Torque distribution method used between power sources of hybrid power system

Abstract

According to the torque distribution method used between the power sources of the hybrid power system, torque distribution needs to be carried out between the power sources for a hybrid electric vehicle with multiple power sources so as to meet the torque requirement of a driver. According to the torque distribution method, an engine and a generator are regarded as a whole, the sum of engine / generator target torque is calculated according to the torque requirement of a driver, then the torque of a driving motor is calculated, and then the generator target torque is calculated according to the engine target torque. The torque of the engine, the generator and the driving motor can be dynamically distributed, so that both the generator and the driving motor can drive and generate electricity, the control strategy and the calibration freedom degree are improved, and the advantages of the hybrid power system are played to the maximum extent. And meanwhile, the method is high in adaptability to the hybrid configuration and high in expandability, when the hybrid configuration changes, the reusability of the whole vehicle software constructed through the method is high, and configuration changes can be covered only through simple expansion.

Description

Technical Field

[0001] The present invention relates to the technical field of hybrid power systems, and in particular to a method for distributing torque between power sources of a hybrid power system. Background Art

[0002] The current hybrid powertrain configuration is diverse, resulting in a complex torque distribution strategy between power sources. In existing hybrid powertrains, the torque distribution method between power sources is strongly related to the hybrid powertrain configuration. When the hybrid powertrain structure changes, the torque distribution method between power sources also changes, resulting in significant changes in the software control system of the entire hybrid system.

[0003] In view of the above problems, the inventors of the present invention finally obtained the present invention after a long period of research and practice. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a method for distributing torque between power sources of a hybrid power system, which has strong adaptability to the configuration of the hybrid power system.

[0005] The technical solution adopted by the present invention is:

[0006] A method for distributing torque between power sources of a hybrid power system is provided, comprising the following steps:

[0007] Step 1: Get the driver's target torque ;

[0008] Step 2: Get the engine start status and clutch status;

[0009] Step 3: Calculate the sum of the engine and generator target torques ;

[0010] Step 4: Calculate the target torque of the drive motor ;

[0011] Step 5: Calculate the target engine torque based on the actual engine operating point adjustment requirements ;

[0012] Step 6: Calculate the generator target torque .

[0013] Further,

[0014] In the step 2, when the engine start state obtained is off;

[0015] In step 3, ;

[0016] In step 4, ;

[0017] In step 5, ;

[0018] In step 6, .

[0019] Further,

[0020] In step 2, when the engine start state is started and the clutch state is open;

[0021] In step 3, ;

[0022] In step 4, .

[0023] Further,

[0024] In step 2, when the engine start state is started and the clutch state is closed;

[0025] In step 3, according to the driver's target torque and the predetermined control strategy to calculate the sum of the target torques of the engine and the generator .

[0026] Furthermore, when there are multiple drive motors, step 4 also includes:

[0027] According to the target torque of the drive motor and a predetermined control strategy to calculate the target torque of each drive motor, the sum of the target torques of each drive motor being equal to the target torque of the drive motor .

[0028] Furthermore, when there are multiple generators, step 6 also includes:

[0029] According to the generator target torque The target torque of each generator is calculated according to the predetermined control strategy. The sum of the target torques of each generator is equal to the target torque of the generator. .

[0030] Compared with the prior art, the beneficial effects of the present invention are:

[0031] The torque distribution method in the present invention can dynamically distribute the torque of the engine, generator, and drive motor, so that the generator and drive motor can both drive and generate electricity, improve the control strategy and calibration freedom, and maximize the advantages of the hybrid system. At the same time, this method has strong adaptability and scalability to hybrid configurations. When the hybrid configuration changes, the vehicle software constructed using this method has high reusability and only needs simple expansion to cover the configuration changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 A schematic diagram of a single drive motor hybrid system configuration is shown;

[0034] Figure 2 A schematic diagram showing a method for distributing torque of a power source of a single drive motor hybrid system according to an embodiment of the present invention is shown;

[0035] Figure 3 A schematic diagram of a dual drive motor hybrid system configuration is shown;

[0036] Figure 4 A schematic diagram of a power source torque distribution method for a dual-drive motor hybrid system according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0037] The above and other technical features and advantages of the present invention are described in more detail below in conjunction with the accompanying drawings.

[0038] As used herein, the term "including" and its variations mean open inclusion, i.e., "including but not limited to". Unless otherwise stated, the term "or" means "and / or". The term "according to" means "at least in part according to". The terms "an example embodiment" and "an embodiment" mean "at least one example embodiment". The term "another embodiment" means "at least one additional embodiment". Other explicit and implicit definitions may also be included below.

[0039] like Figure 1 As shown, Figure 1 For example, in a single-drive motor hybrid configuration, the driver issues a torque request, which involves the torque distribution between the power sources, ignoring the transmission ratio:

[0040] A. When the engine is off and the clutch is open (those skilled in the art will appreciate that in this hybrid configuration, when the engine is off, the clutch will not be closed), the relationship between the driver torque request and the power source distribution torque is as follows:

[0041]

[0042] B. When the engine is started and the clutch is open, the relationship between the driver torque request and the power source distribution torque is as follows:

[0043]

[0044] C. When the engine is started and the clutch is closed, the relationship between the driver torque request and the power source distribution torque is as follows:

[0045]

[0046] in:

[0047] Torque for driver demand;

[0048] is the target torque of the driving motor;

[0049] is the sum of the target torques of the engine and the generator;

[0050] is the target torque of the engine;

[0051] is the generator target torque.

[0052] Reference Figure 2 For hybrid vehicles with multiple power sources, torque distribution needs to be performed between the power sources to meet the driver's torque requirements. The torque distribution method of the present invention regards the engine and the generator as one, first calculates the sum of the engine / generator target torques according to the driver's torque requirements, then calculates the drive motor torque, and then calculates the generator target torque according to the engine target torque. The specific steps are as follows:

[0053] 1. Obtain the driver's target torque .

[0054] 2. Get the engine start status and clutch status.

[0055] 3. Calculate the sum of the target torques of the engine and generator .

[0056] 4. Calculate the drive motor target .

[0057] 5. Calculate the target engine torque according to the actual engine operating point adjustment requirements .

[0058] 6. Calculate the generator target torque .

[0059] In a more specific embodiment, a method for distributing torque between power sources of a hybrid power system comprises the following steps:

[0060] 1. Obtain the driver's target torque .

[0061] 2. Get the engine start status and clutch status.

[0062] A. When the engine is off:

[0063] a. Calculate the drive motor torque ;

[0064] b. Engine torque ;

[0065] c. Generator torque .

[0066] B. When the engine is started and the clutch is open:

[0067] a. Calculate the drive motor torque ;

[0068] b. Calculate the engine target torque according to the predetermined control strategy Understandably, in this state ,The engine drives the generator to store electricity, and the control strategy can be designed according to the power generation demand, such as based on the battery charging power, the power consumption of accessories, the generator limit torque, etc.;

[0069] c. Calculate the generator target torque .

[0070] C. When the engine is started and the clutch is closed:

[0071] a. According to the driver's target torque and the predetermined control strategy to calculate the sum of the target torques of the engine and generator ; It can be understood that the control strategy can be designed according to actual needs, such as focusing on engine efficiency, focusing on safety, focusing on driving comfort, etc. to design different strategies;

[0072] b. Calculate the target torque of the drive motor ;

[0073] c. Calculate the engine target torque according to the predetermined control strategy ;

[0074] d. Calculate the generator target torque .

[0075] The torque distribution method in the present invention can dynamically distribute the torque of the engine, generator, and drive motor when the engine is started and the clutch is engaged, so that the generator and the drive motor can both drive and generate electricity, improve the control strategy and calibration freedom, and maximize the advantages of the hybrid system.

[0076] In addition, when the hybrid system configuration changes, the above torque distribution method can be expanded to quickly realize the torque distribution of the power source. Figure 3 Taking the dual-drive motor hybrid configuration in as an example, Figure 1 The single drive motor hybrid configuration in Figure 3 A driving motor is added to the configuration, and the torque distribution of four power sources can be realized by expanding the method for distributing the torque of the power source in the present invention, such as Figure 4 As shown, the overall torque distribution method has high reusability, and the expansion method is as follows:

[0077] According to the obtained driver torque demand, engine and clutch status, Figure 2 The engine target torque is calculated by the method , Generator target torque And the target torque of the drive motor (drive motor 1 and drive motor 2) .

[0078] based on , and then calculate the target torque of the drive motor 1 according to a predetermined control strategy (the control strategy can be designed based on the torque ratio of the front and rear axles, and of course can also be based on other factors without limitation). ;

[0079] Then calculate the target torque of drive motor 2 .

[0080] contrast Figure 4 and Figure 2 It can be seen that when the configuration of the hybrid power system changes, the software structure of the hybrid power system does not change or only requires a small expansion to adapt to the change in the hybrid power system configuration, which greatly reduces the software development cost.

[0081] The above are only preferred embodiments of the present invention, which are only illustrative and not restrictive. The structures and connection modes of the components in the present invention can be changed, and any equivalent transformations and improvements based on the technical solution of the present invention should not be excluded from the protection scope of the present invention.

Claims

1. A method for distributing torque between power sources of a hybrid power system, characterized in that: The steps include: Step 1: Get the driver's target torque ; Step 2: Get the engine start status and clutch status; Step 3: Calculate the sum of the engine and generator target torques ; Step 4: Calculate the drive motor target torque ; Step 5: Calculate the target engine torque based on the actual engine operating point adjustment requirements ; Step 6: Calculate the generator target torque .

2. A method for distributing torque between power sources of a hybrid power system as claimed in claim 1, characterized in that: In the step 2, when the acquired engine start state is off; In step 3, ; In step 4, ; In step 5, ; In step 6, .

3. The method for distributing torque between power sources of a hybrid power system according to claim 1, characterized in that: In step 2, when the engine start state is started and the clutch state is open; In step 3, ; In step 4, .

4. The method for distributing torque between power sources of a hybrid power system according to claim 1, characterized in that: In step 2, when the engine start state is started and the clutch state is closed; In step 3, according to the driver's target torque and the predetermined control strategy to calculate the sum of the target torques of the engine and the generator .

5. The method for distributing torque between power sources of a hybrid power system as claimed in claim 1, characterized in that: When there are multiple drive motors, step 4 further includes: According to the target torque of the drive motor and a predetermined control strategy to calculate the target torque of each drive motor, the sum of the target torques of each drive motor being equal to the target torque of the drive motor .

6. The method for distributing torque between power sources of a hybrid power system as claimed in claim 1, characterized in that: When there are multiple generators, step 6 also includes: According to the generator target torque The target torque of each generator is calculated according to the predetermined control strategy. The sum of the target torques of each generator is equal to the target torque of the generator. .

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