CN108521155B - A kind of electric vehicle charging early warning method and system - Google Patents

Abstract

The invention discloses an electric vehicle charging early warning method and system. The method includes: acquiring battery information of each single battery in the electric vehicle; measuring the real-time charging voltage of each single battery in real time; Aging degree; obtain early warning information according to the battery type and degree of aging; determine the first warning voltage value and the second warning voltage value; determine whether the real-time charging voltage is greater than the second warning voltage value, and if not, perform high-rate charging mode ; If it is greater than, judge whether the charging real-time voltage is less than the first warning voltage value; if it is less than, send an alarm and change the high-rate charging mode to the small-rate charging mode; otherwise, stop charging. Using the method or system reduces the working pressure of the BMS, avoids charging accidents due to BMS failures, reduces vehicle costs and improves safety.

Description

A kind of electric vehicle charging early warning method and system

technical field

The invention relates to the field of electric vehicles, in particular to an electric vehicle charging early warning method and system.

Background technique

The existing electric vehicle charging safety monitoring is completed by the battery management system (Battery Management System, BMS). This puts a lot of work pressure on BMS itself, resulting in high cost and low efficiency of BMS. After all, the capabilities of the BMS are limited. If the BMS fails, it is easy to cause safety problems such as battery overcharge. The charging warning information in the BMS is usually the charging cut-off voltage of the battery. Since the warning information of the battery in the BMS is integrated when the car leaves the factory, it may become invalid with the aging of the battery, which may easily lead to safety accidents during charging. .

During the charging process of today's electric vehicles, the BMS sends a charging request signal to the charging pile by detecting the information of each single battery. The charging pile is responsible for responding to the charging request of the BMS and delivering the corresponding charging power to the electric vehicle. The entire charging process is controlled by the BMS, and the charging process should take into account the battery charging safety warning to prevent the battery from overcharging and causing accidents. The warning information to prevent charging safety is usually the charging cut-off voltage of the battery, and this warning information is integrated in the BMS when the car leaves the factory, and it is not adjusted with the aging of the battery.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide an electric vehicle charging early warning method and system, which solves the problem that the battery management system cannot give real-time early warning to the electric vehicle battery.

For achieving the above object, the present invention provides the following scheme:

An electric vehicle charging early warning method, comprising:

Obtain the battery information of each single battery in the electric vehicle; the battery information includes the vehicle model and historical charging data;

Real-time measurement of the charging real-time voltage of each single battery;

Determine the battery type of the electric vehicle according to the vehicle model;

Judging the aging degree of the single battery of the electric vehicle according to the historical charging data;

obtaining early warning information of the single battery according to the battery type and the aging degree;

Determine a first warning voltage value and a second warning voltage value according to the warning information; the second warning voltage value is smaller than the first warning voltage value;

Judging whether the real-time charging voltage is greater than the second warning voltage value, and obtaining a first judgment result;

If the first determination result indicates that the real-time charging voltage is not greater than the second warning voltage value, a high-rate charging mode is performed; the high-rate charging mode is charging based on the second set power;

If the first determination result indicates that the real-time charging voltage is greater than the second pre-warning voltage value, determine whether the real-time charging voltage is less than the first pre-warning voltage value, and obtain a second determination result;

If the second determination result indicates that the real-time charging voltage is lower than the first warning voltage value, an alarm is issued and the high-rate charging mode is converted into a small-rate charging mode; the low-rate charging mode is the first set power For standard charging, the second set power is greater than the first set power;

If the second determination result indicates that the real-time charging voltage is not less than the first warning voltage value, the charging is stopped.

Optionally, the acquiring battery information of each single battery in the electric vehicle specifically includes:

The monitoring and early warning platform receives the battery information of each single battery collected in real time by the battery management system and sent by the relay module.

Optionally, the monitoring and early warning platform receives the battery information of each single battery collected in real time by the battery management system and sent by the relay module, specifically including:

Judging whether the monitoring and early warning platform has received the battery information of each single battery sent by the vehicle terminal, and obtaining a third judgment result;

If the third judgment result indicates that the monitoring and early warning platform has not received the information of each single battery sent by the vehicle terminal, it will receive the battery information of each single battery sent by the charging pile; otherwise, according to the The vehicle model determines the battery type of the electric vehicle.

An electric vehicle charging early warning system, comprising:

an information acquisition module, used for acquiring battery information of each single battery in the electric vehicle; the battery information includes the vehicle model and historical charging data;

A real-time voltage measurement module, used for real-time measurement of the real-time charging voltage of each single battery;

a battery type judging module for judging the battery type of the electric vehicle according to the vehicle model;

a battery state judging module, configured to judge the aging degree of the single battery of the electric vehicle according to the historical charging data;

an early warning information determination module, configured to obtain early warning information of the single battery according to the battery type and the aging degree;

an early warning value determination module, configured to determine a first early warning voltage value and a second early warning voltage value according to the early warning information; the second early warning voltage value is smaller than the first early warning voltage value;

a first judgment module, configured to judge whether the real-time charging voltage is greater than the second pre-warning voltage value, and obtain a first judgment result;

The high-rate charging module is used for the first determination result to indicate that the real-time charging voltage is not greater than the second warning voltage value, and then the high-rate charging mode is performed; the high-rate charging mode is based on the second set power as standard charging;

The second judgment module is used to judge whether the real-time charging voltage is less than the first warning voltage value when the first judgment result indicates that the real-time charging voltage is greater than the second pre-warning voltage value, and obtain a second judgment result ;

A charging change module, configured to issue an alarm if the second determination result indicates that the real-time charging voltage is less than the first warning voltage value, and convert the high-rate charging mode into a small-rate charging mode; the small-rate charging mode is: The first set power is used as the standard for charging, and the second set power is greater than the first set power;

A charging stop module, configured to stop charging if the second determination result indicates that the real-time charging voltage is not less than the first warning voltage value.

Optionally, the information acquisition module specifically includes:

The information receiving unit is used for the monitoring and early warning platform to receive the battery information of each single battery collected in real time by the battery management system sent by the relay module.

Optionally, the information receiving unit specifically includes:

a third judging unit, configured to judge whether the monitoring and early warning platform has received the battery information of each single battery sent by the vehicle terminal, and obtain a third judgment result;

The data conversion unit is used for the third judgment result indicating that the monitoring and early warning platform has not received the battery information of each single battery sent by the vehicle terminal, and then receiving the battery information of each single battery sent by the charging pile. Battery information; otherwise, determine the battery type of the electric vehicle according to the vehicle model.

According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

In the present invention, the information of each single cell of the electric vehicle collected by the battery management system is received through the monitoring and early warning platform, the vehicle type, historical charging data and other information are determined according to the information of each single cell, and then the rechargeable battery is monitored in real time according to the above information and warning. The charging pre-warning work of the electric vehicle in the present invention is completed through the monitoring and pre-warning platform, and not only the BMS is needed, thus reducing the work pressure of the BMS, avoiding charging accidents due to BMS failure, reducing the cost of the vehicle and improving the safety.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings required in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some of the present invention. In the embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative labor.

1 is a flowchart of an electric vehicle charging early warning method according to an embodiment of the present invention;

FIG. 2 is a module diagram of an electric vehicle charging early warning system according to an embodiment of the present invention;

3 is a diagram showing the relationship between the battery voltage of the electric vehicle and the remaining battery power according to an embodiment of the present invention;

FIG. 4 is a change trend diagram of battery voltage under different charging rates according to an embodiment of the present invention;

FIG. 5 is a change trend diagram of battery temperature under different charging rates according to an embodiment of the present invention;

6 is a graph of a voltage change rate curve according to an embodiment of the present invention;

Fig. 7 is the temperature change rate curve diagram of the embodiment of the present invention;

Fig. 8 (a) is the variation diagram of the voltage change rate with the voltage according to the embodiment of the present invention;

FIG. 8( b ) is an enlarged view of the variation of the voltage change rate with the voltage according to the embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The purpose of the present invention is to provide an electric vehicle charging early warning method and system, which solves the problem that the battery management system cannot give real-time early warning to the electric vehicle battery.

In order to make the above objects, features and advantages of the present invention more clearly understood, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

FIG. 1 is a flowchart of an electric vehicle charging early warning method according to an embodiment of the present invention. Referring to Figure 1, an electric vehicle charging early warning method includes:

Step 101: Obtain battery information of each single battery in the electric vehicle; the battery information includes the vehicle model and historical charging data;

Step 102: Measure the real-time charging voltage of each single battery in real time;

Step 103: Determine the battery type of the electric vehicle according to the vehicle model;

Step 104: Judging the aging degree of the single battery of the electric vehicle according to the historical charging data;

Step 105: Obtain early warning information of the single battery according to the battery type and the aging degree;

Step 106: Determine a first warning voltage value and a second warning voltage value according to the warning information; the second warning voltage value is smaller than the first warning voltage value;

Step 107: Determine whether the real-time charging voltage is greater than the second pre-warning voltage value, and obtain a first determination result;

Step 108: If the first determination result indicates that the real-time charging voltage is not greater than the second pre-warning voltage value, perform a high-rate charging mode; the high-rate charging mode is charging based on the second set power ;

Step 109: if the first determination result indicates that the real-time charging voltage is greater than the second pre-warning voltage value, then determine whether the real-time charging voltage is less than the first pre-warning voltage value, and obtain a second determination result;

Step 110: If the second determination result indicates that the charging real-time voltage is lower than the first warning voltage value, an alarm is issued and the high-rate charging mode is changed to a small-rate charging mode; the small-rate charging mode is the first charging mode. The set power is standard for charging, and the second set power is greater than the first set power;

Step 111: If the second determination result indicates that the real-time charging voltage is not less than the first warning voltage value, stop charging.

The above method is used to provide more real and reliable early warning information for electric vehicle battery charging safety, and BMS only serves as the information collection function of each single battery, and the extraction and judgment of information are completed through the early warning platform, which greatly reduces the work pressure of BMS , which helps to reduce costs.

Step 101 specifically includes:

The monitoring and early warning platform receives the battery information of each single battery collected in real time by the battery management system and sent by the relay module.

In the above method, the monitoring and early warning platform receives the battery information of each single battery collected in real time by the battery management system and sent by the relay module, which specifically includes:

Judging whether the monitoring and early warning platform has received the battery information of each single battery sent by the vehicle terminal, and obtaining a third judgment result;

If the third judgment result indicates that the monitoring and early warning platform has not received the information of the single cells sent by the vehicle terminal, then the battery information of the single cells sent by the charging pile is received;

Otherwise, the battery type of the electric vehicle is determined according to the vehicle model.

FIG. 2 is a block diagram of an electric vehicle charging early warning system according to an embodiment of the present invention. Referring to Figure 2, an electric vehicle charging early warning system includes:

The information acquisition module 201 is used for acquiring battery information of each single battery in the electric vehicle; the battery information includes the vehicle model and historical charging data;

A real-time voltage measurement module 202, used for real-time measurement of the real-time charging voltage of each single battery;

a battery type determination module 203, configured to determine the battery type of the electric vehicle according to the vehicle model;

a battery state judgment module 204, configured to judge the aging degree of the single battery of the electric vehicle according to the historical charging data;

an early warning information determination module 205, configured to obtain early warning information of the single battery according to the battery type and the aging degree;

an early warning value determination module 206, configured to determine a first early warning voltage value and a second early warning voltage value according to the early warning information; the second early warning voltage value is smaller than the first early warning voltage value;

A first judgment module 207, configured to judge whether the real-time charging voltage is greater than the second pre-warning voltage value, and obtain a first judgment result;

The high-rate charging module 208 is used to perform the high-rate charging mode when the first determination result indicates that the real-time charging voltage is not greater than the second pre-warning voltage value; the high-rate charging mode is to use the second set power to charge the standard;

The second judgment module 209 is used for the first judgment result to indicate that the real-time charging voltage is greater than the second pre-warning voltage value, then judging whether the real-time charging voltage is less than the first pre-warning voltage value, and obtaining a second judgment result;

The charging change module 210 is configured to issue an alarm if the second determination result indicates that the real-time charging voltage is less than the first warning voltage value, and convert the high-rate charging mode into a small-rate charging mode; the small-rate charging mode In order to charge with the first set power as the standard, the second set power is greater than the first set power;

The charging stop module 211 is configured to stop charging if the second determination result indicates that the real-time charging voltage is not less than the first warning voltage value.

In the present invention, the above system is adopted to ensure that the charging early warning work of the electric vehicle is completed through the early warning platform, and not only the BMS is needed, thus reducing the working pressure of the BMS, avoiding charging accidents due to BMS failure, reducing the cost of the vehicle and improving the safety.

The specific method for obtaining the early warning information of the single battery in the early warning information determination module 205 is as follows: a database is set up in the monitoring and early warning platform, and the database stores multiple sets of battery information, and each set of battery information includes the corresponding battery type, aging level and warning information. When the battery type and aging degree of the vehicle are obtained in real time, the corresponding warning information under the same battery type and aging degree can be found in the database. This warning information is the warning information of the single battery.

Wherein, the information acquisition module 201 specifically includes:

The information receiving unit is used for the monitoring and early warning platform to receive the battery information of each single battery collected in real time by the battery management system sent by the relay module.

The information receiving unit specifically includes:

a third judging unit, configured to judge whether the monitoring and early warning platform has received the battery information of each single battery sent by the vehicle-mounted terminal, and obtain a third judgment result;

The data conversion unit is used for the third judgment result to indicate that the monitoring and early warning platform has not received the battery information of the individual cells sent by the vehicle terminal, and then receives the individual cells sent by the charging pile. Battery information for the battery.

In the present invention, the monitoring and early warning platform can also update the warning information of each battery in the database of the monitoring and early warning platform with different aging degrees through regular test tests, which makes the charging monitoring safer.

FIG. 3 is a diagram showing the relationship between the battery voltage of the electric vehicle and the remaining battery power according to the embodiment of the present invention. Referring to FIG. 3 , the early warning information of various types of batteries with different aging degrees is extracted through experiments and is specifically as follows:

(1) Perform constant current charging on batteries of different types and different aging degrees at different charging rates, and do not set the cut-off voltage until the battery deformation records the voltage V and the state of charge SOC of the battery.

(2) Make a curve with the voltage V as the abscissa and dV/dSOC as the ordinate.

(3) There will be a peak in the curve, and the voltage corresponding to the beginning of the peak is the second pre-warning voltage value, and the voltage corresponding to the maximum peak value is the first pre-warning voltage value.

At the same time, the present invention also relates to a method for extracting the first warning voltage value and the second warning voltage value. The specific method is:

(1) Draw the basic voltage and temperature curves when the battery is charged to the bulge under different magnifications, see Figure 4 and Figure 5. Through the comparative analysis of the experimental results, it can be seen that the voltage and temperature rise cannot be used as the characterization parameters for online monitoring of battery charging safety, because the temperature rise and voltage change at different rates are too different. The battery is calibrated and the rules are obtained.

(2) Perform feature extraction on the curve during charging, and demonstrate the effectiveness of using the extracted amount to express the warning information. The curve represented by the voltage change rate (Fig. 6) and the temperature change rate (Fig. 7) can be analyzed from the processed experimental data. It is reasonable to use the voltage change rate and the temperature change rate to characterize the charging safety parameters than the direct use of the temperature and voltage, because the voltage change rate curve and the temperature change rate curve under different magnifications have the same shape.

Taking the voltage change rate as an example, each charging rate corresponds to a peak value, the moment when the peak value starts can be selected as an alternative second warning voltage value, and the moment when the peak value is reached can be selected as an alternative first warning voltage value.

Taking the temperature change rate as an example, each charging rate corresponds to an inflection point, and this inflection point is used as an alternative second warning voltage value.

The second warning voltage value extracted from the temperature change rate is compared with the second warning voltage value extracted from the voltage change rate, and it is found that the information extracted from the voltage change rate is earlier than the information extracted from the temperature change rate.

Through the above analysis, the voltage change rate peak start time and peak peak value are used as early warning information, but there is a certain gap between the values under different charging rates. It is difficult to perform early warning online. It is necessary to identify the charging rate and then decouple it. Finally, an early warning signal is given at the obtained charging rate.

(3) Further processing and simplification of charging safety boundary parameters

Taking the voltage change rate as the ordinate and the voltage as the abscissa, please refer to Figure 8(a) and Figure 8(b). Left and right, the peak value is also very close, about 4.1V or so. Therefore, the voltage corresponding to the peak start is used as the second pre-warning voltage value, and the voltage corresponding to the peak maximum value is the first pre-warning voltage value.

The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the various embodiments can be referred to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant part can be referred to the description of the method.

In this paper, specific examples are used to illustrate the principles and implementations of the present invention. The descriptions of the above embodiments are only used to help understand the methods and core ideas of the present invention; meanwhile, for those skilled in the art, according to the present invention There will be changes in the specific implementation and application scope. In conclusion, the contents of this specification should not be construed as limiting the present invention.

Claims (6)

1. an electric vehicle charging early warning method, is characterized in that, comprises: Obtain the battery information of each single battery in the electric vehicle; the battery information includes the vehicle model and historical charging data; Real-time measurement of the charging real-time voltage of each single battery; Determine the battery type of the electric vehicle according to the vehicle model; Judging the aging degree of the single battery of the electric vehicle according to the historical charging data; obtaining early warning information of the single battery according to the battery type and the aging degree; Determine a first warning voltage value and a second warning voltage value according to the warning information; the second warning voltage value is smaller than the first warning voltage value; Judging whether the real-time charging voltage is greater than or equal to the second warning voltage value, and obtaining a first judgment result; If the first determination result indicates that the real-time charging voltage is not greater than the second warning voltage value, a high-rate charging mode is performed; the high-rate charging mode is charging based on the second set power; If the first determination result indicates that the real-time charging voltage is greater than the second pre-warning voltage value, determine whether the real-time charging voltage is less than the first pre-warning voltage value, and obtain a second determination result; If the second determination result indicates that the real-time charging voltage is lower than the first warning voltage value, an alarm is issued and the high-rate charging mode is changed to a small-rate charging mode; the small-rate charging mode is set to the first setting The power is standard for charging, and the second set power is greater than the first set power; If the second determination result indicates that the real-time charging voltage is not less than the first warning voltage value, stop charging; Wherein, the first warning voltage value and the second warning voltage value are determined according to the dV/dSOC curve and the dT/dSOC curve. 2 . The early warning method according to claim 1 , wherein the acquiring battery information of each single battery in the electric vehicle specifically includes: 2 . The monitoring and early warning platform receives the battery information of each single battery collected in real time by the battery management system and sent by the relay module. 3. The early-warning method according to claim 2, wherein the monitoring and early-warning platform receives the battery information of each single battery collected in real time by the battery management system sent by the relay module, and specifically includes: Judging whether the monitoring and early warning platform has received the battery information of each single battery sent by the vehicle terminal, and obtaining a third judgment result; If the third judgment result indicates that the monitoring and early warning platform has not received the information of each single battery sent by the vehicle terminal, it will receive the battery information of each single battery sent by the charging pile; otherwise, according to the The vehicle model determines the battery type of the electric vehicle. 4. An electric vehicle charging early warning system, characterized in that, comprising: an information acquisition module, used for acquiring battery information of each single battery in the electric vehicle; the battery information includes the vehicle model and historical charging data; A real-time voltage measurement module, used for real-time measurement of the real-time charging voltage of each single battery; a battery type judging module for judging the battery type of the electric vehicle according to the vehicle model; a battery state judging module, configured to judge the aging degree of the single battery of the electric vehicle according to the historical charging data; an early warning information determination module, configured to obtain early warning information of the single battery according to the battery type and the aging degree; an early warning value determination module, configured to determine a first early warning voltage value and a second early warning voltage value according to the early warning information; the second early warning voltage value is smaller than the first early warning voltage value; a first judgment module, configured to judge whether the real-time charging voltage is greater than the second pre-warning voltage value, and obtain a first judgment result; The high-rate charging module is used for the first determination result to indicate that the real-time charging voltage is not greater than the second warning voltage value, and then the high-rate charging mode is performed; the high-rate charging mode is based on the second set power as standard charging; The second judgment module is used for the first judgment result to indicate that the real-time charging voltage is greater than the second pre-warning voltage value, then judging whether the real-time charging voltage is less than the first pre-warning voltage value, and obtaining a second judgment result ; A charging change module, configured to issue an alarm if the second determination result indicates that the real-time charging voltage is lower than the first warning voltage value and convert the high-rate charging mode into a small-rate charging mode; the small-rate charging mode is: The first set power is used as the standard for charging, and the second set power is greater than the first set power; a charging stop module, configured to stop charging if the second determination result indicates that the real-time charging voltage is not less than the first warning voltage value; Wherein, the first warning voltage value and the second warning voltage value are determined according to the dV/dSOC curve and the dT/dSOC curve. 5. The early warning system according to claim 4, wherein the information acquisition module specifically comprises: The information receiving unit is used for the monitoring and early warning platform to receive the battery information of each single battery collected in real time by the battery management system sent by the relay module. 6. The early warning system according to claim 5, wherein the information receiving unit specifically comprises: a third judging unit, configured to judge whether the monitoring and early warning platform has received the battery information of each single battery sent by the vehicle terminal, and obtain a third judgment result; The data conversion unit is used for the third judgment result indicating that the monitoring and early warning platform has not received the battery information of each single battery sent by the vehicle terminal, and then receiving the battery information of each single battery sent by the charging pile. Battery information; otherwise, determine the battery type of the electric vehicle according to the vehicle model.

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