KR20180029860A - Method and apparatus for transmitting wireless power to electric vehicle using plurality of transmission coils - Google Patents

Abstract

Disclosed are a method and a device for transmitting a wireless power using a plurality of transmission coils. The method for transmitting a wireless power using a plurality of transmission coils comprises the following steps of: checking an alignment state of a plurality of transmission coils and a reception coil mounted on an electric vehicle; selecting the transmission coil which satisfies a constraint condition previously set for the alignment state among the plurality of transmission coils; and transmitting a wireless power to the reception coil by using the selected transmission coil.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for transmitting wireless power to an electric vehicle using a plurality of transmission coils,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for transmitting radio power to an electric vehicle using a plurality of transmission coils, And more particularly, to a method and apparatus for transmitting wireless power by selecting a coil that is advantageous for wireless power transmission.

An electric vehicle charging system can basically be defined as a system for charging a battery mounted on an electric car using power from a grid or an energy storage device of a commercial power source. Such an electric vehicle charging system may have various forms depending on the type of electric vehicle. For example, an electric vehicle charging system may include a conductive charging system using a cable or a non-contact wireless power transmission system.

When charging an electric vehicle, a vehicle assembly (VA) mounted on an electric vehicle is connected to a transmission pad of a ground assembly (GA) located in a charging station or charging spots, And charges the battery of the electric vehicle by using power transmitted from the ground assembly through the flow resonance coupling.

On the other hand, the magnetic induction type wireless power transmission system is a system for transmitting electric power using the electromagnetic induction phenomenon between the transmitting and receiving coils. In this wireless power transmission system, there is a large difference in power transmission efficiency depending on the alignment error between the transmitting and receiving coils.

That is, it is necessary to align the ground assembly (GA) or the transmission pad with the vehicle assembly (VA) or the vehicle side pad (reception pad) in order to increase the charging efficiency. If the alignment does not fit well, the driver may have to repeat the alignment process repeatedly, which may result in a poor evaluation of the usability.

As described above, in the wireless charging system of the electric car, there is a demand for a method of efficiently performing alignment between the coils of the transmission pad and the reception pad. In this regard, in the prior art, if the alignment between the GA and the VA does not match well, the driver needs to repeat the alignment process or align the positions by moving and adjusting the positions using a motor or the like mounted on the GA or VA.

However, such a method has a problem that the driver repeatedly performs the alignment process to greatly reduce the user's convenience and increases the cost by installing a separate motor in the GA or VA.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to provide a radio power transmission method using a plurality of transmission coils.

It is another object of the present invention to provide a wireless power transmission apparatus using a plurality of transmission coils.

According to an aspect of the present invention, there is provided a wireless power transmission method using a plurality of transmission coils.

Here, a radio power transmission method using a plurality of transmission coils includes the steps of: checking an alignment state between a plurality of transmission coils and reception coils mounted on an electric vehicle; Selecting a transmit coil among the plurality of transmit coils, and transmitting wireless power to the receive coil using the selected transmit coil.

Here, the step of confirming the alignment state may include a step of confirming a horizontal or vertical separation distance between the center of each of the plurality of transmission coils and the center of the reception coil.

Here, the checking of the alignment state may be repeatedly performed during the movement of the electric vehicle to align the plurality of transmission coils with the reception coil.

Here, the checking of the alignment status may be performed in response to receiving a message requesting wireless power transmission from the electric vehicle.

Here, the step of selecting, among the plurality of transmission coils, transmission coils satisfying a predetermined restriction condition for the alignment state may further include selecting a transmission coil by further considering the charging efficiency of each of the plurality of transmission coils in the alignment state .

The step of selecting the transmission coil further considering the charging efficiency of each of the plurality of transmission coils may further comprise the step of selecting the transmission coil to be wirelessly transmitted to the reception coil for a preset time using the selected transmission coils, Measuring the charging efficiency of each of the predetermined transmission coils based on the transmission result, and selecting the transmission coil having the highest value among the measured charging efficiencies.

The step of measuring the charging efficiency of each of the predetermined transmission coils may further include storing each of the measured charging efficiencies in a memory.

Here, the charging efficiency may mean an amount of power transmitted to the receiving coil for the predetermined time.

Here, the plurality of transmission coils partially overlap each other and can be stacked in a stepwise manner.

Here, the step of selecting, from the plurality of transmission coils, a transmission coil satisfying a predetermined constraint condition for the alignment state may include the step of, when there is no transmission coil satisfying the predetermined constraint condition, And transmitting the data.

According to another aspect of the present invention, there is provided a wireless power transmission apparatus using a plurality of transmission coils.

Wherein the wireless power transmission apparatus using a plurality of transmit coils includes at least one processor and a memory for storing instructions that direct the at least one processor to perform at least one step can do.

Here, the at least one step may include: checking an alignment state between a plurality of transmission coils and reception coils mounted on an electric vehicle; setting a transmission coil satisfying a predetermined restriction condition on the alignment state to the plurality of transmission coils, Selecting among the transmit coils and transmitting the wireless power to the receive coils using the selected transmit coils.

The step of confirming the alignment state may include determining a horizontal or vertical separation distance between the center of each of the plurality of transmission coils and the center of the reception coil.

The checking of the alignment state may be repeatedly performed during the movement of the electric vehicle to align the plurality of transmission coils with the reception coil.

The checking of the alignment status may be performed in response to receiving a message requesting wireless power transmission from the electric vehicle.

Wherein the step of selecting a transmission coil among the plurality of transmission coils satisfying a predetermined constraint condition for the alignment state further includes the step of selecting a transmission coil by further considering the charging efficiency of each of the plurality of transmission coils in the alignment state Step < / RTI >

Wherein the step of selecting the transmission coil further considering the charging efficiency of each of the plurality of transmission coils further includes the step of selecting the transmission coil by using the selected transmission coils, Measuring the charging efficiency of each of the predetermined transmission coils based on the transmission result, and selecting the transmission coil having the highest measured charging efficiency.

The step of measuring the charging efficiency of each of the predetermined transmission coils may further include storing each of the measured charging efficiencies in a memory.

Here, the charging efficiency may mean an amount of power transmitted to the receiving coil for the predetermined time.

Here, the plurality of transmission coils partially overlap each other and can be stacked in a stepwise manner.

Wherein the step of selecting a transmission coil among the plurality of transmission coils satisfying a predetermined constraint condition for the alignment state includes a step of, when there is no transmission coil satisfying the predetermined constraint condition, The method may further include transmitting.

The plurality of transmission coils may have a distance of 75 mm or less in the transverse direction and a distance of 100 mm or less in the longitudinal direction.

When the method and apparatus for transmitting a wireless power using a plurality of transmission coils according to the present invention as described above are used, constraint conditions required when the transmission coil and the reception coil are aligned with each other can be alleviated.

Also, since the difficulty for the user or the driver to align the coils with each other is reduced, the convenience is increased.

Further, as the inter-coil alignment becomes smoother, the efficiency of the wireless power transmission can be improved.

1 is a conceptual diagram for explaining a concept of wireless power transmission for an electric vehicle to which an embodiment of the present invention is applied.
2 is a conceptual diagram illustrating an electric vehicle wireless charging circuit according to an embodiment of the present invention.
3 is a conceptual diagram illustrating an alignment concept in wireless power transmission of an electric vehicle according to an embodiment of the present invention.
4A and 4B are conceptual diagrams for explaining the concept of wireless power transmission using a plurality of transmission coils according to an embodiment of the present invention, in comparison with wireless power transmission using a single transmission coil.
5 is a schematic flow chart of a wireless power transmission method using a plurality of transmission coils according to the present invention.
6 is a flowchart specifically illustrating a wireless power transmission method using a plurality of transmission coils according to the first embodiment of the present invention.
FIG. 7 is a flowchart specifically illustrating a wireless power transmission method using a plurality of transmission coils according to a second embodiment of the present invention.
8 is a configuration diagram of a wireless power transmission apparatus using a plurality of transmission coils according to an embodiment of the present invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. Like reference numerals are used for like elements in describing each drawing.

The terms first, second, A, B, etc. may be used to describe various elements, but the elements should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

In an embodiment of the present invention, an electric vehicle charging system can be basically defined as a system for charging a battery mounted on an electric vehicle using a grid of a commercial power source or electric power of an energy storage device. Such an electric vehicle charging system may have various forms depending on the type of electric vehicle. For example, an electric vehicle charging system may include a conductive charging system using a cable or a non-contact wireless power transmission system.

In one embodiment of the present invention, an electric vehicle (EV) may refer to an automobile as defined in 49 CFR 523.3. The electric vehicle is freely available on the highway and can be driven by electricity supplied from an in-vehicle energy storage device such as a rechargeable battery from a power source outside the vehicle.

In one embodiment of the invention, the power source may include a residential or public electrical service or a generator using vehicle mounted fuel, and the like.

In one embodiment of the present invention, an electric vehicle (EV) is an electric car, an electric automobile, an electric road vehicle (ERV), a plug-in vehicle (PV), a plug- vehicle, etc., and the xEV may be referred to as a BEV (plug-in all-electric vehicle or battery electric vehicle), a plug-in electric vehicle (PEV), a hybrid electric vehicle (HEV), a hybrid plug- ), A plug-in hybrid electric vehicle (PHEV), and the like.

In one embodiment of the present invention, a Plug-in Electric Vehicle (PEV) may be referred to as an electric vehicle that is connected to a power grid and recharges a quantity-loaded primary battery. A plug-in vehicle (PV) may be referred to herein as a rechargeable vehicle through a wireless charging scheme without the use of physical plugs and sockets from electric vehicle supply equipment (EVSE). Heavy duty vehicles (H.D. Vehicles) may refer to any vehicle with four or more wheels as defined in 49 CFR 523.6 or CFR 37.3 (bus).

In one embodiment of the present invention, a light duty plug-in electric vehicle is mainly a rechargeable battery for use in public streets, roads, and highways, or an electric motor powered by an electric motor of another energy device It can refer to a vehicle with three or four wheels. Lightweight plug-in electric vehicles may be specified to have a total weight less than 4.545 kg.

In one embodiment of the present invention, a wireless power charging system (WCS) may refer to a system for controlling between GA and VA, including wireless power transmission, alignment and communication. Wireless power transfer (WPT) can refer to the transmission of electrical power through contactless means to an electric vehicle in an AC power supply network, such as a utility or a grid.

In one embodiment of the present invention, a utility provides electrical energy and is typically implemented in a customer information system (CIS), an Advanced Metering Infrastructure (AMI), a Rates and Revenue system ≪ / RTI > and the like. The utility allows the plug-in electric vehicle to use energy through price tags or discrete events. The utility can also provide information on tariff rates, intervals for measured power consumption, and verification of electric vehicle programs for plug-in electric vehicles.

In one embodiment of the present invention, smart charging can be described as a system in which an EVSE and / or plug-in electric vehicle communicates a vehicle charge rate or discharge rate with a power grid to optimize the time of grid capacity or usage cost ratio. Automatic charging can be defined as the inductive charging operation of the vehicle in a proper position relative to the primary charger assembly capable of transmitting power. Automatic charging can be performed after obtaining the required authentication and authorization.

Interoperability in one embodiment of the invention may refer to a state in which components of the system relative to one another can operate together to perform the desired operation of the overall system. Information interoperability can refer to the ability of two or more networks, systems, devices, applications or components to share and easily use information securely and effectively, with little or no inconvenience to the user .

In one embodiment of the invention, an inductive charging system may refer to a system in which two parts transfer energy electronically in a forward direction from an electricity supply network to an electric vehicle via a loosely coupled transformer. In this embodiment, the induction charging system may correspond to the electric vehicle charging system. An inductive coupler may refer to a transformer that is formed of a GA coil and an VA coil and that transfers power through electrical isolation. Inductive coupling can refer to magnetic coupling between two coils. The two coils can refer to a ground assembly coil and a vehicle assembly coil.

In one embodiment of the present invention, the VA coil may be referred to as a secondary coil, a vehicle coil, a receiver coil, etc., and similarly a ground assembly coil (GA coil may be referred to as a primary coil, a transmit coil, or the like.

In one embodiment of the present invention, the GA may be referred to as a primary device (PD), a primary device, and the like, and VA may be referred to as a secondary device (SD) .

In one embodiment of the present invention, the primary device may be a device that provides contactless coupling to the secondary device, that is, a device external to the electric vehicle. The primary device may be referred to as a primary side device. When the electric vehicle receives power, the primary device can operate as a power source for transmitting power. The primary device may include a housing and all covers.

In one embodiment of the present invention, the secondary device may be an electric vehicle mounting device that provides contactless engagement with the primary device. The secondary device may be referred to as a secondary side device. When the electric vehicle receives electric power, the secondary device can transfer the electric power from the primary device to the electric car. The secondary device may include a housing and all covers.

In one embodiment of the present invention, the ground assembly controller (GA controller) may be part of a GA that adjusts the output power level for the GA coil based on information from the vehicle.

In one embodiment of the present invention, a vehicle controller (VA controller) may be part of a VA that monitors the parameters for a particular vehicle during charging and initiates communication with the GA to control the output power level.

The GA controller described above may be referred to as a primary device communication controller (PDCC), and the VA controller may be referred to as an electric vehicle communication controller (VA controller). The magnetic gap is the distance between the highest plane of the upper portion of the litz wire or the upper portion of the magnetic material of the GA coil and the lowest plane of the magnetic material of the VA coil, Vertical distance can be referred to.

Alignment in one embodiment of the present invention refers to a procedure for finding the relative location of the secondary device to the primary device and / or a procedure for finding the relative location of the primary device to the secondary device for the defined efficient power transfer . Alignment herein may refer to, but is not limited to, alignment of a wireless power transmission system.

In one embodiment of the invention, the vehicle magnetic ground clearance may refer to the vertical distance between the bottom floor of the Litz wire or the insulating material of the VA coil mounted on the vehicle and the road pavement. Vehicle Assembly (VA) The Vehicle Assembly Coil Surface Distance can refer to the vertical distance between the plane bottom of the Litz wire or the magnetic material of the VA coil and the lowest outer surface of the VA coil. Such a distance may include additional items wrapped in a protective cover and coil wrapper.

In one embodiment of the present invention, pairing may refer to a procedure in which a vehicle (electric vehicle) is associated with a single dedicated ground assembly (primary device) arranged to transmit power. Pairing herein may include a procedure for associating a charge spot or a specific ground assembly with a vehicle assembly controller. Correlation / Association may involve establishing a relationship between two peer communication entities. Command and control communication may refer to communication between an electric vehicle and an electric vehicle, which exchanges information necessary to initiate, control, and terminate the wireless power transfer process.

In one embodiment of the present invention, a high level communication may process all information that exceeds the information in the command and control communication. The data link of the high level communication can use PLC (Power line communication), but is not limited thereto. Low power excitation may refer to activating an electric vehicle to sense a primary device to perform precise positioning and pairing, but is not so limited, and vice versa.

In an embodiment of the present invention, a service set identifier (SSID) is a unique identifier consisting of 32-characters attached to a header of a packet transmitted on a wireless LAN. The SSID identifies the basic service set (BSS) that the wireless device attempts to connect to. SSID basically distinguishes several wireless LANs from each other. Therefore, all APs and all terminal / station devices that want to use a particular wireless LAN can use the same SSID. Devices that do not use a unique SSID are not able to join the BSS. Because the SSID is shown as plain text, it may not provide any security features to the network.

In one embodiment of the present invention, an ESSID (Extended Service Set Identifier) is a name of a network to be accessed. It is similar to SSID but can be a more extended concept. A basic service set identifier (BSSID) is usually used to distinguish a specific basic service set (BSS) by 48 bits. In the case of an infrastructure BSS network, the BSSID may be medium access control (MAC) of the AP equipment. For an independent BSS or ad hoc network, the BSSID can be generated with any value.

In one embodiment of the present invention, a charging station may include at least one ground assembly and at least one ground assembly controller that manages at least one ground assembly. The ground assembly may include at least one wireless communication device. The charging station may refer to a place having at least one ground assembly installed in a home, office, public place, road, parking lot, and the like.

In one embodiment of the present invention, rapid charging may mean a method of converting AC power of a power system to DC and directly supplying the converted DC power to a battery mounted in an electric vehicle. At this time, DC voltage can be used.

In one embodiment of the present invention, the slow charging is a method of charging a battery mounted in an electric car using alternating current power supplied to a home or a workplace. The charging is performed through an outlet in each home or workplace, AC power is supplied, and an AC voltage of 220 V may be used as the operating voltage. At this time, the electric vehicle may additionally have an on-board charger which is a device capable of boosting AC power for full-charge charging and converting it to DC power and supplying it to the battery.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a conceptual diagram for explaining a concept of wireless power transmission for an electric vehicle to which an embodiment of the present invention is applied.

1, a wireless power transmission may be performed by at least one component of an electric vehicle 10 and a charging station 13, and may be used to transmit power wirelessly to an electric vehicle 10, . ≪ / RTI >

Here, the electric vehicle 10 can be generally defined as a vehicle (automobile) that supplies electric current derived from a chargeable energy storage device such as the battery 12 as an energy source of an electric motor as a power device.

However, the electric vehicle 10 according to the present invention may include a hybrid vehicle having an electric motor and an internal combustion engine together, and may be a motor vehicle, a motorcycle, a cart, A scooter, and an electric bicycle.

The electric vehicle 10 may include a power receiving pad 11 including a receiving coil for charging the battery 12 wirelessly and may include a plug connection for charging the battery 12 by wire It is possible. At this time, the electric vehicle 10 capable of charging the battery 12 by wire can be referred to as a plug-in electric vehicle (PEV).

Here, the charging station 20 may be connected to a power grid 30 or a power backbone, and may be connected to a power transmission pad 21 through a power link, Or direct current (DC) power.

Also, the charging station 20 can communicate with an infrastructure management system or an infrastructure server that manages a power grid 30 or a power network through wired / wireless communication, and performs wireless communication with the electric vehicle 10 can do.

Here, the wireless communication may be Bluetooth, zigbee, cellular, wireless local area network, or the like.

Also, for example, the charging station 20 can be located at various places such as a parking lot attached to the owner's house of the electric car 10, a parking area for charging an electric car at a gas station, a parking area at a shopping center or a workplace.

The process of wirelessly charging the battery 12 of the electric vehicle 10 is performed by first placing the power supply pad 11 of the electric vehicle 10 in the energy field of the power transmission pad 21, And the receiving coil of the receiving pad 11 are mutually interacted or coupled to each other. An electromotive force is induced in the power reception pad 11 as a result of the interaction or coupling, and the battery 12 can be charged by the induced electromotive force.

In addition, the charging station 20 and the transmission pad 21 may be referred to as a ground assembly (GA) in whole or in part, and the ground assembly may refer to the previously defined meaning.

In addition, all or a part of the internal components of the electric vehicle other than the receiving pad 11 of the electric vehicle 10 may be referred to as a vehicle assembly (VA), in which the vehicle assembly may refer to the previously defined meaning.

Here, the power transmission pad or the power receiving pad may be configured to be non-polarized or polarized.

At this time, if the pad is non-polar, there may be one pole in the center of the pad and an opposite pole in the outer periphery. Here, the flux can be formed to exit from the center of the pad and return at all outer boundaries of the pad.

Also, if the pad is polar, it may have a respective pole at either end of the pad. Here, the magnetic flux can be formed based on the orientation of the pad.

2 is a conceptual diagram illustrating an electric vehicle wireless charging circuit according to an embodiment of the present invention.

Referring to FIG. 2, a schematic configuration of a circuit for charging in an electric car wireless charging system is shown.

2 can be interpreted as expressing all or part of the configuration of the power source Vsrc supplied from the power grid, the charging station 20 in the system of FIG. 1, and the transmission pad 21, and the right side of FIG. 2 The circuit may be interpreted as representing some or all of the electric vehicle including the receiving pad and the battery.

First, FIG left circuit of Figure 2 operates to provide an output power (P _src) corresponding to the power supply (V _src) supplied by the power network to the wireless charging power converter, and the desired wireless charging power converter in the transmitting coil (L ₁₎ The frequency of the supplied power (P _src ) and the power (P ₁ ) subjected to the AC / DC conversion so as to emit the electromagnetic field at the frequency.

Specifically, the wireless charging power converter includes an AC / DC converter for converting power (P _src ) supplied from the power network into DC power when AC power is AC power, and a low frequency converter LF converter). The operating frequency may be determined to be, for example, between 80 and 90 kHz.

The power P ₁ output from the wireless charging power converter can again be supplied to the circuit consisting of the transmitting coil L ₁ , the first capacitor C ₁ and the first resistor R ₁ , C ₁ ) may be determined so as to have an element value such that it has an operating frequency suitable for charging together with the transmitting coil L ₁ . Here, the first resistor R ₁ may mean a power loss caused by the transmission coil L ₁ and the first capacitor C ₁ .

Here, the transmitting coil L ₁ may be electromagnetically coupled as defined by the receiving coil L ₂ and the coupling coefficient m to allow power to be transmitted, or power may be induced to the receiving coil L ₂ . Therefore, the meaning of power transmission in the present invention can be used in combination with the meaning that power is induced.

Here, the electric power P ₂ induced or transmitted to the receiving coil may be provided to the electric vehicle electric power converter. At this time, the second capacitor C ₂ may be determined as an element value having an operating frequency suitable for charging together with the receiving coil L ₂ , and the second resistor R ₂ may be determined as the receiving coil L ₂ and the second May mean a power loss caused by the capacitor C ₂ .

The electric vehicle power converter may include an LF / DC converter that converts the supplied power (P ₂ ) of a specific operating frequency to DC power having a voltage level suitable for the battery (V _HV ) of the electric vehicle.

When outputting the electric power converter to provide power received power (P _HV) converting the (P _2), the output power (P _HV) may be used for charging of the battery (V _HV) embedded in electric vehicle.

Here, the right circuit of FIG. 2 may further include a switch for selectively connecting or disconnecting the receiving coil L ₂ with the battery V _HV .

Here, the resonance frequencies of the transmission coil L ₁ and the reception coil L ₂ may be similar or identical to each other. The reception coil L ₂ may be connected to the electromagnetic field generated by the transmission coil L ₁ , Can be configured to be located in close proximity.

Here, the circuit of FIG. 2 should be understood as an exemplary circuit for power transmission in an electric vehicle wireless charging system that is available for embodiments of the present invention, and is not limited to the circuit in FIG.

On the other hand, since the power loss may increase as the transmitting coil L ₁ and the receiving coil L ₂ are located at a long distance, setting the positions of the transmitting coil L ₁ and the receiving coil L ₂ may be important factors.

At this time, the transmission coil L ₁ is included in the transmission pad 21 in FIG. 1, and the reception coil L ₂ can be included in the reception pad 11 in FIG. In addition, the transmit coil may be referred to as a GA coil (Ground Assembly coil), and the receive coil may be referred to as a VA coil (Vehicle Assembly coil). Therefore, positioning between the power transmission pad and the power reception pads or positioning between the power transmission pads and the power transmission pads will be described below with reference to the drawings.

3 is a conceptual diagram illustrating an alignment concept in wireless power transmission of an electric vehicle according to an embodiment of the present invention.

Referring to FIG. 3, a method of aligning the power transmission pad 21 and the power receiving pad 11 built in the electric vehicle 10 in FIG. 1 can be described. In this case, the positional alignment can correspond to the alignment, which is the above-mentioned term, and thus can be defined as the alignment between the GA and the VA, or the positional alignment between the transmission pad 21 and the receiving pad 11, It does not.

3, the transmission pad 21 may be positioned above the ground surface, or may be positioned such that the upper surface of the transmission pad 21 is exposed below the ground surface.

Further, the receiving pads 11 of the electric vehicle can be defined by different categories according to heights (defined in the z direction) measured on the basis of the ground surface. For example, the height of the receiving pads 11 on the ground surface is 100-150 (mm), class 2 for class 1, 140-210 (mm), and class 3 for class 170-250 (mm). At this time, only the class 1 may be supported according to the receiving pad 11, or the class 1 and 2 may be supported, and partial support may be possible.

Here, the height measured based on the ground surface may correspond to the above-mentioned term vehicle magnetic ground surface.

The position of the transmission pad 21 in the height direction (defined in the z direction) can be determined so as to be located between the maximum class and the minimum class supported by the power receiving pad 11. For example, If only class 1 and class 2 are supported, it is possible to determine that the transmission pad is located between 100 and 210 mm on the basis of the reception pad 11.

Further, the gap between the center of the power transmission pad 21 and the center of the power receiving pad 11 can be determined so as to be located within the limits of the horizontal and vertical directions (defined in the x and y directions). For example, it can be determined to be located within ± 75 (mm) in the horizontal direction (defined in the x direction) and to be located within ± 100 (mm) in the vertical direction (defined in the y direction).

Here, the relative positions of the power transmission pad 21 and the power reception pad 11 can be varied in accordance with their experimental results, and these values are to be understood as exemplary.

The transmission pads 21 and the power reception pads 11 are assumed to include coils and are aligned with each other. More specifically, the power transmission pads 21 and the power reception pads 11, It can be defined as the alignment between the coil (or GA coil) and the receiving coil (or VA coil).

Therefore, in the following description, the arrangement between the transmission coil and the reception coil will be described. In particular, an embodiment of the present invention, in which the transmission coil is composed of a plurality of coils, will be described in detail.

4A and 4B are conceptual diagrams for explaining the concept of wireless power transmission using a plurality of transmission coils according to an embodiment of the present invention, in comparison with wireless power transmission using a single transmission coil.

4A and 4B, a wireless power transmission scheme using a plurality of transmission coils (or GA coils) according to an embodiment of the present invention can be described as compared with a wireless power transmission scheme using a single transmission coil .

First, referring to FIG. 4A, a wireless power transmission scheme 40 using a single transmission coil will be described.

That is, when wireless power is transmitted using a reception coil built in a vehicle assembly (VA) of an electric vehicle and a single first transmission coil 21a, if the gap between the two coil centers is within a certain range, To be transmitted.

This is because, if the gap between the centers of coils is out of a certain range, there is a problem that the efficiency of the wireless power transmission may be greatly reduced or the wireless power transmission may fail.

Therefore, when the electric vehicle does not satisfy the above-mentioned constraint, it is necessary to adjust the center gap between the receiving coils of the electric vehicle and the transmission coils embedded in the ground of the charging station by a method of parking the electric vehicle again, There is a problem that the convenience is greatly reduced.

The wireless power transmission scheme 41 using a plurality of transmission coils according to an embodiment of the present invention can transmit wireless power to an electric vehicle as follows.

4B, the first transmission coil 21a, the second transmission coil 21b, and the third transmission coil 21c may be provided on the ground around the charging station.

Here, the first transmission coil 21a to the third transmission coil 21c may be arranged so that they partially overlap each other, and the distances between the centers of the transmission coils may be arranged to be spaced left and right and / have. Further, each of the transmission coils can be laminated in a stepped manner.

When the electric vehicle enters the region where the transmission coils of the charging station are located to receive the wireless power, the coils having the highest radio power transmission efficiency among the first transmission coil 21a to the third transmission coil 21c are selected, (Or induce) wireless power to the receive coil.

The use of the wireless power transmission scheme 41 using a plurality of transmission coils according to the embodiment of the present invention allows wireless power to be transmitted using a coil having the highest efficiency of wireless power transmission among a plurality of transmission coils, It is possible to alleviate the burden of alignment between the transmission coil and the reception coil compared with the wireless power transmission system 40 using one transmission coil, and the user convenience can be improved.

More specifically, a plurality of transmission coils may be provided near the charging station, such as the first transmission coil 21a to the third transmission coil 21c, and the first transmission coil 21a to the third transmission coil 21c Are assumed to have a center-to-center spacing of 75 (mm). That is, the centers of the first transmission coil 21a and the second transmission coil 21b are spaced by 75 mm and the centers of the second transmission coil 21b and the third transmission coil 21c are spaced by 75 mm Lt; / RTI >

Under these assumptions, the transmit coils have a maximum horizontal spacing of 225 mm total. At least one of the transmitting coil and the receiving coil can maintain a center distance of 75 mm or less as long as the receiving coil of the electric car is located between the maximum horizontal spacing of 225 mm, The alignment between the coils can be achieved.

5 is a schematic flow chart of a wireless power transmission method using a plurality of transmission coils according to the present invention.

Referring to FIG. 5, a radio power transmission method using a plurality of transmission coils includes a step (S100) of confirming an alignment state between a plurality of transmission coils and reception coils mounted on an electric vehicle, (S110) of selecting a transmission coil satisfying the constraint among the plurality of transmission coils, and transmitting (S120) wireless power to the reception coil using the selected transmission coil.

Here, the predetermined condition is the same as the gap (or spacing distance) between the center of the power transmission pad 21 and the center of the power reception pad 11 defined in Fig. For example, it is possible to determine that the gap between the center of the selected transmission coil and the center of the reception coil among the plurality of transmission coils is located within ± 75 mm in the horizontal direction (or left and right direction) Direction) can be defined to be located within ± 100 (mm).

Here, the step of confirming the alignment state (S100) may include the step of ascertaining the horizontal or vertical separation distance between the center of each of the plurality of transmission coils and the center of the reception coil.

Here, the step of confirming the alignment state (S100) can be repeatedly performed during the process of aligning the plurality of transmission coils and the reception coils by moving the electric vehicle. That is, when the electric vehicle moves for wireless charging, the process of confirming the alignment state can be automatically performed.

Here, the step of confirming the alignment state (S100) may be performed in response to receiving a message requesting wireless power transmission from the electric vehicle.

Here, the step (S110) of selecting, among the plurality of transmission coils, transmission coils satisfying a predetermined constraint condition on the alignment state, when the number of selected transmission coils is two or more, And further selecting a transmission coil by further considering the transmission efficiency.

Here, the step of selecting the transmission coil by further considering the radio power transmission efficiency of each of the plurality of transmission coils may include selecting, when the number of the selected transmission coils is two or more, Measuring the radio power transmission efficiency of each of the predetermined transmission coils based on the transmission result, and selecting the transmission coil having the highest value of the measured radio power transmission efficiency have.

Here, measuring the radio power transmission efficiency of each of the selected transmission coils may further include storing the measured respective radio power transmission efficiencies in a memory (or storage device).

Here, the charging efficiency may mean the amount of power transmitted to the receiving coil for a predetermined time, but is not limited thereto, and may be defined as the amount of power generated per unit time in the receiving coil compared to the amount of power supplied per unit time to the transmitting coil.

Here, the step (S110) of selecting, from among the plurality of transmission coils, a transmission coil satisfying a predetermined constraint condition for the alignment state, if there is no transmission coil satisfying a predetermined constraint condition, The method may further include transmitting. Specifically, for example, a message requesting reordering can be transmitted to an Electric Vehicle Communication Controller (EVCC) mounted on an electric car by a Supply Equipment Communication Controller (SECC).

Here, SECC may be a device that is installed at or near the charging station to control communication with an electric vehicle, and EVCC may be an apparatus that is mounted on an electric vehicle and controls communication.

6 is a flowchart specifically illustrating a wireless power transmission method using a plurality of transmission coils according to the first embodiment of the present invention.

Referring to Fig. 6, an example in which the optimum transmission coil is selected based on the alignment and charging efficiencies of the coils among the plurality of transmission coils to perform wireless charging to the electric vehicle can be described.

Assuming that three transmission coils (coil 1, coil 2, and coil 3) are provided as a plurality of transmission coils, it can be determined whether the coil 1 satisfies the constraint condition for the chargeable alignment state (S200 ). At this time, the step S200 may be started when an electric car stops for wireless charging or when a request for wireless charging start of the driver is made.

Here, magnetic field detection, an optical camera, an RFID (RFID), a global positioning system (GPS), and the like may be additionally used to determine whether the device is in a chargeable alignment state.

If the coil 1 does not satisfy the constraint condition, it can be determined whether the coil 2 satisfies the constraint condition for the chargeable alignment state (S220). If the coil 1 satisfies the constraint condition, Charging is performed for the set time, and the charging efficiency information can be stored in the memory (S210).

Next, if the coil 2 does not satisfy the constraint condition, it can be determined whether the coil 3 satisfies the constraint condition for the chargeable alignment state (S240). If the coil 2 satisfies the constraint condition, The charging may be continued for a preset time, and the charging efficiency information may be stored in the memory (S230).

Next, if the coil 3 satisfies the above-mentioned constraint condition, the charging operation can be continued for a predetermined time using the coil 3, and the charging efficiency information can be stored in the memory (S250).

After storing the charging progress and charging efficiency information according to whether the constraint condition for the coil 1 to the coil 3 is satisfied (steps S200 to S250), it is determined whether or not there is a rechargeable (or satisfying constraint) The number of transmission coils can be determined (S260).

At this time, step S260 may correspond to a step of confirming the number of transmission coils having a wireless power transfer (WPT) efficiency (or a maximum value thereof) stored in the memory equal to or greater than a predetermined reference value. Here, if the WPT efficiency is equal to or greater than a predetermined reference value, the corresponding transmitting coil may be a coil usable for charging. If the WPT efficiency is less than a predetermined reference value, the corresponding transmitting coil may be defined as a coil unusable for charging.

As a result of the determination, if there is no rechargeable transmission coil, the vehicle reordering request message may be transmitted to the electric vehicle or the user terminal of the driver so as to recognize that the driver is not in chargeable state (S265).

As a result of the determination, if there are two or more transmission coils that can be recharged, the transmission coil having the highest charging efficiency can be selected based on the charging efficiency information stored in the memory (S270). Here, step S270 may correspond to the step of selecting a coil corresponding to the largest charging efficiency stored in the memory.

And wirelessly charging the electric vehicle using the finally selected transmission coil (S280).

According to the present embodiment, when the electric car operator moves the electric vehicle EV to the approximate alignment position and then starts wireless charging, the electric vehicle wireless charging device actually uses the coils 1 to 3 for a short time (for example, ), It is possible to grasp the respective charging efficiencies, and automatically select the coils having the maximum efficiency over the specified efficiency, so that the high-efficiency wireless charging can be performed.

FIG. 7 is a flowchart specifically illustrating a wireless power transmission method using a plurality of transmission coils according to a second embodiment of the present invention.

Referring to FIG. 7, a method of grasping an alignment state according to an embodiment of the present invention and selecting a transmission coil having a minimum alignment error according to an alignment state among a plurality of transmission coils can be described.

In FIG. 7, it is assumed that there are three transmit coils, each of which may be referred to as coils 1 to 3, but should be understood as being illustrative.

First, the alignment state of the coil 1 is checked, and the alignment error of the coil 1 is measured and stored in the memory (S300). For example, the alignment error of the coil 1 may be defined as the difference between the actual position of the coil 1 and the optimum alignment position of the center of the reception coil corresponding to the transmission coil.

In addition, the measurement of the above-described alignment error value can be performed using means such as magnetic field detection, optical camera, RFID, global positioning system (GPS), and the like.

After step S300 or independently of step S300, alignment can be checked against coil 2, the alignment error can be measured and stored in memory (S310). Independent of steps S300 and S310, or step S300 and step S310, alignment can be checked against coil 3, and the alignment error can be measured and stored in memory (S320). Here, the alignment error between the coil 2 and the coil 3 can be defined similar to the alignment error of the coil 1.

Next, the measured alignment errors for the coil 1, the coil 2, and the coil 3 are compared with each other, and the transmission coil with the smallest alignment error value (best aligned) can be selected (S330). Step S330 may correspond to a step of selecting a transmission coil having a minimum value of the alignment error values stored in the memory.

Next, the charging start request message may be received from the user terminal of the electric vehicle or the driver according to the input of the driver (S340). At this time, if there is no charging start request input by the driver, steps S300 to S330 may be repeatedly performed. At this time, steps S300 to S330 may be performed automatically at predetermined time intervals.

If there is an input of a charging start request from the driver, it can be determined whether the selected transmission coil satisfies the above-described constraint condition (alignment range) (S350). As a result of the determination in step S350, if the selected transmission coil satisfies the constraint condition, wireless charging for the electric vehicle can be performed using the selected transmission coil (S360).

On the other hand, if the selected transmission coil does not satisfy the constraint, any other transmission coils with larger error values are the same as those that do not satisfy the constraint, so that neither transmission coil can be used for wireless charging. Accordingly, at this time, a message requesting the rearrangement of the vehicle may be transmitted to the user terminal of the driver or the electric vehicle (S355).

On the other hand, if it is determined that there is an input or signal to start charging, it is determined whether the selection coil satisfies the rechargeable alignment range requirement. As a result of the determination, if the selection coil satisfies the requirement, the selection coil is connected to the power supply device and the wireless charging is performed through the selection coil. As a result of the determination, if the selection coil does not satisfy the requirement, the driver can request reordering.

8 is a configuration diagram of a wireless power transmission apparatus using a plurality of transmission coils according to an embodiment of the present invention.

8, a wireless power transmission apparatus 100 using a plurality of transmit coils includes at least one processor 110 and at least one processor 110 for executing instructions instructions for executing the program.

The wireless power transmission apparatus 100 using a plurality of transmission coils may be a communication module that communicates with an EVCC or an operator terminal of the driver to receive an input of a driver or transmit a message relating to wireless power transmission to a driver 130).

In addition, the wireless power transmission apparatus 100 using a plurality of transmission coils may further include a storage 140 for storing a result of checking the alignment state or a result of measuring the charging efficiency. Here, the role of the repository 140 may instead be performed by the memory 120, in which case the repository 140 may be omitted.

Wherein at least one step performed by the at least one processor (110) comprises the steps of: confirming an alignment condition between a plurality of transmit coils and receive coils mounted on an electric vehicle; Selecting a satisfactory transmitting coil from among the plurality of transmitting coils, and transmitting the wireless power to the receiving coil using the selected transmitting coil.

The step of confirming the alignment state may include the step of ascertaining a horizontal or vertical separation distance between the center of each of the plurality of transmission coils and the center of the reception coil.

The step of confirming the alignment state may be repeatedly performed during the movement of the electric vehicle to align the plurality of transmission coils with the reception coils. Alternatively, the step of confirming the command state may be repeatedly performed until a transmission coil satisfying a predetermined constraint is selected.

Also, the checking of the alignment status may be performed in response to receiving a message requesting wireless power transmission from the electric vehicle.

Wherein the step of selecting among the plurality of transmission coils satisfying the constraint condition predetermined for the alignment state further includes a step of selecting the transmission coil by further considering the charging efficiency of each of the plurality of transmission coils in the alignment state .

Wherein the step of selecting the transmission coil further considering the charging efficiency of each of the plurality of transmission coils transmits the wireless power to the reception coil for a predetermined time using the selected transmission coils when the number of the selected transmission coils is two or more Measuring the charging efficiency of each of the predetermined transmission coils based on the transmission result, and selecting the transmission coil having the highest charging efficiency measured.

Here, measuring the charging efficiency of each of the selected transmission coils may further include storing the measured charging efficiency in the memory.

Here, the charging efficiency may mean the amount of power transferred to the receiving coil for a predetermined time.

Wherein the step of selecting a transmission coil among the plurality of transmission coils satisfying a predetermined constraint condition on the alignment state includes a step of transmitting a message requesting reordering to the electric vehicle when there is no transmission coil satisfying a predetermined constraint condition .

Here, the plurality of transmission coils may have a distance of 75 mm or less in the transverse direction and a distance of 100 mm or less in the longitudinal direction.

Here, the wireless power transmission apparatus 100 using a plurality of transmission coils may correspond to all or a part of the ground assembly (GA) or the ground assembly controller (GA controller) described above, and thus may be referred to as a GA or a GA controller It is possible.

Examples of the user terminal include a portable computer such as a desktop computer, a laptop computer, a notebook, a smart phone, a tablet PC, a mobile phone, a smart phone, Such as a smart watch, a smart glass, an e-book reader, a portable multimedia player (PMP), a portable game machine, a navigation device, a digital camera, a digital multimedia broadcasting (DMB) A digital audio recorder, a digital audio player, a digital video recorder, a digital video player, a PDA (Personal Digital Assistant), and the like.

The methods according to the present invention can be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer readable medium. The computer readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions recorded on the computer readable medium may be those specially designed and constructed for the present invention or may be available to those skilled in the computer software.

Examples of computer-readable media include hardware devices that are specially configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions may include machine language code such as those produced by a compiler, as well as high-level language code that may be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate with at least one software module to perform the operations of the present invention, and vice versa.

Also, the above-described method or apparatus may be implemented by combining all or a part of the configuration or function, or may be implemented separately.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention as defined by the following claims It can be understood that

Claims (20)

In the wireless power transmission method using a plurality of transmission coils,
Confirming an alignment state between the plurality of transmission coils and the reception coils mounted on the electric vehicle;
Selecting a transmission coil among the plurality of transmission coils satisfying a predetermined constraint condition for the alignment state; And
And transmitting radio power to the receive coil using a selected transmit coil. ≪ Desc / Clms Page number 20 > In claim 1,
The step of confirming the alignment state includes:
And determining a horizontal or vertical separation distance between the center of each of the plurality of transmission coils and the center of the reception coil. In claim 1,
The step of confirming the alignment state includes:
Wherein a message requesting initiation of a wireless power transmission is repeatedly performed until receiving a message from a user of the electric vehicle or the electric vehicle. In claim 1,
The step of confirming the alignment state includes:
And a message for requesting wireless power transmission from the electric vehicle is received from a user of the electric vehicle or the electric vehicle. In claim 1,
Wherein the step of selecting, from among the plurality of transmission coils, a transmission coil satisfying a predetermined constraint condition for the alignment state,
And selecting the transmission coil by further considering the charging efficiency of each of the plurality of transmission coils in the alignment state. In claim 5,
Wherein the step of selecting the transmission coil further considering the charging efficiency of each of the plurality of transmission coils includes:
Transmitting radio power to the receive coil for a predetermined time using predetermined transmit coils when the selected transmit coil is two or more;
Measuring a charging efficiency of each of the selected transmission coils based on the transmission result; And
And selecting the transmitting coil having the highest measured charging efficiency. In claim 6,
Wherein the plurality of transmission coils are partially overlapped with each other and stacked in a stepped manner. In claim 6,
The above-
Means a quantity of power transmitted to the receiving coil for the predetermined time. In claim 1,
Wherein the step of selecting, from among the plurality of transmission coils, a transmission coil satisfying a predetermined constraint condition for the alignment state,
Further comprising the step of transmitting a message requesting reordering to the electric car if there is no transmission coil satisfying the predetermined constraint. In claim 1,
The plurality of transmission coils are connected to each other,
Wherein the plurality of transmission coils have a spacing distance of 75 mm or less in the transverse direction and a spacing distance of 100 mm or less in the longitudinal direction. At least one processor; And
A memory for storing instructions instructing the at least one processor to perform at least one step, the apparatus comprising: a plurality of transmit coils,
Wherein the at least one step comprises:
Confirming an alignment state between the plurality of transmission coils and the reception coils mounted on the electric vehicle;
Selecting a transmission coil among the plurality of transmission coils satisfying a predetermined constraint condition for the alignment state; And
And transmitting radio power to the receive coil using a selected transmit coil. ≪ Desc / Clms Page number 20 > In claim 11,
The step of confirming the alignment state includes:
And determining a horizontal or vertical separation distance between the center of each of the plurality of transmission coils and the center of the reception coil. In claim 11,
The step of confirming the alignment state includes:
Wherein a message requesting start of the wireless power transmission is repeatedly performed until the message is received from the user of the electric car or the electric car. In claim 11,
The step of confirming the alignment state includes:
Wherein the power control is performed in response to receiving a message requesting wireless power transmission from the electric vehicle. In claim 1,
Wherein the step of selecting, from among the plurality of transmission coils, a transmission coil satisfying a predetermined constraint condition for the alignment state,
And selecting the transmission coil by further considering the charging efficiency of each of the plurality of transmission coils in the alignment state. In claim 15,
Wherein the step of selecting the transmission coil further considering the charging efficiency of each of the plurality of transmission coils includes:
Transmitting radio power to the receive coil for a predetermined time using predetermined transmit coils when the selected transmit coil is two or more;
Measuring a charging efficiency of each of the selected transmission coils based on the transmission result; And
And selecting the transmission coil having the highest measured charging efficiency. In claim 16,
Wherein the plurality of transmission coils partially overlap each other and are stacked in a stepped manner. In claim 16,
The above-
Means a quantity of power transmitted to the receiving coil for the predetermined time. In claim 11,
Wherein the step of selecting, from among the plurality of transmission coils, a transmission coil satisfying a predetermined constraint condition for the alignment state,
Further comprising the step of transmitting a message requesting reordering to the electric vehicle when there is no transmission coil satisfying the predetermined constraint. In claim 11,
The centers of the plurality of transmission coils are connected to each other,
Wherein the antenna has a spacing distance of 75 mm or less in the transverse direction and a spacing distance of 100 mm or less in the longitudinal direction.

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