S413 includes the following sub-steps:

[0065] S4131, based on the current power C bat The corresponding maximum allowed charging power P max , the engine torque T ind .

[0066] Please refer to Figure 3 , the engine torque T ind can be obtained by the following sub-steps:

[0067] S4131a, based on the current power C bat The corresponding maximum allowed charging power P max , the engine torque T net .

[0068] During parking regeneration, the clutch between the engine output shaft and the generator input shaft is engaged, and the two are rigidly connected together, the clutch between the drive motor and the downstream device of the power transmission is disconnected, that is, the torque generated by the engine combustion is only used for the engine itself to operate stably and charge the battery. Considering the generator efficiency η charge , the VCU requests the engine torque T net The calculation formula is as follows (T safe is the reserved safety redundancy torque to avoid the problem of battery overcharging caused by unstable torque during engine operation):

[0069]

[0070] Where N represents the current engine speed; η charge represents the generator efficiency, which is usually in the range of 90%-95%, and in this embodiment, the generator efficiency is 92%; T safe represents the reserved safety redundancy torque.

[0071] S4131b, according to the engine torque T net Calculate the total combustion torque T tot of the engine idle speed.

[0072] During parking regeneration, the VCU finally sends the demand torque signal T net, EMS needs to respond to torque control, but EMS needs to pull up engine speed (e.g. to 3000 rpm) to increase engine combustion energy, and to maintain stable speed, speed control is needed, usually torque control and speed control cannot work at the same time, which brings challenges to engine control. In this embodiment, the demand net torque signal T net is superimposed on the engine itself friction torque T friction , plus idle PID control torque T pid , the total combustion torque T tot of the engine can be calculated

[0073] T tot = T friction + T net + T pid

[0074] , wherein the engine net torque T net is the target torque sent by VCU to EMS, T friction represents the engine itself friction torque, T pid represents the engine idle PID control torque. In order to improve the engine power, the engine speed is pulled up to 3000 rpm, and the idle PID control torque T pid can ensure that the engine speed is maintained at a relatively stable level near 3000 rpm, solving the dual demand of battery charging and idle control at the same time.

[0075] The engine idle PID control torque T pid is obtained by the formula T pid = (N-N target ) x f p + (N-N target ) x f i , f p is the proportional term control coefficient, f i is the integral term control coefficient, N is the current engine speed, N target is the target engine speed. In this embodiment, the engine speed is pulled up to 3000 rpm, but in fact the engine speed N cannot be controlled at 3000 rpm, but only near 3000 rpm.

[0076] S4131c, according to the engine total combustion torque T tot , the engine indicated torque T ind is obtained.

[0077] When parking regenerative braking, the effect of ignition angle path on torque is fixed, that is, the ignition angle efficiency η ignThe ignition angle efficiency is set to 50%, compared to 100%, the spark path factor will make the torque decrease, T pid The torque control will adjust the torque of the throttle path, i.e. the throttle opening is increased, so that the engine takes in more fresh air, thereby generating more combustion energy. The basic ignition angle ω bas is measured by experiments, and the curve (η ign ) is also measured by experiments.

[0078] The indicated torque T ind of the engine is obtained by , η ign represents the ignition angle efficiency, η lam represents the air-fuel ratio efficiency. In this embodiment, in order to make the throttle opening larger, the ignition angle efficiency is adjusted to 50% while maintaining the speed, different air-fuel ratios correspond to different efficiencies, and when the air-fuel ratio is adjusted to 1.1, the corresponding air-fuel ratio efficiency is measured to be 96% by experiments. At this time, the ignition angle corresponding to the ignition angle efficiency is ω ign = ω bas -lookup (curve (η ign ), 50%), ω bas is the basic ignition angle, η ign is the ignition angle efficiency, and curve (η ign ) is the ignition angle offset.

[0079] S4132, the target throttle opening α is obtained based on the engine indicated torque T ind .

[0080] According to the indicated torque and the speed, the target charge θ (the amount of air or combustible mixture entering the cylinder during the intake process) can be obtained by table lookup, and after a series of operations, the target throttle opening α is obtained by table lookup. This process is a mature algorithm and will not be described here.

[0081] S4133, the engine throttle opening is controlled according to the target throttle opening α, so that the engine generates more combustion energy.

[0082] In the embodiment of the application, the maximum charging power is obtained by adjusting the target electric quantity, which further affects the net torque sent by the VCU to the EMS, thereby controlling the engine, avoiding the unstable state of the engine caused by the electric quantity, and considering the problems of battery overcharging and idle speed control, etc. Various uncertain factors are controlled to realize the parking regenerative braking of the hybrid vehicle quickly and maintain it until the regenerative braking is completed.

[0083] Please refer to Figure 4This is a flowchart of one embodiment of the parking regenerative engine control method for a plug-in hybrid vehicle according to the present invention. The parking regenerative engine control method for a plug-in hybrid vehicle according to the present invention includes the following steps:

[0084] S421. Obtain the current battery charge C during the parking regeneration process. bat ;

[0085] S422, Based on the set target battery level C target With current battery level C bat The difference C delta With the maximum allowable charging power P max The mapping yields the current battery level C. bat The corresponding maximum allowable charging power P max ;

[0086] S423, Based on current battery level C target Determine whether to respond to VCU requests and turn on vehicle electrical loads to reasonably consume battery power;

[0087] The electrical loads include stable loads and unstable loads. The stable loads may be defined as headlights (high beams), interior lights, fog lights, night lights, and / or hazard lights. The unstable loads may be defined as air conditioning systems, seat heating systems, and / or air purification systems.

[0088] Please see Figure 5 This step includes the following sub-steps:

[0089] S4231, Based on the obtained current battery level C bat Determine the current battery level C bat Is it less than 20%?

[0090] S4232, If the current battery level C is determined... bat If the percentage is less than 20%, requests to turn on the vehicle's electrical loads will not be responded to.

[0091] S4233, if the current battery level C is determined... bat If the current battery level C is greater than or equal to 20%, then the current battery level C is determined. bat Is it less than 30%?

[0092] S4234, If the current battery level C is determined... bat If it is less than 30%, then based on the request to turn on the vehicle's electrical load, turn on the vehicle's stable load;

[0093] S4235, If the current battery level C is determined... bat If the current battery level C is greater than or equal to 30%, then the current battery level C is determined. batand less than a set target battery power C target ;

[0094] S4236, if the current battery power C bat is less than a set target battery power, then based on a request to turn on vehicle electrical loads, turn on all vehicle electrical loads.

[0095] In this embodiment, the electrical load opening control logic is described in detail taking the air conditioner, seat heating system and air purification system as examples: when the VCU turns on the air conditioning system, first detect the temperature in the vehicle, when the temperature in the vehicle is less than 30℃, set the air conditioning target temperature to 30℃, and control the blower and heating components to consume energy for heating the vehicle interior with maximum heating capacity; when the temperature in the vehicle is greater than 30℃, set the air conditioning target temperature to 15℃, and control the blower and cooling components to consume energy for cooling with maximum cooling capacity; in this way, cold and heat are alternated, so that the air conditioning system consumes a large amount of battery power. The seat heating system activates all seat heating functions in the vehicle, and sets the seat heating target temperature to the maximum value supported by the system. The air purification system requests to circulate the air inside the vehicle at the maximum air volume to promote air flow in the vehicle.

[0096] S424, according to the current power C bat corresponding to the maximum allowed charging power P max , control the engine so that the hybrid vehicle parking regeneration is quickly performed and maintained until the regeneration is completed;

[0097] In this embodiment, based on the current battery power, the corresponding electrical load is opened according to the range in which the power is located, so that the power of the engine can be increased to realize fast parking regeneration, and the battery power will not be depleted.

[0098] Please refer to Figure 6 is a flow chart of an embodiment of the plug-in hybrid vehicle parking regeneration method of the present application. The plug-in hybrid vehicle parking regeneration method of this embodiment includes the following steps:

[0099] S100, obtain a parking regeneration trigger signal;

[0100] When the amount of carbon deposition exceeds a certain limit value GPF indicator light is lit, the parking regeneration signal is triggered through the diagnostic instrument, and the regeneration signal is sent to the EMS. After the EMS obtains the parking regeneration signal, it enters the S200 step.

[0101] S200, based on the parking regeneration trigger signal, determine whether the vehicle state meets the parking regeneration enabling condition.

[0102] In a specific example, the EMS can determine whether the vehicle meets the parking regeneration enabling condition by the following set conditions:

[0103] (1) whether the gear is in neutral / park; (2) whether the accelerator pedal opening is 0%; (3) whether the brake pedal opening is 0%; (4) whether the vehicle speed is 0; (5) whether the fuel tank level is greater than a safety value (for example, whether it is greater than 15L); when (1)-(4) above are all satisfied, it indicates that the vehicle state satisfies the parking regeneration enabling condition, and when one of the conditions is not satisfied, it is considered that the vehicle state does not satisfy the parking regeneration enabling condition. If the parking regeneration enabling condition is not satisfied, the engine maintains the current operating state, and the reason why regeneration cannot be triggered can be prompted by the instrument. The current operating state of the engine is determined by the battery charge level. After the high voltage on the vehicle and without the parking regeneration trigger signal, when the charge is <18%, the VCU directly requests the EMS to start the engine and maintain the idle state to charge the battery until the charge is >20%, and then the VCU requests the engine to stop; when the charge is >20%, the VCU does not request the engine to start, and the engine is in a stopped state.

[0104] In order to facilitate the prompt to the user, when (1) the gear is not in neutral / park, the instrument prompts "Please put the gear in neutral or park and trigger the parking regeneration again"; when (2) the accelerator pedal opening is not 0, the instrument prompts "Please release the accelerator pedal and trigger the parking regeneration again"; when (3) the brake pedal opening is not 0%, the instrument prompts "Please release the brake pedal and trigger the parking regeneration again"; when (4) the vehicle speed is not 0%, the instrument prompts "Please stop the vehicle and trigger the parking regeneration again"; and when (5) the fuel tank level is less than 15L, the instrument prompts "Please add fuel to more than 15L and trigger the parking regeneration again".

[0105] S300, if the vehicle satisfies the parking regeneration enabling condition, the engine speed is pulled up to the target speed, the target air-fuel ratio and the ignition angle efficiency are set to start the parking regeneration.

[0106] When the vehicle satisfies the parking regeneration enabling condition, the EMS further judges whether the engine is in an operating state (static state) through the engine speed signal. If the engine is in a static state, the EMS sends a request engine start signal, a stop request signal, a fuel cut-off signal and a service regeneration request signal to the VCU. If the engine is in an operating state, the EMS sends a stop request signal, a fuel cut-off signal and a service regeneration request signal to the VCU. After receiving the above signals sent by the EMS, the VCU confirms the safety arbitration (such as no collision signal, engine runaway, etc.), returns the above confirmation signals to the EMS, and adjusts the target charge of the battery from 20% to the highest charge to ensure safety (usually 80%).

[0107] After the EMS receives the acknowledgement signal returned by the VCU, the engine speed is pulled to a certain value (e.g. 3000 rpm), the target air-fuel ratio is adjusted to be lean to a certain value (e.g. 1.1) to ensure that there is sufficient oxygen to support the combustion of the carbon particles in the particulate filter, and the ignition angle efficiency is adjusted to 50% to increase the throttle opening to allow more oxygen to enter the engine while maintaining the engine speed.

[0108] S400, control the engine torque in the parked regeneration control to enable the parked regeneration to be carried out quickly and maintained until the regeneration is completed, the specific control steps of this step are described with reference to the description in any of the embodiments of the parked regeneration engine control method of the plug-in hybrid vehicle, which will not be repeated here.

[0109] S500, determine whether the parked regeneration progress K is greater than or equal to a third threshold value.

[0110] The calculation formula of the parked regeneration progress K is M start M is the amount of carbon at the start of the parked regeneration current M is the amount of carbon at the current time suc M is the amount of carbon at the completion of the regeneration, which is usually calibrated to 0.6 g, and the third threshold value is set to 100%.

[0111] S600, if greater than or equal to the third threshold value, it is considered that the parked regeneration is completed.

[0112] In this embodiment, if K is less than 100%, it indicates that the parked regeneration is not completed, and steps S400-S500 are repeated until K is greater than or equal to 100%; if K is greater than or equal to 100%, it indicates that the parked regeneration is completed, at this time the VCU requests to turn off all electrical loads, and the target charge amount adjusted to 80% in step P4 is adjusted back to 20%, the VCU requests the EMS to control the engine to stop, and the instrument will prompt "parked regeneration is completed".

[0113] In the embodiments of the present application, the differences in the preconditions for the operation of the engine of the hybrid vehicle and the engine of the fuel vehicle are fully considered, the control of the engine is realized through the joint action of the VCU and the EMS, and on the basis of the parked regeneration engine control method of the plug-in hybrid vehicle, the parked regeneration progress is judged to ensure that the parked regeneration of the hybrid vehicle is carried out quickly and can be maintained until the regeneration is completed. Finally, it is pointed out that the above is only an embodiment of the present application, and does not limit the patent scope of the present application, any equivalent structure or equivalent process transformation using the content of the specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for controlling a parking regenerative engine in a plug-in hybrid vehicle, characterized in that, Includes the following steps: Obtain the current battery level during the parking regeneration process. ; Based on the set target battery level With current battery level The difference With the maximum allowed charging power The mapping yields the current battery level. Corresponding maximum allowable charging power ; Based on the current battery level obtained Corresponding maximum allowable charging power The engine is controlled to enable the hybrid vehicle's parking regeneration to proceed quickly and be maintained until regeneration is complete; this step includes the following sub-steps: Based on current battery level The corresponding maximum allowable charging power To obtain the engine's indicated torque This step includes the following sub-steps: Based on current battery level The corresponding maximum allowable charging power Calculate the engine's net torque. Engine net torque It is obtained through the following formula: (one) In formula (1), Indicates the maximum allowed charging power; N indicates the current engine speed; Indicates generator efficiency; This indicates the reserved safety margin torque; Based on the engine's net torque Calculate the total combustion torque at engine idle speed Total combustion torque at engine idle speed It is obtained through the following formula: (two) In formula (ii), This indicates the engine's own friction torque. This indicates the torque controlled by the PID controller for engine idle speed. Based on the total combustion torque of the engine Obtain the engine's indicated torque. Indicating torque It is obtained through the following formula: (three) In formula (iii), Indicates ignition angle efficiency. Indicates air-fuel ratio efficiency; Based on engine indicated torque The target throttle opening α is obtained; The engine throttle opening is controlled according to the target throttle opening α to enable the engine to generate more combustion energy.

2. The plug-in hybrid vehicle parking regenerative engine control method as described in claim 1, characterized in that, The engine idle speed PID control torque It is obtained through the following formula: (Four) In formula (iv), This is the control coefficient for the proportional term. Here, N is the integral term control coefficient, and N is the current engine speed. This is the target engine speed.

3. The method for controlling a parking regenerative engine in a plug-in hybrid vehicle as described in claim 1, characterized in that, The ignition angle efficiency Corresponding ignition angle It is obtained through the following formula: (five) In formula (5), Basic ignition angle, For ignition angle efficiency, This refers to the ignition angle offset.

4. The method for controlling a parking regenerative engine in a plug-in hybrid vehicle as described in any one of claims 1 to 3, characterized in that, Based on the set target battery level With current battery level The difference With the maximum allowed charging power The mapping yields the current battery level. Corresponding maximum allowable charging power Following the steps above, the following steps are also included: Request to turn on the vehicle's electrical loads to reasonably consume battery power.

5. The method for controlling a parking regenerative engine in a plug-in hybrid vehicle as described in claim 4, characterized in that, The electrical load includes both stable and unstable loads. The step of controlling the opening of the vehicle's electrical load includes the following sub-steps: Based on the obtained current battery level Determine the current battery level. If the value is less than the first threshold, the request to turn on the vehicle's electrical load will not be responded to. If the current battery level is greater than or equal to the first threshold, then determine the current battery level. If the value is less than the second threshold, then based on the request to turn on the vehicle's electrical load, turn on the vehicle's stable load. If it is greater than or equal to the second threshold and less than the set target battery level Based on the request to turn on the vehicle's electrical loads, all electrical loads of the vehicle will be turned on.

6. The method for controlling the parking regenerative engine of a plug-in hybrid vehicle as described in claim 5, characterized in that: The stable loads include headlights (high beams), interior lights, fog lights, night lights, and / or hazard lights, while the unstable loads include air conditioning systems, seat heating systems, and / or air purification systems.

7. A method for regenerating power while parked in a plug-in hybrid vehicle, comprising the following steps: Obtain the parking regeneration trigger signal; Based on the parking regeneration trigger signal, determine whether the vehicle status meets the parking regeneration enable conditions; If the vehicle meets the conditions for parking regeneration, the engine speed is increased to the target speed, and the target air-fuel ratio and ignition angle efficiency are set. The engine is controlled according to any one of claims 1 to 6 to maintain rapid parking regeneration; Determine whether the parking regeneration progress K is greater than or equal to the third threshold; If the value is greater than or equal to the third threshold, then the parking regeneration is considered complete.

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