Pure electric vehicle efficiency consistency online testing method
阅读说明：本技术 纯电动汽车效率一致性在线测试方法 (Pure electric vehicle efficiency consistency online testing method ) 是由 茅卫东 周俊锋 卢亚军 王成文 袁浩 奚新文 于 2019-11-20 设计创作，主要内容包括：本发明属于纯电动汽车效率测试技术领域,具体公开一种纯电动汽车效率一致性在线测试方法,包括如下步骤：计算待检测的纯电动汽车的理论效率信息；采集所述纯电动汽车在转毂设备上的本次测试效率信息；根据所述理论效率信息和所述本次测试效率信息比对效率的一致性。本发明所述的测试方法能够提升整车效率；能够检测系统传统效率是否有异常；并能够准确地判断电池放电效率。(The invention belongs to the technical field of efficiency testing of pure electric vehicles, and particularly discloses an online efficiency consistency testing method for a pure electric vehicle, which comprises the following steps: calculating theoretical efficiency information of the pure electric vehicle to be detected; collecting the current test efficiency information of the pure electric vehicle on hub rotating equipment; and comparing the consistency of the efficiency according to the theoretical efficiency information and the current test efficiency information. The test method can improve the efficiency of the whole vehicle; whether the traditional efficiency of the system is abnormal or not can be detected; and the battery discharge efficiency can be accurately judged.)
1. The method for testing the efficiency consistency of the pure electric vehicle on line is characterized by comprising the following steps:
step 1: calculating theoretical efficiency information of the pure electric vehicle to be detected;
step 2: collecting the current test efficiency information of the pure electric vehicle on hub rotating equipment;
and step 3: and comparing the consistency of the efficiency according to the theoretical efficiency information and the current test efficiency information.
2. The pure electric vehicle efficiency consistency online testing method according to claim 1, characterized in that in step 1, the theoretical efficiency information of the pure electric vehicle is calculated through the following steps:
step 1.1: establishing a model of the pure electric automobile;
step 1.2: customizing a cycle task of the pure electric vehicle and setting working condition parameters;
step 1.3: executing a simulation task and forming a change curve of the vehicle speed along with time and the running mileage of the entire vehicle in the NEDC cycle;
step 1.4: and obtaining theoretical efficiency information of the pure electric vehicle.
3. The pure electric vehicle efficiency consistency online testing method according to claim 2, characterized by comprising the following steps in step 2:
step 2.1: loading the pure electric vehicle onto the hub rotating equipment, and recording input and output currents of all sections of the pure electric vehicle;
step 2.2: connecting a current transformer to an input wire harness of a pure electric vehicle motor and the input wire harness;
step 2.3: connecting the current transformer with an oscilloscope;
step 2.4: and calculating the test efficiency information of the pure electric vehicle.
4. The pure electric vehicle efficiency consistency online testing method according to claim 3, characterized in that step 2 comprises: and collecting the vehicle information of the pure electric vehicle.
5. The pure electric vehicle efficiency consistency online testing method according to claim 4, characterized in that in step 2, the hub rotating equipment adopts a NEDC working condition.
6. The pure electric vehicle efficiency consistency online testing method according to claim 5, characterized in that in the step 2, the efficiency test comprises efficiency tests of an electric vehicle cycle condition curve, electric quantity consumption, braking electric quantity recovery, whole vehicle energy efficiency and driving range.
7. The pure electric vehicle efficiency consistency online testing method according to claim 6, wherein in the step 2, the vehicle information comprises a vehicle type VIN, kilometers, SOC or battery voltage, a rated power of a motor, an experimental environment temperature, a discharged time and an electric quantity sent to the electric vehicle of the pure electric vehicle.
Technical Field
The invention relates to the technical field of efficiency testing of pure electric vehicles, in particular to an online testing method for efficiency consistency of a pure electric vehicle.
Background
With the rapid development of national economy, the increase of the quantity of the residents of the pure electric vehicles is promoted. According to data display, the annual average growth rate of 2005-plus-2018 automobiles is 15.3%, however, the increase of the number of automobiles brings problems of petroleum energy reduction, environmental pollution, urban space congestion and the like, so that new energy automobiles, especially pure electric automobiles, are developed at a high speed, but the pure electric automobiles are not satisfactory all the time due to high cost and short endurance driving mileage. Therefore, the driving mileage of the electric automobile is improved, the whole automobile efficiency is improved, and the power battery is applied more efficiently, so that the electric automobile becomes an important development direction in the field of pure electric automobiles.
At present, the average efficiency of the whole new energy vehicle in China is only 64%, and the space is greatly improved.
Disclosure of Invention
In view of the above, the invention provides an online testing method for efficiency consistency of a pure electric vehicle, which can improve the efficiency consistency among all conversion systems of the pure electric vehicle, and enable the delivered complete vehicle to have higher energy conversion rate on the premise of not increasing the battery capacity so as to improve the endurance mileage of a new energy vehicle.
In order to achieve the purpose, the invention adopts the following technical scheme:
an online efficiency consistency testing method for a pure electric vehicle comprises the following steps:
step 1: calculating theoretical efficiency information of the pure electric vehicle to be detected;
step 2: collecting the current test efficiency information of the pure electric vehicle on hub rotating equipment;
and step 3: and comparing the consistency of the efficiency according to the theoretical efficiency information and the current test efficiency information.
Further, in
step 1.1: establishing a model of the pure electric automobile;
step 1.2: customizing a cycle task of the pure electric vehicle and setting working condition parameters;
step 1.3: executing a simulation task and forming a change curve of the vehicle speed along with time and the running mileage of the entire vehicle in the NEDC cycle;
step 1.4: and obtaining theoretical efficiency information of the pure electric vehicle.
Further,
step 2.1: loading the pure electric vehicle onto the hub rotating equipment, and recording input and output currents of all sections of the pure electric vehicle;
step 2.2: connecting a current transformer to an input wire harness of a pure electric vehicle motor and the input wire harness;
step 2.3: connecting the current transformer with an oscilloscope;
step 2.4: and calculating the test efficiency information of the pure electric vehicle.
Further,
Further, in
Further, in
Further, in
The invention has the beneficial effects that:
(1) the consistency information of the comparison efficiency between the theoretical efficiency information and the current test efficiency information is obtained, the whole vehicle which does not conform to the efficiency is returned to the factory, and the factory leaving efficiency is guaranteed to be better.
(2) The test efficiency and theoretical efficiency data can be comprehensively considered by combining the discharge history of the battery, the running condition of the new energy automobile and other information, and whether the traditional efficiency of the system is abnormal or not can be detected.
(3) According to the historical efficiency information of the vehicle type recorded by the rotating hub and the power analyzer equipment and the efficiency information of the current test of the vehicle type, the comparison coefficient for correction is obtained by utilizing the comparison between the efficiency curves, and the battery discharge efficiency is accurately judged.
Drawings
The above and other objects, features and advantages of the present disclosure will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings. The drawings described below are merely some embodiments of the present disclosure, and other drawings may be derived from those drawings by those of ordinary skill in the art without inventive effort.
FIG. 1 is a flow chart of a test method described in an embodiment of the invention;
FIG. 2 is a flow chart of efficiency transfer in an embodiment of the present invention;
FIG. 3 is a suburban cycle profile according to an embodiment of the present invention;
FIG. 4 is a velocity profile and tolerance for an embodiment of the invention.
Detailed Description
Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings.
While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art so that they can be readily implemented by those skilled in the art. As can be readily understood by those skilled in the art to which the present invention pertains, the embodiments to be described later may be modified into various forms without departing from the concept and scope of the present invention. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" include plural forms as well, unless the contrary is expressly stated. The term "comprising" as used in the specification embodies particular features, regions, constants, steps, actions, elements and/or components and does not exclude the presence or addition of other particular features, regions, constants, steps, actions, elements, components and/or groups.
All terms including technical and scientific terms used hereinafter have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms defined in dictionaries are to be interpreted as meanings complied with in the relevant technical documents and the present disclosure, and cannot be interpreted as having a very formal meaning without definition.
As shown in fig. 1, an online efficiency consistency testing method for a pure electric vehicle includes the following steps:
step 1: calculating theoretical efficiency information of the pure electric vehicle to be detected;
step 2: collecting the current test efficiency information of the pure electric vehicle on hub rotating equipment;
and step 3: and comparing the consistency of the efficiency according to the theoretical efficiency information and the current test efficiency information.
For example, taking an electric vehicle with a certain 150km driving range as an example, the theoretical efficiency of the electric vehicle is 85% in
It should be noted that, the experimental condition of the detection method of the present invention adopts the NEDC condition; acquiring the efficiency information of the pure electric vehicle tested at this time by adopting hub rotating equipment, carrying out an experiment by adopting a working condition shown in fig. 3, and according to the tolerance requirement specified in fig. 4, taking 1 as a reference curve, 2 as a speed tolerance and 3 as a time tolerance in fig. 4; and recording the endurance mileage, the maximum speed, the form time and the average speed in the working condition test process.
Setting the temperature in a hub rotating laboratory to be 25 ℃ (0 ℃ and-15 ℃) and standing for more than or equal to 4 hours, starting a test after the temperature of the whole vehicle and the ambient temperature are kept, simultaneously recording the current speed of the tested vehicle through the hub rotating and oscilloscope control software, immediately pushing the vehicle to a charging position for charging after the test is finished, and recording the capacity (kWh) of a power grid.
In this embodiment, the capacity of the grid is the capacity of the battery for storing the total amount of electric energy input into the pure electric vehicle by the grid.
The vehicle road sliding resistance (1) is obtained as follows:
F＝Av2+Bv+C……(1)，
wherein F is the resistance (N), V is the vehicle speed (km/h), A and B are: road load coefficient, C is the air resistance coefficient.
Since the speed of the vehicle before and after running is zero (i.e. in a stationary state), it can be derived from the kinetic energy theorem that the work done by the driving force during the running of the vehicle on the road is the same as the work done by the resistance force on the vehicle, and therefore the work done by the road resistance force of the vehicle is considered to be the useful work consumed by the vehicle during the running on the road.
The work done by the road resistance of the vehicle is only related to the vehicle speed as can be seen by the formula (1), so the work done by the vehicle in the driving process can be obtained by the formula (2):
wherein W is useful work (J) output, F is resistance (N), and V is velocity (m/s).
The overall vehicle efficiency of the vehicle is obtained by formula (3):
η the drive and transmission efficiency is the drive and transmission efficiency, W is the output useful work (J), and W is the grid power (kWh).
In the embodiment, the driving mileage of the electric vehicle at different temperatures is as follows:
temperature (. degree.C.)
25
0
-10
Endurance mileage (km)
170
140
131
TABLE 1
The discharge characteristics of the power battery at different temperatures are greatly different. For a commonly used lithium battery, the normal operating temperature range is 0-60 ℃. At lower temperatures, such as-40 ℃, the discharge capacity of the monomer is only about 12% at room temperature (20 ℃), and the rate of current generation due to battery chemical reactions is much slower than at room temperature. When this chemical counter-strain becomes very slow, the battery will feed.
The results of the test of the efficiency of the whole vehicle are as follows:
test conditions
Mileage of endurance
Travel time
Output useful work
From the grid
Efficiency of the whole vehicle
NEDC operating mode
170km
5h11min
6.5×107J
28.4kWh
63.9％
TABLE 2
Specifically, in
step 1.1: establishing a model of the pure electric vehicle through Amesim simulation software;
step 1.2: customizing a cycle task of the pure electric vehicle and setting working condition parameters;
step 1.3: and executing a simulation task through the Amesim simulation software and forming a change curve of the vehicle speed along with time and the running mileage of the entire vehicle in the NEDC cycle.
The step of calculating the efficiency information of the pure electric vehicle to be detected through the Amesim simulation software specifically comprises the following steps:
s1: starting Amesim software, clicking a shortcut icon of the Amesim software on a desktop on a PC (personal computer) pre-installed with the Amesim software, so that two windows appear, namely an Amesim help window, an Amesim interface window and a Cruise window, clicking a start button in the Cruise window, starting the Amesim software, and appearing an LMS Amesim window;
s2: establishing a project name, clicking a new command under a File menu in the current interface of an Amesim window, inputting an English name (equivalent to a folder name, taking Amesim test1 as an example) of a project to be established, and clicking an ok button;
s3: the method comprises the steps of establishing a vehicle model, clicking a Sketch mode on the left side of an interface, then selecting an IFPDRIVE icon in a library windows on the right side, and then selecting an ALL folder to generate each icon required for modeling; finally, dragging the needed modules to the left blank in sequence, and connecting the modules;
s4: customizing a cycle task, clicking a parameter mode in a left window of Amesim, clicking a missionsrofile module, setting parameters required to be set under a Title on the right side, selecting NEDC (next direct current) under a cycle working condition, selecting automatic gearbox type, and finishing the setting of the cycle task;
s5: executing simulation, clicking a simulation mode on the left side of the interface, and then clicking a start execution on the next interface, and starting to run the simulation;
s6: and (4) data post-processing, namely clicking a close button after executing a calculation task, clicking a vehicle related module in the model, generating a simulation result on the right side, dragging a certain result into a model window, and generating a curve graph drawn by simulation detailed simulation data.
In S6 of the present embodiment, the graph includes curves of time, driving conditions, and efficiency, and theoretical efficiency information of the pure electric vehicle is obtained through the graph.
Specifically, the
step 2.1: loading the pure electric vehicle onto the hub equipment, and recording input and output currents of all sections of the pure electric vehicle through a current transformer;
step 2.2: connecting a current transformer to input and output wire harnesses of a pure electric vehicle motor, and detecting the change of input and output electric quantity through the current transformer to detect the efficiency value of each section;
step 2.3: connecting the current transformer with an oscilloscope, wherein the oscilloscope can read the input and output electric quantity change;
step 2.4: and calculating the test efficiency information of the pure electric vehicle.
Specifically,
Specifically, in
Specifically, in
As shown in fig. 2, a flow chart of efficiency transfer of a pure electric vehicle is provided, and when analyzing the overall efficiency of the electric vehicle, the transfer efficiency of each link is designed, and an efficiency (i.e., theoretical efficiency information) algorithm of an electric component is described below with reference to the overall energy flow chart.
① Power Battery System efficiency:
the efficiency of the power battery system is mainly the charging and discharging efficiency, namely the ratio of the discharged current to the charged current, which can be measured and calculated by a power analysis instrument, and the efficiency formula (4) is obtained by:
wherein η power battery is power battery efficiency, W power battery output power is power battery total discharge power (kWh), W power battery charge capacity is power battery charge capacity (kWh) charged to the electric power battery.
② efficiency of vehicle charger:
the input and output ends of the vehicle-mounted charger can be measured and calculated by a power analysis instrument, and the efficiency of the vehicle-mounted charger is obtained by the formula (5):
wherein η is the efficiency of the charger, and W is the electric quantity (kWh) at the output end of the charger.
③ drive motor system efficiency:
the driving motor system comprises a motor controller and a driving motor, and the motor controller and the driving motor are integrated when the system efficiency is calculated, namely, the direct current input electric quantity of the motor controller is input, and the mechanical energy output by the driving motor is output.
Short electric energy input by the driving motor system can be obtained through measurement and technology of a power analyzer;
the mechanical energy at the output end of the driving motor system cannot be directly measured in the whole vehicle state at present, and can be measured and calculated in advance through a special motor efficiency test bench;
the efficiency of the drive motor system can be obtained from equation (6):
η the driving motor system has driving motor system efficiency, W output mechanical work is the electric quantity (J) of the output end of the driving motor system, and W motor input electric quantity is the driving motor system input electric quantity (kWh).
The efficiency of the power consumption part is the product of the efficiency of the power battery system, the efficiency of the vehicle-mounted charger and the efficiency of the driving motor system.
The whole vehicle efficiency flow chart shows that:
to improve the efficiency of the pure electric vehicle, the efficiency of a part in each link needs to be improved, including the secondary discharge efficiency of the power battery, the efficiency of the charger, the efficiency of the driving motor system, the mechanical efficiency of the variable counter system, the resistance of the tire, and the like.
Thus, it should be appreciated by those skilled in the art that while a number of exemplary embodiments of the invention have been illustrated and described in detail herein, many other variations or modifications consistent with the principles of the invention may be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the invention. Accordingly, the scope of the invention should be understood and interpreted to cover all such other variations or modifications.
In the description provided herein, numerous specific details are set forth. It is understood, however, that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.
Similarly, it should be appreciated that in the foregoing description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. However, the disclosed method should not be interpreted as reflecting an intention that: that the invention as claimed requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.
Furthermore, those skilled in the art will appreciate that while some embodiments described herein include some features included in other embodiments, rather than other features, combinations of features of different embodiments are meant to be within the scope of the invention and form different embodiments. For example, in the claims, any of the claimed embodiments may be used in any combination.
Thus, it should be appreciated by those skilled in the art that while a number of exemplary embodiments of the invention have been illustrated and described in detail herein, many other variations or modifications consistent with the principles of the invention may be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the invention. Accordingly, the scope of the invention should be understood and interpreted to cover all such other variations or modifications.