Method for testing efficiency of vehicle hybrid power electric drive assembly

Abstract

The invention discloses an efficiency test method for a vehicle hybrid power electric drive assembly, and relates to the technical field of vehicle testing, and the method comprises the following steps: S10, obtaining a preset test condition of a target vehicle, and carrying out the bench test of the hybrid power electric drive assembly of the target vehicle according to the preset test condition; s20, the rotating speed and torque of the output end of the rack input dynamometer motor and the input end of the rack output dynamometer motor in the rack test and the current and voltage output by the battery simulator are obtained; and S30, calculating the efficiency of the hybrid electric drive assembly of the target vehicle according to the rotating speeds and torques of the output end of the rack input dynamometer motor and the input end of the rack output dynamometer motor and the current and voltage of the battery simulator. According to the invention, each input energy and output energy of the hybrid power electric drive assembly are comprehensively considered, and the efficiency test result is more accurate and reliable.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle testing, and in particular to an efficiency testing method for a hybrid electric drive assembly of a vehicle. Background Art

[0002] At present, hybrid vehicles (Hybrid Vehicle) refer to vehicles whose vehicle drive system is composed of two or more single drive systems that can operate simultaneously. The vehicle drive system is composed of two or more single drive systems that can operate simultaneously. Hybrid power not only takes advantage of the engine's long continuous working time and good power, but also takes advantage of the motor's pollution-free and low noise. The two "fight side by side" and learn from each other's strengths to make up for each other's weaknesses. The thermal efficiency of the car can be increased by more than 10%, and the exhaust emissions can be improved by more than 30%. The development of hybrid vehicles is one of the future development trends of automobiles. Among them, the efficiency of the hybrid electric drive assembly of hybrid vehicles is an important indicator for evaluating and affecting fuel economy performance.

[0003] In the prior art, a common method for testing the efficiency of a hybrid electric drive assembly is to conduct bench testing. However, bench testing generally uses fixed operating conditions, speed, and torque of each power source to perform sweep point testing to obtain the power at the input and output ends to calculate the efficiency. This method does not fully consider the energy input and output during the test and has limitations, resulting in inaccurate efficiency test results. Summary of the invention

[0004] An embodiment of the present invention provides an efficiency testing method for a vehicle hybrid electric drive assembly to solve the technical problems in the related art that the efficiency testing method for the existing vehicle hybrid electric drive assembly has limitations in the consideration of input and output energy and the efficiency testing results are inaccurate.

[0005] An embodiment of the present invention provides a method for testing the efficiency of a hybrid electric drive assembly of a vehicle, comprising the following steps:

[0006] Obtaining a preset test condition of a target vehicle, and performing a bench test on a hybrid electric drive assembly of the target vehicle according to the preset test condition;

[0007] Obtaining the speed and torque of the output end of the bench input dynamometer motor and the input end of the bench output dynamometer motor in the bench test, as well as the current and voltage of the battery simulator;

[0008] The efficiency of the hybrid electric drive assembly of the target vehicle is calculated based on the rotational speed and torque of the output end of the bench input dynamometer motor and the input end of the bench output dynamometer motor and the current and voltage of the battery simulator.

[0009] In some embodiments, the step of calculating the efficiency of the hybrid electric drive assembly of the target vehicle according to the output end of the bench input dynamometer motor and the speed and torque of the bench output dynamometer motor and the current and voltage of the battery simulator includes:

[0010] According to the speed and torque of the output end of the test bench input dynamometer motor and the input end of the test bench output dynamometer motor and the current and voltage of the battery simulator, the energy E1 output by the hybrid electric drive assembly to the test bench output end, the energy E2 output to the battery simulator, the energy E3 output to the test bench input end, the energy E4 input by the battery simulator to the hybrid electric drive assembly, the energy E5 input by the test bench input end to the hybrid electric drive assembly, and the energy E6 input by the test bench output end to the hybrid electric drive assembly are calculated.

[0011] According to the formula The efficiency of the hybrid electric drive system of the target vehicle is calculated.

[0012] In some embodiments, the step of obtaining the rotational speed and torque of the output end of the bench input dynamometer motor and the input end of the bench output dynamometer motor in the bench test and the current and voltage of the battery simulator further includes:

[0013] Obtain the speed and torque of the generator and drive motor of the hybrid electric drive assembly during bench testing;

[0014] Analyze the speed and torque of the output end of the test bench input dynamometer motor in the engine map, analyze the speed and torque of the drive motor in the drive motor map, and analyze the speed and torque of the generator in the generator map;

[0015] Based on the analysis results, the structural parameters and control strategies of the hybrid electric drive assembly of the target vehicle are optimized.

[0016] In some embodiments, the step of analyzing the rotation speed and torque of the output end of the test bench input dynamometer motor at the landing point in the engine map includes:

[0017] The engine optimization working area is determined according to the relative position of the rotational speed and torque of the output end of the test bench input dynamometer motor in the engine map and the engine optimal line.

[0018] In some embodiments, the step of optimizing the structural parameters and control strategy of the hybrid electric drive assembly of the target vehicle according to the analysis results includes:

[0019] When the engine of the hybrid electric drive assembly of the target vehicle actually operates in the engine optimization operating area, the torque distribution ratio of the engine in the hybrid electric drive assembly is reduced and the torque distribution ratio of the drive motor is increased, or the engine is controlled to stop working.

[0020] In some embodiments, the step of analyzing the locations of the rotation speed and torque of the drive motor in the drive motor map includes:

[0021] The optimized working area of ​​the drive motor is determined according to the landing points of the speed and torque of the drive motor in the drive motor map.

[0022] In some embodiments, the step of optimizing the structural parameters and control strategy of the hybrid electric drive assembly of the target vehicle according to the analysis results includes:

[0023] When the drive motor of the hybrid electric drive assembly of the target vehicle actually operates in the drive motor optimization working area, the output gear position of the drive motor of the hybrid electric drive assembly is adjusted.

[0024] In some embodiments, the step of analyzing the locations of the rotational speed and torque of the generator in the generator map includes:

[0025] The optimized working area of ​​the generator is determined according to the location of the generator speed and torque in the drive motor map.

[0026] In some embodiments, the step of optimizing the structural parameters and control strategy of the hybrid electric drive assembly of the target vehicle according to the analysis results includes:

[0027] Adjust the speed ratio between the engine and the generator.

[0028] In some embodiments, the preset test condition is a CHTC condition.

[0029] The beneficial effects brought about by the technical solution provided by the present invention include:

[0030] The embodiment of the present invention provides an efficiency test method for a hybrid electric drive assembly of a vehicle, firstly obtaining a preset test condition of a target vehicle, and performing a bench test on the hybrid electric drive assembly of the target vehicle according to the preset test condition; then obtaining the speed and torque of the output end of the bench input dynamometer motor and the input end of the bench output dynamometer motor in the bench test, as well as the current and voltage of the battery simulator; finally, according to the speed and torque of the output end of the bench input dynamometer motor and the input end of the bench output dynamometer motor, as well as the current and voltage of the battery simulator, the efficiency of the hybrid electric drive assembly of the target vehicle is calculated. The present invention comprehensively considers each input energy and output energy, and the efficiency test result is more accurate and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0032] Figure 1 A flow chart of a method for testing the efficiency of a hybrid electric drive assembly of a vehicle provided by an embodiment of the present invention;

[0033] Figure 2 A principle block diagram of a bench test provided by an embodiment of the present invention;

[0034] Figure 3 A schematic diagram of the engine speed and torque at different vehicle speeds projected onto an engine map provided by an embodiment of the present invention;

[0035] Figure 4 A schematic diagram of the rotation speed and torque of the driving motor at different vehicle speeds projected onto the driving motor Map provided by an embodiment of the present invention;

[0036] Figure 5 Another schematic diagram of the projection of the rotation speed and torque of the driving motor at different vehicle speeds on the driving motor Map provided by an embodiment of the present invention;

[0037] Figure 6 A schematic diagram of the rotation speed and torque of a generator at different vehicle speeds projected onto a generator map provided by an embodiment of the present invention;

[0038] Figure 7 This is a schematic diagram of the projection of the rotation speed and torque of the generator on the generator Map diagram at different K values ​​of the planetary gears and different vehicle speeds provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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.

[0040] An embodiment of the present invention provides an efficiency testing method for a vehicle hybrid electric drive assembly, which can solve the technical problems of existing efficiency testing methods for vehicle hybrid electric drive assemblies, such as limitations in consideration of input and output energy and inaccurate efficiency test results.

[0041] See also Figure 1 As shown, an embodiment of the present invention provides a method for testing the efficiency of a hybrid electric drive assembly of a vehicle, comprising the following steps:

[0042] Step S10, obtaining a preset test condition of the target vehicle, and performing a bench test on the hybrid electric drive assembly of the target vehicle according to the preset test condition.

[0043] Specifically, the preset test condition may be a CHTC condition, which is improved on the basis of the C-WTVC (China World Transient Vehicle Cycle). The CHTC condition is suitable for the energy consumption test of heavy-duty hybrid vehicles and electric vehicles, and is also the standard working cycle for fuel consumption certification of heavy-duty commercial vehicles. Through the CHTC condition test, the fuel economy and energy consumption of the vehicle in actual use can be more accurately evaluated.

[0044] Step S20, obtaining the rotation speed and torque of the output end of the bench input dynamometer motor and the input end of the bench output dynamometer motor in the bench test, as well as the current and voltage of the battery simulator.

[0045] Specifically, Figure 2 This is the principle block diagram of the bench test. The bench is equipped with a battery simulator, temperature controller, data acquisition sensor, vehicle controller, bench main control computer, etc. The hybrid electric drive assembly comes with a motor controller and transmission controller.

[0046] The hybrid electric drive assembly of the target vehicle is installed on the test bench, keeping the posture consistent with the whole vehicle. The test bench input dynamometer motor simulates the target vehicle's engine to provide power input, the battery simulator simulates the target vehicle's battery to provide and store electrical energy for the hybrid electric drive assembly, and the test bench output dynamometer motor simulates the road absorbing the output energy.

[0047] The test bench CAN signal inputs the CHTC cycle condition to the test bench input dynamometer motor, the test bench CAN signal controls the drive motor and generator of the hybrid electric drive assembly, the test bench CAN signal controls the battery simulator to simulate the battery of the target vehicle, the test bench CAN signal sends gear information to simulate the driver controlling the throttle and brake, and the motor controller, motor, etc. are cooled during the test. The cooling flow and temperature are consistent with those on the whole vehicle. The output end of the test bench input dynamometer motor and the input end of the test bench output dynamometer motor collect speed and torque through sensors, and the battery simulator collects current and voltage through sensors.

[0048] Step S30 , calculating the efficiency of the hybrid electric drive assembly of the target vehicle according to the rotation speed and torque of the output end of the bench input dynamometer motor and the input end of the bench output dynamometer motor and the current and voltage of the battery simulator.

[0049] Specifically, the step of calculating the efficiency of the hybrid electric drive assembly of the target vehicle according to the rotation speed and torque of the output end of the bench input dynamometer motor and the input end of the bench output dynamometer motor and the current and voltage of the battery simulator includes:

[0050] According to the speed and torque of the output end of the test bench input dynamometer motor and the input end of the test bench output dynamometer motor and the current and voltage of the battery simulator, the energy E1 output by the hybrid electric drive assembly to the output end of the test bench (equivalent to the energy consumed by the vehicle's forward driving wheels), the energy E2 output to the battery simulator (equivalent to the energy recovered by the vehicle's braking and deceleration driving motor in reverse power generation + the energy generated by the generator), the energy E3 output to the input end of the test bench (equivalent to the energy of starting the vehicle's engine), the energy E4 input by the battery simulator to the hybrid electric drive assembly (equivalent to the forward power supply energy of the vehicle's battery), the energy E5 input from the input end of the test bench to the hybrid electric drive assembly (equivalent to the forward driving energy of the vehicle's engine), and the energy E6 input from the output end of the test bench to the hybrid electric drive assembly (equivalent to the reverse recovery energy of the vehicle's braking and deceleration).

[0051] According to the formula The efficiency of the hybrid electric drive system of the target vehicle is calculated.

[0052] The efficiency test method of the vehicle hybrid electric drive assembly in the embodiment of the present invention comprehensively considers various input energies and output energies, and the efficiency test result is more accurate and reliable.

[0053] As an optional implementation, in an embodiment of the invention, the step of obtaining the speed and torque of the output end of the bench input dynamometer motor and the input end of the bench output dynamometer motor in the bench test and the current and voltage of the battery simulator further includes:

[0054] Obtain the speed and torque of the generator and drive motor of the hybrid electric drive assembly during bench testing;

[0055] Analyze the speed and torque of the output end of the test bench input dynamometer motor in the engine map, analyze the speed and torque of the drive motor in the drive motor map, and analyze the speed and torque of the generator in the generator map;

[0056] Based on the analysis results, the structural parameters and control strategies of the hybrid electric drive assembly of the target vehicle are optimized.

[0057] The embodiment of the present invention performs a map landing point analysis on the data recorded during the bench test, and optimizes the structural parameters and control strategy of the hybrid electric drive assembly of the target vehicle according to the analysis result, so as to reduce the energy consumption of the target vehicle.

[0058] As an optional implementation, in an embodiment of the invention, the step of analyzing the location of the speed and torque of the output end of the test bench input dynamometer motor in the engine map includes:

[0059] The engine optimization working area is determined according to the relative position of the rotational speed and torque of the output end of the test bench input dynamometer motor in the engine map and the engine optimal line.

[0060] Taking a hybrid electric drive assembly of a commercial vehicle as an example, after running the CHTC condition on the test bench, the speed and torque of each power source are recorded as shown in Table 1 below, where the engine speed and torque are the speed and torque of the output end (simulated engine) of the test bench input dynamometer motor:

[0061] Table 1

[0062]

[0063] Figure 3 The engine speed and torque landing points at different vehicle speeds are projected onto the engine Map. The red circled points are not distributed near the engine optimal line (the deviation of the relative position from the engine optimal line exceeds 10%), and the green circled points are distributed near the engine optimal line (the deviation of the relative position from the engine optimal line does not exceed 10%). The red circled area can be considered as the engine optimization working area, which can be roughly considered to be a speed of 1400rpm and a torque of less than 150Nm, or a speed of 1400rpm-1600rpm and a torque of less than 200Nm.

[0064] Furthermore, the step of optimizing the structure and control strategy of the hybrid electric drive assembly of the target vehicle according to the analysis results includes:

[0065] When the target vehicle actually operates in the engine optimization operating area, the torque distribution ratio of the engine in the hybrid electric drive assembly is reduced and the torque distribution ratio of the drive motor is increased, or the engine is controlled to stop working.

[0066] pass Figure 3 It can be seen that in the engine optimization working area, the engine efficiency is not high and the fuel consumption is large. Figure 3 When the engine is optimized in the working area, the torque distribution ratio of the engine can be reduced and the torque distribution ratio of the drive motor can be increased or the engine can be controlled to stop working, which can reduce the energy consumption of the target vehicle.

[0067] As an optional implementation, in an embodiment of the invention, the step of analyzing the locations of the rotation speed and torque of the drive motor in the drive motor map includes:

[0068] The optimized working area of ​​the drive motor is determined according to the landing points of the speed and torque of the drive motor in the drive motor map.

[0069] Figure 4 The middle green point is the point where the speed and torque of the drive motor at a certain drive gear under different vehicle speeds are projected onto the drive motor Map. The circled points on the right are not distributed at positions where the drive motor's working efficiency is greater than 95%. It can be considered that the area circled on the right is the optimized working area of ​​the drive motor.

[0070] Furthermore, the step of optimizing the structural parameters and control strategy of the hybrid electric drive assembly of the target vehicle according to the analysis results includes:

[0071] When the drive motor of the hybrid electric drive assembly of the target vehicle actually operates in the drive motor optimization working area, the output gear position of the drive motor of the hybrid electric drive assembly is adjusted.

[0072] See also Figure 4 and Figure 5 As shown, when the drive motor of the hybrid electric drive assembly of the target vehicle actually works in the drive motor optimization working area, the output gear of the drive motor is adjusted so that the point originally circled on the right is moved to the position where the drive motor working efficiency is greater than 95%. In a specific application example, Figure 4 There are 1,626 medium green points, and 287 points with working efficiency greater than 95%, accounting for 17.7%. Based on the target vehicle's common speed of 30-70km / h, by adjusting the output gear of the drive motor (generally increasing the reduction ratio and optimizing the high speed, low torque landing point to a low speed, high torque landing point), the driving motor's working efficiency is increased to 33.15% at points above 95%.

[0073] As an optional implementation, in an embodiment of the invention, the step of analyzing the location of the rotation speed and torque of the generator in the generator map includes:

[0074] The optimized working area of ​​the generator is determined according to the location of the generator speed and torque in the drive motor map.

[0075] Figure 6 The green points in the middle are the points where the generator's speed and torque are projected onto the generator map at different vehicle speeds. The points circled by black circles are not distributed at positions where the drive motor's working efficiency is greater than 90%. The area circled by black circles can be considered the optimized working area of ​​the generator.

[0076] Furthermore, the step of optimizing the structural parameters and control strategy of the hybrid electric drive assembly of the target vehicle according to the analysis results includes:

[0077] Adjust the parameters of the planetary gear set between the engine and the generator.

[0078] See also Figure 7 As shown, by adjusting the K value (characteristic parameter of the planetary gear) of the planetary gear between the engine and the generator, the engine speed and torque landing point will change accordingly.

[0079] In the description of the present invention, it should be noted that the terms "upper", "lower", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present invention. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0080] It should be noted that, in the present invention, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0081] The above description is only a specific embodiment of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but should conform to the widest scope consistent with the principles and novel features of the present invention.

Claims

1. A method for testing the efficiency of a hybrid electric drive assembly of a vehicle, characterized in that: The following steps are involved: Obtaining a preset test condition of a target vehicle, and performing a bench test on a hybrid electric drive assembly of the target vehicle according to the preset test condition; Obtaining the speed and torque of the output end of the bench input dynamometer motor and the input end of the bench output dynamometer motor in the bench test, as well as the current and voltage of the battery simulator; The efficiency of the hybrid electric drive assembly of the target vehicle is calculated based on the rotational speed and torque of the output end of the bench input dynamometer motor and the input end of the bench output dynamometer motor and the current and voltage of the battery simulator.

2. The efficiency test method of a vehicle hybrid electric drive assembly according to claim 1, characterized in that: The step of calculating the efficiency of the hybrid electric drive assembly of the target vehicle according to the rotation speed and torque of the output end of the bench input dynamometer motor and the input end of the bench output dynamometer motor and the current and voltage of the battery simulator comprises: According to the rotation speed and torque of the output end of the test bench input dynamometer motor and the input end of the test bench output dynamometer motor and the current and voltage of the battery simulator, the energy E1 output by the hybrid electric drive assembly to the test bench output end, the energy E2 output to the battery simulator, the energy E3 output to the test bench input end, the energy E4 input by the battery simulator to the hybrid electric drive assembly, the energy E5 input by the test bench input end to the hybrid electric drive assembly, and the energy E6 input by the test bench output end to the hybrid electric drive assembly are calculated; According to the formula The efficiency of the hybrid electric drive system of the target vehicle is calculated.

3. The efficiency testing method of a vehicle hybrid electric drive assembly according to claim 2, characterized in that: The step of obtaining the rotation speed and torque of the output end of the bench input dynamometer motor and the input end of the bench output dynamometer motor in the bench test and the current and voltage of the battery simulator also includes: Obtain the speed and torque of the generator and drive motor of the hybrid electric drive assembly during bench testing; Analyze the output speed and torque of the test bench input dynamometer motor in the engine map, analyze the speed and torque of the drive motor in the drive motor map, and analyze the speed and torque of the generator in the generator map; Based on the analysis results, the structural parameters and control strategies of the hybrid electric drive assembly of the target vehicle are optimized.

4. The efficiency testing method of a vehicle hybrid electric drive assembly according to claim 3, characterized in that: The step of analyzing the rotation speed and torque of the output end of the test bench input dynamometer motor at the drop point in the engine map includes: The engine optimization working area is determined according to the relative position of the rotational speed and torque of the output end of the test bench input dynamometer motor in the engine map and the engine optimal line.

5. The efficiency testing method of a vehicle hybrid electric drive assembly according to claim 4, characterized in that: The step of optimizing the structural parameters and control strategy of the hybrid electric drive assembly of the target vehicle according to the analysis results includes: When the engine of the hybrid electric drive assembly of the target vehicle actually operates in the engine optimization operating area, the torque distribution ratio of the engine in the hybrid electric drive assembly is reduced and the torque distribution ratio of the drive motor is increased, or the engine is controlled to stop working.

6. The efficiency testing method of a vehicle hybrid electric drive assembly according to claim 3, characterized in that: The step of analyzing the locations of the rotation speed and torque of the drive motor in the drive motor map includes: The optimized working area of ​​the drive motor is determined according to the landing points of the speed and torque of the drive motor in the drive motor map.

7. The efficiency testing method of a vehicle hybrid electric drive assembly according to claim 6, characterized in that: The step of optimizing the structural parameters and control strategy of the hybrid electric drive assembly of the target vehicle according to the analysis results includes: When the drive motor of the hybrid electric drive assembly of the target vehicle actually operates in the drive motor optimization working area, the output gear position of the drive motor of the hybrid electric drive assembly is adjusted.

8. The efficiency testing method of a vehicle hybrid electric drive assembly according to claim 3, characterized in that: The step of analyzing the points where the rotation speed and torque of the generator fall in the generator map includes: The optimized working area of ​​the generator is determined according to the location of the generator speed and torque in the drive motor map.

9. The efficiency testing method of a vehicle hybrid electric drive assembly according to claim 8, characterized in that: The step of optimizing the structural parameters and control strategy of the hybrid electric drive assembly of the target vehicle according to the analysis results includes: Adjust the speed ratio between the engine and the generator.

10. The efficiency testing method of a vehicle hybrid electric drive assembly according to claim 1, characterized in that: The preset test condition is the CHTC condition.

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