Range extender mode switching control method and system, range extender and electric vehicle

Abstract

The invention belongs to the technical field of range extender control, and provides a range extender mode switching control method and system, a range extender and an electric vehicle in order to solve the switching stability problem. The control mode for controlling the engine is converted into a target switching control mode, and the required rotating speed of the engine is the current required value; the generator is controlled to keep the previous control mode, and the generator rotating speed demand value is the current demand value; keeping the engine and generator control mode unchanged, and performing unauthorized control to enable the engine required speed to be higher than the generator required speed; when the actual torque value of the engine is larger than or equal to the set value, the generator is controlled to be in a target switching control mode, and the required torque of the generator is gradually transited to the current power generation required torque value from the actual torque value of the engine; and completing mode switching control. Stable transition of the rotating speed in the switching process can be ensured, the service life of the coupling of the range extender is prolonged, and the driving comfort is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of range extender control, and particularly relates to a range extender mode switching control method, system, range extender and electric vehicle. Background Art

[0002] The statements in this part only provide background technical information related to the present invention and do not necessarily constitute prior art.

[0003] When the engine and the generator in the range extender work together, there are various combinations of the control modes of the two components, and different control modes are used under different working conditions. The control mode switching process has a great influence on the speed of the range extender. The current switching process is likely to cause the speed of the range extender to overshoot or drop, that is, spikes or pits appear, and too large a speed change will affect the service life of the range extender coupling. Summary of the Invention

[0004] In order to solve the above problems, the present invention provides a range extender mode switching control method, system, range extender and electric vehicle. The present invention can ensure a smooth transition of the speed during the switching process, improve the service life of the range extender coupling, and at the same time enhance the ride comfort of the whole vehicle.

[0005] According to some embodiments, the present invention adopts the following technical solutions: A range extender mode switching control method includes the following steps: Respond to the range extender mode switching control requirement; Control the control mode of the engine to switch to the target switching control mode, and the engine demand speed is the current demand value; control the generator to still maintain the previous control mode, and the generator speed demand value is the current demand value; Keep the control modes of the engine and the generator unchanged, and override the control to make the engine demand speed higher than the generator demand speed; Obtain the actual torque value of the engine. When the actual torque value of the engine is greater than or equal to the set value, control the generator to be in the target switching control mode, and gradually transition the generator demand torque from the actual torque value of the engine to the current power generation demand torque value; Complete the range extender mode switching control.

[0006] As an alternative embodiment, the range extender mode switching control requirement is that the engine switches from torque control to speed control, and the generator switches from speed control to torque control.

[0007] As an alternative embodiment, the process of controlling the control mode of the engine to switch to the target switching control mode includes: controlling the control mode of the engine to switch from torque control to speed control.

[0008] As an alternative embodiment, the previous control mode of the generator is speed control, and the target switching control mode of the generator is torque control.

[0009] As an alternative embodiment, when the actual torque of the engine is less than the set value, the previous step is continued, the control modes of the engine and the generator are kept unchanged, and the override control is performed to make the required speed of the engine higher than the required speed of the generator; When the actual torque of the engine is greater than or equal to the set value, the override control of the required speed of the engine is no longer performed, and it returns to the current required speed value.

[0010] As an alternative embodiment, the process of gradually transitioning the required torque of the generator from the actual torque value of the engine to the current required torque value for power generation includes: making the required torque of the generator transition from the actual torque value of the engine to the current required torque value for power generation at a set torque change rate.

[0011] As an alternative embodiment, when the range extender mode switching control is completed, the engine is in speed control and the required speed is the current required value; the generator is in torque control and the required torque for power generation is the current required value.

[0012] A range extender mode switching control system includes: A mode switching module configured to respond to a range extender mode switching control requirement; A first control module configured to control the control mode of the engine to switch to the target switching control mode, and the required speed of the engine is the current required value; control the generator to still maintain the previous control mode, and the required speed value of the generator is the current required value; A second control module configured to keep the control modes of the engine and the generator unchanged, and perform override control to make the required speed of the engine higher than the required speed of the generator; A third control module configured to obtain the actual torque value of the engine. When the actual torque value of the engine is greater than or equal to the set value, control the generator to be in the target switching control mode, and make the required torque of the generator gradually transition from the actual torque value of the engine to the current required torque value for power generation; A post-switching control module configured to complete the range extender mode switching control.

[0013] A range extender adopts the above range extender mode switching control method or includes the above range extender mode switching control system.

[0014] An electric vehicle includes the above range extender.

[0015] Compared with the prior art, the beneficial effects of the present invention are: The present invention innovatively proposes a control method for range extender mode switching, a system, a range extender, and an electric vehicle. Aiming at the switching requirements of the entire control mode in which the engine switches from torque control to speed control and the generator switches from speed control to torque control, first, the control mode of the engine is changed to the target switching control mode, and the required engine speed is the current required value. At this time, the generator is still controlled in the previous control mode, and the required generator speed value is the current required value. Then, without changing the control modes of the engine and the generator, the required engine speed is over-controlled to be higher than the required generator speed. When the actual torque value of the engine is greater than or equal to the set value, the generator is controlled in the target switching control mode, and the required generator torque gradually transitions from the actual torque value of the engine to the current power generation required torque value. During the entire switching control process, the actual speed of the engine is maintained within a certain range without large speed fluctuations, ensuring a smooth transition of the mode switching, improving the service life of the range extender coupling, and enhancing the driving comfort of the whole vehicle at the same time.

[0016] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following specific preferred embodiments are given in conjunction with the accompanying drawings and are described in detail as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The specification drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

[0018] Figure 1 is a schematic structural diagram of a range extender according to an embodiment; Figure 2 is a schematic flow diagram of a control method for range extender mode switching according to an embodiment; Wherein, 1. Engine, 2. Coupling, 3. Generator, 4. Generator controller, 5. Power battery, 6. Driving motor, 7. Driving motor controller. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] The present invention will be further described below in conjunction with the drawings and embodiments.

[0020] It should be noted that the following detailed descriptions are all illustrative and are intended to provide further explanations of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0021] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should also be understood that when the terms "comprising" and / or "including" are used in this specification, they specify the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0022] In the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. Embodiment

[0023] It should be pre-explained that the range extender controlled in this embodiment includes an engine, a coupling, and a generator.

[0024] A method for controlling the mode switching of a range extender, as Figure 2 shown, Mode 1: Engine torque control and generator speed control; Mode 2: Engine speed control and generator torque control.

[0025] When the control requirement for the range extender switches from Mode 1 to Mode 2, the following steps are executed: Step (1) Control the engine to switch from the torque control mode (hereinafter simply referred to as torque control) to the speed control mode (hereinafter simply referred to as speed control), and the engine required speed is the current required value; control the generator to still be in speed control, and the generator speed required value is the current required value.

[0026] Step (2) Keep the control modes of the engine and the generator unchanged, but it is necessary to override the engine required speed to be higher than the generator required speed.

[0027] If the engine required speed is equal to the generator required speed, for example, the current engine required speed is 1000 revolutions and the generator required speed is 1000 revolutions; at this time, the engine required speed can be overridden / configured to 1050 revolutions or other values greater than 1000 revolutions.

[0028] The purpose of this step is that if the engine required speed is equal to the generator required speed, for example, the actual engine speed is maintained at 1200 revolutions by the generator at this time, and the engine ECU monitors that the actual speed is equal to the required speed, then the engine ECU will not inject fuel.

[0029] In order for the engine to inject fuel in advance to establish torque, it is necessary to make the engine required speed higher than the generator required speed. At this time, the engine ECU monitors that the actual speed is lower than the required speed, then the engine ECU speed control takes effect, starts fuel injection, and the actual engine torque begins to be established. Only after having a certain actual torque, it is considered that the engine speed control already has a certain control ability at this time.

[0030] In step (3), the actual torque value of the engine is obtained in real time. When the actual torque of the engine is higher than the set value A, in this embodiment, A can be taken as 50 Nm. At this time, the generator is controlled by torque and the speed control is no longer carried out. The initial value of the generator demand torque is the actual torque of the engine, and then it gradually transitions to the current power generation demand torque value. The engine demand speed is no longer over-controlled and returns to the current demand speed value.

[0031] The gradual transition to the current power generation demand torque value in this step means a smooth transition to the current power generation demand torque value or a transition to the current power generation demand torque value at a set torque change rate.

[0032] In step (4), the mode 2 switch is completed at this time. The engine is speed-controlled and the speed demand is the current demand value; the generator is torque-controlled and the power generation demand torque is the current demand value.

[0033] Of course, the values in the above embodiments are all exemplary value settings. In other embodiments, other values can be selected.

[0034] Taking a typical embodiment to illustrate the effect of the method proposed in this embodiment.

[0035] Taking the current actual engine speed of 1200 revolutions, actual torque of 300 Nm, and the engine control mode being torque control; The actual generator speed is 1200 revolutions, the actual torque is -300 Nm, and the generator control mode is speed control and it is in stable power generation as an example for illustration.

[0036] At the next moment, the range extender demand speed is 1000 revolutions and the power generation demand torque is -200 Nm.

[0037] When the range extender control demand switches from mode 1 to mode 2, if it is directly switched, the engine demand speed is 1000 revolutions. The engine needs to transition from the actual speed of 1200 revolutions to 1000 revolutions, and the generator needs to transition from the actual torque of -300 Nm to -200 Nm; When the engine switches to speed control, if the actual speed is lower than the demand speed, fuel injection will stop immediately, and the actual torque of the engine will change from 300 Nm to 0; and at this time, when the actual torque of the generator transitions from -300 Nm to -200 Nm, it will cause the actual speed of the engine to rapidly drop to a value lower than the demand speed, such as 800 revolutions. This speed value is significantly lower than the demand speed of 1000 revolutions. After waiting for the engine speed to rapidly drop, the engine starts to inject a large amount of fuel again, and the actual speed of the engine rises to the demand speed value again. There are significant speed fluctuations throughout the process.

[0038] In summary, it is very difficult to ensure a smooth transition of speed according to the direct switching method.

[0039] If it is replaced with the method provided in this embodiment, a smooth transition of the rotational speed can be achieved. The specific working process is as follows: Still taking the current actual engine speed of 1200 revolutions per minute, the actual torque of 300 Nm, and the engine control mode being torque control as an example; Taking the actual generator speed of 1200 revolutions per minute (the actual speeds of the engine and the generator are the same), the actual torque of -300 Nm, and the generator control mode being speed control and in stable power generation as an example for illustration.

[0040] The required speed of the range extender at the next moment is 1000 revolutions per minute, and the required power generation torque is -200 Nm; Moreover, the control requirement of the range extender switches from mode 1 to mode 2. The generator continues to maintain speed control with a required speed of 1000 revolutions per minute, and the engine also performs speed control simultaneously with a required speed of 1050 revolutions per minute.

[0041] After the actual engine speed gradually drops from 1200 revolutions per minute to 1000 revolutions per minute, the actual engine torque changes from 300 Nm to 0. Since the generator still maintains speed control at 1000 revolutions per minute at this time, the actual engine speed still remains at 1000 revolutions per minute without speed drop. At this time, the required engine speed is higher than the actual engine speed, and the engine has started fuel injection.

[0042] To meet the required speed, when the actual engine torque is greater than a certain value, such as 50 Nm, the speed control ability of the engine has been established at this time. Then, the generator speed control mode is switched to torque control. The actual torque of the generator is basically equivalent to the actual engine torque, approximately -50 Nm. The required torque of the generator is -200 Nm. At this time, the required torque of the generator starts from -50 Nm and gradually transitions to -200 Nm at a rate of -100 Nm / s (torque change rate). At this time, the engine always maintains a required speed of 1000 revolutions per minute.

[0043] In summary, during the whole process, the actual engine speed is maintained at 1000 revolutions per minute, ensuring a smooth transition of the speed. Embodiment

[0044] A range extender mode switching control system includes: A mode switching module configured to respond to the range extender mode switching control requirement; A first control module configured to control the control mode of the engine to be converted to the target switching control mode, and the required engine speed is the current required value; control the generator to still maintain the previous control mode, and the required generator speed value is the current required value; A second control module configured to keep the control modes of the engine and the generator unchanged and override control to make the required engine speed higher than the required generator speed; The third control module is configured to obtain the actual engine torque value. When the actual engine torque value is greater than or equal to the set value, it controls the generator to adopt the target switching control mode and gradually transitions the generator demand torque from the actual engine torque value to the current power generation demand torque value. The post-switching control module is configured to complete the control for the range extender mode switching. Embodiment

[0045] A range extender adopts the range extender mode switching control method of Embodiment 1 or includes the range extender mode switching control system of Embodiment 2.

[0046] Certainly, in some embodiments, as Figure 1 shown, the range extender further includes a generator controller 4, and the generator controller 4 and the generator 3 are connected by a connecting wire.

[0047] In some embodiments, it further includes a drive motor 6. The drive motor 6 and the drive motor controller 7 are connected by a connecting wire. The drive motor controller 7 and the generator controller 4 are supplied with electric energy by a power supply unit. In this embodiment, the power supply unit selects a power battery 5, and the power battery 5 is respectively connected to the drive motor controller 7 and the generator controller 4 by connecting wires. Embodiment

[0048] An electric vehicle includes the range extender provided in Embodiment 3, or adopts the range extender mode switching control method of Embodiment 1 or includes the range extender mode switching control system of Embodiment 2.

[0049] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD - ROM , optical memory, etc.).

[0050] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, and the combination of processes and / or blocks in the flowcharts and / or block diagrams, can be realized by computer program instructions. These computer program instructions can be provided to the processors of general-purpose computers, special-purpose computers, embedded processors, or other programmable data processing devices to generate a machine, so that the instructions executed by the processors of the computer or other programmable data processing devices generate for realizing the processes Figure 1One or more processes and / or boxes Figure 1 An apparatus for the functions specified in one or more boxes.

[0051] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory produce a manufactured article including an instruction device that implements the functions in the process Figure 1 One or more processes and / or boxes Figure 1 The functions specified in one or more boxes.

[0052] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operational steps are performed on the computer or other programmable device to produce a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in the process Figure 1 One or more processes and / or boxes Figure 1 The functions specified in one or more boxes.

[0053] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made by those skilled in the art without creative efforts within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A range extender mode switching control method, characterized in that: The following steps are involved: responding to a range extender mode switching control demand; The control mode of the engine is switched to the target switching control mode, and the engine speed requirement is the current requirement value; the generator is still controlled in the previous control mode, and the generator speed requirement is the current requirement value; Keep the engine and generator control mode unchanged, and override the control to make the engine speed higher than the generator speed; Obtaining the actual torque value of the engine, when the actual torque value of the engine is greater than or equal to the set value, controlling the generator to switch the control mode to the target, and making the generator demand torque gradually transition from the actual torque value of the engine to the current power generation demand torque value; Complete the range extender mode switching control.

2. A range extender mode switching control method as claimed in claim 1, characterized in that: The range extender mode switching control requirement is that the engine switches from torque control to speed control, and the generator switches from speed control to torque control.

3. A range extender mode switching control method as claimed in claim 1, characterized in that: The process of switching the control mode of the engine to the target switching control mode includes: switching the control mode of the engine from torque control to speed control.

4. A range extender mode switching control method as claimed in claim 1, characterized in that: The previous control mode of the generator is speed control, and the target switching control mode of the generator is torque control.

5. A range extender mode switching control method as claimed in claim 1, characterized in that: When the actual engine torque is less than the set value, continue the previous step, keep the engine and generator control mode unchanged, and override the control of the engine demand speed to be higher than the generator demand speed; When the actual engine torque is greater than or equal to the set value, the engine demand speed will no longer be overridden and will be restored to the current demand speed value.

6. A range extender mode switching control method as claimed in claim 1, characterized in that: The process of gradually transitioning the generator demand torque from the actual engine torque value to the current power generation demand torque value includes: transitioning the generator demand torque from the actual engine torque value to the current power generation demand torque value at a set torque change rate.

7. A range extender mode switching control method as claimed in claim 1, characterized in that: When the range extender mode switching control is completed, the engine is speed controlled, and the speed demand is the current demand value; the generator is torque controlled, and the power generation demand torque is the current demand value.

8. A range extender mode switching control system, characterized in that: include: A mode switching module configured to respond to a range extender mode switching control demand; The first control module is configured to control the control mode of the engine to change to the target switching control mode, and the engine required speed is the current required value; control the generator to still maintain the previous control mode, and the generator speed required value is the current required value; The second control module is configured to keep the control mode of the engine and the generator unchanged, and override the control of the engine demand speed to be higher than the generator demand speed; The third control module is configured to obtain the actual torque value of the engine, and when the actual torque value of the engine is greater than or equal to the set value, control the generator to switch the control mode to the target, and gradually transition the required torque of the generator from the actual torque value of the engine to the current required torque value of power generation; The control module after switching is configured to complete the range extender mode switching control.

9. A range extender, characterized in that: A range extender mode switching control method as described in any one of claims 1 to 7 is adopted or a range extender mode switching control system as described in claim 8 is included.

10. An electric vehicle, characterized in that: Including the range extender as described in claim 9.

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