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

Abstract

The present invention belongs to the technical field of range extender control. To solve the problem of smooth switching, a range extender mode switching control method, system, range extender and electric vehicle are provided. The method includes responding to the range extender mode switching control demand; controlling the engine control mode to switch to the target switching control mode, and the engine required speed is the current required value; controlling the generator to still maintain the previous control mode, and the generator speed required value is the current required value; keeping the engine and generator control modes unchanged, and overriding the control of the engine required speed to be higher than the generator required speed; when the engine actual torque value is greater than or equal to the set value, controlling the generator to the target switching control mode, so that the generator required torque gradually transitions from the engine actual torque value to the current power generation required torque value; and completing the mode switching control. The present invention can ensure a smooth speed transition during the switching process, increase the service life of the range extender coupling, and enhance driving comfort.

Description

Technical Field

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

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

[0003] When the engine and generator in a range extender work together, the two components can use a variety of control modes. Different operating conditions require different control modes, and the switching process significantly affects the range extender's speed. The current switching process can easily cause the range extender's speed to surge or dip, resulting in spikes or dips. Excessive speed fluctuations can also affect the service life of the range extender's coupling. Summary of the Invention

[0004] In order to solve the above problems, the present invention proposes 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, increase the service life of the range extender coupling, and improve the driving comfort of the entire vehicle.

[0005] According to some embodiments, the present invention adopts the following technical solutions:

[0006] A range extender mode switching control method comprises the following steps:

[0007] responding to a range extender mode switching control demand;

[0008] 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;

[0009] Keep the engine and generator control mode unchanged, and override the control to make the engine speed higher than the generator speed.

[0010] Obtain the actual engine torque value. When the actual engine torque value is greater than or equal to the set value, control the generator to switch the control mode to the target, and gradually transition the generator demand torque from the actual engine torque value to the current power generation demand torque value.

[0011] Complete the range extender mode switching control.

[0012] As an optional implementation manner, 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.

[0013] As an optional implementation manner, 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.

[0014] As an optional implementation manner, the previous control mode of the generator is speed control, and the target switching control mode of the generator is torque control.

[0015] As an optional implementation, when the actual engine torque is less than the set value, continue with the previous step, keep the engine and generator control mode unchanged, and override the control to make the engine speed higher than the generator speed.

[0016] 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.

[0017] As an optional implementation, 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.

[0018] As an optional implementation, when completing the range extender mode switching control, 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.

[0019] A range extender mode switching control system, comprising:

[0020] a mode switching module configured to respond to a range extender mode switching control demand;

[0021] The first control module is configured to control the engine control mode to switch to the target switching control mode, with the engine required speed being the current required value; and control the generator to still maintain the previous control mode, with the generator speed required value being the current required value;

[0022] The second control module is configured to maintain 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;

[0023] The third control module is configured to obtain an actual engine torque value, and when the actual engine torque value is greater than or equal to a set value, control the generator to switch to a target control mode, and gradually transition the generator required torque from the actual engine torque value to the current power generation required torque value;

[0024] The control module after switching is configured to complete the range extender mode switching control.

[0025] A range extender adopts the above-mentioned range extender mode switching control method or includes the above-mentioned range extender mode switching control system.

[0026] An electric vehicle comprises the above-mentioned range extender.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The present invention innovatively proposes a range extender mode switching control method, system, range extender and electric vehicle. In response to the switching requirements of the entire control mode of switching the engine from torque control to speed control and the generator from speed control to torque control, the control mode of the engine is first converted to a target switching control mode, and the engine demand speed is the current demand value. At this time, the generator is controlled to still maintain the previous control mode, and the generator speed demand value is the current demand value; then the engine and generator control modes are kept unchanged, and the engine demand speed is controlled to be higher than the generator demand speed; when the actual engine torque value is greater than or equal to the set value, the generator is controlled to be in a target switching control mode, and the generator demand torque is gradually transitioned from the engine actual torque value to the current power generation demand torque value. During the entire switching control process, the actual engine speed is maintained within a certain range without large speed fluctuations, ensuring a smooth transition of the mode switch, which can increase the service life of the range extender coupling and improve the driving comfort of the entire vehicle.

[0029] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0031] Figure 1 This is a schematic diagram of the range extender structure according to an embodiment;

[0032] Figure 2 The present invention is a flow chart of a range extender mode switching control method according to an embodiment;

[0033] Among them, 1. Engine, 2. Coupling, 3. Generator, 4. Generator controller, 5. Power battery, 6. Drive motor, 7. Drive motor controller. DETAILED DESCRIPTION

[0034] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0035] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0036] 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 intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0037] In the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other. Example

[0038] It should be noted in advance that the range extender targeted by the control in this embodiment includes an engine, a coupling, and a generator.

[0039] A range extender mode switching control method, such as Figure 2 As shown, mode 1: engine torque control and generator speed control; mode 2: engine speed control and generator torque control.

[0040] When the control demand for the range extender switches from mode 1 to mode 2, the following steps are performed:

[0041] Step (1) controls the engine to switch from a torque control mode (hereinafter referred to as torque control) to a speed control mode (hereinafter referred to as speed control), with the engine speed requirement being the current required value; and controls the generator to still be speed control, with the generator speed requirement being the current required value.

[0042] Step (2) keeps the engine and generator control modes unchanged, but requires the engine's required speed to be higher than the generator's required speed.

[0043] If the engine speed requirement is equal to the generator speed requirement, for example, the current engine speed requirement is 1000 rpm and the generator speed requirement is 1000 rpm, the engine speed requirement can be overridden / configured to 1050 rpm or other values ​​greater than 1000 rpm.

[0044] The purpose of this step is that if the engine demand speed is equal to the generator demand speed, for example, at this time the actual engine speed is maintained at 1200 rpm by the generator, and the engine ECU detects that the actual speed is equal to the demand speed, then the engine ECU will not inject fuel.

[0045] In order for the engine to inject fuel in advance and build up torque, the engine's required speed must be higher than the generator's required speed. At this time, the engine ECU detects that the actual speed is lower than the required speed, so the engine ECU speed control takes effect, starts injection, and the engine's actual torque begins to build up. Only after a certain actual torque is reached, it is considered that the engine speed control has a certain control capability.

[0046] Step (3) obtains the actual engine torque value in real time. When the actual engine torque is higher than the set value A, which in this embodiment can be 50 Nm, the generator is controlled to torque control and speed control is no longer performed. The initial value of the generator torque requirement is the actual engine torque, and then gradually transitions to the current power generation torque requirement. The engine speed requirement is no longer overridden and returns to the current speed requirement.

[0047] The gradual transition to the current power generation demand torque value in this step refers to 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.

[0048] Step (4) now completes the switch to mode 2. The engine is in speed control, and the speed demand is the current demand value; the generator is in torque control, and the power generation demand torque is the current demand value.

[0049] Of course, the numerical values ​​in the above embodiments are exemplary numerical settings, and other numerical values ​​may be selected in other embodiments.

[0050] A typical embodiment is used to illustrate the effect of the method proposed in this embodiment.

[0051] Assume that the current actual engine speed is 1200 rpm, the actual torque is 300 Nm, and the engine control mode is torque control;

[0052] The actual generator speed is 1200 rpm, the actual torque is -300 Nm, and the generator control mode is speed control. This is explained using the example of stable power generation.

[0053] At the next moment, the range extender requires a speed of 1000 rpm and a power generation torque of -200 Nm.

[0054] The range extender control needs to switch from mode 1 to mode 2. If the switch is made directly, the engine speed requirement is 1000 rpm, the engine needs to transition from the actual speed of 1200 to 1000 rpm, and the generator needs to transition from the actual torque of -300 Nm to -200 Nm;

[0055] The engine switches to speed control. If the actual speed is lower than the required speed, fuel injection will be stopped immediately, and the actual engine torque will change from 300Nm to 0. At this time, the actual torque of the generator transitions from -300Nm to -200Nm, which will cause the actual engine speed to drop rapidly to a value lower than the required speed, such as 800 rpm. This speed value is significantly lower than the required speed of 1000 rpm. After the engine speed drops rapidly, the engine starts to inject a large amount of fuel again, and the actual engine speed rises to the required speed value again. There are large speed fluctuations in the whole process.

[0056] In summary, it is difficult to ensure a smooth transition of the speed by using a direct switching method.

[0057] By replacing the method provided in this embodiment, a smooth transition of the rotation speed can be achieved. The specific working process is as follows:

[0058] Still assuming that the current actual engine speed is 1200 rpm, the actual torque is 300 Nm, and the engine control mode is torque control;

[0059] The actual generator speed is 1200 rpm (the actual speed of the engine and the generator is consistent), the actual torque is -300 Nm, and the generator control mode is speed control. This is explained using the example of stable power generation.

[0060] At the next moment, the range extender requires a speed of 1000 rpm and a power generation torque of -200 Nm;

[0061] The range extender control requirement switches from mode 1 to mode 2. The generator continues to maintain speed control with a speed requirement of 1000 rpm. The engine is also speed controlled at the same time with a speed requirement of 1050 rpm.

[0062] After the actual engine speed gradually drops from 1200 rpm to 1000 rpm, the actual engine torque changes from 300Nm to 0. At this time, the generator is still maintaining the speed control at 1000 rpm, so the actual engine speed remains at 1000 rpm without slowing down. At this time, the engine demand speed is higher than the actual engine speed, and the engine has started to inject fuel.

[0063] In order to meet the required speed, when the actual engine torque is greater than a certain value, such as 50Nm, the engine's speed control capability has been established. At this time, the generator speed control mode is switched to torque control. The actual torque of the generator is basically equivalent to the actual torque of the engine, about -50Nm. The required torque of the generator is -200Nm. At this time, the required torque of the generator is controlled to start from -50Nm and gradually transition to -200Nm at -100Nm / s (torque change rate). At this time, the engine maintains the required speed of 1000 rpm.

[0064] In summary, the actual engine speed is maintained at 1000 rpm throughout the entire process, ensuring a smooth transition of speed. Example

[0065] A range extender mode switching control system, comprising:

[0066] a mode switching module configured to respond to a range extender mode switching control demand;

[0067] The first control module is configured to control the engine control mode to switch to the target switching control mode, with the engine required speed being the current required value; and control the generator to still maintain the previous control mode, with the generator speed required value being the current required value;

[0068] The second control module is configured to maintain 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;

[0069] The third control module is configured to obtain an actual engine torque value, and when the actual engine torque value is greater than or equal to a set value, control the generator to switch to a target control mode, and gradually transition the generator required torque from the actual engine torque value to the current power generation required torque value;

[0070] The control module after switching is configured to complete the range extender mode switching control. Example

[0071] 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.

[0072] Of course, in some embodiments, Figure 1 As shown, the range extender further includes a generator controller 4 , and the generator controller 4 is connected to the generator 3 via a connecting line.

[0073] In some embodiments, a drive motor 6 is also included. The drive motor 6 and the drive motor controller 7 are connected by a connecting line. The drive motor controller 7 and the generator controller 4 are provided with power by a power supply unit. In this embodiment, the power supply unit is a power battery 5. The power battery 5 and the drive motor controller 7 and the generator controller 4 are respectively connected by connecting lines. Example

[0074] An electric vehicle includes the range extender provided in the third embodiment, or adopts the range extender mode switching control method of the first embodiment, or includes the range extender mode switching control system of the second embodiment.

[0075] It will be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of one or more computer-usable storage media (including but not limited to disk storage, CD - ROM , optical storage, etc.).

[0076] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0077] These computer program instructions may 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, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0078] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 The steps for the function specified in one or more boxes.

[0079] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made by those skilled in the art that fall within the spirit and principles of the present invention and do not require creative effort are intended to be within the scope of protection 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. Obtain the actual engine torque value. When the actual engine torque value is greater than or equal to the set value, control the generator to switch the control mode to the target, and gradually transition the generator demand torque from the actual engine torque value to the current power generation demand torque value. Complete the range extender mode switching control.

2. A range extender mode switching control method according to 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. The range extender mode switching control method according to claim 1, wherein: 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. The range extender mode switching control method according to claim 1, wherein: The previous control mode of the generator is speed control, and the target switching control mode of the generator is torque control.

5. The range extender mode switching control method according to claim 1, wherein: When the actual engine torque is less than the set value, continue with the previous step, keep the engine and generator control mode unchanged, and override the control to make the engine speed higher than the generator 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. The range extender mode switching control method according to claim 1, wherein: 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. The range extender mode switching control method according to claim 1, wherein: 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 engine control mode to switch to the target switching control mode, with the engine required speed being the current required value; and control the generator to still maintain the previous control mode, with the generator speed required value being the current required value; The second control module is configured to maintain 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 an actual engine torque value, and when the actual engine torque value is greater than or equal to a set value, control the generator to switch to a target control mode, and gradually transition the generator required torque from the actual engine torque value to the current power generation required torque value; The control module after switching is configured to complete the range extender mode switching control.

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

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

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