A vehicle power system electrical balance test method in a low temperature environment

Abstract

The present invention provides a vehicle power system electric balance test method in a low temperature environment, which is a comprehensive test technology for whether the automobile power system can achieve electric balance in a low temperature environment. This test method simulates the relatively harsh vehicle use conditions of low temperature users to cover and verify whether the vehicle power meets the cold start requirements. It only needs to continuously detect the battery SOC value, and does not need to measure the generator power and the vehicle-mounted electrical appliance power. It is simple and easy to operate. It reasonably stipulates the test road conditions and test conditions, stipulates the test mileage and evaluation standards, and relatively scientifically verifies whether the vehicle power system can achieve electric balance when working in a low temperature environment. It can determine whether the vehicle power has a cold start risk before the newly developed model is launched on the market, and avoid defective products from entering the market.

Description

Technical Field

[0001] The invention relates to an automobile road test method, in particular to a test method for verifying whether an automobile power system can achieve electrical balance when working in a low-temperature environment to ensure that the entire vehicle can be started normally. Background Art

[0002] The low temperatures in Northeast China last for a long time in winter, and the temperature in some areas can even drop to -35℃. With the continuous development of the automobile industry, the intelligentization of electrical appliances has gradually become an industry trend. Automobiles with increasingly intelligent electrical appliances also require higher power supply capabilities for the vehicle power system. When the cars of Northeast users are used in low temperature environments for a long time, the power generation of the generator fails to reach an electrical balance with the power of the vehicle electrical load, which will continue to consume the power of the battery. When the battery SOC is low, the battery is in a state of power loss, and the ignition and starting ability of the car will be greatly reduced. There is a high probability that the ignition and starting cannot be normal, which is easy to cause user complaints.

[0003] Patent document CN201010596679.7 discloses a test method for electric balance of a whole vehicle, which uses a data acquisition device and a current sensor to measure the voltage and current of a vehicle battery, a generator and a vehicle electrical appliance, and uses a battery tester to measure the battery charge. The test method includes a dynamic electric balance test and a static electric balance test. In the dynamic electric balance test, the battery charge is discharged to 50% of the rated capacity before the test, and the vehicle is in a driving state. The test lasts for 4 to 5 hours, and the battery charge change before and after the test or the average current ratio of the battery charge and discharge is used to test whether the whole vehicle is in dynamic electric balance; in the static electric balance test, the static current, minimum starting capacity, general available capacity and self-discharge current of the battery are measured, and the static parking time of the vehicle is obtained by calculation, thereby realizing the static electric balance test. This method does not fully consider the extreme use conditions of users in low temperature environments for the test of the power system, such as short-distance driving in low temperature environments, long-term natural static parking, and whether the power system can still meet the cold start requirements is also a technical focus that needs to be considered. Summary of the invention

[0004] The purpose of the present invention is to provide a comprehensive test method for whether an automobile power system can achieve electrical balance in a low temperature environment. By reasonably specifying the test road conditions and test conditions, specifying the test mileage and evaluation standards, it is relatively scientific to verify whether the entire vehicle power system can achieve electrical balance when working in a low temperature environment.

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

[0006] A vehicle power system electric balance test method in a low temperature environment, characterized in that it comprises the following steps:

[0007] Step (1), turn on the signal acquisition device to start the acquisition work and record the battery SOC value of the sample vehicle.

[0008] Step (2), ignite and start the sample vehicle to perform idle high condition, the electrical equipment of the whole vehicle is set according to the user's common state, the whole vehicle idles for 5-8 minutes, and after the idle high condition ends, the vehicle immediately performs the urban high condition without shutting down; in the urban high condition, the electrical equipment of the whole vehicle is set according to the user's common state, the average vehicle speed is controlled at 30-40km / h, and the mileage is 10-12km.

[0009] Step (3): after the sample vehicle completes the idle high operating condition and the urban high operating condition, the engine is immediately turned off to record the battery SOC value and lock the vehicle. Steps (1), (2) and (3) form a cycle.

[0010] Step (4), after an interval of 8±2h, the test is completed after repeating 13 cycles, aiming to simulate the user's short-distance driving conditions within half a month.

[0011] During the test period, no operation of any electrical equipment, including unlocking, is allowed. During the test, the vehicle must be ignited within one minute after being unlocked, and must be locked within one minute after being turned off.

[0012] Step (5), judging the electrical balance of the power system of the sample vehicle working in a low temperature environment according to the evaluation criteria, wherein the evaluation criteria are as follows:

[0013] (Initial SOC value before the first cycle - SOC value at the end of the 13th cycle) / initial SOC value before the first cycle ≤ 5%.

[0014] Furthermore, the user's common status settings for the vehicle electrical equipment can be set using Table 2:

[0015] Table 2 Electrical equipment status setting table

[0016] Appliance Name Status Settings Low beam or high beam, position lights Open Front and rear fog lights Open Brake lights Enable on demand during the experiment Left turn signal Enable on demand during the experiment radio Turn up the volume to 50% air conditioner 20-22℃ warm air Front defrost heating 5-8min Ventilation equipment (blower) 3rd-4th gear Front wiper Enable on demand during the experiment Rear wiper (if in continuous mode) Enable on demand during the experiment Post-defrost heating Always on Heated front seats Maximum power load setting Heated rear seats Maximum power load setting Mirror heating Open Steering wheel heating Open

[0017] When the method of the present invention is used for testing, the ambient temperature of the test vehicle must be less than or equal to -25°C and greater than or equal to -35°C when idling or driving, and the humidity must be less than 90%. If the ambient temperature of the test site is lower than -35°C, the test is suspended and resumed when the ambient temperature returns to -35°C or above.

[0018] In addition, the present invention also requires that the test vehicle needs to travel a certain mileage before the test to ensure that the entire vehicle meets the driving requirements of the test conditions on urban roads.

[0019] The present invention requires the use of a signal acquisition device to monitor the current and voltage of the battery. At the beginning and end of a test condition, the battery SOC value needs to be measured and recorded. After each test condition is completed, an interval of 8±2 hours is required before the next repeated test condition can be carried out.

[0020] The present invention requires that the test vehicle is not allowed to perform any vehicle operation including unlocking at other times, so as to avoid power consumption affecting the test results. At the same time, when conducting the test conditions, the vehicle must be ignited within one minute after being unlocked, and locked within one minute after being turned off, so as to avoid power consumption in the vehicle ON gear affecting the test results.

[0021] The advantages of the present invention are as follows:

[0022] This test method simulates the relatively harsh vehicle operating conditions of low-temperature users to verify whether the vehicle power supply meets the cold start requirements. It only needs to continuously detect the battery SOC value, without measuring the generator power and the power of the on-board electrical appliances. It is simple and easy to operate. It provides a scientific evaluation standard to determine whether the vehicle power supply has a cold start risk before the new development model is launched on the market, so as to prevent defective products from entering the market. DETAILED DESCRIPTION

[0023] The implementation process of this test method is further described below.

[0024] 1. Prepare the test vehicle:

[0025] (1) The prototype vehicle to be tested shall be subjected to a road test of no less than 100 km to meet the driving requirements of the test conditions.

[0026] (2) Test the network sleep and wake-up status and dark current status of the sample vehicle to ensure that there are no abnormalities in the network wake-up and that the dark current of the entire vehicle meets the requirement of less than 20mA.

[0027] (3) The production date of the sample vehicle calibration battery and the date of this test shall not exceed 3 months.

[0028] 2. Arrange collection equipment

[0029] This method requires the use of a signal acquisition device to monitor the current and voltage of the battery. The specific equipment is shown in Appendix 1.

[0030] Table 1 Equipment details

[0031]

[0032]

[0033] (1) Calibrate the battery to 70% SOC at room temperature and then place it on the test vehicle. Replace the calibrated battery on the test vehicle 8 hours or more before the start of this test.

[0034] (2) Connect the CAN device to BCAN to collect the battery sensor signal (or connect the Lin device to the battery sensor Lin line); then connect the device CAN line to the collection device and start the device to run.

[0035] (3) 4 hours before the test, check the battery sensor signal to ensure that SOC_STATE is 2; check the SOC value sent by the sensor on the whole vehicle to ensure that the SOC value on the whole vehicle is in the range of (70±10)%.

[0036] (4) During the test, all battery sensor messages are recorded through the CAN device, and the data is stored separately each time.

[0037] 3. Carry out test conditions

[0038] (1) Before starting the test, please make sure to open the CAN device within one minute to start collecting data and record the battery SOC value. If the equipment debugging time exceeds one minute, start the generator immediately;

[0039] (2) The test vehicle is started and operated in the high idle condition. In the high idle condition, the vehicle electrical equipment is set according to the status in Appendix 2, and the vehicle idles for 5 minutes. After the high idle condition, the vehicle is immediately operated in the urban high condition without shutting off the engine. In the urban high condition, the vehicle electrical equipment is also set according to the status in Appendix 2, and the average vehicle speed must be controlled at about 30 km / h, with a mileage of 10 kilometers.

[0040] (3) After the test vehicle completes the idle high operating condition and the urban high operating condition, the engine is immediately turned off, the battery SOC value is recorded, and the vehicle is locked. Steps (1), (2), and (3) constitute one cycle.

[0041] (4) After an interval of 8±2 hours, the test is completed after repeating 13 cycles.

[0042] As mentioned above, during the test cycle of the test vehicle, no electrical equipment operation including unlocking is allowed. During the test, the vehicle must be ignited within one minute after unlocking, and locked within one minute after shutting down.

[0043] In addition, during the test, the ambient temperature of the test vehicle must be less than or equal to -25°C and greater than or equal to -35°C when idling or driving, and the humidity must not exceed 90%. If the ambient temperature of the test site is lower than -35°C, the test will be suspended and resumed when the ambient temperature returns to -35°C or above.

[0044] 4. Electric balance determination

[0045] According to the evaluation criteria, the electrical balance of the power system of the prototype vehicle working in a low temperature environment is determined. The evaluation criteria are as follows:

[0046] (Initial SOC value before the first cycle - SOC value at the end of the 13th cycle) / initial SOC value before the first cycle ≤ 5%.

Claims

1. A vehicle power system electric balance test method in a low temperature environment, characterized in that: The steps include: Step (1), turn on the acquisition device to start acquisition and record the battery SOC value of the sample vehicle; the sample vehicle must meet the following conditions: (1) A road test of not less than the set mileage has been carried out; (2) There is no abnormality in network wake-up, and the dark current of the whole vehicle is less than the set value; (3) The time interval between the production date of the calibrated battery and the date of this test shall not exceed the set time; Step (2) Ignition starts the sample vehicle to perform the idle high operating condition, and the vehicle electrical equipment is set according to the user's common state. The vehicle idles for 5-8 minutes, and immediately performs the urban high operating condition without shutting off the engine after the idle high operating condition ends. In the urban high operating condition, the vehicle electrical equipment is set according to the user's common state, and the average vehicle speed is controlled at 30-40 km / h, and the mileage is 10-12 km; Step (3) After the sample vehicle has completed the idle high operating condition and the urban high operating condition, the engine is immediately turned off to record the battery SOC value and the battery is locked. Steps (1), (2) and (3) constitute one cycle. Step (4) After an interval of 8±2h, the test is completed after 13 cycles of operation are repeated; During the test period, any electrical equipment operation including unlocking is not allowed. During the test, the vehicle must be started within one minute after being unlocked, and locked within one minute after being turned off. Step (5): according to the evaluation criteria, the electrical balance of the power system of the prototype vehicle operating in a low temperature environment is determined. The evaluation criteria are as follows: (Initial SOC value before the first cycle - SOC value at the end of the 13th cycle) / initial SOC value before the first cycle ≤ 5%; During the test, the ambient temperature is less than or equal to -25°C and greater than or equal to -35°C, and the humidity is not greater than 90%; The method also includes a process of arranging multiple acquisition devices before the test: (1) Calibrate the battery SOC to 68%-72% at room temperature and replace the calibrated battery on the test vehicle at least 8 hours before the start of this test; (2) Connect the data acquisition equipment and run it to collect the battery sensor signals; (3) Check the battery sensor signal and ensure that SOC_STATE is 2 and that the SOC of the vehicle is within the range of 70% ± 10%.

2. The vehicle power system electric balance test method in a low temperature environment according to claim 1, characterized in that: The vehicle electrical equipment is set according to the user's common status, as follows: low beam or high beam, position lights, front and rear fog lights, mirror heating, and steering wheel heating are all set to be turned on, brake lights, left turn signal, front wiper, and rear wiper are set to be turned on as needed during the test, the radio is set to 50% volume, the air conditioner is set to 20-22℃ warm air, the front defrost heating is set to 5-8min, the ventilation equipment is set to 3-4 gears, the rear defrost heating is set to be always on, and the front seat heating and rear seat heating are set to the maximum power load.

3. The vehicle power system electric balance test method in a low temperature environment according to claim 1, characterized in that: Before starting the test condition, ensure that the acquisition equipment is turned on within one minute to start collecting data and record the battery SOC value.

4. The vehicle power system electric balance test method in a low temperature environment according to claim 1, characterized in that: The acquisition device is a CAN or LIN signal acquisition device.

5. The vehicle power system electric balance test method in a low temperature environment according to claim 1, 2 or 3, characterized in that: During the test, all battery sensor messages are recorded by the acquisition equipment, and the data is stored separately each time.

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