KR20200006773A - Apparatus for rapid charger in electric vehicle and method for rapid charging - Google Patents

Abstract

The present invention relates to a quick charging device for an electric vehicle with improved charging efficiency, and a charging method thereof. According to an embodiment of the present invention, the quick charging device includes: a communication processing module which receives battery information including the battery charging state of a battery for an electric vehicle by communicating with the electric vehicle; a charging unit which is formed with a plurality of unit capacity charging modules performing charging for each unit capacity; a maximum efficiency database which stores information on the maximum efficiency of an output capacity for each battery voltage group during a charging operation of the unit capacity charging module; and a central control unit which determines a maximum efficiency combination, a unit capacity charging module combination having the maximum efficiency while satisfying the required charging amount of the battery by considering the maximum efficiency of an output capacity for each battery voltage group in a database with the maximum efficiency after calculating the battery voltage and the required charging amount of the battery according to the charging state of the battery and then, charges the battery of the electric vehicle by using the unit capacity charging module formed in the determined maximum efficiency combination.

Description

Apparatus for rapid charger in electric vehicle and method for rapid charging}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a quick charging device for an electric vehicle and a charging method thereof, and more particularly to a quick charging device for an electric vehicle and a charging method thereof having improved charging efficiency.

In the 2000s, eco-friendly automobile development was designated as a core strategic industry at the national level as well as multinational companies, and has been enthusiastic in developing eco-friendly automobiles.

Negotiated electric vehicles (electric vehicles in the pure sense) are those that connect the power plug to a car in a normal home or charging station, charge the secondary battery using a charging device, and drive the car using the charged electric energy. The Plug-In Hybrid Electric Vehicle basically connects the power plug to the vehicle to charge the secondary battery and drives the vehicle using the charged electric energy. When the charged electric energy is insufficient, general fossil fuel is used for emergency purposes. The plug-in hybrid vehicle is also called a grid-connected hybrid electric vehicle.

On the other hand, the type of charger for an electric vehicle battery is classified into a quick charger and a slow charger.

The fast charger is a DC charger installed in an electric charging station in the same concept as a gas station for gasoline, and the charging time of the battery is within 30 minutes, and the charging capacity is about 50kW or more. AC power supply that charges the power of the battery by using a separate charger, the battery charging time is about 6-7 hours, the charging capacity of the AC power supply within about 10kW.

In charging a battery of an electric vehicle in a short time using the quick charger, the charging efficiency of the quick charger is important.

However, the conventional rapid charger has a problem of inferior charging efficiency because it is rapidly charging with the same output capacity regardless of the battery type. That is, even though batteries with different charge / discharge capacities and battery voltages are adopted in each electric vehicle, the rapid charger is charged with the same output capacity without considering the battery specifications mounted in the electric vehicle, resulting in charging. There is a problem of low efficiency. For example, in the case of medium-capacity fast chargers, the efficiency depends on the magnitude and current of the output voltage.

As a result, the user pays a certain amount of power charge to charge the battery of the electric vehicle, resulting in the consumer paying the power charge caused by the efficiency reduction of the quick charging device for the electric vehicle.

Korean Patent Registration No. 10-1202814

The technical problem of the present invention is to improve the charging efficiency of the rapid charging system for an electric vehicle.

Embodiments of the present invention provide a communication processing module configured to communicate with an electric vehicle and receive battery information including a state of charge of a battery of the electric vehicle battery; A charging unit consisting of a plurality of unit capacity charging modules for charging by unit capacity; A maximum efficiency database in which the unit capacity charging module stores information on the maximum efficiency of the output capacity for each battery voltage group during a charging operation; And after calculating the battery voltage and the battery charging necessary amount according to the battery charging state, considering the maximum efficiency of the output capacity for each battery voltage group in the maximum efficiency database, and charging the unit capacity having the maximum efficiency while satisfying the battery charging requirement. And a central control unit configured to determine a maximum efficiency combination that is a module combination and charge the battery of the electric vehicle by using the unit capacity charging module of the determined maximum efficiency combination.

The central control unit generates a plurality of candidate output combinations consisting of the number of charging modules of the unit-capacity charging module and the output amount for each charging module satisfying the battery charging requirement, and then the candidate output combination having the maximum efficiency among the candidate output combinations. Can be determined as the maximum efficiency combination.

Determining the candidate output combination having the maximum efficiency among the candidate output combinations as the maximum efficiency combination may determine the candidate output combination having the lowest power loss among the candidate output combinations as the maximum efficiency combination.

The plurality of unit capacity charging modules may be characterized in that the charging module having the same unit capacity.

In addition, the present invention, the fast charging device for an electric vehicle, the battery information receiving process for receiving battery information including the state of charge of the battery from the electric vehicle connected for battery charging; A battery charging required amount calculating step of calculating, by the quick charging device for an electric vehicle, a battery voltage and a battery charging amount according to the battery charging state; Determination of the maximum efficiency combination in which the quick charging device for the electric vehicle determines a maximum efficiency combination that is a unit capacity charging module combination having the maximum efficiency while satisfying the battery charging requirement in consideration of the maximum efficiency of the preset output capacity for each battery voltage group. process; And a battery charging process in which the quick charging device for the electric vehicle charges the battery of the electric vehicle as the maximum efficiency combination.

The determining of the maximum efficiency combination may include: generating a candidate output combination that generates a plurality of candidate output combinations including the number of charging modules of the unit-capacity charging module and an output amount for each charging module that satisfy the battery charging requirement; And a maximum efficiency combination extraction process of extracting a candidate output combination having the maximum efficiency among the candidate output combinations and determining the maximum efficiency combination.

Extracting the candidate output combination having the maximum efficiency and determining it as the maximum efficiency combination may determine the candidate output combination having the lowest power loss among the candidate output combinations as the maximum efficiency combination.

According to the embodiment of the present invention, by charging the electric vehicle as a plurality of unit capacities and individual output amounts, it is possible to improve the fast charging efficiency for the battery for the electric vehicle.

1 is a block diagram of a quick charging device for an electric vehicle with improved charging efficiency according to an exemplary embodiment of the present invention.
2 is an illustration of a charging unit consisting of a plurality of unit capacity charging modules in accordance with an embodiment of the invention.
3 is a graph showing the maximum efficiency of each unit capacity charging module according to a specific battery voltage group according to an embodiment of the present invention.
Figure 4 is an illustration of the input and loss based on the maximum efficiency of the unit capacity charging module according to a specific battery voltage group according to an embodiment of the present invention.
5 is an exemplary diagram showing the power loss magnitude of each candidate output combination when charging 7kW according to an embodiment of the present invention.
6 is an exemplary diagram showing the power loss magnitude of each candidate output combination when charging 10kW according to an embodiment of the present invention.
7 is a flowchart illustrating a rapid charging method for an electric vehicle with improved charging efficiency according to an embodiment of the present invention.

Advantages and features of the present invention, and methods for achieving them will be apparent with reference to the embodiments described below in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various forms, and is provided to fully inform the scope of the invention to those skilled in the art. The invention is defined only by the scope of the claims. In addition, in describing the present invention, when it is determined that related related technologies and the like may obscure the gist of the present invention, detailed description thereof will be omitted.

1 is a block diagram of a quick charging device for an electric vehicle with improved charging efficiency according to an embodiment of the present invention, Figure 2 is an illustration of a charging unit consisting of a plurality of unit capacity charging module according to an embodiment of the present invention. 3 is a graph illustrating the maximum efficiency of each unit capacity charging module according to a specific battery voltage group according to an embodiment of the present invention, and FIG. 4 is a unit capacity charging according to a specific battery voltage group according to an embodiment of the present invention. Example of input and loss based on the maximum efficiency of the module, Figure 5 is an illustration showing the power loss of each candidate output combination when charging 7kW according to an embodiment of the present invention, Figure 6 is an embodiment of the present invention For example, the power loss of each candidate output combination when charging 10kW is shown.

The rapid charging apparatus for an electric vehicle of the present invention may include a communication processing module 300, a charging unit 400, a maximum efficiency database 100, and a central control unit 200 as shown in FIG. 1. .

The communication processing module 300 communicates with the electric vehicle to receive battery information including a state of charge of the battery of the electric vehicle battery. When coupled with the battery of an electric vehicle, the battery may be connected through an electric vehicle communication controller (EVCC), which is a communication modem for charging the electric vehicle, or a battery management system (BMS). Information on the status and battery charge can be received from the electric vehicle.

The charging unit 400 is a charger including a plurality of unit capacity charging modules 410 that perform charging for each unit capacity.

The charging unit 400 may include a plurality of unit capacity charging modules 410. For example, the charging unit 400 may be implemented as a charging module having the same unit capacity. That is, as shown in (a) of FIG. 2, the 5kW unit capacity charging module having a 5kW output capacity may be implemented. Likewise, as shown in FIG. 2 (b), it can be implemented as five 2 kW unit capacity charging modules having a 2 kW output capacity, or as shown in FIG. 2 (c) 4 kW unit capacity charging having a 4 kW output capacity. It can be implemented in five modules.

The maximum efficiency database 100 is a storage unit in which information about the maximum efficiency of output capacity for each battery voltage group is stored when the unit capacity charging module 410 is charged. Such a storage medium may include a hard disk drive, a solid state drive, a flash memory, a compact flash card, a secure digital card, and a smart card. Card, MMC card (Multi-Media Card) or a memory stick (Memory Stick) module that can input and output information may be provided inside the device, or may be provided in a separate device.

In general, the maximum efficiency varies according to the size and output capacity of the battery voltage, and thus the maximum efficiency for each output capacity of each unit capacity charging module 410 is allocated to the maximum efficiency database 100 and stored. will be.

For example, when performing the charging output at a specific battery set voltage, as shown in Figure 3, the 5kW unit capacity charging module has a 92% efficiency when outputting 1kW capacity, the 5kW unit capacity charging module is 2kW capacity It has 94% efficiency when outputting, 5kW unit charge module has 95% efficiency when outputting 3kW capacity, and 5kW unit charge module has 94.5% efficiency when outputting 4kW capacity, and charges 5kW unit capacity. The module has a 94.7% efficiency when outputting 2kW capacity, which is stored in the maximum efficiency database 100.

As the efficiency varies depending on the output capacity of the unit capacity charging module 410, a loss that is a difference between an input and an output occurs.

Referring to FIG. 4, for example, when the unit capacity charging module 410 operates for 1 kW of charging, the unit capacity charging module 410 has an efficiency of 92%, and thus, 1 kW output is required only when 1080W is input, thereby providing input and output. Has a difference of 80W.

In addition, when the unit capacity charging module 410 is operated for charging of 2kW capacity, it has a maximum efficiency of 94%. Thus, 2kW output is required only when 2120W is input, resulting in a loss of 120W, which is a difference between an input and an output.

In addition, when the unit capacity charging module 410 is operated for charging of 3kW capacity, it has a maximum efficiency of 95%, and 3150W can be output only when 3150W is input, thereby having a loss of 150W, which is a difference between an input and an output.

In addition, when the unit capacity charging module 410 operates for 4kW capacity charging, it has a maximum efficiency of 94.5%, and 4220W can be output only when 4220W is input, resulting in a loss of 220W which is a difference between an input and an output.

In addition, when the unit capacity charging module 410 is operated for charging of 5kW capacity, it has a maximum efficiency of 94.7% and is capable of outputting 5kW only when 1080W is input, resulting in a loss of 2650W, which is a difference between an input and an output.

On the other hand, as described above, the maximum efficiency is changed as shown in Figure 3 according to the output capacity performed by the unit capacity charging module 410 and as a result, the loss of the unit capacity charging module 410 occurs, Therefore, in the present invention, the unit capacity charging module 410 actually determines the combination of the number of charging modules of the unit capacity charging module 410 and the output amount for each charging module in consideration of the maximum efficiency of the output according to the voltage of the battery.

To this end, the central control unit 200 first determines the battery voltage obtained through the BMS communication, and calculates the battery voltage and the battery charging necessary amount according to the battery charging state. For example, when the battery information is received and the battery capacity is 10kW but currently only 3kW, the battery charge required is 7kW. Similarly, when the battery information is received and the battery capacity is 10kW but currently only 1kW, the battery charge required is 9kW.

After the calculation of the required charging amount as described above, the central control unit 200, in consideration of the maximum efficiency of the output capacity for each battery voltage group in the maximum efficiency database 100, the unit capacity having the maximum efficiency while satisfying the battery charging requirements The maximum efficiency combination that is the combination of the charging module 410 is determined.

That is, the central control unit 200 generates a plurality of candidate output combinations consisting of the number of charging modules of the unit capacity charging module 410 and the output amount for each charging module that satisfies the required amount of battery charging, and then the maximum efficiency among the candidate output combinations. The candidate output combination with is determined as the maximum efficiency combination. Once the maximum efficiency combination is determined, the central control unit 200 charges the battery of the electric vehicle using the unit capacity charging module 410 of the determined maximum efficiency combination.

In determining the maximum efficiency combination having the maximum efficiency among the candidate output combinations, the candidate output combination having the lowest power loss among the candidate output combinations is determined as the maximum efficiency combination.

For example, when the maximum output amount of the unit capacity charging module 410 is 5kW in a specific battery voltage group, and the battery charging requirement is 7kW, four candidate output combinations may be generated as shown in FIG. 5 and below. have.

1) First candidate output combination

1st unit capacity charging module 3kW output / 2nd unit capacity charging module 2kW output / 3rd unit capacity charging module 2kW output

2) Second candidate output combination

1st unit capacity charging module 3kW output / 2nd unit capacity charging module 3kW output / 3rd unit capacity charging module 1kW output

3) Third candidate output combination

1st unit capacity charging module 4kW output / 2nd unit capacity charging module 3kW output

3) 4th candidate output combination

1st unit capacity charging module 5kW output / 2nd unit capacity charging module 2kW output

As described above, the total power loss is calculated for each of the four candidate output combinations for the 7kW charge as follows.

In the case of the first candidate output combination, the first unit charge module has a 95% efficiency at 3 kW output, resulting in 150W loss, and the second unit charge module has a 94% efficiency at 2 kW output, resulting in 120W loss. The third unit capacity charging module has 94% efficiency at 2kW output, resulting in 120W loss, and the total loss at output with the first candidate output combination results in loss of 150W + 120W + 120W = 390W. .

In addition, in the case of the second candidate output combination, the first unit capacity charging module has a 95% efficiency at 3 kW output, resulting in 150W loss, and the second unit capacity charging module has a 95% efficiency at 3 kW output, resulting in 150W loss. The third unit capacity charging module has 92% efficiency at 1kW output, resulting in 80W loss, and the total loss at 150W + 150W + 80W = 380W when outputting with the second candidate output combination. do.

In addition, in the case of the third candidate output combination, the first unit capacity charging module has a 94.5% efficiency at 4kW output, resulting in 220W loss, and the second unit capacity charging module has a 95% efficiency at 3kW output, resulting in 150W loss. In the third candidate output combination, the total loss results in a loss of 220W + 150W = 370W.

In addition, in the case of the fourth candidate output combination, the first unit charge module has a 94.7% efficiency at 5 kW output, resulting in 265W loss, and the second unit charge module has a 94% efficiency at 2 kW output, resulting in 120W loss. In the fourth candidate output combination, the total loss results in a loss of 265W + 120W = 385W.

Therefore, as shown in FIG. 5, 390W loss occurs in the first candidate output combination for the 7kW output, 380W loss occurs in the second candidate output combination, and 370W loss occurs in the third candidate output combination. In the case of the fourth candidate output combination, a loss of 385W is generated, resulting in a loss of 370W, which is the smallest when outputting the third candidate output combination at a 7kW output, resulting in the maximum efficiency of the third candidate output combination. It can be seen that the branch is an output combination.

Similarly, when the maximum output amount of the unit capacity charging module 410 is 5kW, and the battery charge requirement is 10kW, four candidate output combinations may be generated as shown in FIG. 6 and below.

1) First candidate output combination

1st unit capacity charging module 3kW output / 2nd unit capacity charging module 3kW output / 3rd unit capacity charging module 3kW output / 4th unit capacity charging module 1kW output /

2) Second candidate output combination

1st unit capacity charging module 3kW output / 2nd unit capacity charging module 3kW output / 3rd unit capacity charging module 4kW output

3) Third candidate output combination

1st unit capacity charging module 5kW output / 2nd unit capacity charging module 5kW output

3) 4th candidate output combination

1st unit capacity charging module 4kW output / 2nd unit capacity charging module 4kW output / 2nd unit capacity charging module 2kW output

As described above, the total power loss is calculated for each of the four candidate output combinations for charging 10kW.

In the case of the first candidate output combination, the first unit capacity charging module has a 95% efficiency at 3 kW output, resulting in 150 W loss, and the second unit capacity charging module has a 95% efficiency at 3 kW output, resulting in 150 W loss. The third unit capacity charging module has a 95% efficiency at 3 kW output, resulting in 150 W loss, and the fourth unit capacity charging module has a 92% efficiency at 1 kW output, resulting in 80 W loss. The total loss at output with the candidate output combination results in a loss of 150W + 150W + 150W + 80W = 530W.

In addition, in the case of the second candidate output combination, the first unit capacity charging module has a 95% efficiency at 3 kW output, resulting in 150W loss, and the second unit capacity charging module has a 95% efficiency at 3 kW output, resulting in 150W loss. The third unit capacity charging module has a 94.5% efficiency at 4kW output, resulting in a loss of 220W, resulting in a total loss of 150W + 150W + 220W = 520W at the output of the second candidate output combination. do.

In addition, in the case of the third candidate output combination, the first unit capacity charging module has a 94.7% efficiency at 5 kW output, resulting in 265W loss, and the second unit capacity charging module has a 94.7% efficiency at 5 kW output, resulting in 265W loss. The total loss in output at the third candidate output combination results in a loss of 265W + 265W = 530W.

In addition, in the case of the fourth candidate output combination, the first unit capacity charging module has a 94.5% efficiency at 4 kW output, resulting in a loss of 220 W, and the second unit capacity charging module has a 94.5% efficiency at a 4 kW output, resulting in 220W loss. The third unit capacity charging module has a loss of 120W due to the 94% efficiency at 2kW output, and the total loss at the output with the fourth candidate output combination results in a loss of 220W + 220W + 120 = 560W. do.

Therefore, as shown in FIG. 5, 530 W loss occurs in the first candidate output combination for the 10 kW output, 520 W loss occurs in the second candidate output combination, and 530 W loss occurs in the third candidate output combination. In the case of the fourth candidate output combination, a loss of 560W is generated, and as a result, the smallest loss of 520W occurs when the second candidate output combination is output at 10kW output, resulting in the maximum efficiency of the second candidate output combination. It can be seen that the branch is an output combination.

7 is a flowchart illustrating a rapid charging method for an electric vehicle with improved charging efficiency according to an embodiment of the present invention.

In the rapid charging method for an electric vehicle having improved charging efficiency according to the present invention, as shown in FIG. 7, a battery information receiving process (S710), a battery charging requirement calculation process according to battery voltage (S720), and a maximum efficiency combination determination process (S730) , And a battery charging process (S740).

The battery information receiving process S710 is a process in which the quick charging device for an electric vehicle receives battery information including a battery state of charge from an electric vehicle connected for battery charging. Here, the battery information may include various types of information such as battery type, battery voltage, and battery full information in addition to the battery charging state.

In the battery charging required amount calculating process (S720), the quick charging device for an electric vehicle calculates the charging necessary amount according to the battery voltage according to the battery charging state. For example, when the battery information is received and the battery capacity is 10kW but currently only 3kW, the battery charge required is 7kW. Similarly, when the battery information is received and the battery capacity is 10kW but currently only 1kW, the battery charge required is 9kW.

The maximum efficiency combination determination process (S730) is performed after the calculation of the charging requirement as described above, in consideration of the output maximum efficiency for each of the predetermined battery voltage group, the maximum unit capacity charging module combination having the maximum efficiency while satisfying the battery charging requirements Determine the efficiency combination.

Here, the maximum efficiency combination determination process (S730) is a candidate output combination generation process of generating a plurality of candidate output combinations consisting of the number of charging modules of the unit capacity charging module 410 and the output amount for each charging module that satisfies the required amount of battery charging (S731). ) And a maximum efficiency combination extraction process (S732) of extracting a candidate output combination having the maximum efficiency from the candidate output combinations and determining the maximum efficiency combination.

After generating a plurality of candidate output combinations consisting of the number of charging modules of the unit-capacity charging module 410 and the output amount for each charging module that meets the required amount of battery charging, the candidate output combination having the maximum efficiency among the candidate output combinations is used as the maximum efficiency combination. Decide Once the maximum efficiency combination is determined, the central control unit 200 charges the battery of the electric vehicle using the unit capacity charging module 410 of the determined maximum efficiency combination.

In determining the candidate output combination having the maximum efficiency as the maximum efficiency combination, the candidate output combination having the lowest power loss among the candidate output combinations is determined as the maximum efficiency combination.

For example, when the maximum output amount of the unit capacity charging module 410 is 5kW, and the battery charge requirement is 7kW, four candidate output combinations are generated, as shown in FIG. The three candidate output combinations are determined as the maximum efficiency combination.

Similarly, when the maximum output amount of the unit capacity charging module 410 is 5kW, and the battery charge requirement is 10kW, four candidate output combinations are generated as shown in FIG. 5, and the second candidate output having the least loss among them is shown. The combination is determined as the maximum efficiency combination.

The battery charging process S740 is a process of charging the battery of the electric vehicle as the maximum efficiency combination determined in the maximum efficiency combination determination process S730.

The embodiments in the above description of the present invention are presented by selecting the most preferred examples to help those skilled in the art from the various possible examples, and the technical spirit of the present invention is not necessarily limited or limited only by the embodiments. In addition, various changes, modifications, and other equivalent embodiments may be made without departing from the technical spirit of the present invention.

100: Maximum Efficiency Database
200: central control unit
300: communication processing unit
400: charging unit

Claims (5)

A communication processing module in communication with the electric vehicle to receive battery information including a battery state of charge of the battery for the electric vehicle;
A charging unit consisting of a plurality of unit capacity charging modules for charging by unit capacity;
A maximum efficiency database in which the unit capacity charging module stores information on the maximum efficiency of the output capacity for each battery voltage group during a charging operation; And
After calculating the battery voltage and the required amount of battery charge according to the state of charge of the battery, in consideration of the maximum efficiency of the output capacity for each battery voltage group in the maximum efficiency database, the unit capacity charging module having the maximum efficiency while satisfying the battery charge requirements A central control unit for determining the maximum efficiency combination that is a combination and for charging the battery of the electric vehicle using the unit capacity charging module of the determined maximum efficiency combination;
Fast charging device for an electric vehicle improved charging efficiency comprising a.
The method according to claim 1, wherein the central control unit,
After generating a plurality of candidate output combinations consisting of the number of charging modules of the unit-capacity charging module and the output amount for each charging module satisfying the battery charging requirement, the candidate output combination having the maximum efficiency among the candidate output combinations is determined as the maximum efficiency combination. Fast charging device with improved charging efficiency.
The method of claim 1, wherein the plurality of unit capacity charging module,
Fast charging device for an electric vehicle with improved charging efficiency, characterized in that the charging module having the same unit capacity.
A battery information receiving process, wherein the quick charging device for an electric vehicle, receives battery information including a state of charge of a battery from an electric vehicle connected for battery charging;
A battery charging required amount calculating step of calculating, by the quick charging device for an electric vehicle, a battery voltage and a battery charging amount according to the battery charging state;
Determination of the maximum efficiency combination in which the quick charging device for an electric vehicle determines the maximum efficiency combination that is a unit capacity charging module combination having the maximum efficiency while satisfying the battery charging requirement in consideration of the maximum efficiency of the preset output capacity for each battery voltage group. process; And
A battery charging process, wherein the quick charging device for an electric vehicle charges a battery of an electric vehicle as the maximum efficiency combination;
Fast charging method for an electric vehicle improved charging efficiency comprising a.
The method of claim 4, wherein the determination of the maximum efficiency combination comprises:
A candidate output combination generation step of generating a plurality of candidate output combinations each consisting of the number of charging modules of the unit-capacity charging module and an output amount for each charging module that satisfy the required amount of battery charging; And
A maximum efficiency combination extraction process of extracting a candidate output combination having the maximum efficiency among the candidate output combinations and determining the maximum efficiency combination;
Fast charging method for an electric vehicle improved charging efficiency comprising a.

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