Coil structure for wireless charging of electric vehicle, coil manufacturing method, and wireless charging pad using coil structure

Abstract

Disclosed is a coil structure using electromagnetic induction by means of an alternating current electrical signal in order to generate a magnetic field, the coil structure comprising a coil conduction wire formed by extending and arranging, in parallel, a plurality of conduction wire elements in a first direction, which is the direction of a current path, wherein the plurality of conduction wire elements are arranged to be spaced a predetermined first interval apart from each other on a cross section perpendicular to the first direction of the coil conduction wire, and the coil conduction wire is wound to form a coil.

Description

Coil structure for wireless charging of electric vehicles, coil manufacturing method, and wireless charging pad using the coil structure

[0001] The present invention relates to a coil structure for wireless charging of an electric vehicle, a coil manufacturing method, and a wireless charging pad using the coil structure, and more particularly, to a coil structure that increases current transfer characteristics and reduces heat generation.

[0002] Electric vehicles (EVs) use battery power to drive a motor, and thus have the advantages of producing fewer air pollutants such as exhaust fumes and noise, being less prone to breakdowns, having a longer lifespan, and being easier to drive than conventional gasoline engine vehicles.

[0003] Electric vehicles are categorized by their propulsion system into hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and electric vehicles (EVs). HEVs have an engine as their primary power source and a motor as an auxiliary power source. PHEVs have a motor as their primary power source and an engine that powers the vehicle when the battery is discharged. EVs have a motor but no engine.

[0004] An electric vehicle charging system can be fundamentally defined as a system that charges the batteries mounted on an electric vehicle using power from the commercial power grid or energy storage devices. These systems can take various forms depending on the type of electric vehicle. For example, an electric vehicle charging system may include a conductive charging system using cables or a contactless wireless power transfer system.

[0005] When charging an electric vehicle, a vehicle assembly (VA) mounted on the electric vehicle forms an inductive resonant coupling with a transmitting pad of a ground assembly (GA) located at a charging station or charging spot, and the battery of the electric vehicle can be charged using power transmitted from the ground assembly through the inductive resonant coupling.

[0006] Meanwhile, in a magnetic induction-based wireless power transmission system, the structure of the transmitting and receiving pads is a crucial factor in ensuring power transfer efficiency. Specifically, the transmitting and receiving pads are embedded with ferrite, a magnetic material that aids wireless power transfer, and a coil is formed surrounding the ferrite structure. The transmitting and receiving pads also include a winding frame that secures the coil and maintains the structure of the transmitting and receiving pads.

[0007] Conventional Litz wire has an inner core surrounded by an outer core, and each inner core forms a circle in a cross-section perpendicular to the direction of the current path. Due to the shape of the Litz wire, the heat generated is not easily transferred to the outside quickly. Furthermore, considering the current transmission characteristics, which increase losses as heat generation continues, long-term use is difficult. Consequently, adding a cooling function to a power transmission system using Litz wire is expected to increase costs. Even if a cooling function is added to the system, the low thermal conductivity of the Litz wire, which allows heat generated inside to be transferred to the outside, can have a negative impact on efficiency.

[0008] The present invention aims to provide a coil structure that increases current transfer characteristics and reduces heat generation, a coil manufacturing method, and a wireless charging pad using the coil structure.

[0009] In addition, the present invention seeks to provide a coil structure capable of efficiently securing a wide area that can be energized within the same space.

[0010] According to one aspect of the present invention, a coil structure provided is a coil structure for generating a magnetic field by using electromagnetic induction by an alternating current signal, and includes a coil conductor formed by arranging a plurality of conductor elements in parallel and extending in a first direction which is a direction of a path of a current, and on a cross-section of the coil conductor perpendicular to the first direction, the plurality of conductor elements are arranged while being spaced apart from each other by a first predetermined interval, and the coil conductor can be wound to form a coil.

[0011] At this time, each of the plurality of conductor elements can form a square on a cross-section perpendicular to the first direction of the coil conductor.

[0012] At this time, the plurality of conductor elements may be arranged while being spaced apart from each other by the first interval in a second direction on a cross-section perpendicular to the first direction of the coil conductor, and may be arranged while being spaced apart from each other by the second interval in a third direction different from the second direction on a cross-section perpendicular to the first direction of the coil conductor, thereby forming a laminated structure on a cross-section perpendicular to the first direction of the coil conductor.

[0013] At this time, the length of the first side of the square, the length of the second side, and the first interval can be determined based on the electrical characteristics and heat dissipation characteristics of the plurality of conductor elements.

[0014] At this time, a dielectric layer may be placed in the gap between the conductor elements spaced apart by the first interval.

[0015] At this time, a dielectric layer may be disposed in the gap between the conductor elements spaced apart by the first interval in the second direction among the plurality of conductor elements and in the gap between the conductor elements spaced apart by the second interval in the third direction.

[0016] At this time, the first interval may vary depending on the length of the second side.

[0017] According to one aspect of the present invention, a method for manufacturing a coil is provided, which is a method for manufacturing a coil for generating a magnetic field by using electromagnetic induction by an alternating current signal, the method including: forming a coil conductor by arranging a plurality of conductor elements extending in a first direction, which is a direction of a current path, in parallel; and forming a coil by winding the coil conductor. The forming step may be a step of arranging the plurality of conductor elements to be spaced apart from each other by a first predetermined interval on a cross-section of the coil conductor that is perpendicular to the first direction.

[0018] At this time, each of the plurality of conductor elements can form a square on a cross-section perpendicular to the first direction of the coil conductor.

[0019] At this time, the step of forming the coil conductor may be a step of arranging the plurality of conductor elements so as to be spaced apart from each other by the first interval in a second direction on a cross-section of the coil conductor that is perpendicular to the first direction, and so as to be spaced apart from each other by the second interval in a third direction different from the second direction on a cross-section of the coil conductor that is perpendicular to the first direction, thereby forming a laminated structure on a cross-section of the coil conductor that is perpendicular to the first direction.

[0020] At this time, the length of the first side of the square, the length of the second side, and the first interval can be determined based on the electrical characteristics and heat dissipation characteristics of the plurality of conductor elements.

[0021] At this time, the step of forming the coil conductor may include a step of arranging a dielectric layer in a gap between conductor elements spaced apart by the first interval.

[0022] At this time, the step of forming the coil conductor may include a step of arranging a dielectric layer in a gap between the conductor elements spaced apart by the first interval in the second direction among the plurality of conductor elements and in a gap between the conductor elements spaced apart by the second interval in the third direction.

[0023] At this time, the first interval may vary depending on the length of the second side.

[0024] According to one aspect of the present invention, a wireless charging pad is provided as a pad for wirelessly transmitting or receiving power by using electromagnetic induction by an alternating current signal flowing in a coil conductor, and may include a coil formed by winding a coil conductor to surround a central space. The coil conductor is formed by arranging a plurality of conductor elements in parallel and extending in a first direction, which is a direction of a current path, and the plurality of conductor elements may be arranged while being spaced apart from each other by a first predetermined interval on a cross-section of the coil conductor perpendicular to the first direction.

[0025] At this time, each of the plurality of conductor elements can form a square on a cross-section perpendicular to the first direction of the coil conductor.

[0026] At this time, the plurality of conductor elements may be arranged while being spaced apart from each other by the first interval in a second direction on a cross-section perpendicular to the first direction of the coil conductor, and may be arranged while being spaced apart from each other by the second interval in a third direction different from the second direction on a cross-section perpendicular to the first direction of the coil conductor, thereby forming a laminated structure on a cross-section perpendicular to the first direction of the coil conductor.

[0027] At this time, the length of the first side of the square, the length of the second side, and the first interval can be determined based on the electrical characteristics and heat dissipation characteristics of the plurality of conductor elements.

[0028] At this time, a dielectric layer may be placed in the gap between the conductor elements spaced apart by the first interval.

[0029] At this time, a dielectric layer may be disposed in the gap between the conductor elements spaced apart by the first interval in the second direction among the plurality of conductor elements and in the gap between the conductor elements spaced apart by the second interval in the third direction.

[0030] According to the present invention, a coil structure that increases current transfer characteristics and reduces heat generation, a coil manufacturing method, and a wireless charging pad using the coil structure can be provided.

[0031] In addition, according to the present invention, a coil structure can be provided that can efficiently secure a large area that can be energized within the same space.

[0032] FIG. 1 is a conceptual diagram of an example of a wireless power transmission system for an electric vehicle to which one embodiment of the present invention is applied.

[0033] Figures 2 and 3 are conceptual diagrams of the x, y, and z axes specified in SAE J2954 that can be applied to one embodiment of the present invention.

[0034] FIG. 4 is a conceptual diagram illustrating an electric vehicle wireless charging circuit according to one embodiment of the present invention.

[0035] FIG. 5 is an equivalent circuit of a single-phase-single-phase wireless power transmission system according to one embodiment of the present invention.

[0036] FIG. 6 is a conceptual cross-sectional view and an elevation view of a transmission pad according to one embodiment of the present invention.

[0037] Fig. 7 illustrates a Ritz line according to a conventional embodiment.

[0038] Figure 8 illustrates a coil according to one embodiment of the present invention.

[0039] Fig. 9 is a cross-sectional view of one coil conductor of Fig. 8.

[0040] FIG. 10 is a drawing for explaining a coil structure according to another embodiment of the present invention.

[0041] FIG. 11 is a cross-sectional view of one coil conductor of FIG. 8 according to another embodiment of the present invention.

[0042] Fig. 12 is a cross-sectional view of a coil conductor according to another embodiment of the present invention.

[0043] Fig. 13 is a cross-sectional view of a coil conductor according to another embodiment of the present invention.

[0044] Fig. 14 is a cross-sectional view of a coil conductor according to another embodiment of the present invention.

[0045] Figure 15 shows a copper thickness unit conversion table according to one embodiment of the present invention.

[0046] Fig. 16 illustrates a six-layer PCB structure according to one embodiment of the present invention.

[0047] Fig. 17 illustrates an 8-layer PCB structure according to another embodiment of the present invention.

[0048] Fig. 18 illustrates a 16-layer PCB structure according to another embodiment of the present invention.

[0049] FIG. 19 is a drawing for explaining the shape according to the number and width of wiring in the inner layer of a PCB according to one embodiment of the present invention.

[0050] FIG. 20 is a side view of a PCB inner layer having a plurality of wires according to one embodiment of the present invention.

[0051] Figure 21 shows a plan view and a side perspective view of wiring according to one embodiment of the present invention.

[0052] Figure 22 is a table showing impedance values ​​according to the width, length, and frequency of the wiring according to one embodiment of the present invention.

[0053] Figure 23 illustrates two planes according to one embodiment of the present invention.

[0054] FIG. 24 is a drawing for explaining RF radiation energy generated between two planes according to one embodiment of the present invention.

[0055] FIG. 25 is a drawing for explaining a 20H rule for controlling an RF radiation shape according to one embodiment of the present invention.

[0056] Figure 26 is a flowchart for explaining a coil manufacturing method according to one embodiment of the present invention.

[0057] FIG. 27 is a flowchart for explaining a method for manufacturing a coil using a coil conductor having a laminated structure according to one embodiment of the present invention.

[0058] FIG. 28 is a block diagram illustrating a generalized configuration of hardware that controls a sequence for wireless power transfer included within a transmitting pad and / or a receiving pad of the present invention, or in connection with a transmitting pad and / or a receiving pad of the present invention.

[0059] The present invention is susceptible to various modifications and embodiments. Specific embodiments are illustrated and described in detail in the drawings. However, this is not intended to limit the present invention to specific embodiments, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention.

[0060] While terms such as "first" and "second" may be used to describe various components, these components should not be limited by these terms. These terms are used solely to distinguish one component from another. For example, without departing from the scope of the present invention, a first component may be referred to as a "second component," and similarly, a second component may also be referred to as a "first component." The term "and / or" includes a combination of multiple related items described herein or any of multiple related items described herein.

[0061] In the embodiments of the present application, “at least one of A and B” may mean “at least one of A or B” or “at least one of combinations of one or more of A and B.” Furthermore, in the embodiments of the present application, “at least one of A and B” may mean “at least one of A or B” or “at least one of combinations of one or more of A and B.”

[0062] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening.

[0063] The terminology used in this application is only used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, it should be understood that the terms "comprise" or "have" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0064] Unless otherwise defined, 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 pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0065] Meanwhile, even if a technology was known prior to the filing date of this application, it may be included as part of the composition of the invention of this application, if necessary, and such technology will be described in this specification to the extent that it does not obscure the spirit of the invention. However, in describing the composition of the invention of this application, a detailed description of matters that were known prior to the filing date of this application and would be clearly understood by those skilled in the art may obscure the spirit of the invention, and therefore, an excessively detailed description of the known technology will be omitted.

[0066] Some terms used in this specification are defined as follows:

[0067] An electric vehicle (EV) may refer to an automobile as defined in 49 CFR (Code of Federal Regulations) 523.3, among other provisions. An EV is capable of highway travel and can be powered by electricity supplied by an onboard energy storage device, such as a rechargeable battery, from an external power source. This power source may include a residential or public power service, or a generator powered by onboard fuel.

[0068] An electric vehicle (EV) can be referred to as an electric car, electric automobile, ERV (electric road vehicle), PV (plug-in vehicle), xEV (plug-in vehicle), etc., and an xEV can be referred to as or distinguished as a BEV (plug-in all-electric vehicle or battery electric vehicle), PEV (plug-in electric vehicle), HEV (hybrid electric vehicle), HPEV (hybrid plug-in electric vehicle), PHEV (plug-in hybrid electric vehicle), etc.

[0069] A plug-in electric vehicle (PEV) can be referred to as an electric vehicle that recharges its onboard primary battery by connecting to the power grid.

[0070] A plug-in vehicle (PV) may be referred to herein as a vehicle that can be recharged wirelessly from an Electric Vehicle Supply Equipment (EVSE) without using a physical plug and socket.

[0071] Heavy duty vehicles (HD Vehicles) may refer to any vehicle with four or more wheels as defined in 49 CFR 523.6 or CFR 37.3 (bus).

[0072] A light-duty plug-in electric vehicle (LDEV) may refer to a vehicle with three or four wheels that is propelled by an electric motor powered by a rechargeable battery or other energy source, primarily intended for use on public streets, roads, and highways. A LEV may be defined as having a gross weight of less than 4.545 kg.

[0073] A wireless power charging system (WCS) may refer to a system for controlling between a Supply Device (or Ground Assembly, GA) and an EV device (or Vehicle Assembly, VA), including wireless power transfer, alignment, and communication.

[0074] Wireless power transfer (WPT) can refer to the transfer of electrical power from an alternating current (AC) power supply network, such as a utility or grid, to an electric vehicle through contactless means.

[0075] A utility provides electrical energy and can be defined as a collection of systems, typically including a Customer Information System (CIS), Advanced Metering Infrastructure (AMI), and a Rates and Revenue system. Utilities enable plug-in electric vehicles to access energy through price lists or discrete events. Utilities can also provide information on tariffs, metered power consumption intervals, and EV program qualifications for plug-in electric vehicles.

[0076] Smart charging can be described as a system where EVSE and / or electric vehicles (including plug-in hybrid electric vehicles) communicate with the power grid to optimize vehicle charge or discharge rates to grid capacity or time of day for cost-to-use ratios.

[0077] Automatic charging can be defined as the act of positioning a vehicle in a suitable location relative to a primary charger assembly capable of transmitting power and charging it either conductively or inductively. Automatic charging can be performed after obtaining the necessary authentication and authorization.

[0078] Interoperability can refer to the state in which components of a system can work together to achieve the intended function of the entire system. Information interoperability can refer to the ability of two or more networks, systems, devices, applications, or components to share information securely and effectively and easily with little or no user inconvenience.

[0079] An inductive charging system can refer to a system that electromagnetically transfers energy in the forward direction from the power supply network to an electric vehicle via a loosely coupled transformer. In this embodiment, the inductive charging system can correspond to an electric vehicle charging system.

[0080] An inductive coupler is a transformer that is formed by a primary device and a secondary device and transmits power through electrical isolation.

[0081] Inductive coupling can refer to the magnetic coupling between two coils. The two coils can refer to the primary coil / ground assembly coil and the secondary coil / vehicle assembly coil.

[0082] A supply power circuit (SPC) / ground assembly (GA) may refer to an assembly disposed on the primary / ground assembly or infrastructure side, including a primary coil / GA coil and other suitable components. The other suitable components may include at least one component for controlling impedance and resonant frequency, ferrite for reinforcing a magnetic path, and electromagnetic shielding materials. For example, the SPC or GA may include a power / frequency conversion device necessary to function as a power source of a wireless charging system, an SPC controller / GA controller, and wiring from the grid, and wiring between each unit and filtering circuits, a housing, etc.

[0083] An EV power circuit (EVPC) / vehicle assembly (VA) may refer to an assembly placed in a vehicle, including a secondary coil / VA coil and other suitable components. The other suitable components may include at least one component for controlling impedance and resonant frequency, ferrite for reinforcing the magnetic path, and electromagnetic shielding materials. For example, an EVPC or VA may include a rectifier / power converter necessary to function as a vehicle component of a wireless charging system, an EVPC controller / VA controller, and wiring for a vehicle battery, as well as wiring between each unit and filtering circuits, a housing, etc.

[0084] The aforementioned SPC may be referred to or distinguished as a ground assembly (GA), etc., and similarly, the EVPC may be referred to or distinguished as a vehicle assembly (VA), etc.

[0085] The aforementioned GA may be referred to as a primary device (PD), a primary device, etc., and similarly, the VA may be referred to as a secondary device (SD), a secondary device, etc.

[0086] The aforementioned GA may be referred to as a supply device, a power supply-side device, etc., and similarly, the VA may be referred to as an electric vehicle device (EV device), an electric vehicle-side device, etc.

[0087] A primary device may be a device external to the electric vehicle that provides contactless coupling to the secondary device. The primary device may be referred to as a primary-side device. When the electric vehicle receives power, the primary device may act as a power source that transmits power. The primary device may include a housing and all covers.

[0088] A secondary device may be a device mounted on an electric vehicle that provides contactless coupling to the primary device. The secondary device may be referred to as a secondary device. When the electric vehicle receives power, the secondary device can transfer power from the primary device to the electric vehicle. The secondary device may include a housing and all covers.

[0089] The supply power electronics may be part of the SPC or GA that regulates the output power level to the primary coil / GA coil based on information from the vehicle. The EV power electronics may be part of the EVPC or VA that monitors certain vehicle parameters during charging and initiates communication with the SPC or GA to control the output power level.

[0090] The supply power electronics described above may be referred to as ground assembly electronics (GA electronics), a ground assembly controller (GA controller), or a primary device communication controller (PDCC), and the electric vehicle power electronics (EV power electronics) may be referred to as vehicle assembly electronics (VA electronics), a vehicle assembly controller (VA controller), or an electric vehicle communication controller (VA controller).

[0091] The magnetic gap may refer to the vertical distance between the highest plane of the upper portion of the litz wire or the upper portion of the magnetic material of the primary coil / GA coil and the lowest plane of the lower portion of the litz wire or the magnetic material of the secondary coil / VA coil when they are aligned with each other.

[0092] Ambient temperature may refer to the ground level temperature measured in the atmosphere of a target subsystem that is not directly exposed to sunlight.

[0093] Vehicle ground clearance can refer to the vertical distance between the road or pavement and the lowest part of the vehicle's floor pan.

[0094] Vehicle magnetic ground clearance may refer to the vertical distance between the lowest plane of the floor of the Litz wire or the insulating material of the secondary coil / VA coil mounted on the vehicle and the road pavement.

[0095] Secondary coil surface distance / Vehicle assembly (VA) coil surface distance may refer to the vertical distance between the bottommost plane of the Litz wire or the magnetic material of the secondary coil / VA coil and the lowest outer surface of the secondary coil / VA coil. This distance may include additional items packaged with protective covering material and coil packaging material.

[0096] The secondary coil described above may be referred to as a VA coil, a vehicle coil, a receiver coil, etc., and similarly, the primary coil may be referred to as a ground assembly coil (GA coil), a transmit coil, etc.

[0097] An exposed conductive component may refer to a conductive component of an electrical device (e.g., an electric vehicle) that can be touched by a person and is not normally conductive but may become conductive in the event of a fault.

[0098] Hazardous live component may refer to a live component that may, under certain conditions, cause a hazardous electric shock.

[0099] Live component may refer to any conductor or conductive part that is electrically active in its basic use.

[0100] Direct contact can refer to contact between living beings, such as humans.

[0101] Indirect contact may refer to contact with exposed, conductive, live components due to an insulation failure (see IEC 61140).

[0102] Alignment may refer to a process of finding the relative position of a secondary device to a primary device for a specified efficient power transfer, and / or a process of finding the relative position of a primary device to a secondary device. In this specification, alignment may refer to, but is not limited to, the positional alignment of a wireless power transfer system.

[0103] Pairing may refer to the process of associating a vehicle (electric vehicle) with a single dedicated ground assembly (primary device) arranged to transfer power. In this specification, pairing may include the process of associating a charging spot or a specific SPC / ground assembly with an EVPC / vehicle assembly controller.

[0104] Correlation / Association may include the process of establishing a relationship between two peer communication entities.

[0105] Command and control communication may refer to communication between an electric vehicle power supply unit and an electric vehicle that exchanges information necessary to initiate, control, and terminate the wireless power transfer process.

[0106] High-level communication can handle all information beyond what command and control communication can handle. Data links for high-level communication can use, but are not limited to, power line communication (PLC).

[0107] Low power excitation may refer to, but is not limited to, activating the electric vehicle to detect the primary device for precision positioning and pairing, and vice versa.

[0108] A Service Set Identifier (SSID) is a unique 32-character identifier attached to the header of packets transmitted over a wireless LAN. The SSID identifies the basic service set (BSS) to which a wireless device is attempting to connect. Essentially, SSIDs distinguish multiple wireless LANs. Therefore, all access points (APs) and terminal / station devices attempting to use a specific wireless LAN can use the same SSID. Devices that do not use a unique SSID cannot join a BSS. Because SSIDs are visible in plaintext, they may not provide any security features to the network.

[0109] The ESSID (Extended Service Set Identifier) ​​is the name of the network you want to connect to. It's similar to the SSID, but can be a more extensive concept.

[0110] A BSSID (Basic Service Set Identifier) ​​is typically 48 bits long and is used to identify a specific BSS (Basic Service Set). For infrastructure BSS networks, the BSSID can be the MAC (Medium Access Control) of the AP device. For independent BSSs or ad hoc networks, the BSSID can be generated with any value.

[0111] A charging station may include at least one ground assembly and at least one ground assembly controller that manages the at least one ground assembly. The ground assembly may include at least one wireless communication device. A charging station may refer to a location equipped with at least one ground assembly, such as a home, office, public space, road, or parking lot.

[0112] In this specification, association may be used as a term meaning the procedure for establishing wireless communication between an Electric Vehicle Communication Controller (EVCC) and a Supply Equipment Communication Controller (SECC) that controls charging infrastructure.

[0113] Electric vehicle charging systems may include, but are not limited to, conductive charging systems using cables or contactless wireless power transfer systems. Essentially, an electric vehicle charging system can be defined as a system that charges the battery mounted on an electric vehicle using power from the commercial power grid or an energy storage device. These systems can take various forms depending on the type of electric vehicle.

[0114] SAE TIR J2954, the leading standard for wireless charging, establishes industry-standard specification guidelines that define acceptance criteria for interoperability, electromagnetic compatibility, minimum performance, safety, and testing for wireless charging of light-duty electric and plug-in electric vehicles.

[0115] A Wireless Communication System (WCS) based on the J2954 standard, which represents an example of a wireless charging system, may consist of a utility interface, a high-frequency power inverter, a coupling coil, a rectifier, a filter, an optional regulator, and communication between the vehicle energy charging / storage system and the power inverter connected to the utility. The utility interface is similar to a conventional EVSE connection to a single-phase or three-phase AC power source.

[0116] Hereinafter, with reference to the attached drawings, preferred embodiments of the present invention will be described in more detail. In order to facilitate an overall understanding in describing the present invention, identical reference numerals will be used for identical components in the drawings, and redundant descriptions of identical components will be omitted.

[0117] FIG. 1 is a conceptual diagram of an example of a wireless power transfer (WPT) system for an electric vehicle to which one embodiment of the present invention is applied.

[0118] Referring to FIG. 1, wireless power transfer can be performed by at least one component of an electric vehicle (10) and a charging station (20), and can be used to wirelessly transfer power to the electric vehicle (10).

[0119] However, the electric vehicle (10) according to the present invention may include a hybrid vehicle having both an electric motor and a general internal combustion engine, and may include not only an automobile but also a motorcycle, a cart, a scooter, and an electric bicycle.

[0120] Here, an electric vehicle (10) can be generally defined as a vehicle (automobile) that supplies current induced from a rechargeable energy storage device, such as a battery (12), as an energy source for an electric motor, which is a power device.

[0121] In addition, the electric vehicle (10) may include a receiving pad (11) including a receiving coil to wirelessly charge the battery (12), and may also include a plug connection to charge the battery (12) via a wire. In this case, an electric vehicle (10) capable of charging the battery (12) via a wire may be referred to as a plug-in electric vehicle (PEV).

[0122] Here, the charging station (20) can be connected to a power grid (30) or a power backbone and can provide alternating current (AC) or direct current (DC) power to a transmitting pad (21) including a transmitting coil via a power link.

[0123] In addition, the charging station (20) can communicate with a power grid (30) or an infrastructure management system or infrastructure server that manages the power grid through wired or wireless communication, and can perform wireless communication with an electric vehicle (10). Here, wireless communication may include Bluetooth, Zigbee, cellular, a wireless local area network, etc.

[0124] Additionally, for example, the charging station (20) may be located in various locations, such as a parking lot attached to the home of an electric vehicle owner (10), a parking area for charging electric vehicles at a gas station, a parking area at a shopping center or workplace, etc.

[0125] Here, the process of wirelessly charging the battery (12) of the electric vehicle (10) can be performed by first positioning the receiving pad (11) of the electric vehicle (10) in an energy field by the transmitting pad (21), and then allowing the transmitting coil of the transmitting pad (21) and the receiving coil of the receiving pad (11) to interact or couple with each other. As a result of the interaction or coupling, an electromotive force is induced in the receiving pad (11), and the battery (12) can be charged by the induced electromotive force.

[0126] Additionally, the charging station (20) and the transmitting pad (21) may be referred to as a supply power circuit (SPC) or a ground assembly (GA), in whole or in part, and the SPC or ground assembly may refer to the meaning defined above.

[0127] In addition, the receiving pad (11) of the electric vehicle (10) and all or part of other internal components of the electric vehicle may be referred to as an electric vehicle power circuit (EVPC) or a vehicle assembly (VA), where the EVPC or vehicle assembly may refer to the meaning defined above.

[0128] Here, the transmitting pad (21) or the receiving pad (11) may be configured as non-polarized or polarized.

[0129] Here, if the pad is non-polar, it may have one pole at the center of the pad and an opposite pole at the outer periphery. Here, the flux can be formed to exit at the center of the pad and return at all outer boundaries of the pad.

[0130] Additionally, if the pads are polarized, each end of the pad can have a pole. Here, the magnetic flux can be formed based on the orientation of the pad.

[0131] In the present invention, the transmitting pad (21) or the receiving pad (11) may be collectively referred to as a wireless charging pad.

[0132] Figures 2 and 3 are conceptual diagrams of the x, y, and z axes specified in SAE J2954 that can be applied to one embodiment of the present invention.

[0133] Referring to FIGS. 2 and 3, in the right-hand coordinate system, the forward or front-back direction of the vehicle can be defined as the x-axis, the driver side for a left-hand side vehicle or the left and right sides of the vehicle can be defined as the y-axis, the upward or up-and-down direction of the vehicle can be defined as the z-axis, the magnetic center of the coil of the transmitting pad (21) or receiving pad (11) can be defined as x=0 and y=0, and the ground surface can be defined as z=0.

[0134] FIG. 4 is a conceptual diagram illustrating an electric vehicle wireless charging circuit according to one embodiment of the present invention.

[0135] The circuit on the left side of Fig. 4 can be interpreted as representing all or part of the power supplied from the power grid (Vsrc), the charging station (20) in Fig. 1, and the configuration of the transmitting pad (21), and the circuit on the right side of Fig. 4 can be interpreted as representing all or part of the electric vehicle including the receiving pad and the battery.

[0136] The left circuit of Fig. 4 provides output power (Psrc) corresponding to power (Vsrc) supplied from a power grid to a wireless charging power converter, and the wireless charging power converter can output power (P1) obtained by performing AC / DC conversion and the frequency of the provided power (Psrc) so as to emit an electromagnetic field at a desired operating frequency from a transmitting coil (L1).

[0137] The wireless charging power converter may include at least one of an AC / DC converter that converts AC power supplied from the power grid (Psrc) into DC power, and a low-frequency converter (or LF converter) that converts DC power into power at an operating frequency suitable for wireless charging. The operating frequency may be determined to be, for example, between 80 and 90 kHz, but is not limited thereto.

[0138] The power (P1) output from the wireless charging power converter can be supplied again to a circuit composed of a transmitting coil (L1), a first capacitor (C1), and a first resistor (R1). At this time, the first capacitor (C1) can be determined to have an element value that allows it to have an operating frequency suitable for charging together with the transmitting coil (L1). In addition, the first resistor (R1) here can mean a power loss generated by the transmitting coil (L1) and the first capacitor (C1).

[0139] Here, the transmitting coil (L1) and the receiving coil (L2) are electromagnetically coupled, defined by a coupling coefficient m, so that power can be transmitted, or power can be induced to the receiving coil (L2). Therefore, in the present invention, the meaning of power being transmitted can be used interchangeably with the meaning of power being induced.

[0140] Here, the power (P2) induced or transmitted to the receiving coil can be provided to the electric vehicle power converter. At this time, the second capacitor (C2) can be determined to have an element value that allows it to have an operating frequency suitable for charging together with the receiving coil (L2), and the second resistor (R2) can mean the power loss generated by the receiving coil (L2) and the second capacitor (C2).

[0141] The electric vehicle power converter may include an LF / DC converter that converts the provided power (P2) at a specific operating frequency back into DC power having a voltage level suitable for the battery (VHV) of the electric vehicle.

[0142] When the electric vehicle power converter converts the provided power (P2) into power (PHV), the output power (PHV) can be used to charge the battery (VHV) built into the electric vehicle.

[0143] The right circuit of Fig. 4 may further include a switch for selectively connecting or disconnecting the receiving coil (L2) from the battery (VHV).

[0144] The resonance frequencies of the transmitting coil (L1) and the receiving coil (L2) can be configured to be similar or identical to each other, and the receiving coil (L2) can be configured to be positioned at a close range to the electromagnetic field generated by the transmitting coil (L1).

[0145] The circuit of FIG. 4 should be understood as an exemplary circuit for power transmission in an electric vehicle wireless charging system available for embodiments of the present invention, and the spirit of the present invention is not limited to the circuit of FIG. 4.

[0146] Meanwhile, since power loss may increase as the distance between the transmitting coil (L1) and the receiving coil (L2) increases, setting the positions of the two may be an important factor.

[0147] At this time, the transmitting coil (L1) may be included in the transmitting pad (21) in Fig. 1, and the receiving coil (L2) may be included in the receiving pad (11) in Fig. 1. In addition, the transmitting coil may be referred to as a primary coil or a GA coil (Ground Assembly coil), and the receiving coil may be referred to as a secondary coil or a VA coil (Vehicle Assembly coil). Therefore, the mutual positioning of the transmitting pad (21) and the receiving pad (11) or the mutual positioning of the electric vehicle (10) and the transmitting pad (21) is also an important factor.

[0148] The positional alignment between the transmitting pad (21) in FIG. 1 and the receiving pad (11) built into the electric vehicle (10) may correspond to the previously described term alignment, and therefore may be defined as the positional alignment between the SPC / GA and the EVPC / VA, and is not limited to the positional alignment of the transmitting pad (21) and the receiving pad (11).

[0149] Depending on the embodiment, the transmission pad (21) may be located below the ground surface, above the ground surface, or may be located so that the upper surface of the transmission pad (21) is exposed below the ground surface. At this time, as shown in FIGS. 2 and 3, the x-axis may indicate the front-back direction of the vehicle, the y-axis may indicate the left-right direction of the vehicle, and the z-axis may indicate the up-down direction of the vehicle.

[0150] In addition, the receiving pad (11) of the electric vehicle can be defined by different categories according to the height measured from the ground surface (defined in the z direction), and for example, if the height of the receiving pad (11) from the ground surface is 100-150 (mm), it can be set as class 1, if it is 140-210 (mm), it can be set as class 2, and if it is 170-250 (mm), it can be set as class 3. At this time, partial support may be possible, such as supporting only class 1 or supporting both classes 1 and 2, depending on the receiving pad (11).

[0151] The height measured relative to the ground surface can correspond to the vehicle magnetic ground clearance, a term previously described.

[0152] In addition, the position of the transmission pad (21) in the height direction (defined in the z direction) can be determined to be located between the maximum class and the minimum class supported by the reception pad (11). For example, if the reception pad (11) supports only classes 1 and 2, the transmission pad can be determined to be located between 100 and 210 (mm) from the reception pad (11).

[0153] Additionally, the gap between the center of the transmitting pad (21) and the center of the receiving pad (11) can be determined to be located within limits in the horizontal and vertical directions (defined in the y and x directions). For example, it can be determined to be located within ±75 (mm) in the horizontal direction (defined in the y direction), and it can be determined to be located within ±100 (mm) in the vertical direction (defined in the x direction).

[0154] Here, the relative positions of the transmitting pad (21) and the receiving pad (11) may have different limits depending on the experimental results, and the above figures should be understood as exemplary.

[0155] In addition, the transmission pad (21) and the reception pad (11) are assumed to each include a coil and are explained as alignment between the pads, but more specifically, it can be defined as alignment between the primary coil (transmission coil or GA coil) and the secondary coil (reception coil or VA coil) built into the transmission pad (21) and the reception pad (11), respectively.

[0156] FIG. 5 is an equivalent circuit of a single-phase wireless power transfer (WPT) system according to one embodiment of the present invention.

[0157] The magnetic / inductive coupling or resonant structure formed between the primary coil and the secondary coil of various embodiments of the present invention can be equivalently expressed by the transformer of FIG. 5.

[0158] Referring to FIG. 5, a single-phase AC-DC rectifier circuit (210) for applying an AC signal to the front end of the primary coil and a SPWM (sinusoidal pulse width modulation) inverter (220) are illustrated.

[0159] Also referring to FIG. 5, a rectifier (110) for transmitting power from the secondary coil to the load / battery and a charger (120) are shown.

[0160] A wireless power transmission device according to one embodiment of the present invention may include a power transmission circuit. The power transmission circuit illustrated in FIG. 5 may include, as a technical feature, a structure including a single-phase AC-DC rectifier circuit (210) and an SPWM inverter (220) on the primary coil side.

[0161] The power transmission circuit of FIG. 5 according to one embodiment of the present invention may include as technical features a single-phase AC-DC rectifier circuit (210) for transmitting power to the primary coil side, and a PI control structure based on a measurement value on the single-phase AD-DC rectifier circuit (210) for controlling the SPWM inverter (220).

[0162] The SPWM inverter (220) can receive the output of the single-phase AC-DC rectifier (210), generate an AC signal, and transmit the AC signal as an output to the primary coil.

[0163] An AC signal rectified by the operation of the rectifier (110) and charger (120) can be applied to the battery to charge the battery.

[0164] Figure 6 is a conceptual cross-sectional view and an elevation view of a transmission pad (21) according to one embodiment of the present invention.

[0165] Referring to FIG. 6, a transmitting coil (21d) included in a transmitting pad (21) in a device performing wireless power transmission by a single-phase operation as in FIG. 5 is illustrated. The transmitting pad (21) of FIG. 6 can provide a single-phase operation mode. In addition, by using a receiving pad (11) including a receiving coil (not shown) having a shape corresponding to that of the transmitting pad (21) of FIG. 6, the receiving pad (11) can receive wireless power by a single-phase operation mode. A coil and hardware configuration for the single-phase operation mode of the receiving pad (11) can be easily implemented by those skilled in the art by modifying FIG. 6.

[0166] Referring to FIG. 6, the transmission pad (21) may include an outer case (21a) forming an outer shape, an aluminum shield (21b) installed in a flat shape inside the outer case (21a), a flat ferrite (21c) installed on top of the aluminum shield, and a transmission coil (21d) installed on top of the flat ferrite (21c). Here, the upper part may mean above the ground based on the ground on which the transmission pad (21) is installed.

[0167] Here, ferrite, the material used in the flat ferrite (21c), is a magnetic substance containing iron oxide, which can play an auxiliary role in transmitting and receiving wireless power by reducing magnetic resistance and assisting the flow of magnetic flux.

[0168] In the present invention, the transmitting pad or the receiving pad may be referred to as a wireless charging pad.

[0169] Fig. 7 illustrates a Ritz line according to a conventional embodiment.

[0170] A conventional litz wire (40) has a shape in which inner cores (41) are wrapped around outer cores (42). Each inner core (41) forms a circle in a cross-section perpendicular to the direction of the current path.

[0171] The heat generated due to the shape of the Ritz line (40) is not easily transferred to the outside quickly, and considering the current transmission characteristics in which the loss increases as the heat generation continues, it is difficult to use it for a long period of time.

[0172] Therefore, the present invention seeks to provide a coil structure capable of increasing the transmission / transmission characteristics of current and reducing heat generation.

[0173] Figure 8 illustrates a coil according to one embodiment of the present invention.

[0174] The coil may be a transmitting coil (21d) of the transmitting pad (21) shown in Fig. 6, or may be a receiving coil of the receiving pad.

[0175] Fig. 9 is a cross-sectional view of one coil conductor (300) of Fig. 8.

[0176] Hereinafter, the description will be made with reference to FIGS. 8 and 9.

[0177] The coil conductor (300) is a single wire, and the coil conductor (300) can be wound at least once to form a coil structure. The coil structure is a coil structure for wireless power transmission by electromagnetic inductive coupling between a transmitting coil and a receiving coil, and can be a part of at least one of a power transmitting pad device including a transmitting coil and a power receiving pad device including a receiving coil.

[0178] At this time, the directions of the x, y, and z axes of FIGS. 8 and 9 may mean the same direction as the directions of the x, y, and z axes of FIGS. 2 and 3, or may mean different directions.

[0179] A coil structure according to one embodiment of the present invention may include a coil conductor (300) formed by arranging a plurality of conductor elements (310) in a parallel manner (i.e., in parallel) extending in a first direction (e.g., -y direction) which is the direction of the path of the current.

[0180] At this time, a plurality of conductor elements (310) can be arranged while being spaced apart from each other by a predetermined first interval (e.g., an interval of s3) on a cross-section perpendicular to the first direction (-y direction) of the coil conductor (300).

[0181] For example, the conductor element (311) and the conductor element (312) may be arranged while being spaced apart from each other by the first interval. The conductor element (312) and the conductor element (313) may be arranged while being spaced apart from each other by the first interval.

[0182] A coil conductor (300) formed by arranging the conductor elements (310) in the manner described above can be wound to form a coil.

[0183] The coil conductor (300) can form a square shape (e.g., a rectangle) on a cross-section perpendicular to the first direction of the coil conductor (300).

[0184] Additionally, each of the plurality of conductor elements (310) may form a square on a cross-section perpendicular to the first direction of the coil conductor (300). For example, as illustrated in FIG. 9, each of the plurality of conductor elements (310) may form a rectangle on the cross-section. In another embodiment, each of the plurality of conductor elements (310) may form a square on the cross-section.

[0185] At this time, the plurality of conductor elements (310) can be defined by the length (width) (s1) of the first side of the rectangular shape, the length (thickness) (s2) of the second side, and the first spacing (s3). The length (s1) of the first side, the length (s2) of the second side, and the first spacing (s3) can be determined based on the electrical characteristics and heat dissipation characteristics of the plurality of conductor elements (310).

[0186] For example, for charging a 22kWh battery of an electric vehicle, the target specifications related to current driving capability may be 87.5kHz, 3-phase 380VAC, and peak current = 57.89A.

[0187] The resistance of the copper wire is 1.69 x 10 -8 Ω·m, so in direct current supply, less heat is generated when the same current flows through the unit area. On the other hand, in the case of alternating current, the skin depth is approximately 0.22 mm at 87.5 kHz due to the skin effect. Therefore, since the skin depth is low due to the skin effect, the length of the first side (s1) must be determined so as to minimize power loss for charging. At this time, the skin effect refers to the phenomenon in which current tends to flow on the surface of the conductor in alternating current. The skin depth refers to the depth of the conductor that can flow on the surface of the conductor depending on the alternating current frequency.

[0188] At this time, the first gap (s3) may vary depending on the length of the second side (s2). That is, since the first gap (s3) between the conductor elements is related to the processability in the factory and the thickness of the copper plate, as the thickness of the copper conductor increases, the first gap (s3) may also increase relatively. At this time, 0.3 mm is most commonly used as the blade specification of the drill bit for copper plate processing due to the manufacturing characteristics. When the blade specification of the drill bit for copper plate processing is 0.25 mm, the manufacturing efficiency is reduced due to the characteristic of the blade breaking easily, so a drill bit for copper plate processing with a blade specification of 0.25 mm is not applied.

[0189] A dielectric layer may be placed in a gap where a plurality of conductor elements (310) are spaced apart by a first interval (s3). That is, the gap may be filled with a dielectric material.

[0190] For example, the dielectric material may include at least one of materials such as ceramic, epoxy, and aluminum.

[0191] For example, ceramics, which can be used as a material for voids, are the most insensitive to temperature changes due to heat. Selecting ceramics as a material for voids can reduce the impact on the product's total life cycle due to temperature-related expansion or contraction.

[0192] For example, epoxy, which can be used as a material for the above-mentioned gap, is easy to process and inexpensive. Furthermore, epoxy has the disadvantage of poor thermal properties within the same coil conductor shape. However, increasing the number of laminated conductor elements significantly reduces temperature resistance, so this can be addressed by differential application depending on the environmental conditions of the vehicle.

[0193] FIG. 10 is a drawing for explaining a coil structure according to another embodiment of the present invention.

[0194] FIG. 11 is a cross-sectional view of one coil conductor (300) of FIG. 8 according to another embodiment of the present invention.

[0195] Hereinafter, the description will be made with reference to FIGS. 10 and 11.

[0196] The coil conductor (300) is a single wire, and the coil conductor (300) can be wound at least once to form a coil structure. The coil structure is a coil structure for wireless power transmission by electromagnetic inductive coupling between a transmitting coil and a receiving coil, and can be a part of at least one of a power transmitting pad device including a transmitting coil and a power receiving pad device including a receiving coil.

[0197] A plurality of conductor elements (310, 320) may be arranged while being spaced apart from each other by a first interval (s3) in a second direction (-x direction) on a cross-section that is perpendicular to the first direction (-y direction) of the coil conductor (300), and may be arranged while being spaced apart from each other by a second interval (s4) in a third direction (z direction) different from the second direction (-x direction) on a cross-section that is perpendicular to the first direction (-y direction) of the coil conductor (300), thereby forming a laminated structure on a cross-section that is perpendicular to the first direction (-x direction) of the coil conductor (300).

[0198] At this time, since the second direction and the third direction are directions on a cross-section (a cross-section perpendicular to the first direction), the second direction and the third direction are commonly perpendicular to the first direction, and the second direction and the third direction form different directions within the cross-section.

[0199] At this time, the length of the first side (s1), the length of the second side (s2), the first spacing (s3), and the second spacing (s4) can be determined based on the electrical characteristics and heat dissipation characteristics of the plurality of conductor elements (310).

[0200] A dielectric layer may be disposed in a gap (340) between the conductive elements spaced apart by a first spacing (s3) in the second direction (-x direction) among the plurality of conductive elements (310, 320) and in a gap (350) between the conductive elements spaced apart by a second spacing (s4) in the third direction (z direction). For example, the material applied to the dielectric may include at least one of materials such as ceramic, epoxy, and aluminum.

[0201] Fig. 12 is a cross-sectional view of a coil conductor according to another embodiment of the present invention.

[0202] Unlike FIGS. 9 and 11, each of the plurality of conductor elements (310, 320) can form a square on a cross-section perpendicular to the first direction, which is the direction of the current path.

[0203] Fig. 13 is a cross-sectional view of a coil conductor according to another embodiment of the present invention.

[0204] A plurality of conductor elements (310, 320, 330) may be arranged while being spaced apart from each other by a first interval in a second direction on a cross-section perpendicular to the first direction of the coil conductor (300), and may be arranged repeatedly while being spaced apart from each other by a second interval in a third direction different from the second direction on a cross-section perpendicular to the first direction of the coil conductor (300), thereby forming a laminated structure on a cross-section perpendicular to the first direction of the coil conductor (300). In Fig. 13, a three-layer laminated structure is exemplified, but the number of layers may vary as needed.

[0205] Fig. 14 is a cross-sectional view of a coil conductor according to another embodiment of the present invention.

[0206] For example, in the embodiment of Fig. 13, the coil structure has a rectangular cross-section of the conductor element and a three-layer laminated structure, but as in the embodiment of Fig. 14, the conductor element may have a square cross-section and a three-layer laminated structure. The shape of the cross-section and the number of laminates are not limited thereto and may be set in various ways.

[0207] In the embodiments of FIGS. 8 to 14 above, embodiments in which the cross-sections of the conductor elements (310, 320, 330) are rectangular or square are illustrated, but the spirit of the present invention is not limited to such limited embodiments. In other embodiments of the present invention, the cross-sections of the conductor elements (310, 320, 330) may form various shapes having regularity.

[0208] Below, the background supporting the effect of the coil structure of the present invention is explained.

[0209] Figure 15 shows a copper thickness unit conversion table according to one embodiment of the present invention.

[0210] Fig. 16 illustrates a six-layer PCB structure according to one embodiment of the present invention.

[0211] Hereinafter, the description will be made with reference to FIGS. 15 and 16.

[0212] Skin depth( ) refers to the depth of the conductor through which current can flow from the surface of the conductor, depending on the frequency of the alternating current. The AC resistance of a conductor varies depending on the frequency of the voltage or current supplied. High-frequency current tends to flow on the surface of the conductor. This is because there is a greater charge concentration near the surface of the conductor. The charge concentration decreases from the surface to the inside of the conductor. That is, the charge concentration has a maximum value at the surface of the conductor and a value of zero at the center of the conductor. The skin depth is the point where the current density reaches approximately 37% of the surface charge concentration of the conductor. Therefore, the skin depth varies with changes in the frequency, relative permeability, and resistivity of the conductor.

[0213] A six-layer PCB may include two copper foils (410, 470), three prepregs (420, 440, 460), and two copper clad laminates (CCL) (430, 450).

[0214] For example, the thickness of the copper foil included in the copper foil (410, 470) and the copper foil laminate (430, 450) may be 1 oz (= 0.0348 mm).

[0215] Fig. 17 illustrates an 8-layer PCB structure according to another embodiment of the present invention.

[0216] Fig. 18 illustrates a 16-layer PCB structure according to another embodiment of the present invention.

[0217] Referring to FIGS. 16 to 18 together, the heat generation of the copper conductor can be suppressed by adjusting the thickness of the conductor element in consideration of the skin depth according to the frequency.

[0218] In addition, the current transfer characteristics can be increased by freely designing the amount of current flowing in the conductor elements, the copper plate area (i.e., the area of ​​the conductor elements), and the arrangement shape of the conductor elements, taking into account the skin effect according to the frequency.

[0219] FIG. 19 is a drawing for explaining the shape according to the number and width of wiring in the inner layer of a PCB according to one embodiment of the present invention.

[0220] FIG. 20 is a side view of a PCB inner layer having a plurality of wires according to one embodiment of the present invention.

[0221] Hereinafter, the description will be made with reference to FIGS. 19 and 20.

[0222] For example, if the thickness of the inner layer trace (e.g., 511) of a PCB is 1 oz and the width (w1) is 1 mm, it can be assumed that 1 A can flow through one trace. For example, if the number of traces increases to 10, the current can increase from 1 A to 10 A. That is, the thickness and width of the trace can be adjusted by setting the current allocated to each PCB trace. Meanwhile, by applying a heat calculation method per PCB trace, the width of the trace required to transmit a given current while limiting the temperature of the trace to a predetermined value or less can be calculated. The heat calculation method per PCB trace can utilize a conventional, widely known calculation method.

[0223] By increasing the number of wires in the inner layers of the PCB (and utilizing multiple layers), as shown in FIGS. 19 and 20, various shapes can be created and standardized, thereby minimizing heat generation. For example, the spacing between wires can be 0.3 mm.

[0224] For example, the present invention can increase the number of conductor elements in the same way as increasing the number of wires in the inner layer of the PCB. That is, a plurality of conductor elements (510, 520, 530, 540) can be arranged while being spaced apart from each other by a first interval in a second direction on a cross-section that is perpendicular to a first direction, which is a direction of a current path of the coil conductor (500), and can be arranged while being spaced apart from each other by a second interval in a third direction that is different from the second direction on a cross-section that is perpendicular to the first direction of the coil conductor (500), thereby forming a laminated structure (e.g., four layers) on the cross-section that is perpendicular to the first direction of the coil conductor (500).

[0225] Therefore, the effect that can be obtained by increasing the number of wires in the inner layer of the PCB can also be obtained in the coil structure of the present invention. That is, by determining the width and thickness of each of the plurality of conductor elements and the spacing between the conductor elements, the coil conductor can be manufactured so that the current transfer characteristics are improved and the conductor elements have low heat generation characteristics.

[0226] Figure 21 shows a plan view and a side perspective view of wiring according to one embodiment of the present invention.

[0227] Figure 22 is a table showing impedance values ​​according to the width, length, and frequency of the wiring according to one embodiment of the present invention.

[0228] Referring to FIGS. 21 and 22 together, the impedance may vary depending on the width (W10) and length (length in the direction of the current path) (L10) of the PCB wiring (610), and the frequency. At this time, the thickness (T10) of the PCB wiring (610) may be 35 μm.

[0229] Figure 23 illustrates two planes according to one embodiment of the present invention.

[0230] FIG. 24 is a drawing for explaining RF radiation energy generated between two planes according to one embodiment of the present invention.

[0231] Referring to FIGS. 23 and 24 together, a power plane (710) and a ground plane (720) formed to the same size may be spaced apart by a distance d. At this time, RF radiation energy may be generated between the power plane (710) and the ground plane (720).

[0232] At this time, fringing of RF current occurs at the end of the substrate and between the power and ground, which can control the occurrence of RF radiation.

[0233] FIG. 25 is a drawing for explaining a 20H rule for controlling an RF radiation shape according to one embodiment of the present invention.

[0234] The 20H rule refers to making the power plane (710) physically 20 times (20H) smaller than the ground plane (720) as a shape that reduces the size of RF energy radiation and noise radiation. Here, H is the thickness of the prepreg, which can be approximately 6 mil.

[0235] The point where the ground plane (720) is 10H larger than the power plane (710) may be the point where the impedance change of the plane begins.

[0236] The point where the ground plane (720) is 20H larger than the power plane (710) may be the point where the 70% flux boundary is reached.

[0237] The point where the ground plane (720) is 100H larger than the power plane (710) may be the point where the 98% flux boundary is reached.

[0238] Referring to FIG. 11 and FIG. 25 together, the first spacing (s3) between the conductor elements (310) and the second spacing (s4) between the conductor elements (310) and the conductor elements (320) to control the RF radiation shape between the conductor elements (310, 320) can be determined based on the 20H rule described above.

[0239] Referring to FIGS. 15 to 25, the amount of current flowing in a conductor can be calculated according to the frequency. The formulas for the skin effect and the skin depth, as well as the skin depth that can be used to conduct current for a conductor at a given frequency, can be calculated. As a result, it can be seen that the external conducting area is distributed the widest in the order of a single circular conductor, a multi-circular conductor, and a multi-rectangular conductor. Therefore, as shown in FIGS. 9 to 13, in order to efficiently secure a large area that can conduct current within the same space on a cross-section perpendicular to the direction of the current path of the conductor elements, each of the conductor elements can form a square.

[0240] Figure 26 is a flowchart for explaining a coil manufacturing method according to one embodiment of the present invention.

[0241] In step (S810), a plurality of conductor elements extending in a first direction, which is the direction of the current path, may be arranged in parallel to form a coil conductor. At this time, the plurality of conductor elements may be arranged to be spaced apart from each other by a first predetermined interval on a cross-section of the coil conductor that is perpendicular to the first direction.

[0242] In step (S830), the coil conductor can be wound to form a coil.

[0243] At this time, after arranging the conductor elements in step (S810), a step of arranging a dielectric layer in the gap between the conductor elements spaced apart from each other by the first gap may be included before forming the coil conductor. For example, the gap may be filled with a material including at least one of ceramic, epoxy, and aluminum.

[0244] FIG. 27 is a flowchart for explaining a method for manufacturing a coil using a coil conductor having a laminated structure according to one embodiment of the present invention.

[0245] In step (S811), a plurality of conductor elements extending in a first direction, which is the direction of the current path, are arranged in a second direction on a cross-section perpendicular to the first direction, with a first predetermined interval between them, and are arranged in a third direction different from the second direction on a cross-section perpendicular to the first direction, with a second interval between them, thereby forming a layered structure on a cross-section perpendicular to the first direction, thereby forming a coil conductor.

[0246] In step (S830), the coil conductor can be wound to form a coil.

[0247] At this time, after arranging the conductor elements in step (S811), before forming the coil conductor, a step of arranging a dielectric layer in the gaps between the conductor elements spaced apart by the first interval in the second direction among the plurality of conductor elements and in the gaps between the conductor elements spaced apart by the second interval in the third direction may be included. For example, the gaps may be filled with a material including at least one of materials such as ceramic, epoxy, and aluminum.

[0248] In FIGS. 26 and 27, each of the plurality of conductor elements may form a square on a cross-section perpendicular to the first direction of the coil conductor. At this time, the length (width) of the first side of the square, the length (thickness) of the second side, and the first spacing may be determined based on the electrical characteristics and heat dissipation characteristics of the plurality of conductor elements. The first spacing may vary depending on the length of the second side.

[0249] The coil structure described in FIGS. 8 to 27 can be applied to the wireless charging pad of FIG. 6, i.e., the transmitting coil of the transmitting pad or the receiving coil of the receiving pad (not shown).

[0250] Referring to FIGS. 1 and 6 together, a wireless charging pad, for example, a transmitting pad (21), may include a coil formed by winding a coil conductor to surround a central space. The coil conductor may be formed by arranging a plurality of conductor elements in parallel and extending in a first direction, which is a direction of a current path. In addition, the plurality of conductor elements may be arranged while being spaced apart from each other by a first predetermined interval on a cross-section of the coil conductor perpendicular to the first direction.

[0251] FIG. 28 is a block diagram illustrating a generalized configuration of hardware that controls a sequence for wireless power transfer included within a transmitting pad and / or a receiving pad of the present invention, or in connection with a transmitting pad and / or a receiving pad of the present invention.

[0252] For convenience of explanation, the hardware that controls the sequence for wireless power transmission may be referred to as a controller (1000).

[0253] At least a part of the process of a wireless charging method for controlling a sequence for wireless power transmission through a wireless charging system according to one embodiment of the present invention can be executed by the controller (1000) of FIG. 28.

[0254] The controller (1000) may be placed on the electric vehicle (10) side, on the electric vehicle power supply equipment (EVSE) (20) side, or on the transmission pad (21) side.

[0255] The controller (1000) may include at least one processor (1100), a memory (1200) storing at least one command for executing the above-described operation through the processor (1100), and a communication interface (1300) connected to a network and performing communication. The controller (1000) for wireless power transmission may further include a storage device (1400) capable of storing at least one command for executing the above-described operation or data generated during the execution process. The controller (1000) for wireless power transmission may further include an input interface (1500) and an output interface (1600) for interaction with a user. Each component included in the controller (1000) for wireless power transmission may be connected by a system bus (1700) and may communicate with each other.

[0256] A controller (1000) or computing system according to one embodiment of the present invention may include at least one processor (1100) and a memory (1200) that stores instructions that instruct the at least one processor (1100) to perform at least one step. At least some steps of a method according to one embodiment of the present invention may be performed by the at least one processor (1100) loading and executing instructions from the memory (1200).

[0257] The processor (1100) may mean a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which methods according to embodiments of the present invention are performed.

[0258] Each of the memory (1200) and the storage device (1400) may be configured with at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory (1200) may be configured with at least one of a read-only memory (ROM) and a random access memory (RAM).

[0259] Here, at least one command may include at least one of a sequence that can mutually identify at least one of an electric vehicle (10), an electric vehicle power supply equipment (EVSE) (20), and a transmission pad (21), a sequence for wireless communication association between at least one or two of the electric vehicle (10), an electric vehicle power supply equipment (EVSE) (20), and a transmission pad (21), a sequence for performing alignment and / or pairing by mutual positioning, and a sequence for allowing application of an AC signal so that power is transmitted after alignment and / or pairing.

[0260] Additionally, the controller (1000) may include a communication interface (1300) that performs communication via a wireless network.

[0261] Additionally, the controller (1000) may further include a storage device (1400), an input interface (1500), an output interface (1600), etc.

[0262] Additionally, each component included in the controller (1000) can be connected to each other by a bus (1700) and communicate with each other.

[0263] Examples of the controller (1000) of the present invention may include a desktop computer, a laptop computer, a notebook, a smart phone, a tablet PC, a mobile phone, a smart watch, a smart glass, an e-book reader, a portable multimedia player (PMP), a portable game console, a navigation device, a digital camera, a digital multimedia broadcasting (DMB) player, a digital audio recorder, a digital audio player, a digital video recorder, a digital video player, a PDA (Personal Digital Assistant), etc. The operation of the method according to an embodiment of the present invention can be implemented as a computer-readable program or code on a computer-readable recording medium. The computer-readable recording medium includes all types of recording devices that store information that can be read by a computer system. Additionally, computer-readable recording media can be distributed across network-connected computer systems so that computer-readable programs or codes can be stored and executed in a distributed manner.

[0264] Additionally, the computer-readable recording medium may include hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, etc. The program instructions may include not only machine language codes produced by a compiler, but also high-level language codes that can be executed by a computer using an interpreter, etc.

[0265] While some aspects of the present invention have been described in the context of a device, they may also represent a description of a corresponding method, wherein a block or device corresponds to a method step or a feature of a method step. Similarly, aspects described in the context of a method may also be described as a corresponding block or item or a feature of a corresponding device. Some or all of the method steps may be performed by (or using) a hardware device, such as, for example, a microprocessor, a programmable computer, or an electronic circuit. In some embodiments, at least one or more of the most important method steps may be performed by such a device.

[0266] In embodiments, a programmable logic device (e.g., a field-programmable gate array) may be used to perform some or all of the functions of the methods described herein. In embodiments, the field-programmable gate array may operate in conjunction with a microprocessor to perform one of the methods described herein. In general, the methods are preferably performed by some hardware device.

[0267] Although the present invention has been described above with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various modifications and changes may be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below.

Claims

1. A coil structure for generating a magnetic field by using electromagnetic induction by an alternating current signal. A coil conductor formed by arranging a plurality of conductor elements in a first direction, which is the direction of the current path, and extending in parallel, In a cross-section perpendicular to the first direction of the coil conductor, the plurality of conductor elements are arranged while being spaced apart from each other by a first predetermined interval, The above coil conductor is wound to form a coil, Coil structure.

2. A coil structure in the first paragraph, wherein each of the plurality of conductor elements forms a square in a cross-section perpendicular to the first direction of the coil conductor.

3. In paragraph 1, The above plurality of conductor elements are arranged while being spaced apart from each other by the first interval in a second direction on a cross-section perpendicular to the first direction of the coil conductor, and are arranged while being spaced apart from each other by the second interval in a third direction different from the second direction on a cross-section perpendicular to the first direction of the coil conductor, thereby forming a laminated structure on a cross-section perpendicular to the first direction of the coil conductor. Coil structure.

4. In the second paragraph, the length of the first side of the square, the length of the second side, and the first spacing are determined based on the electrical characteristics and heat dissipation characteristics of the plurality of conductor elements, a coil structure.

5. A coil structure in which a dielectric layer is arranged in the gap between the conductor elements spaced apart by the first interval in the first paragraph.

6. In the third paragraph, a coil structure in which a dielectric layer is disposed in the gap between the plurality of conductor elements spaced apart by the first interval in the second direction and in the gap between the conductor elements spaced apart by the second interval in the third direction.

7. A coil structure in the fourth paragraph, wherein the first gap varies depending on the length of the second side.

8. A method for manufacturing a coil for generating a magnetic field by using electromagnetic induction by an alternating current signal, A step of forming a coil conductor by arranging a plurality of conductor elements extending in a first direction, which is the direction of the current path, in parallel; and A step of forming a coil by winding the above coil conductor; Including, The forming step is a step of arranging the plurality of conductor elements spaced apart from each other by a first predetermined interval on a cross-section perpendicular to the first direction of the coil conductor. Method of manufacturing coils.

9. A coil manufacturing method in the 8th paragraph, wherein each of the plurality of conductor elements forms a square in a cross-section perpendicular to the first direction of the coil conductor.

10. In the 8th paragraph, the step of forming the coil conductor is: A step of arranging the plurality of conductor elements so as to be spaced apart from each other by the first interval in a second direction on a cross-section perpendicular to the first direction of the coil conductor, and so as to be spaced apart from each other by the second interval in a third direction different from the second direction on a cross-section perpendicular to the first direction of the coil conductor, thereby forming a laminated structure on a cross-section perpendicular to the first direction of the coil conductor. Method of manufacturing coils.

11. A coil manufacturing method in claim 9, wherein the length of the first side of the square, the length of the second side, and the first spacing are determined based on the electrical characteristics and heat dissipation characteristics of the plurality of conductor elements.

12. A method for manufacturing a coil, wherein the step of forming the coil conductor in the 8th paragraph includes the step of arranging a dielectric layer in the gap between the conductor elements spaced apart by the first interval.

13. A method for manufacturing a coil in accordance with claim 10, wherein the step of forming the coil conductor includes the step of arranging a dielectric layer in the gaps between the conductor elements spaced apart by the first spacing in the second direction among the plurality of conductor elements and in the gaps between the conductor elements spaced apart by the second spacing in the third direction.

14. A coil manufacturing method in the 11th paragraph, wherein the first gap varies depending on the length of the second side.

15. A pad for wirelessly transmitting or receiving power by using electromagnetic induction due to an alternating current signal flowing in the coil conductor, comprising a coil formed by winding a coil wire to surround a central space. The above coil conductor is formed by arranging a plurality of conductor elements in parallel and extending in a first direction, which is the direction of the current path. In a cross-section perpendicular to the first direction of the coil conductor, the plurality of conductor elements are arranged while being spaced apart from each other by a first predetermined interval. Wireless charging pad.

16. A wireless charging pad in claim 15, wherein each of the plurality of conductor elements forms a square in a cross-section perpendicular to the first direction of the coil conductor.

17. In paragraph 15, The above plurality of conductor elements are arranged while being spaced apart from each other by the first interval in a second direction on a cross-section perpendicular to the first direction of the coil conductor, and are arranged while being spaced apart from each other by the second interval in a third direction different from the second direction on a cross-section perpendicular to the first direction of the coil conductor, thereby forming a laminated structure on a cross-section perpendicular to the first direction of the coil conductor. Wireless charging pad.

18. A wireless charging pad in claim 16, wherein the length of the first side of the square, the length of the second side, and the first interval are determined based on the electrical characteristics and heat dissipation characteristics of the plurality of conductive elements.

19. A wireless charging pad in accordance with claim 15, wherein a dielectric layer is disposed in the gap between the conductor elements spaced apart by the first interval.

20. In the 17th paragraph, a wireless charging pad, wherein a dielectric layer is disposed in the gap between the conductive elements spaced apart by the first interval in the second direction among the plurality of conductive elements and in the gap between the conductive elements spaced apart by the second interval in the third direction.

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