Rapid detection method for economic performance of new energy vehicles

Abstract

The method for rapid detection of economic performance of new energy vehicles includes the construction of vehicle driving conditions, the collection of total voltage, total current and SOC information of vehicle power batteries, the calculation of vehicle loading drive / braking force, the calculation of energy consumption rate, driving range and braking energy recovery efficiency, normalization processing, obtaining a comprehensive evaluation coefficient of economic performance and steps for determining the economic performance of the tested vehicle. Compared with existing standards, the method significantly shortens the test time and realizes rapid testing of economic performance of new energy vehicles. It does not require the installation of any sensors or the acquisition of external power grid data, and directly uses a collection terminal to obtain vehicle information for real-time detection and determine economic performance. It is convenient, efficient and easy to operate. It solves the problems of complicated testing standards and expensive testing equipment faced by the economic performance testing of the new energy vehicle industry, and promotes the stable and sustainable development of the new energy vehicle industry.

Description

Technical Field

[0001] The invention relates to the technical field of vehicle detection, and specifically provides a method for quickly detecting the economic performance of a new energy vehicle. Background Art

[0002] Economic performance testing mainly involves energy consumption rate and driving range. The economic performance test methods specified in the new energy vehicle economic test standards (SAEJ1634 "Energy Consumption and Mileage Test Procedure for Pure Electric Vehicles", SAE J1711 "Recommended Practice for Fuel Economy and Emission Pollution Testing of Hybrid Electric Vehicles", EN 1821-1 "Measurement of Operating Performance of Electric Road Vehicles", JEVS Z111 "Standard Energy Consumption Test Method for Electric Vehicles", GB / T 28382-2012 "Technical Conditions for Pure Electric Passenger Vehicles", GB / T 18386-2017 "Energy Consumption and Driving Range Test Method for Electric Vehicles", GB / T 18386.1-2021 "Energy Consumption and Driving Range Test Method for Electric Vehicles Part 1: Light Vehicles") generally have problems such as complex test content and process, high test cost, and long test cycle. In addition, the applicability of the test conditions used in the above standards to new energy vehicles needs to be improved, and cannot meet the needs of rapid performance testing of new energy vehicles.

[0003] At present, the constant speed driving range announced by many manufacturers and the driving range calculated by the Ministry of Industry and Information Technology according to the NEDC working condition standard are far from the actual driving range of new energy vehicles under complex working conditions, further increasing the gap between the expected and actual driving range. In addition, the driving range test cycle is too long, the test preparation conditions are harsh, and the long test cycle and complex process will cause irreversible life damage to the power battery. Energy consumption, driving range and brake energy feedback change with the specific changes of the performance of key components of new energy vehicles in use after the decline of performance. The lack of effective rapid detection methods makes it difficult to test the economic performance of new energy vehicles. Summary of the invention

[0004] In order to solve the technical problems existing in the above-mentioned background technology, the present invention provides a method for quickly detecting the economic performance of new energy vehicles.

[0005] The technical solution of the present invention is as follows:

[0006] The rapid detection method of the economic performance of new energy vehicles includes the following steps:

[0007] S1. According to the type of vehicle to be detected, a simplified vehicle driving condition of time t and speed v is constructed, and the time t satisfies:

[0008] t≤200s;

[0009] S2. Place the vehicle to be tested on the vehicle performance test bench and connect it to a data acquisition terminal device based on CAN bus communication to obtain the total voltage, total current and SOC information of the vehicle power battery through the acquisition terminal device;

[0010] S3. Based on the constructed vehicle driving conditions, the vehicle performance test bench uses an AC electric dynamometer to load the driving / braking force F on the vehicle under test. t ;

[0011] S4, calculating the energy consumption rate C, driving range D and braking energy recovery efficiency η of the vehicle;

[0012] S4.1. Based on the constructed vehicle driving conditions, after the test, calculate the energy consumption rate C:

[0013]

[0014] Where: the unit of energy consumption rate C is Wh / km, t1 is the start time of the vehicle driving condition, the unit is s, t2 is the end time of the vehicle driving condition, the unit is s, U e is the rated voltage of the battery pack, in V, I is the battery pack terminal current when the vehicle is running, in A, D s is the distance traveled by the car corresponding to the vehicle driving condition, in km, K SOC and K T They are the correction coefficients for considering the battery pack SOC range and ambient temperature factors during rapid detection;

[0015] S4.2. Based on the constructed vehicle driving conditions, after the test, calculate the driving range D:

[0016]

[0017] Where: D is the driving range, in km, Δ SOC is the change of SOC corresponding to the vehicle driving condition, in %, f(SOC) and f(T) are the correction factors considering the battery pack SOC range and ambient temperature in the fast detection;

[0018] S4.3. Based on the constructed vehicle driving conditions, after the test, calculate the braking energy recovery efficiency, which is the recovered braking energy / maximum theoretical braking energy:

[0019]

[0020] Where: n is a positive integer, indicating the number of deceleration sections in the vehicle driving condition, t i is the test time of the i-th deceleration process, in seconds, U i is the battery terminal voltage during the i-th deceleration process, in V, Ii is the battery pack terminal current during the i-th deceleration process, in A, m is the vehicle reference mass, in kg, V i1 and V i2 are the starting speed and ending speed of the i-th deceleration process, respectively, in km / h, and V i1 >V i2 , V i is the real-time vehicle speed during the i-th deceleration process, in km / h, F if is the friction loss force of the test bench during the i-th deceleration process, in N, C SOC , C I They are the correction coefficients for the battery pack SOC range and energy feedback current influencing factors considered during rapid detection;

[0021] S5, normalizing the energy consumption rate C and the driving range data D, and converting the dimensional expressions C and D into dimensionless expressions;

[0022] S6, the normalized energy consumption rate C norm , Driving range D norm The comprehensive evaluation coefficient of economic performance C is obtained by weighted calculation of the braking energy recovery efficiency. e ;

[0023] S7, based on the comprehensive evaluation coefficient of economic performance C e Determine the economic performance of the vehicle under test.

[0024] In the method for rapid detection of economic performance of new energy vehicles as described above, in the S1 step, the vehicle driving condition is a NEDC cycle condition (applicable to M1, N1, and M2 vehicles with a maximum design gross mass not exceeding 3500kg) or a C-WTVC cycle condition (applicable to vehicles other than M1, N1, and M2 vehicles with a maximum design gross mass not exceeding 3500kg).

[0025] In the above-mentioned method for rapid detection of economic performance of new energy vehicles, in step S3, the specific calculation method is:

[0026] S3.1. Calculate the energy ΔE that needs to be compensated by loading the driving / braking force at time t compared with the actual road test resistance of the vehicle under test. t :

[0027]

[0028] Where: V t is the speed of the car, in km / h, m is the mass of the car being tested, J D is the moment of inertia of the vehicle performance test bench after matching the flywheel assembly, r is the roller radius of the vehicle performance test bench, a tis the acceleration of the car at time t;

[0029] S3.2: Calculate the compensation ΔE t The driving / braking force ΔF required to be applied by the AC electric dynamometer:

[0030]

[0031] S3.3. Calculate the driving / braking force F applied to the vehicle under test by the AC dynamometer t :

[0032]

[0033] Where: G is the vehicle's gravity, in N, f is the rolling resistance coefficient, C D is the air resistance coefficient, A is the windward area, the unit is m 2 , f0 is the fixed loss of the vehicle performance test bench, f1 is the linear loss coefficient, f2 is the quadratic loss coefficient, and f3 is the cubic loss coefficient.

[0034] In the above-mentioned method for rapid detection of economic performance of new energy vehicles, in step S4.1, K SOC The calculation method is:

[0035] K SOC =0.96142+0.0022·P SOC -4.27637 10 -5 ·P SOC 2 +3.02787 10 -7 ·P SOC 3

[0036] Where: SOC takes the average value of the SOC interval during the entire test process, and P SOC Indicated by %, the unit is %;

[0037] K T The calculation method is:

[0038] K T =0.92027+0.00996·T-3.87264·10 -4 ·T 2 +5.2562·10 -6 ·T 3

[0039] Where: T is the ambient temperature, in °C.

[0040] After the above step S4.1 is completed, in the step S4.2, f(SOC) is used The multiplication factor fPSOC Expressed as, or, using the compensation amount f of the driving range DSOC To express, and when using f DSOC When f DSOC The specific value is determined by the battery pack manufacturer, and / or, model, and / or, capacity, and / or, batch;

[0041] When using f PSOC When f PSOC The calculation method is:

[0042] f PSOC =(1.00283-5.6197·10 -4 ·P SOC +2.04545·10 -6 ·P SOC 2 )-1

[0043] at this time:

[0044]

[0045] Furthermore, in the step S4.2, f(T) is expressed as The multiplication factor f PT Expressed as, or, using the compensation amount f of the driving range DT Indicates that, and when using f DT When f DT The specific value is determined by the battery pack manufacturer, and / or, model, and / or, capacity, and / or, batch;

[0046] When using f PT When f PT The calculation method is:

[0047] f PT =1-(0.92027+0.00996·T-3.87264·10 -4 ·T 2 +5.2562·10 -6 ·T 3 )

[0048] Where: T is the ambient temperature, in °C;

[0049] at this time:

[0050]

[0051] In step S4.3, F if The calculation method is:

[0052]

[0053] Furthermore, in step S4.3, C SOC The calculation method is:

[0054] C SOC =1.09838-0.02071·P SOC +4.02482 10 -4 ·P SOC 2 ·-2.84976·10 -6 ·P SOC 3

[0055] Where: SOC takes the average value of the SOC interval during the entire test process, and P SOC Indicated by %, the unit is %;

[0056] C I The calculation method is:

[0057] C I =0.99413-0.09531·I C -0.00922·I C 2

[0058] Where: I C Take the average value of the energy feedback current during the entire test process and express it as a multiple of the rated capacity of the battery pack.

[0059] In the above-mentioned method for rapid detection of economic performance of new energy vehicles, in step S5, the normalized formula of energy consumption rate C is:

[0060]

[0061] Where: C N The power consumption per 100 kilometers announced by the tested vehicle, in kWh / 100km;

[0062] The normalized formula for the driving range D is:

[0063]

[0064] Where: D N It is the NEDC pure electric range announced by the tested vehicle, in km.

[0065] In the above-mentioned method for rapid detection of economic performance of new energy vehicles, in step S6, the energy consumption rate C norm The weight W1 ranges from 0.3 to 0.45, and the driving range D normThe weight W2 is 0.3 to 0.45, the braking energy recovery efficiency weight W3 is 0.1 to 0.3, and the weights satisfy:

[0066] 0.7≤W1+W2≤0.9, W1+W2+W3=1.0;

[0067] at this time:

[0068] C e =C norm ·W1+D norm ·W2+η·W3.

[0069] The beneficial effects of the present invention are as follows: (1) Compared with the existing standards, the vehicle energy consumption and driving range detection method provided by the present invention needs to be tested from the time when the power battery is fully charged to the time when it is fully discharged, which results in a long test cycle and harsh test preparation conditions. The test conditions of the present application only take 200 seconds at most, including the preparation time, and the entire economic performance test takes less than 5 minutes, thus realizing the rapid test of the economic performance of new energy vehicles;

[0070] (2) Compared with the existing detection methods, the method for rapid detection of economic performance of new energy vehicles provided by the present invention does not require the installation of any sensors or the acquisition of external power grid data. Instead, the method directly uses the acquisition terminal to obtain vehicle information for real-time detection and determines economic performance. It is convenient, efficient, and easy to operate in practice.

[0071] (3) The method for rapid detection of the economic performance of new energy vehicles of the present invention is based on the vehicle performance test bench, and proposes a rapid detection and calculation method for the energy consumption rate, driving range and braking energy recovery efficiency that reflect the economic performance of new energy vehicles. At the same time, a method for correcting the detection results by the battery pack SOC, ambient temperature and energy feedback current factors during rapid detection is proposed to improve the accuracy of the detection of the economic performance of new energy vehicles;

[0072] (4) The method for rapid detection of economic performance of new energy vehicles provided by the present invention obtains a comprehensive evaluation coefficient of economic performance based on weighted calculation when determining economic performance, and determines economic performance according to the value of the comprehensive evaluation coefficient. The method for rapid detection of economic performance of the present application solves the problems of complicated detection standards and expensive detection equipment faced by the new energy vehicle industry in economic performance detection, and promotes the stable and sustainable development of the new energy vehicle industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] By reading the detailed description of the preferred embodiment below, the scheme and advantages of the present application will become clear to those skilled in the art. The accompanying drawings are only for the purpose of illustrating the preferred embodiment and are not to be considered as limiting the present invention.

[0074] In the attached picture:

[0075] Figure 1 It is a structural schematic diagram of a vehicle performance test bench in an embodiment;

[0076] Figure 2 It is a simplified schematic diagram of NEDC cycle operating conditions in the embodiment;

[0077] Figure 3 It is a simplified schematic diagram of C-WTVC cycle operation in the embodiment;

[0078] Figure 4 The relationship between the vehicle speed, loading force, battery pack voltage and battery pack current and time t in the actual vehicle test of the test vehicle in the embodiment is as follows:

[0079] The components represented by the reference numerals in the figure are:

[0080] 1. Front roller group frame; 2. Roller group; 3. T-type reducer; 4. Retractable transmission shaft; 5. Rear roller group frame; 6. Mechanical flywheel; 7. Main and auxiliary roller synchronous chain; 8. AC electric dynamometer; 9. Moving guide rail; 10. Axle weight meter; 11. Speed ​​torque sensor. DETAILED DESCRIPTION

[0081] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings.

[0082] Example

[0083] This embodiment provides a method for quickly detecting the economic performance of new energy vehicles. Figure 1 The detection method is based on a vehicle performance test bench, which includes a front roller group frame 1, a roller group 2, a T-type reducer 3, a retractable transmission shaft 4, a rear roller group frame 5, a mechanical flywheel 6, a main and auxiliary roller synchronous chain 7, an AC power dynamometer 8, a mobile guide rail 9, an axle load meter 10 and a speed torque sensor 11. Its specific structure is the same as that of the existing test bench, and no redundant elaboration is made here. The detection method specifically includes the following steps:

[0084] S1. According to the type of vehicle to be detected, a simplified vehicle driving condition of time t and speed v is constructed, and the time t satisfies:

[0085] t≤200s;

[0086] Specifically, the vehicle driving condition is a NEDC cycle condition (applicable to M1, N1, and M2 vehicles with a maximum design total mass not exceeding 3500kg) or a C-WTVC cycle condition (applicable to vehicles other than M1, N1, and M2 vehicles with a maximum design total mass not exceeding 3500kg). The simplified NEDC cycle condition is as follows: Figure 2As shown, the simplified C-WTVC cycle condition is as follows Figure 3 As shown, the vehicle driving condition adopts the simplified NEDC cycle condition or C-WTVC cycle condition, which meets the requirements of the rapid test of new energy vehicles in this application. The test condition takes only 200 seconds at most, including the preparation time, and the entire economic performance test takes less than 5 minutes, realizing the rapid test of the economic performance of new energy vehicles;

[0087] S2. Place the vehicle to be tested on the vehicle performance test bench and connect it to the data acquisition terminal device based on CAN bus communication. According to the national standard "GB / T 32960.3-2016 Technical Specifications for Electric Vehicle Remote Service and Management System Part 3: Communication Protocol and Data Format", obtain the total voltage, total current and SOC information of the vehicle power battery through the acquisition terminal device;

[0088] S3. Based on the constructed vehicle driving conditions, the vehicle performance test bench uses an AC electric dynamometer to load the driving / braking force F on the vehicle under test. t , specifically:

[0089] S3.1. Calculate the energy ΔE that needs to be compensated by loading the driving / braking force at time t compared with the actual road test resistance of the vehicle under test. t :

[0090]

[0091] Where: V t is the speed of the car, in km / h, m is the mass of the car being tested, J D is the moment of inertia of the vehicle performance test bench after matching the flywheel assembly, r is the roller radius of the vehicle performance test bench, a t is the acceleration of the car at time t;

[0092] S3.2: Calculate the compensation ΔE t The driving / braking force ΔF required to be applied by the AC electric dynamometer:

[0093]

[0094] S3.3. Calculate the driving / braking force F applied to the vehicle under test by the AC dynamometer t :

[0095]

[0096] Where: G is the vehicle's gravity, in N, f is the rolling resistance coefficient, C D is the air resistance coefficient, A is the windward area, the unit is m 2, f0 is the fixed loss of the vehicle performance test bench, f1 is the linear loss coefficient, f2 is the quadratic loss coefficient, and f3 is the cubic loss coefficient;

[0097] S4, calculating the energy consumption rate C, driving range D and braking energy recovery efficiency η of the vehicle;

[0098] S4.1. Based on the constructed vehicle driving conditions, after the test, calculate the energy consumption rate C:

[0099]

[0100] Where: the unit of energy consumption rate C is Wh / km, t1 is the start time of the vehicle driving condition, the unit is s, t2 is the end time of the vehicle driving condition, the unit is s, U e is the rated voltage of the battery pack, in V, I is the battery pack terminal current when the vehicle is running, in A, D s is the distance traveled by the car corresponding to the vehicle driving condition, in km, K SOC and K T They are the correction coefficients for considering the battery pack SOC range and ambient temperature factors during rapid detection;

[0101] Among them, K SOC The calculation method is:

[0102] K SOC =0.96142+0.0022·P SOC -4.27637 10 -5 ·P SOC 2 +3.02787 10 -7 ·P SOC 3

[0103] Where: SOC takes the average value of the SOC interval during the entire test process, and P SOC Indicated by %, the unit is %;

[0104] K T The calculation method is:

[0105] K T =0.92027+0.00996·T-3.87264·10 -4 ·T 2 +5.2562·10 -6 ·T 3

[0106] Where: T is the ambient temperature, in °C;

[0107] S4.2. Based on the constructed vehicle driving conditions, after the test, calculate the driving range D:

[0108]

[0109] Where: D is the driving range, in km, Δ SOC is the change of SOC corresponding to the vehicle driving condition, in %, f(SOC) and f(T) are the correction factors considering the battery pack SOC range and ambient temperature in the fast detection;

[0110] Among them, f(SOC) is used The multiplication factor f PSOC Expressed as, or, using the compensation amount f of the driving range DSOC To express, and when using f DSOC When f DSOC The specific value is determined by the battery pack manufacturer, and / or, model, and / or, capacity, and / or, batch. If the battery pack manufacturer, model, capacity, and batch are different, f DSOC It has a unique value, which is determined by the manufacturer, model, capacity, and batch of the battery pack, and no further explanation is given here;

[0111] When using f PSOC When f PSOC The calculation method is:

[0112] f PSOC =(1.00283-5.6197·10 -4 ·P SOC +2.04545·10 -6 ·P SOC 2 )-1

[0113] at this time:

[0114]

[0115] f(T) The multiplication factor f PT Expressed as, or, using the compensation amount f of the driving range DT Indicates that, and when using f DT When f DT The specific value is determined by the battery pack manufacturer, and / or, model, and / or, capacity, and / or, batch. If the battery pack manufacturer, model, capacity, and batch are different, f DT It has a unique value, which is determined by the manufacturer, model, capacity, and batch of the battery pack, and no further explanation is given here;

[0116] When using f PT When fPT The calculation method is:

[0117] f PT =1-(0.92027+0.00996·T-3.87264·10 -4 ·T 2 +5.2562·10 -6 ·T 3 )

[0118] Where: T is the ambient temperature, in °C;

[0119] at this time:

[0120]

[0121] S4.3. Based on the constructed vehicle driving conditions, after the test, calculate the braking energy recovery efficiency, which is the recovered braking energy / maximum theoretical braking energy:

[0122]

[0123] Where: n is a positive integer, indicating the number of deceleration sections in the vehicle driving condition, t i is the test time of the i-th deceleration process, in seconds, U i is the battery terminal voltage during the i-th deceleration process, in V, I i is the battery pack terminal current during the i-th deceleration process, in A, m is the vehicle reference mass, in kg, V i1 and V i2 are the starting speed and ending speed of the i-th deceleration process, respectively, in km / h, and V i1 >V i2 , V i is the real-time vehicle speed during the i-th deceleration process, in km / h, F if is the friction loss force of the test bench during the i-th deceleration process, in N, C SOC , C I They are the correction coefficients for the battery pack SOC range and energy feedback current influencing factors considered during rapid detection;

[0124] Among them, F if The calculation method is:

[0125]

[0126] C SOC The calculation method is:

[0127] C SOC =1.09838-0.02071·P SOC +4.02482 10-4 ·P SOC 2 -2.84976 10 -6 ·P SOC 3

[0128] Where: SOC takes the average value of the SOC interval during the entire test process, and P SOC Indicated by %, the unit is %;

[0129] C I =0.99413-0.09531·I C -0.00922·I C 2

[0130] Where: I C Take the average value of the energy feedback current during the entire test process and express it as a multiple of the rated capacity of the battery pack. For example, for a 100Ah battery pack, 0.9 means 0.9*100=90A.

[0131] S5. Based on the power consumption per 100 kilometers and NEDC pure electric cruising range data announced by the tested vehicle, the energy consumption rate C and the cruising range data D are normalized, and the dimensioned expressions C and D are converted into dimensionless expressions with a value of about 1;

[0132] Among them, the normalized formula of energy consumption rate C is:

[0133]

[0134] Where: C N The power consumption per 100 kilometers announced by the tested vehicle, in kWh / 100km;

[0135] The normalized formula for the driving range D is:

[0136]

[0137] Where: D N NEDC pure electric range announced by the tested vehicle, in km

[0138] S6, the normalized energy consumption rate C norm , Driving range D norm The comprehensive evaluation coefficient of economic performance C is obtained by weighted calculation of the braking energy recovery efficiency. e ;

[0139] Considering the strong correlation between energy consumption rate and driving range, the weights are reasonably distributed according to the importance of energy consumption rate, driving range and braking energy recovery efficiency to economic performance, among which the energy consumption rate C normThe weight W1 ranges from 0.3 to 0.45, and the driving range D norm The weight W2 is 0.3 to 0.45, the braking energy recovery efficiency weight W3 is 0.1 to 0.3, and the weights satisfy:

[0140] 0.7≤W1+W2≤0.9, W1+W2+W3=1.0;

[0141] at this time:

[0142] C e =C norm ·W1+D norm ·W2+η·W3

[0143] S7, based on the comprehensive evaluation coefficient of economic performance C e Determine the economic performance of the vehicle under test;

[0144] If C e ≥0.8, the vehicle's economic performance is considered to be intact;

[0145] If 0.6≤C e <0.8, the vehicle's economic performance is basically intact;

[0146] If 0.4≤C e <0.6, the vehicle is judged to need repair;

[0147] If C e <0.4, the vehicle should be stopped or the battery pack should be replaced.

[0148] The feasibility of the technical solution of the present application has been verified after multiple experiments. This embodiment provides the test data of one of the experiments, which are as follows.

[0149] In this experiment, the M1 vehicle was selected for the actual vehicle test. The reference mass was 1182kg, the rated voltage of the battery pack was 192V, and the battery pack capacity was 100Ah. The relationship between the vehicle speed, loading force, battery pack voltage and battery pack current and time t was shown in the figure. Figure 4 shown.

[0150] The SOC of this experiment was 72.37% at the beginning and 71.80% at the end, with an average value of 72.09%. The ambient temperature was 10°C, and the overall experimental process included:

[0151] (1) Calculation of energy consumption rate of new energy vehicles:

[0152] Calculate K SOC =1.011, K T =0.986;

[0153] at this time:

[0154]

[0155] (2) Calculation of driving range of new energy vehicles:

[0156] Calculate f PSOC =-0.027, f PT =0.014;

[0157] at this time:

[0158]

[0159] (3) Calculation of energy recovery efficiency of energy feedback braking of new energy vehicles:

[0160] C SOC =0.629;

[0161] The deceleration section of the test condition of this experiment is: 23s~28s, the starting speed and the ending speed of the deceleration process are 15km / h and 0km / h respectively; 85s~96s, the starting speed and the ending speed of the deceleration process are 32km / h and 0km / h respectively; 155s~163s, the starting speed and the ending speed of the deceleration process are 50km / h and 35km / h respectively; 176s~188s, the starting speed and the ending speed of the deceleration process are 35km / h and 0km / h respectively;

[0162] At the same time, the average value of the energy feedback current during the entire test process is expressed as a multiple of the rated capacity of the battery pack, I C =0.03, C I =0.991;

[0163] at this time:

[0164]

[0165] (4) Normalization processing:

[0166] The NEDC pure electric range is 220km, and the power consumption per 100km is 8.9kWh.

[0167] calculate

[0168] (5) Weighted calculation of comprehensive evaluation coefficient of economic performance:

[0169] Take W1 = 0.4; W2 = 0.4; W3 = 0.2;

[0170] at this time:

[0171] C e =0.858·0.4+0.83·0.4+0.295·0.2=0.734

[0172] It can be seen that 0.6≤C e <0.8, the vehicle’s economic performance is judged to be basically intact, and the judgment result is consistent with the vehicle’s actual performance.

[0173] The economic performance of new energy vehicles can be tested by the above method, which takes only 200 seconds at most, including preparation time, and the entire economic performance test takes less than 5 minutes, thus realizing the rapid test of the economic performance of new energy vehicles. During the test, no sensors need to be installed, and no external power grid data needs to be obtained. The vehicle information can be directly obtained by the acquisition terminal for real-time detection to determine the economic performance, which is convenient, efficient and easy to operate in practice. A rapid detection and calculation method for the energy consumption rate, driving range and braking energy recovery efficiency reflecting the economic performance of new energy vehicles is proposed, and a correction method for the detection results of the battery pack SOC, ambient temperature and energy feedback current factors during rapid detection is proposed to improve the accuracy of the economic performance detection of new energy vehicles. The problems of complicated testing standards and expensive testing equipment faced by the economic performance detection of the new energy vehicle industry are solved, and the stable and sustainable development of the new energy vehicle industry is promoted.

Claims

1. A rapid detection method for the economic performance of new energy vehicles, characterized in that: The steps include: S1. According to the type of vehicle to be detected, a simplified vehicle driving condition of time t and speed v is constructed, and the time t satisfies: t≤200s; S2. Place the vehicle to be tested on the vehicle performance test bench and connect it to a data acquisition terminal device based on CAN bus communication to obtain the total voltage, total current and SOC information of the vehicle power battery through the acquisition terminal device; S3. Based on the constructed vehicle driving conditions, the vehicle performance test bench uses an AC electric dynamometer to load the driving / braking force F on the vehicle under test. t ; S4, calculating the energy consumption rate C, driving range D and braking energy recovery efficiency η of the vehicle; S4.

1. Based on the constructed vehicle driving conditions, after the test, calculate the energy consumption rate C: Where: the unit of energy consumption rate C is Wh / km, t1 is the start time of the vehicle driving condition, the unit is s, t2 is the end time of the vehicle driving condition, the unit is s, U e is the rated voltage of the battery pack, in V, I is the battery pack terminal current when the vehicle is running, in A, D s is the distance traveled by the car corresponding to the vehicle driving condition, in km, K SOC and K T They are the correction coefficients for considering the battery pack SOC range and ambient temperature factors during rapid detection; S4.

2. Based on the constructed vehicle driving conditions, after the test, calculate the driving range D: Where: D is the driving range, in km, Δ SOC is the change of SOC corresponding to the vehicle driving condition, in %, f(SOC) and f(T) are the correction factors considering the battery pack SOC range and ambient temperature in the fast detection; S4.

3. Based on the constructed vehicle driving conditions, after the test, calculate the braking energy recovery efficiency, which is the recovered braking energy / maximum theoretical braking energy: Where n is a positive integer, indicating the number of deceleration sections in the vehicle driving condition, t i is the test time of the i-th deceleration process, in seconds, U i is the battery terminal voltage during the i-th deceleration process, in V, I i is the battery pack terminal current during the i-th deceleration process, in A, m is the vehicle reference mass, in kg, V i1 and V i2 are the starting speed and ending speed of the i-th deceleration process, respectively, in km / h, and V i1 >V i2 , V i is the real-time vehicle speed during the i-th deceleration process, in km / h, F if is the friction loss force of the test bench during the i-th deceleration process, in N, C SOC , C I They are the correction coefficients for the battery pack SOC range and energy feedback current influencing factors considered during rapid detection; S5, normalizing the energy consumption rate C and the driving range data D, and converting the dimensional expressions C and D into dimensionless expressions; S6, the normalized energy consumption rate C norm , Driving range D norm The comprehensive evaluation coefficient of economic performance C is obtained by weighted calculation of the braking energy recovery efficiency. e ; S7, based on the comprehensive evaluation coefficient of economic performance C e Determine the economic performance of the vehicle under test.

2. The method for rapid detection of economic performance of new energy vehicles according to claim 1, characterized in that: In the step S1, the vehicle driving condition is a NEDC cycle condition or a C-WTVC cycle condition.

3. The method for rapid detection of economic performance of new energy vehicles according to claim 2 is characterized in that: In the step S3, the specific calculation method is: S3.

1. Calculate the energy ΔE that needs to be compensated by loading the driving / braking force at time t compared with the actual road test resistance of the vehicle under test. t : Where: V t is the speed of the car, in km / h, m is the mass of the car being tested, J D is the moment of inertia of the vehicle performance test bench after matching the flywheel assembly, r is the roller radius of the vehicle performance test bench, a t is the acceleration of the car at time t; S3.2: Calculate the compensation ΔE t The driving / braking force ΔF required to be applied by the AC electric dynamometer: S3.

3. Calculate the driving / braking force F applied to the vehicle under test by the AC dynamometer t : Where: G is the vehicle's gravity, in N, f is the rolling resistance coefficient, C D is the air resistance coefficient, A is the windward area, the unit is m 2 , f0 is the fixed loss of the vehicle performance test bench, f1 is the linear loss coefficient, f2 is the quadratic loss coefficient, and f3 is the cubic loss coefficient.

4. The method for rapid detection of economic performance of new energy vehicles according to claim 3 is characterized in that: In step S4.1, K SOC The calculation method is: K SOC =0.96142+0.0022·P SOC -4.27637·10 -5 ·P SOC 2 +3.02787·10 -7 ·P SOC 3 Where: SOC takes the average value of the SOC interval during the entire test process, and P SOC Indicated by %, the unit is %; K T The calculation method is: K T =0.92027+0.00996·T-3.87264·10 -4 ·T 2 +5.2562·10 -6 ·T 3 Where: T is the ambient temperature, in °C.

5. The method for rapid detection of economic performance of new energy vehicles according to claim 4 is characterized in that: In the step S4.2, f(SOC) is used The multiplication factor f PSOC Expressed as, or, using the compensation amount f of the driving range DSOC To express, and when using f DSOC When f DSOC The specific value is determined by the battery pack manufacturer, and / or, model, and / or, capacity, and / or, batch; When using f PSOC When f PSOC The calculation method is: f PSOC =(1.00283-5.6197·10 -4 ·P SOC +2.04545·10 -6 ·P SOC 2 )-1 at this time:

6. The method for rapid detection of economic performance of new energy vehicles according to claim 5 is characterized in that: In step S4.2, f(T) is expressed as The multiplication factor f PT Expressed as, or, using the compensation amount f of the driving range DT Indicates that, and when using f DT When f DT The specific value is determined by the battery pack manufacturer, and / or, model, and / or, capacity, and / or, batch; When using f PT When f PT The calculation method is: f PT =1-(0.92027+0.00996·T-3.87264·10 -4 ·T 2 +5.2562·10 -6 ·T 3 ) Where: T is the ambient temperature, in °C; at this time:

7. The method for rapid detection of economic performance of new energy vehicles according to claim 6, characterized in that: In step S4.3, F if The calculation method is:

8. The method for rapid detection of economic performance of new energy vehicles according to claim 7 is characterized in that: In step S4.3, C SOC The calculation method is: C SOC =1.09838-0.02071·P SOC +4.02482·10 -4 ·P SOC 2 -2.84976·10 -6 ·P SOC 3 Where: SOC takes the average value of the SOC interval during the entire test process, and P SOC Indicated by %, the unit is %; C I The calculation method is: C I =0.99413-0.09531·I C -0.00922·I C 2 Where: I C Take the average value of the energy feedback current during the entire test process and express it as a multiple of the rated capacity of the battery pack.

9. The method for rapid detection of economic performance of new energy vehicles according to claim 8, characterized in that: In step S5, the normalized formula of energy consumption rate C is: Where: C N The power consumption per 100 kilometers announced by the tested vehicle, in kWh / 100km; The normalized formula for the driving range D is: Where: D N It is the NEDC pure electric range announced by the tested vehicle, in km.

10. The method for rapid detection of economic performance of new energy vehicles according to claim 9, characterized in that: In step S6, the energy consumption rate C norm The weight W1 ranges from 0.3 to 0.45, and the driving range D norm The weight W2 is 0.3 to 0.45, the braking energy recovery efficiency weight W3 is 0.1 to 0.3, and the weights satisfy: 0.7≤W1+W2≤0.9, W1+W2+W3=1.0; at this time: C e =C norm ·W1+D norm ·W2+η·W3。

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