KR102623497B1 - Fast charger for electric vehicle with extended service life and charging method using the same - Google Patents

Abstract

In the rapid charging method of an electric vehicle according to an embodiment of the present invention, a charger cable including a direct current power port for rapid charging, an alternating current power port for slow charging, and a communication port for communication with the electric vehicle is connected to the charging port of the electric vehicle. , Step (S1) of starting rapid charging of the electric vehicle battery by supplying direct current power through the direct current power port, the charge of the electric vehicle battery is 80% or more, and the charging speed included in the communication signal between the charging port and the communication port Step (S2) of maintaining rapid charging of the electric vehicle battery through the DC power port until the charging speed is below the preset first speed through information about When this happens, stopping the supply of DC power and applying AC power to the charging port through the AC power port (S3), and when AC power is supplied to the charging port, the uncharged amount of the electric vehicle battery is charged through the AC power port. Including the step of slow charging all or part of the charger (S4), the maintenance cost of the charger is reduced by supplying alternating current power instead of direct current power to the section where the charging speed rapidly decreases in the latter part of fast charging, thereby reducing the usage time of the power module. This can be greatly reduced.

Description

Fast charger for electric vehicles with extended service life and charging method using the same {FAST CHARGER FOR ELECTRIC VEHICLE WITH EXTENDED SERVICE LIFE AND CHARGING METHOD USING THE SAME}

The present invention relates to a rapid charger for extending the service life of electric vehicle batteries and a rapid charging method using the same.

An electric vehicle is a vehicle that obtains its driving energy from electrical energy rather than from combustion of fossil fuels like existing internal combustion engine vehicles. It produces no exhaust gases, makes very little noise, and has lower maintenance costs and carbon dioxide emissions than conventional internal combustion engine vehicles. There are many advantages, including improvement of environmental problems due to the reduction effect.

In order to operate these electric vehicles, charging the battery to drive the motor is essential, and charging stations equipped with one or more chargers are being installed in various places such as apartment complexes, large supermarkets, parking lots of public institutions, as well as highway rest areas. When the charger cable is connected to the charging port exposed to the outside, the electric vehicle battery is charged by receiving alternating current or direct current power from the charger. The charging port and charger cable of an electric vehicle must be of the same standard to enable electrical connection and charge the battery. Charger cables and charging ports are, depending on the type of standard, a port, pin, or connector that can receive direct current power, a port, pin, or connector that can receive alternating current power, or a port that can receive both direct current and alternating current power. It is equipped with pins or connectors.

For example, referring to Figure 4a, in the case of the CCS (Combined Charging System) type 1 standard, which is widely used in Korea and North America, there are 5 pins (or connectors) for slow charging at the top and 2 pins (or connectors) for fast charging at the bottom. It consists of a combo type including a connector). Among the five pins at the top, the top two are AC power supply pins or connectors, and the bottom two are communication pins or connectors including a ground wire. The 2 pins at the bottom are pins or connectors for supplying direct current power.

In addition, referring to Figure 4b, the NACS (North American Charging Standard) type standard used in several countries, including North America, consists of a total of 5 pins or connectors, and the top 2 pins are optional for direct current or alternating current power. It is a pin or connector for supply, and the three pins at the bottom are pins or connectors for communication.

When AC power is supplied to the charging port of an electric vehicle, it is converted to direct current power through the OBC (On Board Charger) included in the electric vehicle and then supplied to the battery for charging. In this case, charging takes place at a low speed because it must go through an OBC with relatively low output. On the other hand, when direct current power is supplied to the charging port of an electric vehicle, it is directly connected to the battery for charging without going through the OBC, so charging can be done at a relatively high output and rapid charging is possible. At this time, large-capacity direct current power must be supplied from a charger, and for this, a charger capable of producing high output is needed.

A charger that supplies direct current power receives alternating current power from an external power source, converts it into direct current power through an internal power module, and supplies power to the charging port of the electric vehicle. Power modules use expensive components such as SiC power devices for stable conversion of direct current power. Recently, the output that a single power module can exert is limited to approximately 30kW, so for fast charging, about four power modules are mounted on the charger, and these power modules account for more than 40% of the total price of the charger. The lifespan of a power module is very dependent on the usage time, and as usage time accumulates, the maintenance cost burden of replacing the power module is very high.

When fast charging of DC power is performed with a charger containing multiple power modules, the initial charging speed is very fast due to the characteristics of the battery and surrounding systems, but as the charging amount increases, the later charging speed rapidly decreases. Therefore, in order to charge an electric vehicle battery to 100%, the power module must be used for a long time while maintaining a rapidly decreasing charging speed in the second half, resulting in an inefficient charging environment that only increases charger maintenance costs.

In an embodiment of the present invention, when fast charging is performed using a charger cable configured to separately include a DC power port and an AC power port or to share the same port, the initial charging is performed quickly by DC power, and the charging amount is maintained at a certain level. When this exceeds this and the charging speed decreases below a certain level, the electric vehicle fast charging method and charger are provided that drastically reduce the maintenance costs of the charger by reducing the usage time of the power module by switching to slow charging using AC power. .

The problem to be solved by the present invention is not limited to the problem(s) mentioned above, and other problem(s) not mentioned will be clearly understood by those skilled in the art from the description below.

The fast charging method for an electric vehicle according to an embodiment of the present invention involves connecting a charger cable including a direct current power port for fast charging, an alternating current power port for slow charging, and a communication port for communication with the electric vehicle to the charging port of the electric vehicle. connecting and starting rapid charging of the electric vehicle battery by supplying direct current power through the direct current power port (S1); Until the charge of the electric vehicle battery is 80% or more and the charging speed is below the first speed preset through information about the charging speed included in the communication signal between the charging port and the communication port, the DC power Maintaining rapid charging of the electric vehicle battery through a port (S2); When the charge amount is 80% or more and the charging speed is less than the first speed, stopping supply of direct current power and applying alternating current power to the charging port through the alternating current power port (S3); And when AC power is supplied to the charging port, a step (S4) of slowly charging all or part of the uncharged amount of the electric vehicle battery through the AC power port.

In the above embodiment, when AC power is not supplied to the charging port after step S3, application of AC power through the AC power port is stopped, and the DC power is supplied until the charging speed is below the preset second speed. Re-maintaining rapid charging of the electric vehicle battery by supplying direct current power through a power port (S31); And when the charging speed is lower than the preset second speed, stopping the supply of DC power and reapplying AC power to the charging port through the AC power port (S32).

In the above embodiment, the second speed may be less than the first speed.

In the above embodiment, the first speed may be 11 kW and the second speed may be 7 kW.

In the above embodiment, the DC power port and the AC power port may share a connector formed of two metals.

An electric vehicle fast charger according to an embodiment of the present invention includes a charger cable including a direct current power port for rapid charging, an alternating current power port for slow charging, and a communication port for communication with the electric vehicle; And a control unit that switches between a DC power supply mode through the DC power port and an AC power supply mode through the AC power port to charge the electric vehicle battery through the charger cable, wherein the charger cable is connected to the electric vehicle. When connected to the charging port of the battery, the control unit switches to the DC power supply mode, the charger cable supplies DC power to the charging port through the DC power port to start rapid charging, and the charge amount of the electric vehicle battery Until this becomes 80% or more, and the charging speed becomes less than or equal to the first speed preset through information about the charging speed included in the communication signal between the charging port and the communication port, the control unit operates in a direct current power supply mode. maintains, and when the charge amount is 80% or more and the charging speed is less than or equal to the first speed, the control unit switches to AC power supply mode, and the charger cable supplies AC power to the charging port through the AC power port. When AC power is supplied to the charging port, the charger cable can slowly charge all or part of the uncharged amount of the electric vehicle battery through the AC power port.

In the above embodiment, after the charger cable applies AC power to the charging port through the AC power port, if AC power is not supplied to the charging port, the control unit switches to the DC power supply mode and charges. Until the speed is below the preset second speed, the charger cable charges the electric vehicle battery by supplying direct current power through the DC power port, and when the charging speed is below the second speed, the control unit switches to AC power supply mode, and the charging cable applies AC power to the charging port through the AC power port. When AC power is supplied to the charging port, the electric vehicle battery is supplied through the AC power port. All or part of the uncharged amount can be slowly charged.

In the above embodiment, the second speed may be less than the first speed.

In the above embodiment, the first speed may be 11 kW and the second speed may be 7 kW.

In the above embodiment, the DC power port and the AC power port may share a connector formed of two metals.

The electric vehicle fast charger and charging method according to an embodiment of the present invention is a charger cable including a DC power port and an AC power port as separate independent pins or connectors, or a charger cable that selectively uses DC power or AC power through the same pin or connector. When fast charging an electric vehicle using a charger cable that can be supplied, the initial charging should be done with DC power, and when the charge amount exceeds a certain level and the charging speed decreases below a certain level, AC power is used. By switching to slow charging, the usage time of the power module is reduced, significantly reducing charger maintenance costs.

1 and 2 are flowcharts showing each step of the fast charging method for an electric vehicle according to embodiments of the present invention.
Figure 3 is a block diagram schematically showing each configuration of an electric vehicle charger according to an embodiment of the present invention.
Figure 4 is a diagram schematically showing the types of standards applied to electric vehicle chargers.

The advantages and/or features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail below in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and will be implemented in various different forms, but the present embodiments only serve to ensure that the disclosure of the present invention is complete and are within the scope of common knowledge in the technical field to which the present invention pertains. It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.

1 and 2 are flowcharts showing each step of the fast charging method for an electric vehicle according to embodiments of the present invention.

Referring to FIG. 1, the rapid charging method of an electric vehicle according to an embodiment of the present invention is performed by connecting a charger cable included in an electric vehicle charger to a charging port attached to the electric vehicle. The charger cable includes a direct current power port for fast charging, an alternating current power port for slow charging, and a communication port for communication with the electric vehicle. The DC power port and AC power port may be configured with separate pins or connectors, as shown in the CCS1 standard of FIG. 4A. Additionally, the DC power port and AC power port may be configured to share a pair of pins or connectors made of two metals, as in the NACS standard of FIG. 4b. The communication port transmits and receives communication signals containing information about the charging of the electric vehicle battery, such as charging amount, charging speed, voltage, charging elapsed time, or expected time required, to and from the charging port of the electric vehicle. The communication signal may be a Power Line Communication (PLC), Pulse Width Modulation (PWM), or Controller Area Network (CAN) signal.

In step S1, the charger cable is connected to the charging port of the electric vehicle, and first, direct current power is supplied to the charging port of the electric vehicle through the direct current power port to begin rapid charging of the electric vehicle battery.

In step S2, fast charging through the DC power port is maintained until the charge of the electric vehicle battery reaches 80% or more and the charging speed becomes below the preset first speed. The preset first speed may be approximately 10 kW or more and 15 kW or less, and may be set to a specific value such as 11 kW, for example.

In step S3, when the charge amount is more than 80% and the charging speed is less than the first speed, the supply of DC power is stopped, and AC power is applied to the charging port of the electric vehicle through the AC power port. When applying AC power, AC power may be received from the charging port of the electric vehicle and supplied to the battery or built-in system through current flow, but since AC power is not accepted, AC power may not be supplied to the inside of the electric vehicle. Application of AC power is a pre-test process for supplying AC power, and whether AC power is supplied to the charging port after application of AC power is related to the current charging speed, that is, the output supplied from the charger. Since the charging speed is determined by the battery's charge amount, electrochemical characteristics, and the allowable value of power supplied from the charge amount, it cannot be unilaterally changed by the charger. Depending on the allowable range of related systems, such as the OBC of electric vehicles, slow charging using AC power is set to occur only at or below a certain charging speed. For example, a specific charging rate may be set at 11 kW, while at other times it may be set at 7 kW. When AC power exceeding the set charging speed is applied, the charging port blocks the supply of AC power. Since the charger does not have information about the specific charging speed of the electric vehicle being charged, the specific charging speeds of commercially available electric vehicles are sequentially applied to enable slow charging using AC power. When AC power below the set charging speed is applied, the charging port can allow the supply of AC power.

In step S4, when AC power is supplied to the charging port, the uncharged amount of the electric vehicle battery is charged through the AC power port. At this time, all or part of the uncharged amount can be charged, and slow charging is performed using AC power.

After step S3, if AC power is not supplied to the charging port, step S4 is performed through steps S31 and S32. If AC power is not supplied to the charging port, that is, if the charging speed (output) of AC power applied from the AC power port is greater than the charging speed for slow charging set for the electric vehicle, the application of AC power through the AC power port is stopped. , rapid charging of the electric vehicle battery is maintained again by supplying direct current power through the direct current power port until the charging speed is below the preset second speed (S31). Re-maintaining fast charging through the supply of direct current power means resuming charging by direct current power, and although it is slower than the initial charging speed, it is an expression to distinguish it from charging by alternating current power. The second speed is a value less than the first speed, for example, it can be 5kW or more and less than 10kW, or it can be a specific value such as 7kW.

In step S32, when the charging speed becomes lower than the second speed, the supply of DC power is stopped, and AC power is reapplied to the charging port through the AC power port. Afterwards, when AC power is supplied to the charging port, all or part of the uncharged amount of the electric vehicle battery is slowly charged through the AC power port in step S4. If AC power is not supplied to the charging port, the process returns to step S31 and steps S31 to S4 are performed.

Figure 3 is a block diagram schematically showing each configuration of an electric vehicle charger according to an embodiment of the present invention.

Referring to FIG. 3, the electric vehicle fast charger includes a charger cable that is connected to the charging port of the electric vehicle to supply power, and a control unit that switches between supply modes by direct current power or alternating current power.

The charger cable includes a direct current power port for fast charging, an alternating current power port for slow charging, and a communication port for communication with the electric vehicle. As described above, the DC power port and AC power port may be configured with separate pins or connectors, or may be configured to share the same pins or connectors. A pin or connector may be formed of two metal pairs.

The control unit switches between the DC power supply mode through the DC power port and the AC power supply mode through the AC power port. Mutual conversion means selectively applying two modes.

When the charger cable is connected to the charging port of the electric vehicle battery, the control unit switches to the DC power supply mode, and the charger cable supplies DC power to the charging port through the DC power port to start rapid charging.

Until the charge of the electric vehicle battery reaches 80% or more and the charging speed becomes below the first speed preset through information about the charging speed included in the communication signal between the charging port and the communication port, the control unit operates in DC power supply mode. maintain. The preset first speed may be approximately 10 kW or more and 15 kW or less, and may be set to a specific value such as 11 kW, for example.

When the charge amount is more than 80% and the charging speed is below the first speed, the control unit switches to AC power supply mode, and the charger cable applies AC power to the charging port through the AC power port.

When AC power is supplied to the charging port, the charger cable slowly charges all or part of the uncharged amount of the electric vehicle battery through the AC power port.

When AC power is not supplied to the charging port, the control unit switches to DC power supply mode, and until the charging speed is below the preset second speed, the charger cable is connected to the electric vehicle by supplying DC power through the DC power port. Charge the battery. The second speed is a value less than the first speed, for example, it can be 5kW or more and less than 10kW, or it can be a specific value such as 7kW.

When the charging speed is below the second speed, the control unit switches to AC power supply mode, and the charging cable applies AC power to the charging port through the AC power port. When AC power is supplied to the charging port, the AC power port Slowly charges all or part of the uncharged amount of the electric vehicle battery. When AC power is not supplied to the charging port, charging can be resumed through the DC power port, and when the speed falls below a certain speed, slow charging can be appropriately repeated through application of AC power and supply of AC power. Since the technical features previously described in relation to FIGS. 1 and 2 are applicable, overlapping content will be omitted for brevity of the following description.

According to the electric vehicle fast charging method and fast charger that are embodiments of the present invention, charging is performed by supplying AC power, rather than DC power, for the low-speed charging section that occurs in the latter half of fast charging, thereby reducing the usage time of the power module included in the charger. This can be significantly reduced, and thus the maintenance costs of the charger can be greatly reduced.

In the case of the 100kW fast charger currently used, four 30kW or five 20kW power modules are built in. Although the output of a single power module is trending towards higher output, the price is still high. The built-in power module may be used entirely during the entire charging time, or may be used entirely during high-speed charging at the beginning of charging, but only a portion may be used during low-speed charging at the end.

Looking at the current pattern of fast charging, as described above, the charging speed decreases sharply towards the latter part of charging. As an example, let's look at the case of charging a 100 kWh electric vehicle battery with a 100 kW fast charger. When the battery's charge level is 0 to 60%, the charging speed reaches maximum speed. Thereafter, as the charging amount increases, the charging speed rapidly decreases, and when it is over 90%, it decreases to approximately 7 to 11 kW.

Looking at the output and charging time measurements of the charger by section based on the currently installed charger, up to 60% (60kWh) of the charge amount is 36 minutes at an output of 100kW, and up to 60 to 80% (20kWh) of the charge amount is 15 minutes at an output of 50kW, and 80 to 90% ( It takes 15 minutes at 25kW to reach 10kWh, and 85 minutes at 7kW to reach 90 to 100% charge (10kWh). In other words, it takes 66 minutes to charge from 0 to 90% of the initial charge, but then it takes a whopping 85 minutes to charge to 100%. Although it is said to be fast charging, in order to achieve 100% full charging, slow charging is actually achieved due to the slow charging speed in the latter half. If the power module built into the rapid charger is continuously used during the long charging period in the latter part of the battery, the lifespan of the power module is inefficiently drastically reduced.

According to embodiments of the present invention, the charging mode is switched to supply AC power rather than DC power in the latter half of fast charging, which has the advantage of reducing the maintenance cost of the charger by preventing inefficient use of the power module. there is. Since the charging time for 10% of the charge amount in the second half is actually longer than the time for charging 90% of the first half, applying the fast charging method and fast charger according to the present invention increases the lifespan of the power module by at least two times. You can do it.

Although the specific embodiments according to the present invention have been described so far, it goes without saying that various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the scope of the patent claims described below as well as equivalents to the claims of this patent.

As described above, although the present invention has been described with reference to limited embodiments and drawings, the present invention is not limited to the above embodiments, and those skilled in the art can make various modifications and modifications from these descriptions. Transformation is possible. Accordingly, the spirit of the present invention should be understood only by the scope of the claims set forth below, and all equivalent or equivalent modifications thereof shall fall within the scope of the spirit of the present invention.

11: Charger cable
13: control unit

Claims (10)

In the fast charging method of an electric vehicle,
A charger cable including a DC power port for rapid charging, an AC power port for slow charging, and a communication port for communication with the electric vehicle is connected to the charging port of the electric vehicle to supply DC power through the DC power port. starting rapid charging of the electric vehicle battery (S1);
Until the charge of the electric vehicle battery is 80% or more and the charging speed is below the first speed preset through information about the charging speed included in the communication signal between the charging port and the communication port, the DC power Maintaining rapid charging of the electric vehicle battery through a port (S2);
When the charge amount is 80% or more and the charging speed is less than the first speed, stopping supply of DC power and applying AC power at the first speed to the AC power port (S3); and
When the AC power port receives AC power at the first speed and charging is performed, a step (S4) of slowly charging all or part of the uncharged amount of the electric vehicle battery through the AC power port,
If charging does not occur after step S3 because the AC power port does not accept AC power at the first speed, application of AC power at the first speed through the AC power port is stopped, and the charging speed is preset. Re-maintaining rapid charging of the electric vehicle battery by supplying direct current power through the direct current power port until the second speed or lower (S31);
When the charging speed becomes lower than the second speed, stopping the supply of DC power and applying AC power at the second speed to the AC power port (S32); and
When the AC power port receives AC power at the second speed and charging is performed, slowly charging all or part of the uncharged amount of the electric vehicle battery through the AC power port in step S4. A fast charging method for electric vehicles.
delete According to paragraph 1,
A fast charging method for an electric vehicle, wherein the second speed is less than the first speed.
According to paragraph 1,
A fast charging method for an electric vehicle, characterized in that the first speed is 11kW and the second speed is 7kW.
According to paragraph 1,
A fast charging method for an electric vehicle, wherein the direct current power port and the alternating current power port share a connector formed of two metals.
In an electric vehicle fast charger,
A charger cable including a direct current power port for rapid charging, an alternating current power port for slow charging, and a communication port for communication with the electric vehicle; and
A control unit configured to switch between a DC power supply mode through the DC power port and an AC power supply mode through the AC power port to charge the electric vehicle battery through the charger cable,
When the charger cable is connected to the charging port of the electric vehicle battery, the control unit switches to the DC power supply mode, and the charger cable supplies DC power to the charging port through the DC power port to start rapid charging. ,
Until the charge level of the electric vehicle battery reaches 80% or more and the charging speed becomes below the first speed preset through information about the charging speed included in the communication signal between the charging port and the communication port, the control unit maintains the direct current power supply mode,
When the charge amount is 80% or more and the charging speed is less than or equal to the first speed, the control unit switches to AC power supply mode, and the charger cable applies AC power at the first speed to the AC power port,
When the AC power port receives AC power at the first speed and charging is performed, the charger cable slowly charges all or part of the uncharged amount of the electric vehicle battery through the AC power port,
If charging is not performed because the AC power port does not accept AC power at the first speed, the control unit switches to DC power supply mode, and the charger continues until the charging speed becomes lower than the preset second speed. The cable charges the electric vehicle battery by supplying direct current power through the direct current power port, and when the charging speed is lower than the second speed, the control unit switches to the alternating current power supply mode, and the charging cable is connected to the alternating current power supply mode. When the AC power of the second speed is applied to the power port and the AC power port receives the AC power of the second speed and charging is performed, the charger cable connects the uncharged amount of the electric vehicle battery through the AC power port. An electric vehicle fast charger characterized by slow charging of all or part of the.
delete According to clause 6,
An electric vehicle fast charger, characterized in that the second speed is less than the first speed.
According to clause 6,
An electric vehicle fast charger, characterized in that the first speed is 11kW and the second speed is 7kW.
According to clause 6,
An electric vehicle fast charger, characterized in that the direct current power port and the alternating current power port share a connector formed of two metals.