KR20240163311A - Ease on board charger employing electric car - Google Patents

Abstract

The embodiment relates to a slow charger for an electric vehicle.
Specifically, these chargers are miniaturized by configuring the slow charger into a single PCB, and are simple and elegant in terms of internal appearance, allowing for quick field replacement and shortened manufacturing time.
And, while charging is performed on-site for the electric vehicle, the amount of power being charged or completed is measured and quickly notified to the user. In addition, in connection with this, the phenomenon of ground faults occurring during charging is reduced and leakage current is detected to efficiently perform leakage current processing.
In addition, it notifies users in advance of the risk of electric leakage depending on the frequency of use of the charging connector.

Description

{Ease on board charger employing electric car}

The present specification relates to a slow charger for charging an electric vehicle using commercial AC power.

Unless otherwise indicated herein, the materials described in this section are not prior art to the claims of this application and their inclusion in this section is not an admission that they are prior art.

In general, eco-friendly electric vehicles are powered by batteries that charge electricity instead of being powered by the oxidation of fuel. Therefore, they are gaining attention as an alternative means of transportation to protect fossil fuels and the environment.

There are two charging methods for these electric vehicles: rapid charging and slow charging. Rapid charging can charge 5 to 15 times faster than slow charging, but it is about 10 times more expensive. Also, even with rapid charging, due to the characteristics of the battery, only 80% can be charged rapidly, and the remaining 20% must be charged slowly. Therefore, it takes at least 2 hours to fully charge an electric vehicle using a 50KW rapid charger. For reference, slow chargers charge with a capacity of 10KW or less.

Therefore, it is not easy for users to wait next to the charger until charging is complete.

Meanwhile, electric vehicles require batteries as a power source, and these batteries must be charged by supplying power from an external source. However, the number of electric charging stations is much smaller than the number of gas stations or LPG charging stations, making this somewhat less useful.

So, a slow charger that charges using a household commercial AC power source was developed.

These slow chargers are made up of an ICCB charging unit that plugs into, for example, a household AC power outlet and converts household current into charging current to charge the electric vehicle, and a charging coupler that connects to the electric vehicle's battery.

However, as shown in Fig. 1, the existing configuration is difficult to miniaturize as it consists of a full-length product, has low price competitiveness, takes too much time to manufacture, is unreasonable in terms of internal appearance, and takes too much time for on-site replacement.

The prior art in this context is as follows.

KR 101610523 B1(2016 April 01 day) KR 101751092 B1(2014 August 01 day) For reference, Document 1 relates to a device for preventing sparks in a slow charger, and Document 2 relates to a slow charger having a magnetic element housing that takes into account radiation noise shielding and PCB wires.

The disclosed content is intended to provide a slow charger for an electric vehicle that is miniaturized, has a simple and attractive internal appearance, and shortens the manufacturing time and quick on-site replacement.

In such cases, while charging is performed on-site for the electric vehicle, the amount of power being charged or completed is measured and quickly notified to the user. In addition, in conjunction with this, the phenomenon of ground faults occurring during charging is reduced and leakage current is detected to efficiently handle leakage current.

For reference, this fault phenomenon mainly occurs between the slow charger and the charging connector.

A slow charger for an electric vehicle according to an embodiment of the present invention,

It is based on a single PCB and, when charging an electric vehicle with commercial AC power, it converts commercial AC power into power per unit time for the electric vehicle and performs charging and measurement in conjunction.

So, while charging the electric vehicle on site with this unit of power per hour, the amount of power being charged or completed is measured and quickly notified to the user.

In addition, it is characterized by efficiently performing leakage processing by detecting leakage while reducing ground faults by charging with this amount of power per unit time.

The above detection of leakage current is performed through a zero-phase current transformer located between the slow charger and the charging connector. Then, the occurrence of zero-phase current by the zero-phase current transformer is transmitted from the charging connector to control the interruption operation of the leakage current blocking unit.

In addition, it is characterized by counting the number of times the charging connector has been charged and notifying in advance of a risk of electric leakage when the number exceeds a set threshold number, i.e., when there is a risk of fire.

According to the embodiment, the slow charger is miniaturized by configuring it as a single PCB, and the internal appearance is simple and beautiful, and the field replacement is quick and the manufacturing time is shortened.

And, while charging is performed on-site for the electric vehicle, the amount of power being charged or completed is measured and quickly notified to the user. In addition, in connection with this, the ground fault phenomenon that occurs when charging is reduced and leakage current is detected, and leakage current processing is performed efficiently accordingly.

In addition, it effectively prevents fire by notifying users in advance of the risk of electric leakage depending on the frequency of use of the charging connector.

Figure 1 is a drawing showing a conventional slow charger for an electric vehicle.
Figures 2a and 2b are drawings conceptually explaining a slow charger for an electric vehicle according to an embodiment of the present invention.
Figure 3 is a drawing showing a system of a slow charger according to an embodiment of the present invention.
Figure 4 is a block diagram showing the configuration of a slow charger according to an embodiment.
Figure 5 is a flow chart showing the operation of a slow charger according to an embodiment in sequence.
Figure 6 is a drawing showing the configuration of a conversion unit applied to a slow charger according to an embodiment of the present invention.

Figures 2a and 2b are drawings conceptually explaining a slow charger for an electric vehicle according to an embodiment.

Specifically, FIG. 2a is a drawing for explaining the concept of a slow charger according to an embodiment, and FIG. 2b is a drawing for explaining the operation of this slow charger.

As shown in FIGS. 2a and 2b, a slow charger (100) according to an embodiment of the present invention first miniaturizes the slow charger by configuring it as a single PCB, and reduces the manufacturing time and enables simple and beautiful internal appearance while allowing quick on-site replacement.

And, while charging the electric vehicle on site, it measures the amount of power being charged or completed and quickly informs the user. In addition, in connection with this, it detects leakage current and efficiently performs leakage processing while reducing the ground fault phenomenon that occurs when charging. For reference, this ground fault phenomenon mainly occurs between the slow charger and the charging connector.

It also effectively prevents fire by notifying users in advance of the risk of electric leakage depending on the frequency of use of the charging connector.

To this end, a slow charger (100) according to an embodiment is based on a single PCB as shown in Fig. 2, and when charging an electric vehicle with commercial AC power, the commercial AC power is converted into power per unit time for the electric vehicle and charging and measurement are performed in conjunction.

So, while charging is performed on-site for the electric vehicle in question with this unit of power per hour, the amount of power being charged or completed is measured and quickly notified to the user (see Figure 2b).

In addition, since it charges with this amount of power per unit time, it detects leakage current while reducing ground faults, and efficiently performs leakage processing.

The detection of the above leakage current is performed through a zero-phase current transformer located between the slow charger (100) and the charging connector, and the occurrence of zero-phase current by the zero-phase current transformer is transmitted from the charging connector to control the interruption operation of the leakage current blocking unit.

In addition, if the number of charges received from the charging connector is counted and exceeds the set threshold number, i.e. if there is a risk of fire, information on the risk of electric leakage is notified in advance to perform replacement or repair.

The above charging count is detected based on contact information with a slow charger (100). The above contact information is obtained by installing a device that detects contact with a slow charger on the inner side of the charging connector or detecting whether charging is performed based on whether charging power is input.

This operation is performed for each charging connector, and when information on whether image current is generated is received, the device identification information of the charging connector is also received and processed. This device identification information uses, for example, the device serial number.

Specifically, the charger (100) largely includes an RF reader, a converter, a relay, a display unit, an image transformer, a leakage current blocking unit, and a control unit on a single PCB.

First, the RF reader detects user information for controlling whether or not to use commercial AC power by controlling the control unit, using a user RFID card in the vicinity. The conversion unit converts the commercial AC power into power per unit time for the electric vehicle according to the authentication result of the user information.

In this case, the control unit compares the user information detected by the RF reader with the registered user information for authentication, and if the two pieces of information are identical, controls the conversion operation of the conversion unit to initiate charging.

The above electric vehicle unit time power is set and converted differently for each electric vehicle type. The electric vehicle types are classified into, for example, electric motorcycles, electric scooters, electric industrial mobility devices, electric agricultural mobility and work devices, and micro electric vehicles.

Next, the relay measures the electric power per unit time for the electric vehicle according to the control of the control unit, and the display unit displays this information to quickly inform the user of the amount of electric power being charged or completed on site.

So, while charging the electric vehicle on site, the amount of power being charged or completed is measured and quickly notified to the user.

The above-mentioned image current transformer detects whether the electric vehicle's unit time power measured by the above-mentioned relay generates a zero current and transmits it through the charging connector.

Then, the leakage current cutoff unit detects a current other than the zero-phase current according to the occurrence of the zero-phase current under the control of the control unit, that is, cuts off the power to be supplied when a leakage current occurs.

So, by charging with this amount of power per unit time, it detects leakage current and efficiently performs leakage processing while reducing ground faults.

The above control unit counts the number of charging times received from the charging connector and, if the number exceeds a set threshold number, controls the display operation of the display unit to provide advance notice of leakage risk information.

Therefore, one embodiment of the present invention miniaturizes the slow charger by configuring it as a single PCB, and reduces the internal appearance by making it simple and attractive, and by enabling quick on-site replacement and manufacturing time.

And, while charging the electric vehicle on site, the amount of power being charged or completed is measured and quickly notified to the user. In addition, in connection with this, the phenomenon of ground faults occurring during charging is reduced and leakage current is detected to efficiently perform leakage current processing.

In addition, it effectively prevents fire by notifying users in advance of the risk of electric leakage depending on the frequency of use of the charging connector.

Figure 3 is a diagram illustrating a system of a slow charger according to an embodiment.

As illustrated in FIG. 3, the system according to one embodiment includes a commercial outlet, a user RFID card, a slow charger (100), and a charging connector.

The above commercial outlet provides commercial AC power to the slow charger, and power can be supplied using a household outlet.

The above RFID card is carried by the user, and when the user is placed close to the slow charger, the user information is detected and the user is authenticated. If the user authentication is successful, the slow charger supplies commercial AC power and begins charging.

The above slow charger (100) converts commercial AC power into the unit time power of the electric vehicle according to the charging start operation and charges it, and quickly displays the amount of power during charging or completed charging to immediately inform the user of the charging level while in the charging state.

The above charging connector receives charging power through the above slow charger (100) and charges the electric vehicle. In this case, it monitors whether there is a current leak by linking with the above-mentioned slow charger (100) and transmits the monitoring result to the slow charger (100) via communication to notify the user.

Figure 4 is a block diagram illustrating the configuration of a slow charger according to an embodiment.

As shown in Fig. 4, a slow charger (100) according to an embodiment largely includes an RF reader (101), a converter (102), a relay (103), a display unit (104), an image transformer (105), a leakage current blocking unit (106), and a control unit (107) in a single PCB.

The RF reader (101) reads the RFID card or tag of a user in the vicinity under the control of the control unit (107) to confirm user information. This user information is intended to control whether or not commercial AC power is used for household purposes. For reference, these cards are for charging payments.

The above-mentioned conversion unit (KW/H) (102) converts the commercial AC power into power per unit time for the electric vehicle according to the authentication result of the user information under the control of the above-mentioned control unit (107) and performs charging suitable for the electric vehicle.

The above relay (103) measures the power per unit time appropriate for the electric vehicle and quickly informs the user of the amount of power being charged or completed.

The above display unit (104) displays power information per unit time under the control of the above control unit (107).

The above-mentioned zero-phase current transformer (105) detects leakage current by the zero-phase current according to the power per unit time, thereby reducing the ground fault phenomenon and efficiently performing leakage processing by detecting leakage current. The zero-phase current transformer (105) is located between the slow charger and the charging connector. Information about the zero-phase current is transmitted to the leakage protection unit (106), i.e., the RCD/leakage circuit breaker (106), through the charging connector. The above-mentioned zero-phase current transformer (105) converts the three-phase current into the primary current. If there is no leakage current according to the power per unit time, the currents flowing in the circuit cancel each other out and become 0, and if a leakage current occurs, the currents flowing in the circuit do not cancel each other out and are detected.

The above leakage current cutoff unit (106) controls the conversion operation of the above conversion unit (102) depending on whether or not a zero-phase current is detected by the above-detected zero-phase current transformer (105), and cuts off the power supply when a current other than the zero-phase current is detected, i.e., when a leakage current occurs.

The control unit (107) authenticates the user information by the RF reader (101) by comparing it with the registered user information, and if the two pieces of information are the same, the authentication is successful, and the commercial AC power is converted into the electric vehicle per unit time through the conversion unit. On the other hand, if the two pieces of information are different, the authentication is failed, and this conversion operation is suspended. In addition, the control unit (107) controls the on-off operation of the leakage current blocking unit (106) according to the information on whether or not a zero-phase current is generated received from the charging connector. That is, if the zero-phase current information is received, it is recognized as a normal state and the on-off operation is suspended, and if information other than the zero-phase current is received, it is recognized as a leakage state and the power supply is cut off. Meanwhile, the control unit (107) counts the number of charging times for each charging connector according to the contact information with the slow charger received from the charging connector, and if it is more than the set threshold number, it controls the display operation of the display unit (104) to notify the leakage risk information in advance.

Figure 5 is a drawing showing the configuration of a conversion unit applied to a slow charger according to an embodiment.

As illustrated in FIG. 5, a conversion unit (102) according to an embodiment may have the structure below to efficiently perform conversion according to the type of electric vehicle when converting commercial AC power into electric power per unit time of an electric vehicle.

The above types of electric vehicles are classified into electric motorcycles, electric scooters, electric industrial mobility devices, electric agricultural mobility and work devices, and micro electric vehicles.

The above structure largely includes a full bridge rectifier (102-1), a transformer (102-2), and a bidirectional switch (102-3).

The full-bridge rectifier (102-1) has an input terminal connected to a commercial AC power source and an output terminal connected to the primary winding of the transformer (102-2). It includes a first switch, a second switch, a third switch, and a fourth switch connected in a full-bridge manner.

The above transformer (102-2) connects a full bridge rectifier (102-1) to the primary side and induces it to the secondary side.

The above two-way switch (102-3) connects the fifth switch and the sixth switch, which are connected in series, in parallel between the secondary winding of the transformer (102-2) and the load. The load may be a relay.

In this state, the control unit (107) controls the full bridge rectifier (102-1) and the bidirectional switch (102-3) based on PWM to convert commercial AC power into power per unit time of the electric vehicle.

In this case, the electric vehicle's power per unit time is set for each electric vehicle type, and the pulse width of the PWM is set and controlled in response to the electric vehicle's power per unit time.

For example, in the case of an electric motorcycle, the power per unit time is lower than that of a general electric vehicle, so the pulse width is set to a relatively higher pulse width. Considering that this pulse width is for public use, it is set to a pulse width corresponding to the power per half hour.

On the other hand, in the case of micro electric vehicles, the pulse width is set to be higher than that of electric motorcycles and lower than that of general electric vehicles. For example, it would be a pulse width corresponding to the power per 1/4 hour.

Therefore, the conversion operation of the charging power is controlled according to the power per unit time of various types of electric vehicles.

The specific actions are as follows.

First, in order to convert the electric power per unit time of the commercial AC power source to an electric vehicle, the switching operation of the full-bridge rectifier (102-1) is controlled using PWM control. In this case, the control is performed by varying the first duty cycle corresponding to the electric power per unit time of the electric vehicle set for each type of electric vehicle.

And, based on the first duty cycle, one pair of switches and another pair of switches of the full bridge rectifier (102-1) are switched alternately.

Therefore, the conversion operation of the charging power is controlled according to the power per unit time of various types of electric vehicles.

Next, the switching loss can be reduced by controlling the bidirectional switch (102-3) based on the change in the magnitude of this variable voltage.

At this time, a pair of switches of the bidirectional switch (102-3) are switched alternately based on the second duty cycle. The second duty cycle may be greater than the first duty cycle by 0.5 or less in consideration of reducing switching loss.

Specifically, when one pair of switches of the full bridge rectifier (102-1) is turned on, the lower switch of the bidirectional switch (102-3) is turned on. And, when the other pair of switches of the full bridge rectifier (102-1) is turned on, the upper switch of the bidirectional switch (102-3) is turned on.

Therefore, the switching loss that may occur when converting the charging power according to the power per unit time of various types of electric vehicles can be reduced.

Additionally, a capacitor is installed at the output terminal of the full bridge rectifier (102-1) or at the input terminal of the bidirectional switch (102-3) to apply a stable voltage.

Alternatively, a diode rectifier may be further connected in parallel between the commercial AC power source and the input terminal of the full bridge rectifier (102-1) to convert it into various charging power sources. In addition, a voltage doubler for amplifying the output voltage may be further connected between the bidirectional switch (102-3) and the load.

The voltage doubler includes a first diode, a second diode, a first capacitor, and a second capacitor, and the drain terminal of the upper switch of the bidirectional switch (102-3) is connected to a node between the first diode and the second diode. And, the source terminal of the lower switch is connected to a node between the first capacitor and the second capacitor.

Figure 6 is a flow chart showing the operation of a slow charger according to an embodiment of the present invention in sequence.

As illustrated in FIG. 6, a slow charger according to an embodiment first selects charging, for example, and then a specific notification part of the display unit blinks to confirm whether charging is taking place or the location.

Then, set the charging power amount using your membership card or credit card and go through the payment process.

Then, the color of the charger changes and it switches to charging mode. When you move the vehicle to the charger and insert the charging connector, charging begins and the LED on the charger also changes to the charging color.

The specific actions are as follows.

First, the RF reader detects user information for controlling whether or not commercial AC power is used by a user RFID card in the vicinity under the control of the control unit (S601).

Then, the control unit compares the user information by the RF reader with the registered user information for authentication, and if the two pieces of information are identical, the authentication is successful and the commercial AC power (S602) is converted into the electric power per unit time for the electric vehicle through the conversion unit (S603).

On the other hand, if the two pieces of information are different, this conversion operation is suspended due to authentication failure.

If the above conversion unit is authenticated successfully, it converts the commercial AC power into power per unit time for the electric vehicle and performs charging suitable for the electric vehicle. For example, information on power per unit time for the electric vehicle is input as setting information according to user key operation.

The above relay quickly measures the amount of power converted by the above conversion unit per unit time for the electric vehicle to suit the electric vehicle and measures the amount of power being charged or completed (S604).

The above display unit displays the electric power per unit time measured by the relay as user interface information (S605) to immediately inform the user.

So, while charging the electric vehicle on site, the amount of power being charged or completed is measured and quickly notified to the user.

Meanwhile, the above-mentioned zero-phase current transformer detects whether zero-phase current is generated for the electric vehicle per unit time measured by the above-mentioned relay (S606) and charges the electric vehicle through the charging connector of the electric vehicle.

And, when the control unit receives image current information through the charging connector, it recognizes it as a normal state and suspends the interruption operation of the leakage current cutoff unit.

On the other hand, if information other than image current is transmitted through the charging connector (S607), it is recognized as a current leakage state and the power to be supplied through the current leakage cutoff unit is cut off (S608).

So, by charging with this amount of power per unit time, it detects leakage current and efficiently performs leakage processing while reducing ground faults.

In addition, the control unit counts the number of charges for each charging connector based on contact information with a slow charger received from the charging connector, and if the number exceeds a set threshold number, controls the display operation of the display unit to notify of leakage risk information in advance.

Therefore, one embodiment of the present invention miniaturizes the slow charger by configuring it as a single PCB, and reduces the internal appearance by making it simple and attractive, and by enabling quick on-site replacement and manufacturing time.

And, while charging is performed on-site for the electric vehicle, the amount of power being charged or completed is measured and quickly notified to the user. In addition, in connection with this, the phenomenon of ground faults occurring during charging is reduced and leakage current is detected to efficiently perform leakage current processing.

In addition, it notifies users in advance of the risk of electric leakage depending on the frequency of use of the charging connector.

Meanwhile, these slow chargers have a considerably high number of charging cycles for the charging connector, so in cases where charging is unavoidable due to an emergency, they temporarily lower the power per unit time for electric vehicles to reduce the risk of leakage.

To this end, if the number of charging times mentioned above is greater than the threshold number, the control unit controls the conversion operation of the conversion unit to convert the electric vehicle's power per unit time to a lower value by a set threshold value and temporarily charge the electric vehicle.

In such cases, different threshold values are set for each type of electric vehicle to enable efficient charging.

For example, in the case of electric motorcycles, the power per unit time is lower than that of regular electric vehicles, so the threshold is set relatively higher. This threshold is set as the power per half hour, taking into account whether a fire occurs.

On the other hand, for micro electric vehicles, the threshold is set higher than that of electric motorcycles but lower than that of regular electric vehicles. For example, it would be power per 1/4 hour.

Therefore, in another embodiment, in an emergency situation where charging is unavoidable due to the high risk of electric leakage due to the use of a charging connector, the risk of electric leakage is reduced through the above method, thereby effectively preventing fire.

Meanwhile, in addition to these slow chargers, you can use a general battery charger. That is, you can charge by transmitting and receiving information by connecting a general battery charger to the charging connector.

For reference, this method is used in the same way as a slow charger according to an embodiment. That is, when information on whether an image current is generated is transmitted through the charging connector mentioned above, the information is received through this method.

The background is roughly as follows.

Typically, public slow chargers for electric vehicles have a dedicated communication method for connection, and electric vehicles that use them have a central controller inside that controls the communication.

However, general battery chargers without a dedicated communication interface cannot connect. This includes many electric powered mobility devices such as electric motorcycles and electric scooters.

So, we use a normal battery charger by communicating with the charging connector.

For example, the control unit is connected to the charging connector and transmits and receives a pilot signal to determine whether charging should begin.

The above pilot signal can be, for example, a PWM signal, and can be used to control power transmission start or stop, power amount, etc. according to amplitude change and duty cycle. For reference, when used in a slow charger, information on whether zero-phase current is generated is used.

The above control unit controls to sequentially perform procedures according to the communication protocol. That is, it processes the pilot function using the pilot signal input through the pilot port.

100 : Slow charger
101 : RF Reader
102 : Conversion Unit (KW/H)
103 : Relay
104 : Display section
105 : Image transformer
106: Leakage current device (RCD/leakage current circuit breaker)
107 : Control Unit

Claims (3)

In a slow charger for an electric vehicle using commercial AC power,
An RF reader that detects user information using a user RFID card to check whether the above commercial AC power is being used;
A conversion unit that converts the commercial AC power into power per unit time for an electric vehicle based on the authentication result of the user information detected by the RF reader;
A relay for measuring the electric power per unit time for an electric vehicle converted in the above conversion unit;
A display section that displays the electric power per unit time measured by the above relay for electric vehicles;
A zero-phase current transformer that detects whether zero-phase current is generated for the electric vehicle per unit time measured by the above relay and transmits it to the charging connector of the electric vehicle;
A leakage circuit breaker that controls the conversion operation of the conversion unit according to whether or not the image current detected by the image transformer is generated; and
A slow charger for an electric vehicle, characterized in that it comprises a control unit that compares user information detected by the RF reader with registered user information to control the conversion operation of the conversion unit and controls the interruption operation of the leakage current blocking unit according to information on whether image current is generated or not received from the charging connector; on a single circuit board. In claim 1,
The above control unit
A slow charger for an electric vehicle, characterized in that it controls the display operation of the display unit to notify information on the risk of electric leakage when the number of charging times received from the charging connector is greater than a set threshold number; In claim 2,
The above control unit
A slow charger for an electric vehicle, characterized in that when the number of charging times is greater than or equal to the threshold number, the conversion operation of the conversion unit is controlled to convert the electric vehicle's power per unit time to a value lower than the set threshold value to temporarily charge the electric vehicle.

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