WO2022036831A1

WO2022036831A1 - Battery heating strategy optimization method based on battery and charging capacity of charging pile

Info

Publication number: WO2022036831A1
Application number: PCT/CN2020/121187
Authority: WO
Inventors: 严国刚; 张巍; 李春; 熊金峰; 张建利; 薛凯哲; 朱恒; 方兰兰; 邱远红
Original assignee: 金龙联合汽车工业（苏州）有限公司
Priority date: 2020-08-18
Filing date: 2020-10-15
Publication date: 2022-02-24
Also published as: CN112083338B; CN112083338A

Abstract

A battery heating strategy optimization method based on a battery and the charging capacity of a charging pile, comprising: obtaining an output current I2 of a charging pile when a charging gun of the charging pile is connected to a power battery system; obtaining the temperature and SOC value of a power battery in real time, and querying a DC charging rate table to obtain the maximum allowable charging current I1 of the power battery; and comparing I2 and I1, and if I2 is greater than or equal to I1, querying the DC charging rate table and using the lowest temperature corresponding to the maximum allowable charging current of the power battery as a target battery heating temperature, or if I2 is less than I1, querying the DC charging rate table and using the lowest temperature corresponding to I2 as the target battery heating temperature, such that continuous charging with a small current can be achieved, and because the battery generates heat during a charging process, the effects of reducing energy consumption and keeping warm can be achieved, thereby optimizing the battery heating strategy to achieve the purpose of reducing energy consumption and saving resources. The present solution is especially suitable for charging scenarios at night in cold areas.

Description

Optimization method of battery heating strategy based on charging capacity of battery and charging pile

technical field

The invention belongs to the field of electric vehicle power battery management, and in particular relates to a battery heating strategy optimization method based on the charging capability of a battery and a charging pile.

Background technique

When a new energy vehicle is charged at different temperatures, it is necessary to query the corresponding DC charging rate table according to the current SOC and temperature values to obtain the current allowable charging current of the battery. Under normal circumstances, the output current of the charging pile can respond to the charging current required by the battery. However, due to the different charging pile products on the market, especially the relatively early charging piles, the charging capacity is weak and the output current provided is relatively low, which cannot reach the battery's output current. need.

Since the current required by the battery at different temperatures is different, when the battery temperature is lower, the battery can receive a lower current and the charging speed is correspondingly reduced. In order to achieve a better charging environment, the battery needs to heat itself to increase the demand capacity. For most heating strategies, an optimal temperature for the battery is generally set, ignoring the energy consumption of this process and the maximum capacity that the charging pile can provide. When the output current of the charging pile can completely follow the requested current of the battery, the battery is suitable for rapid heating to the maximum adaptive value to achieve the maximum charging speed. However, if the output capacity of the charging pile is very weak and cannot meet the demand value of the battery, the energy of heating the battery to a higher temperature at this time is wasted. Alternatively, if the battery does not pursue charging speed, it is also not necessary to heat the temperature to the maximum adaptive value. Hence the invention.

SUMMARY OF THE INVENTION

In view of the above-mentioned technical problems, the purpose of the present invention is to provide a battery heating strategy optimization method based on the charging capacity of the battery and the charging pile, comparing the demanded current of the battery and the output current of the charging pile, and the lower value of the two corresponds to the DC current of the battery. The temperature in the charging rate table is set as the target temperature for battery heating, which can reduce the energy consumption of the entire vehicle and optimize the configuration.

The technical scheme of the present invention is:

A battery heating strategy optimization method based on the charging capability of a battery and a charging pile, comprising the following steps:

S01: When the charging gun of the charging pile is connected to the power battery system, obtain the output current I2 of the charging pile;

S02: Obtain the temperature and SOC value of the power battery in real time, and query the DC charging rate table to obtain the maximum allowable charging current value I1 of the power battery;

S03: Compare the output current I2 of the charging pile and the maximum allowable charging current I1 of the power battery. If I2 is greater than or equal to I1, query the DC charging rate table and use the minimum temperature corresponding to the maximum allowable charging current of the power battery as the battery heating target temperature;

S04: If I2 is less than I1, query the DC charging rate table and use the lowest temperature corresponding to I2 as the battery heating target temperature.

In a preferred technical solution, before the step S01, it also includes:

The vehicle network time is obtained, and if the charging time is greater than the first threshold, it is determined that the vehicle is charged at night; otherwise, step S01 is performed.

In a preferred technical solution, when it is judged to be charging at night, the battery management system detects the minimum temperature T of the battery in the power battery system, and if T is less than the second threshold, it is judged to be charging at night in a cold area, and the following steps are performed:

S11: Obtain the required charging duration h, the required charging capacity c, and obtain the charging current I=c/h, then the charging rate of the battery required current I1 is I/nominal capacity C;

S12: Obtain the SOC value, and check the DC charging rate table according to min{I1, I2} to obtain the battery heating target temperature.

In a preferred technical solution, the method for calculating the charging demand duration h in the step S11 includes:

Obtain the time t1 when the charging gun of the charging pile is connected to the power battery system;

Obtain the driving time t2 of the second day through the itinerary or historical data;

Calculate h=t2-t1.

The invention also discloses a battery heating strategy optimization system based on the charging capability of the battery and the charging pile, comprising:

The output current acquisition module of the charging pile: when the charging gun of the charging pile is connected to the power battery system, the output current I2 of the charging pile is obtained;

The maximum allowable charging current calculation module of the battery can obtain the temperature and SOC value of the power battery in real time, and query the DC charging rate table to obtain the maximum allowable charging current value I1 of the power battery;

The first processing operation module compares the output current I2 of the charging pile and the maximum allowable charging current I1 of the power battery. If I2 is greater than or equal to I1, query the DC charging rate table and use the minimum temperature corresponding to the maximum allowable charging current of the power battery as the battery heating. Target temperature; if I2 is less than I1, query the DC charging rate table and use the lowest temperature corresponding to I2 as the battery heating target temperature.

In a preferred technical solution, a first judging module is further included to obtain the vehicle network time, and if the charging time is greater than the first threshold, it is judged to be charging at night, otherwise, the first processing and computing module is executed.

In a preferred technical solution, a second processing and computing module is also included. When it is determined that it is charging at night, the battery management system detects the minimum temperature T of the battery in the power battery system. Perform the following steps:

Calculate h=t2-t1.

Compared with the prior art, the beneficial effects of the present invention are:

The method of the present invention is based on the output capacity of the charging pile and the charging capacity of the battery, compares the demanded current of the battery with the output current of the charging pile, and takes the lower value of the two corresponding to the temperature in the battery DC charging rate table, and sets the temperature as the heating value of the battery. Target temperature, heating to target temperature, continuous low-current charging, due to the heat of the battery during the charging process, it can reduce consumption and increase heat preservation, so that the battery heating strategy can be optimized to achieve the purpose of reducing energy consumption and saving resource allocation, especially It is suitable for charging at night in cold areas.

Description of drawings

Below in conjunction with accompanying drawing and embodiment, the present invention is further described:

1 is a flowchart of a method for optimizing a battery heating strategy based on the charging capability of a battery and a charging pile according to the present invention;

FIG. 2 is a flow chart of an optimization method including charging at night in cold regions according to the present invention.

detailed description

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the specific embodiments and the accompanying drawings. It should be understood that these descriptions are exemplary only and are not intended to limit the scope of the invention. Also, in the following description, descriptions of well-known structures and techniques are omitted to avoid unnecessarily obscuring the concepts of the present invention.

A battery heating strategy optimization system based on the charging capabilities of batteries and charging piles, including:

The output current acquisition module of the charging pile: when the charging gun of the charging pile is connected with the power battery system, the output current I2 of the charging pile is obtained; when the charging gun is connected with the power battery system, information exchange will be carried out, and the information of both parties can be obtained.

The maximum allowable charging current calculation module of the battery can obtain the temperature and SOC value of the power battery in real time, and query the DC charging rate table to obtain the maximum allowable charging current value I1 of the power battery; the temperature and SOC value of the power battery can be obtained through the battery management system BMS.

After the target temperature is obtained, it can be heated by the power battery system, and the power battery system can be the system disclosed in CN 110635183 A, which is not repeated in the present invention.

The first judging module obtains the network time of the vehicle, and if the charging time is greater than the first threshold, it is judged that it is charging at night, otherwise, the first processing and computing module is executed. For example, the time information of the GPRS module, the wireless communication module, etc. can be obtained to obtain the network time.

The second processing and computing module, when it is judged to be charging at night, the battery management system detects the minimum temperature T of the battery in the power battery system, and if T is less than the second threshold, it is judged to be charging in the cold area at night, and the following steps are performed:

S11: Obtain the charging demand duration h and the demanded charging capacity c, and obtain the charging current I=c/h, then the charging rate of the battery demand current I1 is I/nominal capacity C; the calculation method of the charging demand duration h includes:

Calculate h=t2-t1.

As shown in Figure 1, a battery heating strategy optimization method based on the charging capacity of batteries and charging piles includes the following steps:

When judging whether it is suitable for charging at night in cold areas, as shown in Figure 2, the following steps are included:

The vehicle network time is obtained, and if the charging time is greater than the first threshold, it is determined to be charged at night, otherwise step S01 is performed; the first threshold may be 20:00 and so on. When it is determined to be charged at night, the battery management system detects the minimum temperature T of the battery in the power battery system. If T is less than the second threshold, it is determined to be charged in a cold area at night, and the following steps are performed:

The second threshold may be 0° and so on.

The following is an example of a power battery, and its DC charging rate table is as follows:

Example 1:

Step 1: When the battery is charging, first obtain the charging capacity of the charging pile, and the output current capacity I2 is less than or equal to 0.5C;

Step 2: When the battery temperature is -2°C and the SOC is 50, check the DC charging rate table, and get the allowable current value I1 that the battery can accept is 0C. At this time, the battery cannot be charged because the temperature does not meet the charging conditions and needs to be set. battery heating target temperature;

Step 3: Since the output capacity of the charging pile is only 0.5C, you only need to check the DC charging rate table and set the battery heating target temperature to the lowest temperature corresponding to the 0.5C capacity. In this case, you only need to set the battery heating temperature to 12 °C. Because even if the battery temperature is heated to higher than 12°C at this time, the charging pile has reached the maximum output power, and raising the target temperature at this time is only a waste of energy consumption.

Step 4: The whole charging process is a dynamic change process. If the output power of the charging pile also changes, follow I1 and I2, whichever is smaller, and then refer to the SOC to adjust the target temperature.

Example 2:

Step 1: When charging the battery, first obtain the charging capacity of the charging pile, and the output current capacity I2 is greater than 1C, indicating that the charging pile can fully meet the needs of the battery;

Step 2: Since the charging pile can meet the requirements of the battery, it is only necessary to set the target temperature of the battery to the required temperature at the maximum working capacity.

Example 3:

Charge at night, start charging at 24:00 in the evening, start driving at 6:00 in the morning the next day, SOC=17, and the charging time length is 6h. The required capacity value of the rechargeable battery this time is about 200Ah, and the nominal capacity of the battery is 240Ah.

Step 1: When charging the battery, first obtain the charging capacity of the charging pile, and the output current capacity I2 is 0.2C;

Step 2: The calculation result of the required charging rate of the battery is about c/h/C=200/6/240=0.14C;

Step 3: Since the required charging current value of the battery is 0.14C lower than the output capacity of the charging pile 0.2C, it is only necessary to check the table according to the standard of taking the smaller value of the two, that is, 0.14C. At this time, the target heating temperature of the battery needs to be set as 6 ℃, the charging process is affected by the heat of the battery, the battery temperature will increase slightly, and the charging speed will increase slightly. The charging process at night also has a thermal insulation effect and reduces heating energy consumption.

It should be understood that the above-mentioned specific embodiments of the present invention are only used to illustrate or explain the principle of the present invention, but not to limit the present invention. Therefore, any modifications, equivalent replacements, improvements, etc. made without departing from the spirit and scope of the present invention should be included within the protection scope of the present invention. Furthermore, the appended claims of this invention are intended to cover all changes and modifications that fall within the scope and boundaries of the appended claims, or the equivalents of such scope and boundaries.

Claims

A method for optimizing a battery heating strategy based on the charging capability of a battery and a charging pile, comprising the following steps:

S01: When the charging gun of the charging pile is connected to the power battery system, obtain the output current I2 of the charging pile;

S02: Obtain the temperature and SOC value of the power battery in real time, and query the DC charging rate table to obtain the maximum allowable charging current value I1 of the power battery;

S03: Compare the output current I2 of the charging pile and the maximum allowable charging current I1 of the power battery. If I2 is greater than or equal to I1, query the DC charging rate table and use the minimum temperature corresponding to the maximum allowable charging current of the power battery as the battery heating target temperature;

S04: If I2 is less than I1, query the DC charging rate table and use the lowest temperature corresponding to I2 as the battery heating target temperature.
The battery heating strategy optimization method based on the charging capability of the battery and the charging pile according to claim 1, wherein before the step S01, the method further comprises:

The vehicle network time is obtained, and if the charging time is greater than the first threshold, it is determined that the vehicle is charged at night; otherwise, step S01 is performed.
The battery heating strategy optimization method based on the charging capacity of the battery and the charging pile according to claim 2, wherein when it is determined to be charged at night, the battery management system detects the lowest temperature T of the battery in the power battery system, and if T is less than the th When the second threshold is reached, it is judged to be charging in a cold area at night, and the following steps are performed:

S11: Obtain the required charging duration h, the required charging capacity c, and obtain the charging current I=c/h, then the charging rate of the battery required current I1 is I/nominal capacity C;

S12: Obtain the SOC value, and check the DC charging rate table according to min{I1, I2} to obtain the battery heating target temperature.
The battery heating strategy optimization method based on the charging capacity of the battery and the charging pile according to claim 1, wherein the method for calculating the charging demand duration h in the step S11 includes:

Obtain the time t1 when the charging gun of the charging pile is connected to the power battery system;

Obtain the driving time t2 of the second day through the itinerary or historical data;

Calculate h=t2-t1.
A battery heating strategy optimization system based on the charging capabilities of batteries and charging piles, characterized in that it includes:

The output current acquisition module of the charging pile: when the charging gun of the charging pile is connected to the power battery system, the output current I2 of the charging pile is obtained;

The maximum allowable charging current calculation module of the battery can obtain the temperature and SOC value of the power battery in real time, and query the DC charging rate table to obtain the maximum allowable charging current value I1 of the power battery;

The first processing operation module compares the output current I2 of the charging pile and the maximum allowable charging current I1 of the power battery. If I2 is greater than or equal to I1, query the DC charging rate table and use the minimum temperature corresponding to the maximum allowable charging current of the power battery as the battery heating. Target temperature; if I2 is less than I1, query the DC charging rate table and use the lowest temperature corresponding to I2 as the battery heating target temperature.
The battery heating strategy optimization system based on the charging capability of the battery and the charging pile according to claim 5, further comprising a first judgment module to obtain the vehicle network time, and if the charging time is greater than the first threshold, it is judged to be charging at night, Otherwise, execute the first processing operation module.
The battery heating strategy optimization system based on the charging capacity of the battery and the charging pile according to claim 6, further comprising a second processing and computing module, when it is determined to be charged at night, the battery management system detects the battery in the power battery system. The lowest temperature T, if T is less than the second threshold, it is determined that the charging is in the cold area at night, and the following steps are performed:

S11: Obtain the required charging duration h, the required charging capacity c, and obtain the charging current I=c/h, then the charging rate of the battery required current I1 is I/nominal capacity C;

S12: Obtain the SOC value, and check the DC charging rate table according to min{I1, I2} to obtain the battery heating target temperature.
The battery heating strategy optimization system based on the charging capacity of batteries and charging piles according to claim 5, wherein the method for calculating the charging demand duration h in the step S11 includes:

Obtain the time t1 when the charging gun of the charging pile is connected to the power battery system;

Obtain the driving time t2 of the second day through the itinerary or historical data;

Calculate h=t2-t1.