Control method for operation management of range extender

Abstract

The invention relates to a control method for operation management of a range extender, which relates to the technical field of extended-range hybrid power, and comprises the following steps: judging whether a starting instruction is sent to the range extender or not; judging an engine control total state machine according to the engine rotating speed; whether an engine idling state machine is started or not is judged; whether an engine idling timing sub-state machine is started or not is judged; judging whether timing is cleared and the rotating speed is recalculated; whether an engine warm-up timing sub-state machine is entered or not and whether an idle speed calculation sub-state machine is returned or not are judged; judging whether an engine running state machine is entered or not; judging whether to enter a rotating speed control mode or a torque control mode; judging whether to return to the mode idling sub-state or not; judging engine shutdown request maintenance; and judging whether a shutdown state machine is entered or not. The problem that power generation is not stable when the extended-range engine is started for the first time is solved, the service life of the engine is greatly prolonged, the problems that heat dissipation is insufficient and the water temperature is too high are solved, and better compatibility is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of range-extended hybrid vehicles, and in particular to a control method for managing an operating mode of a range extender. Background Art

[0002] In the prior art, after receiving the range extender start command from the HCU, the ISG motor drives the engine to start, and after reaching the engine operating speed, the range extender is directly operated to generate electricity, and the speed control mode, torque control mode or fuel cut-off mode are selected according to the requirements of the control command. The shutdown method is: after receiving the range extender shutdown command, a shutdown command is directly issued to the engine, or in the absence of a shutdown command, the engine speed is lower than the reasonable value and an abnormal shutdown is performed.

[0003] At the same time, there are the following problems during use:

[0004] 1. When the engine is just started and enters idle speed, the speed PID is unstable, resulting in the frequency being difficult to control in the first few seconds and poor power generation efficiency.

[0005] 2. When the range extender is started at low or extremely low temperatures, the engine oil inside is not fully lubricated and starts to run under load, which greatly increases the wear of the engine.

[0006] 3. When the engine is shut down, the motor still has a large load on it, which can easily cause the motor load to stall the engine.

[0007] 4. Shutting down directly from a high-load working area will result in insufficient heat dissipation and excessively high water temperatures in some circuits. Summary of the invention

[0008] In recent years, the proportion of extended-range hybrid in the technical field of hybrid vehicles has gradually increased, especially in the engineering machinery and agricultural machinery industries, which has made up for the shortcomings of pure electric vehicles, such as insufficient endurance and slow charging. In the extended-range hybrid system, it is particularly important to coordinate the starting relationship and power torque between the ISG motor and the extended-range engine. The purpose of the present invention is to optimize the starting, idling and shutdown process of the extended-range engine to make the working entry point of the generator motor and the extended-range engine more reasonable and increase the service life.

[0009] In order to achieve the above object, the technical solution of the present invention provides a control method for range extender operation management, comprising the following steps:

[0010] Step 1, when it is detected that the SOC is lower than the corresponding preset value or the driving torque is greater than the corresponding preset value, a start command is sent to the range extender;

[0011] Step 2: The ISG motor starts the engine. If the engine speed is greater than the corresponding preset value within the corresponding preset time, the engine control state machine is entered. Otherwise, the number of engine start failures is increased by 1, and the engine shutdown process is entered.

[0012] Step 3, after entering the engine control general state machine, first enter the engine idle state machine, when entering, the engine state is set to the corresponding value of the idle stage, and when this state machine exits, the idle timer is set to 0;

[0013] Step 4, enter the engine idle timing sub-state machine to determine whether the speed is within the set range, if not, keep it until the speed is stable, if yes, enter the idle timing;

[0014] Step 5: After entering the idle timing, if the speed exceeds the range, clear the timing and recalculate;

[0015] Step 6: If the water temperature is lower than the set value during the idle sub-state calculation, the engine warm-up timing sub-state machine is entered; if the water temperature is greater than the corresponding preset value or the warm-up time exceeds the corresponding preset value, the engine returns to the idle calculation sub-state machine;

[0016] Step 7, when the idle timer reaches the corresponding preset value and there is no engine shutdown request, the first start idle flag position is set to 1, and the engine running state machine is entered;

[0017] Step 8, after entering the engine running state machine, if the speed control flag position is 1, then enter the speed control mode, otherwise enter the torque control mode, if the fuel cut-off signal is received, then enter the fuel cut-off mode;

[0018] Step 9, when the engine shutdown request is received, the mode idle sub-state is returned to. During this process, the power of the ISG motor is gradually ramped and unloaded, and the engine speed is gradually ramped to idle speed;

[0019] Step 10: If the engine shutdown request is terminated during this period, the engine will be directly returned to the engine running state machine without judging the idle time. During this process, the engine speed will gradually ramp to the working range, and the motor load will gradually ramp to the set value.

[0020] Step 11, if the engine shutdown request is maintained, after determining that the idle speed corresponds to a preset value, the shutdown phase is entered, and the number of engine shutdown failures is set to 0;

[0021] Step 12: If the engine speed is less than the corresponding preset value and there is no shutdown request during the control process of the entire engine control state machine, the engine is considered abnormal and directly enters the shutdown state machine, and the number of engine shutdown failures is increased by 1;

[0022] Step 13, after entering the engine shutdown state machine, wait for the engine speed to be less than the corresponding preset value, and the shutdown is completed.

[0023] Preferably, the preset values ​​corresponding to the SOC and the driving torque in step 1 are 20% and 80% respectively.

[0024] Preferably, in step 2, the time corresponding to the preset value is 2 seconds, and the engine speed corresponding to the preset value is 400 revolutions.

[0025] Preferably, in step 6, the preset value corresponding to the water temperature is 60° C., and the preset value corresponding to the warm-up time is 30 seconds.

[0026] Preferably, the preset value corresponding to the idle timer in step 7 is 3S.

[0027] Preferably, the preset value corresponding to the idle time in step 11 is 2S.

[0028] Preferably, the engine speed in step 12 corresponds to a preset value of 300 rpm.

[0029] Preferably, the engine speed in step 13 corresponds to a preset value of 5 revolutions.

[0030] In summary, the present invention includes the following beneficial technical effects:

[0031] 1. The problem of unstable power generation when the range-extended engine is started for the first time has been optimized, and the engine enters the power generation mode after idling steadily.

[0032] 2. The range extender is protected by increasing the idle speed and idling time during low-temperature starting, which ensures sufficient lubrication and greatly increases the life of the engine.

[0033] 3. The problem of insufficient heat dissipation and excessive water temperature is solved by ramping back to idle speed for a period of time before shutting down the machine.

[0034] 4. Dynamically coordinated engine speed and range extender power provide better compatibility when shutdown and start-up requirements occur repeatedly. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a diagram of the control software architecture of the startup part related to the present invention;

[0036] Figure 2 It is the overall state architecture diagram of the engine control. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] The embodiment of the present invention discloses a control method for range extender operation management, which includes the following contents:

[0039] 1. During vehicle driving, when the SOC is detected to be lower than 20% (can be calibrated) or the driving torque is greater than 80% (can be calibrated), a start command is sent to the range extender;

[0040] 2. The ISG motor drives the engine to start. If the engine speed is greater than 400 rpm (can be marked) within 2 seconds (can be marked), the engine control general state machine will be entered. Otherwise, the number of engine start failures will be increased by 1, and the engine shutdown process will be entered;

[0041] 3. After entering the engine control general state machine, the engine idle state machine is first entered. When entering, the engine state is set to 7 (idle stage). When this state machine exits, the idle timer is set to 0;

[0042] 4. Enter the engine idle timing sub-state machine to determine whether the speed is within the set range. If not, keep it until the speed is stable. If yes, enter the idle timing;

[0043] 5. After entering the idle timing, if the speed exceeds the range, clear the timing and recalculate;

[0044] 6. If the water temperature is lower than the set value during the idle speed sub-state calculation, the engine warm-up timing sub-state machine is entered; if the water temperature is greater than 60°C (can be calibrated) or the warm-up time exceeds 30S (can be calibrated), the engine returns to the idle speed calculation sub-state machine;

[0045] 7. When the idle timer reaches 3S (markable) and there is no engine shutdown request, the first start idle flag position is set to 1 and the engine running state machine is entered;

[0046] 8. After entering the engine running state machine, if the speed control flag is in position 1, it enters the speed control mode, otherwise it enters the torque control mode. If the fuel cut-off signal is received, it enters the fuel cut-off mode;

[0047] 9. When receiving the engine shutdown request, it returns to the mode idle sub-state. During this process, the power of the ISG motor is gradually ramped and unloaded, and the engine speed is gradually ramped to idle;

[0048] 10. If the engine shutdown request is terminated during this period, the engine will return to the running state machine directly without judging the idle time. During this process, the engine speed will gradually ramp to the working range, and the motor load will gradually ramp to the set value;

[0049] 11. If the engine shutdown request is maintained, the engine will enter the shutdown phase after idling for 2S (can be marked) and the number of engine shutdown failures will be set to 0;

[0050] 12. If the engine speed is less than 300 rpm (markable) and there is no shutdown request during the control process of the entire engine control state machine, the engine is considered abnormal and directly enters the shutdown state machine, and the number of engine shutdown failures is increased by 1;

[0051] 13. After entering the engine shutdown state, wait for the engine speed to be less than 5 revolutions and the shutdown is completed.

[0052] The present invention provides a control method for range extender operation management, which achieves the following optimizations by adding start / stop idle speed judgment and warm-up judgment to the range extender start state process, optimizing the shutdown exit conditions and adding a process for dynamically returning to the working state when the shutdown demand ends:

[0053] 1. The problem of unstable power generation when the range-extended engine is started for the first time has been optimized, and the engine enters the power generation mode after idling steadily.

[0054] 2. The range extender is protected by increasing the idle speed and idling time during low-temperature starting, which ensures sufficient lubrication and greatly increases the life of the engine.

[0055] 3. The problem of insufficient heat dissipation and excessive water temperature is solved by ramping back to idle speed for a period of time before shutting down the machine.

[0056] 4. Dynamically coordinated engine speed and range extender power provide better compatibility when shutdown and start-up requirements occur repeatedly.

[0057] Implementation Example 1:

[0058] 1. Power on the extended-range hybrid vehicle and press the KeyStart button to put the vehicle into operation.

[0059] 2. After the vehicle runs at 40KM / H for a period of time, press the accelerator pedal to 90%, and the range extender is turned on.

[0060] 3. The IS motor drives the engine to start. After 2S, the engine speed is greater than 400 rpm. At this time, the engine enters the overall control state machine.

[0061] 4. After entering the range extender, the engine will enter idle speed and stabilize for 3 seconds.

[0062] After 5.3 seconds, the engine enters the speed control state. At this time, the motor increases the load, the engine speed curve and the load power torque increase at the same time, and gradually reach the power generation capacity.

[0063] 6. After a period of time, release the accelerator pedal, the extended-range engine returns to the idle state, the motor power and engine speed ramp down at the same time, and after the speed stabilizes, it enters the shutdown stage.

[0064] 7. When the engine speed is less than 5, the shutdown is completed.

[0065] Implementation Example 2:

[0066] 1. Power on the extended-range hybrid vehicle and press the KeyStart button to put the vehicle into operation.

[0067] 2. After the vehicle runs at 40KM / H for a period of time, press the accelerator pedal to 90%, and the range extender is turned on.

[0068] 3. The IS motor drives the engine to start. After 2S, the engine speed is greater than 400 rpm. At this time, the engine enters the overall control state machine.

[0069] 4. After entering the range extender, the water temperature is 0℃, which is lower than the set value. The engine enters the warm-up state, and the idle speed increases and maintains for 30 seconds.

[0070] 5. After the 30-second warm-up time, the engine enters idle and stabilizes for 3 seconds. During this time, the range extender does not generate electricity.

[0071] After 6.3 seconds, the engine enters the speed control state. At this time, the motor increases the load, the engine speed curve and the load power torque increase at the same time, and gradually reach the power generation power.

[0072] 7. After a period of time, release the accelerator pedal, the extended-range engine returns to the idle state, and the motor power and engine speed ramp down at the same time.

[0073] 8. If the speed is not stabilized, press the accelerator pedal again to 90%. At this time, the power generation demand exists again and the shutdown command ends.

[0074] 9. The engine shutdown process is interrupted, and the engine returns directly from the idle state to the speed idling state. The engine speed curve and load power torque increase at the same time and gradually reach the power generation capacity.

[0075] 10. After a period of time, release the accelerator pedal, the extended-range engine returns to the idle state, the motor power and engine speed ramp down at the same time, and enter the shutdown stage after the speed stabilizes.

[0076] 11. When the engine speed is less than 5, the shutdown is completed.

[0077] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A control method for range extender operation management, characterized in that: The following steps are involved: Step 1, when it is detected that the SOC is lower than the corresponding preset value or the driving torque is greater than the corresponding preset value, a start command is sent to the range extender; Step 2: The ISG motor starts the engine. If the engine speed is greater than the corresponding preset value within the corresponding preset time, the engine control state machine is entered. Otherwise, the number of engine start failures is increased by 1, and the engine shutdown process is entered. Step 3, after entering the engine control general state machine, first enter the engine idle state machine, when entering, the engine state is set to the corresponding value of the idle stage, and when this state machine exits, the idle timer is set to 0; Step 4, enter the engine idle timing sub-state machine to determine whether the speed is within the set range, if not, keep it until the speed is stable, if yes, enter the idle timing; Step 5: After entering the idle timing, if the speed exceeds the range, clear the timing and recalculate; Step 6: If the water temperature is lower than the set value during the idle sub-state calculation, the engine warm-up timing sub-state machine is entered; if the water temperature is greater than the corresponding preset value or the warm-up time exceeds the corresponding preset value, the engine returns to the idle calculation sub-state machine; Step 7, when the idle timer reaches the corresponding preset value and there is no engine shutdown request, the first start idle flag position is set to 1, and the engine running state machine is entered; Step 8, after entering the engine running state machine, if the speed control flag position is 1, then enter the speed control mode, otherwise enter the torque control mode, if the fuel cut-off signal is received, then enter the fuel cut-off mode; Step 9, when the engine shutdown request is received, the mode idle sub-state is returned to. During this process, the power of the ISG motor is gradually ramped and unloaded, and the engine speed is gradually ramped to idle speed; Step 10: If the engine shutdown request is terminated during this period, the engine will be directly returned to the engine running state machine without judging the idle time. During this process, the engine speed will gradually ramp to the working range, and the motor load will gradually ramp to the set value. Step 11, if the engine shutdown request is maintained, after determining that the idle speed corresponds to a preset value, the shutdown phase is entered, and the number of engine shutdown failures is set to 0; Step 12: If the engine speed is less than the corresponding preset value and there is no shutdown request during the control process of the entire engine control state machine, the engine is considered abnormal and directly enters the shutdown state machine, and the number of engine shutdown failures is increased by 1; Step 13, after entering the engine shutdown state machine, wait for the engine speed to be less than the corresponding preset value, and the shutdown is completed.

2. A control method for range extender operation management according to claim 1, characterized in that: The preset values ​​corresponding to the SOC and the driving torque in step 1 are 20% and 80% respectively.

3. A control method for range extender operation management according to claim 2, characterized in that: In step 2, the corresponding preset value of the time is 2 seconds, and the corresponding preset value of the engine speed is 400 revolutions.

4. A control method for range extender operation management according to claim 3, characterized in that: In step 6, the corresponding preset value of the water temperature is 60°C, and the corresponding preset value of the warm-up time is 30S.

5. A control method for range extender operation management according to claim 4, characterized in that: The preset value of the idle timer in step 7 is 3S.

6. A control method for range extender operation management according to claim 5, characterized in that: The preset value of the idle time in step 11 is 2S.

7. A control method for range extender operation management according to claim 6, characterized in that: In step 12, the engine speed corresponds to a preset value of 300 rpm.

8. A control method for range extender operation management according to claim 7, characterized in that: In step 13, the engine speed corresponds to a preset value of 5 revolutions.

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