WO2019098648A1

WO2019098648A1 - Wireless charging method of electric vehicle

Info

Publication number: WO2019098648A1
Application number: PCT/KR2018/013828
Authority: WO
Inventors: Honggi KO; Suyeon Lee; Jaeheon Jeong
Original assignee: Renault-Samsung Motors Co., Ltd.
Priority date: 2017-11-16
Filing date: 2018-11-13
Publication date: 2019-05-23
Also published as: KR102483208B1; KR20190056083A

Abstract

The present invention relates to a control method of an electric vehicle for performing wireless charging in an electric vehicle capable of both wireless charging and wired charging. In the electric vehicle according to the present invention, the wireless charging device and the ECU of the vehicle transmit and receive messages according to a predetermined and constant sequence, and perform the relay control between the auto-parking and charging and the wireless charging device and the battery only with inputting the user's button, so that it enables precise electric vehicle control without user intervention. In relation to the wireless charging method of the electric vehicle according to the present invention, since the electric vehicle is controlled with a simple button input, it is possible to provide an efficient wireless charging method even to a socially weak person who has an inconvenience such as a disabled person or an elderly person.

Description

WIRELESS CHARGING METHOD OF ELECTRIC VEHICLE

The present invention relates to a charging method for an electric vehicle, and more particularly to a wireless charging method.

As an environmentally friendly means of transportation, interest and expectations for electric vehicles are increasing but short driving distances, lack of charging stations, and long charging times are factors that electric vehicles are not spread as popular as interest. If charging is possible while the electric vehicle is running, this problem will be solved, but even if there is a technology capable of charging during moving by supplying electric power to a moving object, it would be virtually impossible to install these charging facilities on all roads where cars are driven.

There are limits to this but even so, wireless charging has its own meaning. When wireless charging is used, simply placing an electric vehicle in a place where wireless charging is possible may perform charging without connecting a connector like wired charging.

Therefore, users who are uncomfortable such as elderly or disabled people can perform charging without having to get off the car. Even if users are not uncomfortable, in the hot summer, the cold winter, or the rainy weather, convenient charging can be provided with users being inside the electric vehicle.

But, unlike wired charging that is possible wherever an electric vehicle is placed when connectors are connected, since wireless charging requires that a charger for supplying the electric power and an electric vehicle for receiving the electric power should be aligned in the correct position to achieve high charging efficiency, more precise operational control is required for electric vehicle control. Also, since an electric vehicle with a wireless charging function basically has a wired charging function in most cases, switching between wireless charging and wired charging should be done properly.

The invention of Korean Patent No. 10-1627798, one of the prior arts, discloses only a wireless charging method in which an electric vehicle is charged with electric power supplied from a power feeding portion mounted on the ground in a magnetic induction manner, but does not disclose a device and a control method for supporting wireless charging for wired-chargeable vehicles.

The inventors of the present invention have made efforts to solve the problem of electric vehicle wireless charging in the prior art. If an electric vehicle has both wired and wireless charging devices, in order to complete switching between wired and wireless charging and a control method for increasing charging efficiency when using wireless charging, after many efforts, the present invention has been completed.

An object of the present invention is to provide a method for switching between wireless charging and wired charging in an electric vehicle control method capable of both wired charging and wireless charging.

Another object of the present invention is to provide a more precise control method capable of increasing the charging efficiency when the electric vehicle is charged by the wireless charging method.

Another object of the present invention is to provide a wireless charging method capable of controlling a detailed electric vehicle without user intervention so as to provide an environment in which a wireless charging method can be efficiently used even for a user with an inconvenience in behavior such as a disabled person or an elderly person.

Moreover, other objects of the present invention which are not explicitly stated will be further considered within the scope easily deduced from the following detailed description and the effects thereof.

Embodiments of the present invention provide a wireless charging method of an electric vehicle having both a wireless charging device and a wired charging device and including an Electric Control Unit (ECU) composed of one or more processors, the method including: when the electric vehicle is switched on, if it is determined that a wireless electric power reception pad is installed by checking whether the wireless electric power reception pad is installed, setting to a wireless charging mode, and when the wireless charging station is within a predetermined distance in the wireless charging mode, informing a user that wireless charging is available; if it is determined that the wireless charging device is normal by checking whether the wireless charging device is normal, activating an auto-parking function of an electric vehicle, and when a user's auto-parking instruction is inputted, placing the electric vehicle at a wireless charger location with the auto-parking function; and determining whether positions of the wireless electric power reception pad of the electric vehicle and the wireless charger are aligned within a predetermined distance, and if it is aligned within a predetermined distance, receiving a charging start instruction of the user to start wireless charging, and if it is not aligned within the predetermined distance, receiving a user's auto-parking instruction again.

In an embodiment, the ECU may determine whether the wireless electric power reception pad is installed or whether the wireless charging device is normal by receiving a predetermined code from the wireless charging device.

In an embodiment, when the charging station capable of wireless charging is within a predetermined distance, the ECU may control a relay between the wireless charging device and a battery in the electric vehicle to be in a connected state, and when wireless charging is finished, the ECU may control the relay between the wireless charging device and the battery to be in a disconnected state.

According to an aspect of the present invention, there is provided an electric vehicle including both a wireless charging method and a wired charging method, such that the inconvenience caused by the shortage of the charging infrastructure can be solved.

Further, by providing a wireless charging method capable of finely controlling an electric vehicle, there is also an advantage that the wireless charging efficiency can be increased and the charging time can be shortened accordingly. By using wireless charging, since users with limited mobility, such as the disabled or the elderly, can use the charging without getting off the electric vehicle, it also has the effect of increasing the accessibility of the weak to the electric vehicle.

On the other hand, even if the effects are not explicitly mentioned here, the effects described in the following specification, which are expected by the technical characteristics of the present invention, and the provisional effects thereof are handled as described in the specification of the present invention.

FIG. 1 is a schematic structural view of an electric vehicle according to a preferred embodiment of the present invention.

FIG. 2 is a flowchart of a wireless charging method according to a preferred embodiment of the present invention.

FIG. 3 is a structure for checking whether a wireless charging module is abnormal in the course of wireless charging according to a preferred embodiment of the present invention.

FIG. 4 is a User Interface (UI) receiving input from a user for auto-parking and wireless charging start according to a preferred embodiment of the present invention.

※ The accompanying drawings are included to provide a further understanding of the technical idea of the present invention, and thus the scope of the present invention is not limited thereto.

Below, configurations of the present invention in various embodiments and effects resulting therefrom will be described with reference to the accompanying drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may obscure the subject matter of the present invention.

FIG. 1 shows a schematic structure of an electric vehicle for performing a preferred embodiment of the present invention.

The electric vehicle 10 of the present invention includes a wired charging conversion unit 110, a wireless charging system 120, a relay unit 130, a battery 140, and an electric vehicle control 150.

The wired charging conversion unit 110 includes an AC to DC converter 112 and a DC to DC converter 114. The AC power delivered from the wired charger 20 is converted into a DC power through the AC to DC converter 112. The AC to DC converter 112 will not be used if it is the wired charger 20 that uses DC for charging. The DC converted power is again transmitted to the battery 140 through the DC to DC converter 114. Since the voltage received from the wired charger 20 and the voltage to be stored in the battery 140 are different from each other even in the same DC, DC to DC conversion is required.

The wireless charging system 120 includes a wireless electric power reception pad 122 and a rectifier/voltage regulator 124. The wireless electric power reception pad 122 is composed of a wireless charging current collecting pad and receives electric power wirelessly transmitted from the wireless charger 30. Since electric power is transmitted wirelessly, alignment between the wireless charger 30 and the wireless electric power reception pad 122 is important. This is because even if the alignment between the wireless charger 30 and the wireless electric power reception pad 122 is slightly changed, the wireless transmission/reception efficiency greatly changes.

Since the wireless electric power reception pad 122 receives a high frequency current from 20 kHz to 85 kHz from the wireless charger 30, the current is converted to a current that can be stored in the battery 140 through a rectifier or a voltage regulator. The rectifier/voltage regulator 124 serves as a kind of AC to DC converter.

The converted DC power passes through the relay unit 130 before being transmitted to the battery 140. The relay unit 130 connects the output power of the wired charging conversion unit 110 or the wireless charging system 120 to the battery 140 under the control of the electric vehicle control 140.

The electric vehicle control 150 includes at least one processor and a memory and controls the relay unit 130 such that the output of the wireless charging system 120 is transmitted to the battery 140 depending on whether the wireless charging is performed. The electric vehicle control 150 may be one of an Electric Control Unit (ECU) and an Electric Vehicle Controller (EVC) in a vehicle. In addition, the wireless charging system 120 may include an ECU. The electric vehicle control 150 and the wireless charging system 120 transmit and receive signals using various vehicle communication networks such as Control Area Network (CAN), Multimedia Oriented Systems Transport (MOST), FlexRay, and Local Interconnect Network (LIN).

FIG. 2 is a schematic flowchart of an electric vehicle proceeding with wireless charging according to any preferred embodiment of the present invention. Wireless charging is often used by drivers with limited mobility, such as the disabled or the elderly, and the charging efficiency is high when the transmitter of the wireless charger is aligned with the receiver of the electric vehicle so that precise vehicle control is required.

Table 1 shows an example of a defined sequence for wireless charging.

Title	WCS	EVC	comment
Communication	0x00	0x01	CAN communication check
start WCS checking	0x02	0x03
Going WCS checking	0x04	0x05	fault diagnosys
End of WCS checking	0x06	0x07	goto index = 0x10;
WCS fail	0x08	0x09	display at monitor "unused WCS" and wait
Ready to find a charging station	0x10	0x11	if ( detection ) index = 0x20;
charging station detected	0x20	0x21	detected charging station
start interlock checking	0x22	0x23
going interlock checking	0x24	0x25	fault diagnosys
end of interlock checking	0x26	0x27	goto index = 0x30;
Interlock fail	0x28	0x29	display at monitor "problem of WCS" and wait
ready to push a auto-parking	0x30	0x31	if ( detection ) park start button = enable;
Start auto-parking	0x40	0x41	park start button = disable & park stop button =enable;
Going auto-parking	0x42	0x43	if (park stop button ) index = 0x46;
end of auto-parking	0x46	0x47	park stop button =disnable % goto index = 0x50;
auto-parking fail	0x48	0x49	display at monitor " bad park" and index = 0x30;
ready to push a charging	0x50	0x51	park button = enable;If (Alignment == 0b111) charge button = enable; if ( charge button push ) goto index = 0x60;if ( park button push ) goto index = 0x30;
start of relay close	0x60	0x61	all button = disable;
going of relay close	0x62	0x63
end of relay close	0x64	0x65	if (Relay == ON) goto index = 0x70;
Start charging	0x70	0x71	charge stop button = enable;
Going charging	0x72	0x73	if (charge stop button ) goto index = 0x76;else if ( SOC >= 80) goto index = 0x76;
end of charging	0x76	0x77	goto index = 0x80;
start relay open	0x80	0x81	all button = disable;
going relay open	0x82	0x83
end of relay open	0x84	0x85	if (Relay == OFF) goto index = 0x90;
end of sequence	0x90	0x91	If (alignment ==0b111) index=0x50;else if (alignment !=0b111 && detect == 1 ) index=0x30;else index=0x10;

The Wireless Charging System (WCS) 120 first transmits a message 0x00 indicating that the WCS 120 is installed to the Electric Vehicle Control (EVC) 150 through the CAN communication (S210), and the EVC 150 confirms whether software for wireless charging is installed in the EVC 150 and transmits a confirmation message 0x01 to the EVC 150 (S212).

Once it is confirmed that the software for wireless charging is installed, the WCS 120 performs a self-check to proceed with wireless charging and transmits messages 0x02, 0x04, and 0x06 to the EVC 150, and the EVC 150 transmits confirmation messages 0x03, 0x05, and 0x07 in response.

If the self-check result is abnormal, the EVC 150 transmits a check failure message 0x08 and the WCS 120 does not proceed with charging. If there is no abnormality, the WCS 120 stays in a standby state for searching for a charging station and transmits a message 0x10 to the EVC 150.

When it is detected that the wireless charging station is within the predetermined range in the standby state, the WCS 120 transmits a message 0x20 informing the EVC 150 that the wireless charging station is detected (S214). The EVC 150 transmits a response 0x21 to the wireless charging station detection message to the WCS 120 (S216).

When a wireless charging station is detected, before proceeding with wireless charging, interlocking of each module for wireless charging is checked (S218). The interlocking check is performed by a Wireless Charging System (WCS) 126 included in the WCS 120 as shown in FIG. 3. The WCS 126 checks whether or not the connectors included in the wireless electric power reception pad 122, the rectifier/voltage regulator 124, the relay unit 130, and the like are connected and whether operation is normal and transmits messages 0x22, 0x24, and 0x26 related thereto to the EVC 150. The EVC 150 transmits messages 0x23, 0x25, and 0x27 confirming message reception in response to a message transmitted by the WCS 126 (S220).

If interlocking is abnormal, the WCS 120 transmits a message 0x28 to the EVC 150 indicating that the interlocking check is failed. After transmitting a message 0x29 confirming this to the WCS 120, the EVC 150 may display an indication of a problem with the wireless charging system on a device such as an instrument panel or navigation system of an electric vehicle.

On the other hand, if the interlocking is normal, the WCS 120 enters a standby state to proceed with auto-parking and transmits a message 0x30 indicating that the EVC 150 is ready for auto-parking (S224). The EVC 150 transmits a response message 0x31 after receiving the message, activates the auto-parking button of the display, and waits for the user's input (S226).

FIG. 4 shows the display state when auto-parking is activated. The screen 410 for auto-parking guidance is displayed on the display and the start button 412 is activated so that the user is ready to start auto-parking when the user touches it.

When the user touches the start button 412 to start auto-parking, the WCS 120 transmits a message 0x40 to the EVC 150 to notify the start of auto-parking. The EVC 150 deactivates the start button 412 of the display after transmitting a response message 0x41. The WCS 120 proceeds to auto-parking and transmits the related messages 0x42 and 0x46 to the EVC 150, and when the auto-parking is completed, the WCS 120 checks whether the auto-parking is successful. Since the alignment of the transmitter and receiver is a very important issue in terms of transmission efficiency in wireless charging, it is necessary to check whether the wireless charging transmitter and the WCS 120 are properly aligned by auto-parking.

If the transmitter and receiver are not aligned properly, the WCS 120 transmits an auto-parking failure message 0x48 to the EVC 150 and activates the auto-parking start button 412 again to wait for the user's input. If the transmitter and receiver are well aligned, the WCS 120 transmits a message 0x50 to the wireless charging standby state to the EVC 150 and the EVC 150 transmits a response message 0x51 and then waits for the user's input. As shown in FIG. 4, a screen 420 indicating wireless charging and a wireless charging start button 422 are displayed, and when the user touches the start button 422, wireless charging starts.

Before starting wireless charging again, a user can check the alignment of the wireless charging transmitter and receiver. If it is determined that the alignment is not performed well in a situation where the user is waiting for input, the auto-parking start button 412 may be reactivated and the auto-parking advance request (S224) may be repeated.

When the user touches the wireless charging start button 422, the WCS 120 transmits a wireless charging start message 0x70 (S228). The EVC 150 activates a charging stop button (not shown) while transmitting a message 0x71 responding thereto (S230).

When the user touches the charging stop button or the battery is charged with enough electric power, the WCS 120 transmits a message 0x76 to the EVC 150 indicating that the charging is over and the EVC 150 transmits a message 0x77 to the WCS 120 in response thereto. Once charging is complete, since the relays that are connected for wireless charging must be open, the WCS 120 transmits messages 0x80, 0x82, and 0x84 to the EVC 150 on the procedure for opening each relay of the relay unit 130, and the EVC 150 transmits response messages 0x81, 0x83, and 0x85 for each to WCS 120 to terminate the wireless charging procedure.

After completing the wireless charging procedure, the WCS 120 and the EVC 150 exchange wireless charging end messages 0x90 and 0x91, respectively. Thereafter, it waits for the wireless charging procedure according to the state of the electric vehicle. For example, when wireless charging transmitter and receiver are aligned, the wireless charging start button 422 is activated and in the charging start standby state (S228), the wireless charging standby state message 0x50 is transmitted to wait for the user to input the wireless charging start button 422, and if alignment is required, it waits while the auto-parking start button 412 is activated. If there is no alignment and no wireless charging station is detected, it returns to the state for wireless charging station detection and transmits a message 0x10 for it to start the preparation step for wireless charging from the very first step.

When a detailed wireless charging method according to the preferred embodiment of the present invention is used, in addition to the handicapped and elderly people, even the novice driver who can not park easily can align the electric vehicle for wireless charging easily by touching the button, such that everyone can make wireless charging easy and accurate.

For reference, an electric vehicle charging method according to an embodiment of the present invention may be implemented in the form of a program command that can be executed through various computer means and may be recorded in a computer readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. It may be understood that program instructions stored in the medium are specially designed and configured for the present disclosure or are well known to those skilled in computer software and used.

Examples of computer readable media may include magnetic media such as hard disks, floppy disks, and magnetic tape, optical recording media such as CD-ROMs and DVDs, magneto-optical media such as floptical disks, and a hardware device specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions include high-level language code that can be executed by a computer using an interpreter, as well as machine code accords such as those produced by a compiler. The hardware device may be configured to operate as at least one software module to perform operations of the present invention and vice versa.

The protected scope of the present invention is not limited to the description and the expression of the embodiments explicitly described above. It is again added that the protected scope of the present invention is not limited by obvious changes or substitutions in the technical field to which the present invention belongs.

Claims

A wireless charging method of an electric vehicle having both a wireless charging device and a wired charging device and including an Electric Control Unit (ECU) composed of one or more processors, the method comprising:

when the electric vehicle is switched on, if it is determined that a wireless electric power reception pad is installed by checking whether the wireless electric power reception pad is installed, setting to a wireless charging mode, and when the wireless charging station is within a predetermined distance in the wireless charging mode, informing a user that wireless charging is available;

if it is determined that the wireless charging device is normal by checking whether the wireless charging device is normal, activating an auto-parking function of an electric vehicle, and when a user's auto-parking instruction is inputted, placing the electric vehicle at a wireless charger location with the auto-parking function; and

determining whether positions of the wireless electric power reception pad of the electric vehicle and the wireless charger are aligned within a predetermined distance, and if it is aligned within a predetermined distance, receiving a charging start instruction of the user to start wireless charging, and if it is not aligned within the predetermined distance, receiving a user's auto-parking instruction again.
The method of claim 1, wherein the ECU determines whether the wireless electric power reception pad is installed or whether the wireless charging device is normal by receiving a predetermined code from the wireless charging device.
The method of claim 1, wherein when the charging station capable of wireless charging is within a predetermined distance, the ECU controls a relay between the wireless charging device and a battery in the electric vehicle to be in a connected state, and when wireless charging is finished, the ECU controls the relay between the wireless charging device and the battery to be in a disconnected state.