CN104237803A - Method for detecting electrical property of battery of electric vehicle on basis of battery working condition simulation - Google Patents

Abstract

The invention discloses a method for detecting electrical property of a battery of an electric vehicle on the basis of battery working condition simulation. The method comprises the following steps of (1) storing battery working condition running data to an appointed file by using an electric vehicle battery management system; (2) analyzing the battery working condition running data file and processing the battery working condition running data to running standard data of a certain electric vehicle line under a battery working condition according to requirements of battery detecting equipment; (3) performing circular charging and discharging detection on a detected battery according to the working condition and recording running detecting data of the detected battery under a simulated working condition; and (4) analyzing the running detecting data of the detected battery under the simulated working condition and evaluating circulation electrical property of the battery. In order to solve the problem that the electrical property of the existing electric vehicle power battery is difficult to detect and evaluate, the method for detecting the electrical property of the battery of the electric vehicle on the basis of battery working condition simulation is a method capable of accurately detecting and evaluating the electrical property of the power battery in a running environment of a fixed line of the electric vehicle.

Description

Electric vehicle battery electrical performance detection method based on battery working condition simulation

technical field

The invention relates to the field of detection of power batteries of electric vehicles, in particular, a method for detecting the electrical properties of power batteries of electric vehicles running on a fixed circuit is designed.

Background technique

As a future means of transportation, electric vehicles are more concerned about the mileage, acceleration performance, and climbing ability of electric vehicles. The performance of electric vehicles depends largely on the performance of the battery as power. The requirements for battery electrical performance generally focus on energy density, power characteristics, cycle life, etc. The electrical performance of the power battery system directly affects the power and economy of the vehicle, which in turn affects the development and promotion of electric vehicles.

Electric vehicle battery testing has always been the focus of research in the process of electric vehicle technology development and industrialization. Electric vehicle battery testing and evaluation technology will promote electric vehicle technology progress, demonstration promotion and industrial development. At present, battery testing in national standards and industry standards usually uses constant current or constant power charging and discharging to test the electrical performance of the battery. The reflected electrical performance will be different, and the basic electrical performance of the battery does not mean that the actual operating electrical performance is good. On the other hand, batteries from different manufacturers have some differences in electrical performance due to different materials, processes and structures. Some batteries have excellent electrical performance in smooth road conditions, and some batteries have better electrical performance in complex road conditions. Battery testing under constant conditions is not specific. It cannot reflect the road conditions of these batteries to adapt to the electrical performance. The latest battery testing standard provides several reference working condition testing curves, but the curves are relatively simple and the number of current changes is small, which cannot accurately reflect and represent the actual working conditions of electric vehicles. Battery detection requires actual operating conditions, but it is difficult to collect battery data from actual operating electric vehicles, and it takes a long period to collect data from actual operating electric vehicles. Therefore, the current electric vehicle power battery detection method lacks pertinence, the detection is out of the actual battery operating conditions, and the detection results cannot well reflect and evaluate the road conditions of the battery to adapt to the electrical performance. The electrical performance evaluation technology of the battery needs to be improved.

Contents of the invention

In order to solve the difficult problem of detecting and evaluating the electric performance of the power battery of the electric vehicle in the prior art, the present invention provides a method for accurately detecting and evaluating the electric performance of the power battery of the electric vehicle under the fixed line operation environment.

In order to solve the problems referred to above, the technical scheme that the present invention takes is:

A method for detecting electrical performance of an electric vehicle battery based on battery working condition simulation, characterized in that: comprising the following steps, 1), the step of recording battery working condition data: monitoring the operation of the electric vehicle on each fixed line in real time through the electric vehicle battery management system , the voltage and current output of the battery, and save the operating data of the battery condition to the specified file; 2), the analysis and processing steps of the operating data of the battery condition: analyze the operating data file of the battery condition, and extract According to the requirements of the battery testing equipment, the battery operating data will be processed into the standardized data of the battery operating condition of a certain electric vehicle line; Import the standardized data of the battery working condition of each electric vehicle line into the battery testing equipment, set the protection parameters of the battery testing, perform cycle charge and discharge testing on the tested battery according to the working conditions, and record the testing data of the simulated working conditions of the tested battery; 4), analysis and evaluation of battery performance steps: analyze the detection data of the simulated operating conditions of the tested battery, obtain the cycle characteristics of the internal resistance, capacity and power attenuation of the battery, and evaluate the cycle electrical performance of the battery under the electric vehicle operating line .

The aforementioned electric vehicle battery electrical performance detection method based on battery working condition simulation is characterized in that: in step 1), the battery management system of the electric vehicle is equipped with a voltage sensor for each single battery, and monitors each single battery in real time. The voltage state of the single battery, and monitor the overall output state of the vehicle battery. The operating status of the electric vehicle battery is aimed at the vehicle battery. As long as the total current, voltage and power data of the vehicle battery are collected, they are divided into categories according to the load. Three situations of light load, medium load and heavy load are recorded and saved to the specified file.

The aforementioned electric vehicle battery electrical performance testing method based on battery working condition simulation is characterized in that: in step 2), in order to facilitate direct import of battery testing equipment as battery testing conditions, it is necessary to process battery work according to the requirements of battery testing equipment. When the number n of electric vehicle battery operating record data points is greater than the maximum number of steps m that can be set by the detection equipment, it is necessary to sample and simplify the battery operating data, and use the average value Sampling method, maximum value sampling method or minimum value sampling method, the number of data points after sampling is less than or equal to the maximum number of steps that can be set by the detection device.

The aforementioned electric vehicle battery electrical performance detection method based on battery working condition simulation is characterized in that: in step 2), the number of data points in the operating record of the electric vehicle battery working condition is n, and the maximum number of steps that can be set by the battery testing equipment is m, if the quotient of n divided by m is rounded to an integer greater than 1, record x=[n/m], then it is necessary to sample and process each (x+1) data in the battery operating data into one data point, specifically (x+1) data to take the average, maximum or minimum.

The aforementioned electric vehicle battery electrical performance testing method based on battery working condition simulation is characterized in that: in step 3), the standardized data of the battery working condition can be directly set as the discharge condition of the tested electric vehicle battery, that is, battery testing The device simulates the discharge state of the battery when it is running in this working condition, and performs the same discharge detection as the working condition of the tested battery.

The aforementioned electric vehicle battery electrical performance detection method based on battery working condition simulation is characterized in that: in step 3), before performing discharge detection, it is necessary to set the protection parameters of the battery detection, after the discharge detection is completed, then press the battery The testing national standard or enterprise standard requires the battery to stand still, and then standard charge the battery according to the battery testing national standard or enterprise standard, and save the simulated operating data and analysis data of the tested battery recorded by the battery testing equipment.

The aforementioned electric vehicle battery electrical performance testing method based on battery working condition simulation is characterized in that: in step 3), the number of cycle charge and discharge tests on the tested battery is not less than 50 times.

The beneficial effect that the present invention reaches:

The battery working condition data of the fixed line is collected from the actual operation of the electric vehicle. The collected working condition data has the characteristics of authenticity, accuracy and strong pertinence; after the collected battery working condition data is processed according to the requirements of the battery testing equipment, it can be directly imported into the battery The detection equipment is used as the battery detection condition, and then the cycle is set for battery detection. The detection process is simple and easy to operate; this battery detection method simulates the actual battery working condition to detect the battery, and can select the most suitable battery for different road conditions. The detection results have a very high reference value.

Description of drawings

Figure 1 is the overall structure diagram of the electric vehicle battery electrical performance detection method based on the battery working condition simulation.

Figure 2 is a flow chart of battery operation data record collection.

Fig. 3 is a flowchart of the analysis and processing of the operating data of the battery operating condition.

Fig. 4 is a graph of unprocessed battery working condition voltage and current data.

Fig. 5 is a graph of the voltage and current data of the battery working condition after processing.

Fig. 6 is a flow chart of simulating the working condition of the battery and detecting the battery.

Fig. 7 is a flowchart of the analysis and evaluation of the detection results of the simulated battery operating conditions.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings. The following examples are only used to illustrate the technical solution of the present invention more clearly, but not to limit the protection scope of the present invention.

As shown in Figure 1, a kind of electric vehicle battery electrical performance detection method based on battery operating condition simulation of the present invention comprises the following steps:

1) As shown in Figure 2, the battery operating condition data recording steps: monitor the voltage and current output of the power battery when the electric vehicle is running on a fixed line through the battery management system of the electric vehicle, and record the current, voltage and power data of the battery Save to the specified file (can be realized by SD card export or GPRS transmission, etc.). Electric vehicles equipped with the same power system and model run on a fixed line, and the power output curve of its power battery has certain rules, which are closely related to road conditions and load conditions. The road condition of the fixed line is basically determined, and the load can be divided into light load, medium load and heavy load according to the load of the electric vehicle. The load of the electric bus is related to the bus station and time, so the battery work of the electric vehicle A large amount of monitoring data should be used to extract the typical light-load, medium-load and heavy-load working condition data of the line.

The battery management system of electric vehicles is equipped with a voltage sensor for each single battery to monitor the voltage status of each single battery in real time and monitor the overall output status of the vehicle battery. The operating status of the electric vehicle battery is for the whole vehicle battery, as long as the total current, voltage and power data of the whole vehicle battery are collected, divided into light load, medium load and heavy load according to the load, and recorded in three situations, and saved to the specified file .

2), as shown in Figure 3, the battery operating condition data analysis and processing steps: analyze the battery operating condition operating file, extract the battery operating condition operating data of the electric vehicle running on a certain line, and process it into a certain line according to the requirements of the battery testing equipment Standardized data on battery operating conditions for electric vehicle lines. The operating data of the battery working condition includes the current, voltage and power data of the battery. According to the testing conditions that can be set by the battery testing equipment, power or current is selected as the testing condition of the battery. Then the standardized data of the battery testing only needs to save the power or current data of the battery working condition. That's it.

The battery management system records all the battery operating data from the start to the stop of the battery management system of the electric vehicle, including the data that needs to be removed when the battery management system is started but the car is not running, interference signals and error data. Figure 4 is an electric bus The battery working condition data of the line, the current and voltage data of the original battery working condition contain invalid data such as data time stamp error, repeated data and abnormal data. Figure 5 is the processed battery working condition data. A data file contains multiple line operation data, and it is necessary to analyze the time and data rules to extract the battery operating data of the complete operation of one line of electric vehicles from the data file.

After extracting the battery working condition data of the electric vehicle fixed line, in order to directly import the battery testing equipment as the battery testing condition, it is necessary to process the battery working condition data according to the requirements of the battery testing equipment. The number of testing conditions of the battery testing equipment is limited, and the number of data points n of the electric vehicle battery operating condition record data points may be greater than the maximum number of steps m that can be set by the testing equipment, so it is necessary to sample and simplify the operating data of the battery operating condition, and the average value sampling method can be used , Take the maximum value sampling method or the minimum value sampling method, the number of data points after sampling is less than or equal to the maximum number of steps that can be set by the detection device. For example, the battery testing equipment can be set to 10,000 steps, and the battery operating data has 20,000 data points, so the battery operating data should be less than or equal to 10,000 after sampling. After the battery operating data processing is completed, it is a standard battery testing condition, which can be directly imported into the battery testing equipment for battery testing.

Simplified method of battery operating data sampling:

The number of data points in the electric vehicle battery operating condition record is n, and the maximum number of steps that can be set by the battery testing equipment is m. If the quotient of n divided by m is rounded to an integer greater than 1, record x=[n/m], then the battery worker needs to Each (x+1) data sample in the operating data is processed into one data point. Specifically, the (x+1) data can be used to obtain the average value, maximum value or minimum value.

3) As shown in Figure 6, the steps of simulating the battery working condition to run and test the battery: import the standardized data of the battery working condition of the electric vehicle line into the battery testing equipment, set the protection parameters of the battery testing, and then test the battery according to the working condition The battery is discharged and tested, and the operating data of the simulated working condition of the tested battery is recorded. The battery working condition data in the previous step has been processed according to the requirements of the battery testing equipment, and the standardized data of the battery working condition can be directly set as the discharge condition of the battery of the electric vehicle under test, that is, the battery testing equipment simulates the discharge state of the battery in the working condition Carry out the same discharge test as the working condition on the battery under test. Set the protection parameters for battery detection. The protection parameters include battery total voltage protection, maximum current protection, single cell voltage protection, charge and discharge time protection, and high temperature protection. After setting the protection parameters for battery detection, discharge the tested battery according to the working condition, and then let the battery stand for a period of time (such as 30 minutes) according to the requirements of the national or enterprise standards for battery testing. After standing still, standard charge the battery according to the national or enterprise standards for battery testing, and save the operating data and analysis data of the simulated working conditions of the tested battery recorded by the battery testing equipment.

4) As shown in Figure 7, the steps of analyzing and evaluating battery performance: After the battery has been tested for many times, analyze the data of the simulated working condition of the tested battery, and obtain the charging efficiency, internal resistance, capacity, power attenuation and consistency of the battery. , to evaluate the cycle electrical performance of this battery under the electric vehicle operating circuit. The number of battery cycle tests is generally not less than 50 times, the more the number of tests, the more accurate, and the number of cycles can be determined according to the actual situation. Record and analyze the battery test results of the cycle test, take the number of battery cycle tests as the X-axis, and the electrical performance parameters such as charging efficiency, internal resistance, capacity, power, and consistency as the vertical coordinates, and draw a comparison of the electrical performance parameters of various batteries picture. The consistency, internal resistance, and capacity of the battery are basically positively correlated, and the consistency of the battery becomes poor. Without battery voltage equalization, as the number of charge and discharge increases, the capacity of the battery will decrease and the internal resistance will increase. Through the comparison and evaluation of the electrical performance of various batteries, the battery with the best comprehensive performance under the electric vehicle operating line is obtained, and then provides a reference for the electric vehicle on this line to choose the most suitable battery.

The basic principles, main features and advantages of the present invention have been shown and described above. Those skilled in the industry should understand that the present invention is not limited by the above-mentioned embodiments. What are described in the above-mentioned embodiments and the description only illustrate the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will also have Variations and improvements are possible, which fall within the scope of the claimed invention. The protection scope of the present invention is defined by the appended claims and their equivalents.

Claims (7)

1. the batteries of electric automobile electrical property detection method based on battery Work condition analogue, it is characterized in that: comprise the following steps, 1), battery operating mode service data recording step: by cell management system of electric automobile Real-Time Monitoring electric automobile when each line operation, the voltage and current of battery exports situation, and battery operating mode service data is saved in specified file; 2), battery operating mode Operational Data Analysis treatment step: analyze battery operating mode service data file, extract the battery operating mode service data of electric automobile when certain circuit runs, and require according to battery detection equipment the standardized data that the battery operating mode this battery operating mode service data being processed into certain electric automobile circuit is run; 3), simulated battery operating mode is run and is detected battery step: the battery operating mode standardized data of this electric automobile circuit is imported battery detection equipment, after the Protection parameters of battery detecting is set, by this working condition, cycle charge discharge electro-detection is carried out to detected battery, record the detection data that tested battery simulated condition is run; 4), analysis and evaluation battery performance step: analyze the detection data that tested battery simulated condition is run, obtain the cycle characteristics of the internal resistance of battery, capacity and power attenuation, assess the cycle electric performance of this battery under this electric automobile working line.

2. a kind of batteries of electric automobile electrical property detection method based on battery Work condition analogue according to claim 1, it is characterized in that: in step 1), the battery management system of electric automobile is all configured with voltage sensor for each block cell, the voltage status of each block cell of Real-Time Monitoring, and the output state total to car load battery is monitored, batteries of electric automobile working condition running state is for car load battery, as long as gather total electric current of car load battery, voltage and power data, underloading is divided into by load weight, in carry and heavy duty 3 kinds of situations carry out record, and be saved in specified file.

3. a kind of batteries of electric automobile electrical property detection method based on battery Work condition analogue according to claim 2, it is characterized in that: in step 2) in, for convenience of directly importing battery detection equipment as battery detecting condition, need the requirement treatment of battery floor data according to battery detection equipment, remove the exceptional value in data and improper value, when batteries of electric automobile operating mode log data count n be greater than the maximum step number m that checkout equipment can arrange time, need to carry out sampling to battery operating mode service data to simplify, the average method of sampling is got in employing, get the maximal value method of sampling or get the minimum value method of sampling, number of data points after sampling is less than or equal to the maximum step number that checkout equipment can be arranged.

4. a kind of batteries of electric automobile electrical property detection method based on battery Work condition analogue according to claim 3, it is characterized in that: in step 2) in, batteries of electric automobile operating mode log data is counted as n, the maximum step number that battery detection equipment can be arranged is m, if n rounds divided by the business of m be greater than 1, note x=[n/m], so need to become 1 data point to every (x+1) individual data sampling processing in battery operating mode service data, concrete individual to (x+1) data to be averaged, maximal value or minimum value.

5. a kind of batteries of electric automobile electrical property detection method based on battery Work condition analogue according to claim 4, it is characterized in that: in step 3), the standardized data of battery operating mode directly can be set to the discharging condition of tested batteries of electric automobile, and namely the discharge condition of battery detection equipment simulated battery when this operating mode is run carries out the discharge examination same with this operating mode to tested battery.

6. a kind of batteries of electric automobile electrical property detection method based on battery Work condition analogue according to claim 5; it is characterized in that: in step 3); before doing discharge examination; need the Protection parameters that battery detecting is set; after discharge examination completes; then by battery detecting national standard or company standard requirement to battery standing; by battery detecting GB or enterprise's mark requirement, standard charging is carried out to battery again after leaving standstill, preserve the tested battery simulated condition service data of battery detection equipment record and analyze data.

7. a kind of batteries of electric automobile electrical property detection method based on battery Work condition analogue according to claim 6, is characterized in that: in step 3), carries out cycle charge discharge electro-detection number of times be no less than 50 times to detected battery.