CN117501581A - Wireless power transmitting apparatus including coil structure for wireless power transmission and power transmission circuit, and wireless power receiving apparatus - Google Patents

Abstract

Disclosed is a wireless power transmitting pad prepared to transmit wireless power to a receiving pad including a secondary coil. The wireless power transmission pad includes: a primary coil disposed around the central space; ferrite forming magnetic coupling with the primary coil; and a housing supporting the primary coil and the ferrite. The primary coil of the wireless power transmission pad is formed in a state in which a flat wire or a planar wire is wound at least once.

Description

Wireless power transmitting apparatus including coil structure for wireless power transmission and power transmission circuit, and wireless power receiving apparatus

Technical Field

The present disclosure relates to a wireless power transmitting device/pad and a wireless power receiving device/pad for Wireless Power Transmission (WPT), and more particularly, to a coil structure and a power transmission circuit configured to improve power transmission efficiency during wireless power transmission.

Background

An Electric Vehicle (EV) is driven by an electric motor through electric power stored in a battery, and generates less pollution (e.g., exhaust gas and noise) and has advantages of less malfunction, longer life, and simplified driving operation as compared to a conventional gasoline engine vehicle.

EVs may be classified into Hybrid Electric Vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and Electric Vehicles (EVs) based on a driving power source. HEVs have an engine as the primary power source and an electric motor as the secondary power source. The PHEV has an electric motor and a battery as main power sources, and an engine used when the battery is discharged. The EV has an electric motor but no engine.

An electric vehicle charging system may be defined as a system that charges a battery installed in an electric vehicle using electricity obtained from a commercial power grid or stored in an energy storage device. Such an electric vehicle charging system may have various forms according to the type of electric vehicle. For example, an electric vehicle charging system may include a conductive charging system using a cable or a contactless wireless power transfer system.

During a charging session, a receiving pad of a vehicle component (VA) mounted on an electric vehicle may form an inductive resonant coupling with a transmitting pad of a ground component (GA) mounted at a charging station or charging point, and a battery of the EV may be charged using power transmitted from the ground component through the inductive resonant coupling.

Meanwhile, the structures of the transmitting pad and the receiving pad may be a key factor for ensuring high power transmission efficiency in the magnetic resonance type wireless power transmission system. Specifically, in a typical configuration of a transmitting pad or a receiving pad including a ferrite structure and a coil, the power transmission efficiency may be changed according to the ferrite structure made of ferrite of a magnetic material that facilitates wireless power transmission and/or the structure of the coil wound around the ferrite structure.

Thus, there is a need for a coil structure that can improve power transmission efficiency in a wireless power transmission system.

Disclosure of Invention

Technical problem

In order to solve the above-described problems, it is an object of the present disclosure to provide a novel coil structure that can improve efficiency of a process of supplying electric power from a power supply device or an electric vehicle power supply equipment (EVSE) to an electric vehicle.

It is another object of the present disclosure to provide a Wireless Power Transfer (WPT) device with high power transfer efficiency employing a novel coil structure.

Another object of the present invention is to provide a power transmission circuit for driving a wireless power transmission device employing a novel coil structure.

Technical proposal

A wireless power transmitting pad for achieving the above object according to an embodiment of the present disclosure is a wireless power transmitting pad prepared to wirelessly transmit power to a receiving pad including a secondary coil. The wireless power transmission pad includes: a primary coil disposed around the central space; a ferrite member configured to form a magnetic coupling with the primary coil; and a housing configured to support the primary coil and the ferrite member. The primary coil includes a flat wire wound at least once.

The corners of the primary coil may be at least partially rounded.

The corners of the cross section of the flat wire of the primary coil may be at least partially rounded.

The primary coil may have a planar structure in which a long axis of a cross section of the flat wire is perpendicular to a central axis of the primary coil.

The primary coil may have a vertical type structure in which a long axis of a cross section of the flat wire is parallel to a central axis of the primary coil.

The primary coil may have a shape in which each of a plurality of flat wire elements is wound to surround the central space.

The plurality of flat wire elements may be arranged in a concentric shape sharing a central axis of the primary coil.

The ferrite member may be arranged such that a first area on which the primary coil is projected on a virtual horizontal plane perpendicular to a central axis of the primary coil is included in a second area on which the ferrite member is projected on the virtual horizontal plane.

The ferrite member may be formed to include a void corresponding to at least a portion of the central space of the primary coil.

The wireless power receiving pad according to the embodiment of the present disclosure is a wireless power receiving pad prepared to wirelessly receive power from a transmitting pad including a primary coil. The wireless power receiving pad includes: a secondary coil disposed around the central space; a ferrite member configured to form a magnetic coupling with the secondary coil; and a housing configured to support the secondary coil and the ferrite member. The secondary coil includes a flat wire wound at least once.

The corners of the secondary coil may be at least partially rounded.

The corners of the cross section of the flat wire of the secondary coil may be at least partially rounded.

The ferrite member may be arranged such that a first area of the secondary coil projected on a virtual horizontal plane perpendicular to the central axis of the secondary coil is included in a second area of the ferrite member projected on the virtual horizontal plane.

A wireless power transmission system according to an embodiment of the present disclosure includes: a transmitting pad including a primary coil; and a receiving pad including a secondary coil. The transmitting pad includes: a primary coil arranged to surround the central space; a ferrite member configured to form a magnetic coupling with the primary coil; and a housing configured to support the primary coil and the ferrite member. The primary coil includes a flat wire wound at least once.

Advantageous effects

In view of electromagnetic characteristics, the exemplary embodiments of the present disclosure can realize a power transmission device/pad and a power reception device/pad having high power transmission efficiency.

According to an exemplary embodiment of the present disclosure, power transmission efficiency of a power transmitting device/pad placed in an electric vehicle or an electric vehicle power supply apparatus (EVSE) and a power receiving device/pad placed in an electric vehicle increases.

According to exemplary embodiments of the present disclosure, by increasing the space factor and the ratio of the surface area to the cross-sectional area, a power transmission device/pad and a power reception device/pad having increased ratios of current transmission paths to volumes may be achieved.

According to the exemplary embodiments of the present disclosure, the power transmission device/pad and the power reception device/pad can be easily cooled, and cooling costs are allowed to be reduced.

According to exemplary embodiments of the present disclosure, when the ferrite pad is arranged to be magnetically coupled to the coil, the power transmission device/pad and the power reception device/pad can be realized with less space restrictions.

According to the exemplary embodiments of the present disclosure, by placing the ferrite core inside the coil such that the ferrite core is magnetically coupled to the coil, the power transmission device/pad and the power reception device/pad can be realized with less space restrictions.

Drawings

Fig. 1 is a diagram illustrating a wireless power transmission system to which exemplary embodiments of the present disclosure may be applied;

FIGS. 2 and 3 are diagrams illustrating Cartesian coordinate systems compatible with the definitions in the SAE J2954 standard and applicable to embodiments of the present disclosure;

fig. 4 is a circuit diagram illustrating an equivalent circuit of an electric vehicle wireless charging circuit according to an exemplary embodiment of the present disclosure;

Fig. 5 is a conceptual sectional view and a front view illustrating a power transmission pad according to an exemplary embodiment of the present disclosure;

fig. 6 is a conceptual sectional view and a front view illustrating a power receiving pad according to an exemplary embodiment of the present disclosure;

fig. 7 is a diagram illustrating a general conceptual structure of a power transmission pad or a power reception pad according to an exemplary embodiment of the present disclosure;

fig. 8 is a front view showing a general conceptual structure of a power transmission pad or a power reception pad according to an exemplary embodiment of the present disclosure;

fig. 9 is a cross-sectional view showing a general conceptual structure of a power transmission pad or a power reception pad according to an exemplary embodiment of the present disclosure;

fig. 10 is a top view illustrating a general conceptual structure of a power transmission pad or a power reception pad according to an exemplary embodiment of the present disclosure;

fig. 11 is a conceptual diagram illustrating a flat wire wound to constitute a power transmission pad or a power reception pad according to an exemplary embodiment of the present disclosure;

fig. 12 to 14 are diagrams illustrating conceptual structures of a power receiving pad according to an exemplary embodiment of the present disclosure;

fig. 15 and 16 are diagrams illustrating conceptual structures of power transmission pads according to exemplary embodiments of the present disclosure;

Fig. 17 and 18 are diagrams illustrating conceptual structures of a power transmission pad according to another exemplary embodiment of the present disclosure;

fig. 19 and 20 are diagrams illustrating conceptual structures of a power transmission pad according to another exemplary embodiment of the present disclosure;

fig. 21 is a block diagram illustrating a conceptual structure of a power transmission circuit for wireless power transmission according to an exemplary embodiment of the present invention;

fig. 22 is a circuit diagram showing a conceptual structure of an embodiment of the three-phase AC-DC rectifying circuit shown in fig. 21;

fig. 23 is a circuit diagram showing a conceptual structure of an embodiment of the SPWM inverter shown in fig. 21;

fig. 24 is a circuit diagram showing a conceptual structure of an embodiment of the rectifier shown in fig. 21;

fig. 25 is a circuit diagram showing a conceptual structure of the embodiment of the charger shown in fig. 21;

fig. 26 is a circuit diagram showing a conceptual configuration of a three-phase AC-DC rectifying circuit according to an embodiment of the present disclosure;

FIG. 27 is a block diagram showing a conceptual structure of an embodiment of a controller suitable for controlling the circuit of FIG. 22 or FIG. 26 using voltage and/or current values measured in the circuit of FIG. 22 or FIG. 26;

fig. 28 is a diagram illustrating a coil structure and a magnetic field simulation result of a power transmission pad according to an exemplary embodiment of the present disclosure.

Fig. 29 is a diagram showing a coil structure and a magnetic field simulation result of a power transmission pad according to another exemplary embodiment of the present disclosure;

fig. 30 is a diagram illustrating a coil structure and a magnetic field simulation result of a power transmission pad according to another exemplary embodiment of the present disclosure;

fig. 31 is a diagram showing a coil structure and a magnetic field simulation result of a power transmission pad according to another exemplary embodiment of the present disclosure;

fig. 32 is a graph showing that the magnetic field simulation results of the power transmission pad according to the embodiments of fig. 28 to 31 may be at a level equal to each other; and

fig. 33 is a block diagram showing an overall configuration of hardware included in or associated with a wireless power transmitting pad and/or a wireless power receiving pad to control a sequence for wireless power transmission.

Detailed Description

For a clearer understanding of the features and advantages of the present disclosure, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. It should be understood, however, that the disclosure may not be limited to the particular embodiments disclosed herein, but rather to include all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure. In the drawings, like or corresponding components may be referred to by the same or similar reference numerals.

Terms including ordinal numbers (such as "first" and "second") or another identifier (such as "a" and "B") may be used to distinguish a component from other components, but may not be intended to be limited to a particular component. For example, a second component may be referred to as a first component, and similarly, a first component may also be referred to as a second component, without departing from the scope of the present disclosure. As used herein, the term "and/or" may include the presence of one or more associated listed items as well as any and all combinations of listed items.

When an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled logically or physically to the other element or be indirectly connected or coupled to the other element through the object therebetween. Conversely, when an element is referred to as being "directly connected" or "directly coupled" to another element, it should be understood that there are no intervening objects between the elements. Other words used to describe the relationship between elements should be interpreted in a similar fashion.

These terms may be used herein for the purpose of describing particular example embodiments only, and may not be intended to limit the present disclosure. Singular forms also include plural references unless the context clearly dictates otherwise. Moreover, the expression "comprising" or "comprises" may be used to indicate that there is a stated feature, quantity, process step, operation, element or combination of components, but may not be intended to exclude the presence or addition of another feature, quantity, process step, operation, element or combination of components.

Unless otherwise defined, all terms (including technical or scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant literature and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

The terms used in the present disclosure are defined as follows.

"Electric Vehicle (EV)": an automobile, as defined in 49cfr 523.3, is intended for highway use, powered by an electric motor drawing current from an on-board energy storage device (e.g., a battery) that can be charged from an off-board source (e.g., a residential or utility service or an on-board fuel generator).

The EVs may include electric vehicles, electric Road Vehicles (ERVs), plug-in vehicles (PV), electric power vehicles (xevs), and the like, and xevs may be classified as plug-in all-electric vehicles (BEV), battery electric vehicles, plug-in electric vehicles (PEV), hybrid Electric Vehicles (HEV), hybrid plug-in electric vehicles (HPEV), plug-in hybrid electric vehicles (PHEV), and the like.

"plug-in electric vehicle (PEV)": an electric vehicle charges an on-board primary battery by connection to an electrical grid.

"plug-in vehicle (PV)": an electric vehicle recharged from an Electric Vehicle Supply Equipment (EVSE) by wireless charging without the use of a physical plug or physical socket.

"heavy vehicle (h.d. vehicle)": any four-wheel vehicle or more as defined in 49cfr 523.6 or 49cfr 37.3 (bus).

"light plug-in electric vehicle": three-or four-wheeled vehicles are propelled by an electric motor that draws current from a rechargeable battery or other energy device, primarily for public streets, roads and highways, and rated total vehicle weight is less than 4545kg.

"Wireless Power charging System (WCS)": a system for wireless power transfer and control of interactions including operations for alignment and communication between a supply device (or ground assembly) and an EV device (or vehicle assembly).

"Wireless Power Transfer (WPT)": power is transferred between a power source such as a utility, a grid, an energy storage device, a fuel cell generator, and an EV through a contactless channel such as electromagnetic induction and resonance.

"utility": a collection of systems that provide electrical energy and include Customer Information Systems (CIS), advanced Metering Infrastructure (AMI), rate and revenue systems, and the like. Utilities may power EVs through tariffs and discrete events. Moreover, the utility may provide information related to EV certification, intervals for power consumption measurements, and rates.

"Intelligent charging": a system in which EVSEs and/or EVs (including PEVs or PHEVs) communicate with a power grid to optimize the charge or discharge ratio of the EVs by reflecting the capacity or usage fees of the power grid.

"automatic charging": a process in which inductive charging is automatically performed after a vehicle is in place corresponding to a primary charger assembly that can transfer power through conductive or inductive charging. After obtaining the necessary authentication and rights, automatic billing may be performed.

"interoperability": components of the system interact with corresponding components of the system to perform states of operations aimed at by the system. In addition, information interoperability may refer to the ability of two or more networks, systems, devices, applications, or components to effectively share and easily use information without inconveniencing a user.

"inductive charging System": a system for transferring energy from a power source to an EV via a two-part gapped core transformer, wherein the two halves of the transformer (i.e., the primary and secondary coils) are physically separated from each other. In the present disclosure, the inductive charging system may correspond to an EV power transmission system.

"inductive coupler": a transformer formed by a primary coil or Ground Assembly (GA) in the primary device and a secondary coil or Vehicle Assembly (VA) in the secondary device, which transformer allows transmission of electric power through electrical insulation.

"inductive coupling": magnetic coupling between the two coils. One of the two coils may be referred to as a primary coil or GA coil, and the other of the two coils may be referred to as a secondary coil or vehicle component VA coil.

"supply circuit (SPC)" or "ground component (GA)": components arranged on the primary or ground component or on the infrastructure side comprising the primary coil (or GA coil) and other components. Other components may include at least one component for controlling impedance and resonant frequency, ferrite implementing a magnetic circuit, and electromagnetic shielding material. For example, the SPC or GA may include a power/frequency conversion unit and an SPC controller (or GA controller) required to serve as a power source of the wireless power charging system, wiring from the power grid, and wiring between each unit, a filter circuit, and a housing.

"EV power circuit (EVPC)" or "vehicle component (VA)": a component mounted on the vehicle, the component including the secondary coil (or VA coil) and other components. Other components may include at least one component for controlling impedance and resonant frequency, ferrite implementing a magnetic circuit, and electromagnetic shielding material. For example, the EVPC or VA may include a power/frequency conversion unit and an EVPC controller (or VA controller) necessary as vehicle components of the wireless power charging system, wiring to the vehicle battery, and wiring between each unit, a filter circuit, and the case.

The SPC may be referred to as or identified by a ground component (GA) or the like. Similarly, the EVPC may be referred to as or identified by a vehicle component (VA) or the like.

The GA may be referred to as a primary device, etc., and the VA may be referred to as an EV device, a secondary device, etc.

The GA may be referred to as a supply device, a power source side device, or the like, and the VA may be referred to as an EV device, an EV side device, or the like.

"Primary unit": an apparatus for contactless coupling with a secondary device is provided. In other words, the primary device may be a device external to the EV. When the EV is receiving power, the primary device may operate as a source of power to be transmitted. The primary unit may comprise a housing and all covers.

"secondary device": an EV-mounted device that provides contactless coupling with the primary. In other words, the secondary device may be provided within the EV. When the EV is receiving power, the secondary device may transfer power from the primary device to the EV. The secondary device may include a housing and all covers.

"supply electronics" indicates the portion of the SPC or GA that adjusts the output power level of the primary coil (or GA coil) based on information from the vehicle. "EV power electronics" indicates a portion of the EVPC or VA that monitors particular on-board parameters during charging and initiates communication with the EVPC or GA to facilitate adjustment of the output power level.

The power electronics may be referred to as GA electronics, GA controller, or Primary Device Communication Controller (PDCC), and the EV power electronics may be referred to as VA electronics, VA controller, or Electric Vehicle Communication Controller (EVCC).

"magnetic gap": when aligned, the perpendicular distance between the plane of the higher of the top of the litz wire or the top of the magnetic material in the primary coil/GA coil and the plane of the lower of the bottom of the litz wire or the bottom of the magnetic material in the secondary coil/VA coil.

"ambient temperature": ground level temperature of air measured at the subsystem under consideration and not in direct sunlight.

"vehicle ground clearance": vertical distance between the ground and the lowest part of the vehicle floor.

"vehicle magnetic ground clearance": the perpendicular distance between the plane of the lower of the litz wire or the bottom of the magnetic material in the secondary coil or VA coil mounted on the vehicle and the ground.

"secondary coil surface distance" or "VA coil magnetic surface distance": the distance between the plane closest to the surface of the magnetic or conductive component and the lower outer surface of the secondary or VA coil when installed. Such distances may include any protective covering and additional items that may be packaged in secondary or VA coil housings.

The secondary coil may be referred to as a VA coil, a vehicle coil, or a receiver coil. Similarly, the primary coil may be referred to as a GA coil or a transmit coil.

"exposed conductive component": conductive components of electrical equipment (e.g., electric vehicles) may be touched and typically not energized, but may be energized when a fault occurs.

"dangerous live assembly": live components that can generate harmful electrical shocks under certain conditions.

"live component": any conductor or conductive component is intended to be energized in normal use.

"direct contact": human contact with the charged assembly. See IEC 61140 standard.

"indirect contact": human contact with exposed, conductive and energized components that are energized by insulation failure. See IEC 61140 standard.

"alignment": a process of finding a relative position of the secondary device with respect to the primary device and/or a relative position of the primary device with respect to the secondary device for efficient power transfer. In the present disclosure, the alignment may be for alignment in a wireless power transfer system, but may not be limited thereto.

"pairing": a process of associating a vehicle (EV) with a single dedicated power supply device (primary device) arranged such that power transmission is possible. Pairing may include a process of associating an EVPC or VA controller with an SPC or GA controller of the charging point.

The correlation or association procedure may comprise a procedure to establish a relationship between two peer communication entities.

"command and control communication": for exchanging communication of information required to start, control and end a wireless power transmission process between an electric vehicle power supply device and an electric vehicle.

Advanced communication (HLC) ": digital communication of all information not covered by command and control communication can be handled. The data link of HLC may use Power Line Communication (PLC), but is not limited thereto.

"Low Power Excitation (LPE)": the provisioning device (or primary device) is activated for fine positioning and pairing so that the EV can detect the technology of the provisioning device and vice versa.

"Service Set Identifier (SSID)": the unique identifier includes 32 characters attached to the header of a packet transmitted over the wireless LAN. The SSID identifies a Basic Service Set (BSS) to which the wireless device attempts to connect. The SSID distinguishes between a plurality of wireless LANs. Therefore, all Access Points (APs) and all terminal/station apparatuses that want to use a particular wireless LAN can use the same SSID. Devices that do not use a unique SSID cannot join the BSS. Because the SSID is shown as plain text, the SSID may not provide any security features to the network.

"Extended Service Set Identifier (ESSID)": the name of the network to which it is desired to connect. ESSID is similar to SSID but is a more extended concept.

"Basic Service Set Identifier (BSSID)": the BSSID including 48 bits is used to distinguish a specific BSS. With an infrastructure BSS network, the BSSID may be configured for Medium Access Control (MAC) of the AP device. For an independent BSS or Ad-hoc network, the BSSID may be generated with any value.

The charging station may include at least one GA and at least one GA controller configured to manage the at least one GA. The GA may include at least one wireless communication device. The charging station may refer to a place or location provided in a home, office, public place, road, parking area, etc. including at least one GA.

In this specification, "association" may be used as a term that indicates a process of establishing wireless communication between an Electric Vehicle Communication Controller (EVCC) and a Supply Equipment Communication Controller (SECC) that controls a charging infrastructure.

The electric vehicle charging system may include a conductive charging system using a cable or a contactless wireless power transmission system, but is not limited thereto. An electric vehicle charging system may be defined as a system that charges a battery installed in an electric vehicle using electric power obtained from a commercial electric grid or stored in an energy storage device, and may have various forms according to the type of electric vehicle.

The SAE TIR J2954 standard, which is one of the most representative industry standards for wireless charging, establishes an industry standard specification guide defining acceptable standards for interoperability, electromagnetic compatibility, minimum performance, safety and testing of wireless charging for lightweight electric and plug-in electric vehicles.

As an example of a wireless charging system, a Wireless Charging System (WCS) according to the J2954 standard may include a grid interface, a high frequency power inverter, a power transfer coil, a filter, a rectifier, an optional regulator, and a communication circuit between the vehicle energy charging/storage system and the grid connected power inverter. The grid interface may be similar to a conventional EVSE connection for single-phase or three-phase AC power.

Exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings.

Fig. 1 is a diagram of a wireless power transmission system to which exemplary embodiments of the present disclosure may be applied.

As shown in fig. 1, wireless power transmission may be performed by at least one component of an Electric Vehicle (EV) 10 and a charging station 20, and may be used to transmit power to the EV 10 without any conductive wires.

The EV 10 according to the exemplary embodiment of the present disclosure may include a Hybrid Electric Vehicle (HEV) having an electric motor and an internal combustion engine, and may include not only automobiles but also motorcycles, carts, scooters, and electric bicycles.

EV 10 may generally be defined as a vehicle that supplies electric power obtained from a rechargeable energy storage, such as battery 12, to an electric motor in a driveline of EV 10.

EV 10 may include a power receiving pad 11, power receiving pad 11 having a receiving coil adapted to receive power for charging battery 12 by wireless power transmission, and may include a receptacle or inlet adapted to receive power for charging battery 12 by conductive charging. Specifically, the EV 10 configured for conductively charging the battery 12 may be referred to as a plug-in electric vehicle (PEV).

The charging station 20 may be connected to the grid 30 or the electric mains, and AC power received from the grid 30 or the electric mains may be provided to the power transmission pad 21 having the transmission coil through the electric link.

Charging station 20 may be in communication with grid 30 or an infrastructure management system or infrastructure server that manages the grid, and may be configured to perform wireless communications with EV 10. Wireless communication may be performed through bluetooth, zigbee, cellular, wireless Local Area Network (WLAN), etc.

The charging station 20 may be located at various places including, but not limited to, a parking area of a house of an owner of the EV 10, a parking lot for charging the EV at a gas station, a parking lot at a shopping mall or a work place, and the like.

Wireless power transmission to the battery 12 of the EV 10 may be performed as follows. First, the power receiving pad 11 of the EV 10 is arranged in the energy field above the power transmitting pad 21. Then, the receiving coil in the power receiving pad 21 and the transmitting coil in the power transmitting pad 11 may be coupled to each other and interact with each other. Due to coupling or interaction, an electromotive force may be induced in the power receiving pad 11, and the battery 12 may be charged by the induced electromotive force.

The charging station 20 and the power transmission pad 21 as a whole or in part may be referred to as a power supply circuit (SPC) or a Ground Assembly (GA), the meaning and function of which are defined hereinabove.

Further, the power receiving pad 11 together with all or some of the other internal components of the EV 10 may be referred to as an EV power circuit (EVPC) or a vehicle component (VA), the meaning and function of which are defined above.

Here, each of the power transmitting pad 21 and the power receiving pad 11 may be configured as a non-polarized or polarized pad.

The non-polarizing pad may have one pole in the center of the electricity and the opposite pole around its periphery. In this case, the magnetic flux may be formed to leave from the poles in the center of the electricity and return from the outside of the point to the poles in the periphery.

The polarizing pad may have two poles symmetrically arranged at opposite positions on the pad. In this case, the magnetic flux may be formed according to the orientation of the pad.

In this specification, the power transmitting pad 21 and the power receiving board 11 may be collectively referred to as a wireless charging pad.

Fig. 2 and 3 illustrate a cartesian coordinate system compatible with the definition in the SAE J2954 standard and applicable to embodiments of the present disclosure.

As shown in fig. 2 and 3, in an exemplary embodiment, in a right-hand cartesian coordinate system, the +x axis may be set to point toward the rear of the vehicle, and the-X axis may be set to point toward the front of the vehicle. The +y axis may be set to point to the right side of the vehicle, i.e. to the driver side of the left hand side of the vehicle, -the Y axis may be set to point to the left side of the vehicle. The +z axis may be set to point in an upward direction, and the-Z axis may be set to point in a downward direction. The core of the coil of the power transmission pad 21 or the power reception pad 11 may be defined as x=0 and y=0, and the ground surface may be defined as z=0.

Fig. 4 is a circuit diagram of an equivalent circuit of an electric vehicle wireless charging circuit according to an exemplary embodiment of the present disclosure.

The left-hand part of the circuit shown in fig. 4 may be interpreted as a representation of all or part of the power supply Vsrc supplied from the power grid and the charging station 20 including the power transmitting pad 21, and the right-hand part of the circuit shown in fig. 4 may be interpreted as a representation of all or part of the electric vehicle including the power receiving pad and the battery.

The left part of the circuit shown in fig. 4 may correspond to the power V supplied from the grid _src Output power P of (2) _src Is provided to the primary side power converter. Primary side power converter executable power P _src To convert the converted output power P ₁ Output to the transmitting coil L ₁ So that the coil L is sent ₁ An electromagnetic field may be generated at a desired operating frequency.

The primary side power converter may include an AC-DC converter configured to convert the power P and a Low Frequency (LF) converter _src Conversion to DC power, power P _src Is AC power supplied from the grid, the LF converter is configured to convert DC power into AC power having an operating frequency suitable for wireless charging. For example, the operating frequency for wireless charging may be determined to be in the frequency range of 80kHz-90kHz, but is not limited thereto.

Power P output by primary side power converter ₁ Can be supplied to the transmitting coil L ₁ First capacitor C ₁ A first resistor R ₁ Is provided. Specifically, a first capacitor C ₁ Can be determined as the capacitance with the transmitting coil L ₁ Together, a value of an operating frequency suitable for wireless charging is established. First resistor R ₁ Can represent the transmitting coil L ₁ And a first capacitor C ₁ Is a power loss in the power supply.

In addition, a transmitting coil L ₁ Can be connected with the receiving coil L through the coupling coefficient m ₂ Electromagnetic coupling such that power P ₂ Is transmitted to the receiving coil L ₂ Or in the receiving coil L ₂ The power P is induced in ₂ . Thus, the meaning of power transmission in the present disclosure may be used interchangeably with the meaning of power induction.

At the receiving coil L ₂ Is induced in or transmitted to the receiving coil L ₂ Power P of (2) ₂ May be provided to the secondary side power converter. Specifically, the second capacitor C ₂ Can be determined as the capacitance with the receiving coil L ₂ Together, a value of an operating frequency suitable for wireless charging is established. Second resistor R ₂ Can represent the receiving coil L ₂ And a second capacitor C ₂ Is a power loss in the power supply.

The secondary side power converter may include an AC-DC converter configured to supply power P at an operating frequency ₂ Conversion to a Battery V with EV-adapted _HV Is a DC power of a voltage level of (a) a voltage level of (b).

From power P supplied to secondary side power converter ₂ Converted power P _HV Can be used for the battery V installed inside the EV _HV And (5) charging.

The right-hand portion of the circuit shown in fig. 4 may further include a circuit for selectively coupling the receive coil L ₂ And battery V _HV A switch that is connected or disconnected.

Transmitting coil L ₁ And a receiving coil L ₂ The resonant frequencies of (2) may be similar or identical to each other, and the receiving coil L ₂ Can be positioned by the transmitting coil L ₁ In the electromagnetic field generated.

It should be noted that the circuit of fig. 4 illustrates WPT used in the EV WPT system of the exemplary embodiment of the present disclosure, and the present disclosure is not limited to the circuit illustrated in fig. 4.

On the other hand, because the power loss can follow the transmission coil L ₁ And receiving coil L ₂ The distance between the two coils increases, so the transmission coil L is properly arranged ₁ And receiving coil L ₂ May be an important factor.

Transmitting coil L ₁ Can be included inIn the transmitting pad 21 shown in fig. 1, and the receiving coil L ₂ May be included in the receiving pad 11 shown in fig. 1. Further, the transmit coil may be referred to as a primary coil or a Ground Assembly (GA) coil, and the receive coil may be referred to as a secondary coil or a Vehicle Assembly (VA) coil. Thus, the positional alignment between the transmitting pad and the receiving pad or the positional alignment between the EV and the transmitting pad may also be an important factor.

The positional alignment between the transmitting pad 21 and the receiving pad 11 in the electric vehicle 10 shown in fig. 1 may correspond to the above-described term "alignment", and thus 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.

The routing pad 21 may be positioned below the ground surface, may be positioned on the ground surface, or may be positioned below the ground surface with its top surface exposed above the ground surface. At this time, as shown in fig. 2 and 3, the X-axis may indicate the front-rear 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.

Furthermore, the receiving pad 11 of the EV may be defined by different categories according to its height (defined in the z-direction) measured from the ground. For example, the receiving pad 11 having a height of about 100-150 millimeters (mm) from the ground may be classified as type 1. The receiving pad 11 having a height of about 140-210mm may be classified as type 2. The receiving pad 11 having a height of about 170-250mm may be classified as type 3. The receiving pad may support only some of types 1 to 3. For example, only type 1 may be supported by the receiving pad 11, or types 1 and 2 may be supported by the receiving pad 11.

The height of the receiving pad measured from the ground may correspond to the term "vehicle magnetic ground clearance" as defined previously.

Meanwhile, the vertical position (i.e., the position in the Z direction) of the power transmission pad 21 may be determined to be arranged between the maximum type and the minimum type supported by the power reception pad 11. For example, in the case where the receiving pad supports only types 1 and 2, the vertical position of the power transmitting pad 21 may be in a range between about 100mm and 210mm with respect to the power receiving pad 11.

Further, the gap between the center of the power transmission pad 21 and the center of the power reception pad 11 may be determined to be arranged within the limits of the horizontal direction and the vertical direction (defined in the X-direction and the Y-direction). For example, the gap (e.g., Δy) may be determined to be within ±75mm in the transverse direction (defined in the Y direction) and within ±100mm in the longitudinal direction (defined in the X direction).

The relative positions of the power transmission pad 21 and the power reception pad 11 may be changed according to the experimental result, and it should be noted that the above-mentioned values are provided as examples.

Although the alignment between the pads has been described on the assumption that each of the transmission pad 21 and the reception pad 11 includes a coil, the alignment between the pads may be more specifically defined by the alignment between the transmission coil (or GA coil) and the reception coil (or VA coil) included in the transmission pad 21 and the reception pad 11, respectively.

Fig. 5 is a conceptual sectional view and a front view of the power transmission pad 21 according to an exemplary embodiment of the present disclosure.

As shown in fig. 5, the power transmission pad 21 may include a housing 21a forming an outer shape of the power transmission pad 21, an aluminum shield 21b having a flat plate shape and mounted inside the housing 21a, and a ferrite pad 21c mounted on or above the aluminum shield 21b, and a transmission coil 21d mounted on or above the ferrite pad 21 c. Here, "above or over" means an upward direction with respect to the ground on which the power transmission pad 21 is mounted.

Here, the ferrite for the ferrite pad 21c is a magnetic material containing iron oxide, and can play an auxiliary role in transmitting and receiving wireless power by reducing magnetic resistance and promoting flow of magnetic flux.

Fig. 6 is a conceptual sectional view and a front view of the power receiving pad 11 according to an exemplary embodiment of the present disclosure.

As shown in fig. 6, the power receiving pad 11 may include an aluminum bottom plate 11d disposed at the bottom of the vehicle, a housing 11a disposed below the aluminum bottom plate 11d, a ferrite pad 11b disposed inside the housing 11a, and a receiving coil 11c disposed inside the housing 11a and below the ferrite pad 11b (e.g., toward the ground when the power receiving pad is mounted under the vehicle). The center portion of the ferrite pad 11b may protrude downward such that the side surface of the protruding portion faces the inner surface of the receiving coil 11c. Further, the edge portion of the ferrite bead 11b may be bent downward such that the bent edge surrounds the outer surface of the receiving coil. However, the different embodiments of the present disclosure are not limited to the embodiment of fig. 6, and it is apparent to those skilled in the art that the edge portion of the ferrite pad 11b may not flex or protrude downward in alternative embodiments.

In contrast to the power transmission pad 21 shown in fig. 5, the power reception pad 11 shown in fig. 6 may not include the aluminum shield 21b.

Fig. 7 to 10 are diagrams illustrating conceptual structures of a power transmission pad or a power reception pad according to an exemplary embodiment of the present disclosure. Fig. 10 is a top view of the power transmitting pad or the power receiving pad, fig. 9 is a sectional view taken along a line A-A of fig. 10, fig. 8 is a front view of the pad, and fig. 7 is an exploded view for explaining the general conceptual structure of the pad.

At least a portion of the configurations shown in fig. 7-10 meet specifications of industry standard SAE J2954 and IEC 61980-3 Technical Specification (TS), which are standard documents for wireless charging of electric vehicles.

According to SAE J2954 standard and IEC 61980-3TS, the primary or secondary coil of a wireless power transmission system applicable to a light electric vehicle may comprise litz wire and ferromagnetic material.

The litz wire (litz wire) has an advantage in that the current flow does not become unstable with an increase in current, the loss is small, so that a stable current flow can be maintained, and the temperature of the coil is less elevated, compared with a conventional copper wire. Accordingly, litz wire is a suitable material for an electric vehicle wireless power transfer system using an operating frequency of 79 to 90 kHz. Typically, the price of litz wire is set to a price per meter. There have been attempts to use litz wire in electric vehicle wireless power transmission systems in consideration of these characteristics of litz wire.

However, the wireless power transmission system of the lightweight electric vehicle requires a litz wire having a large current capacity (e.g., at least 50A or more), which is several tens of times more expensive than a general litz wire, and may cause an increase in manufacturing cost of the electric vehicle.

Because electric vehicle wireless charging systems wirelessly transfer large amounts of power, strict thermal management is always important. In addition, it is important to manage heating of foreign matter such as metal.

The electric vehicle wireless charging standard documents (SAE J2954 standard and IEC 61980-3 TS) also specify standards for acceptable heating in the primary and secondary coils of electric vehicle wireless charging systems.

However, due to the structure of the litz wire in which the inner strands are surrounded by the outer strands, it is difficult to rapidly discharge the generated heat to the outside of the litz wire. Further, as heat generation continues, the current loss in the litz wire increases. Therefore, it is difficult to use the litz wire for a long time. Thus, the power transmission system using litz wire requires a cooling arrangement, which further increases the cost.

Even if a cooling arrangement is added to the system, the thermal conductivity of the litz wire may be too low to rapidly discharge the generated heat to the outside of the litz wire and thus the overall cooling efficiency may still be low.

Furthermore, there may be some opinion that a support structure maintaining the shape of the coil made of litz wire may compromise the safety of the system.

Although litz wire has a strength higher than that of conventional copper wires and is convenient to maintain the shape of the wire, litz wire is rectilinear and a coil made of litz wire may require a frame to maintain the shape of the litz wire and the coil. Such a frame is made of a dielectric with a low dielectric constant to reduce electromagnetic effects on the operation of the coil. Dielectrics with low dielectric constants are generally susceptible to heat and are therefore insufficient for high power charging, such as 22 Kilowatts (KW), which generates a large amount of heat. Furthermore, because the frame is in contact with the litz wire, the frame may hinder heat exchange, undergo a change in its shape during repeated heating and cooling processes, or cause a fire.

Accordingly, the present disclosure provides alternative embodiments to those using litz wire.

Fig. 11 is a conceptual diagram of a flat wire wound to constitute a power transmission pad or a power reception pad according to an exemplary embodiment of the present disclosure.

The flat and rectangular wire shown in fig. 11 may be a modification of commercially available flat wires to accommodate the purposes of this disclosure.

Commercially available flat wires typically have corners at nearly right angles. These commercially available flat wires are used to increase the space factor. Wires according to alternative embodiments of the present disclosure maintain their flat shape with corners that are at least partially rounded.

Hereinafter, for convenience of explanation, the electric wire shown in fig. 11 is referred to as a "flat wire". However, the scope or spirit of the present disclosure should not be limited by the names. The embodiments of the wire proposed by the present disclosure with reference to fig. 11-20 have the following characteristics: 1) Having a flat or planar shape, and 2) having partially circular and/or partially rectangular sides. The electric wire having such characteristics according to the embodiment of the present disclosure may be a flat electric wire having a shape optimized to generate an electromagnetic field suitable for wireless power transmission in a state of being wound into a coil.

Flat and rectangular wires are available in various sizes, for example, single or multiple strands (e.g., eight strands), a thickness range of 1.0-1.9 millimeters (mm), and a width range of 3-20 mm. In addition, the rectangular wire may be wound into a coil having the form of a Continuous Transposed Conductor (CTC).

The advantage of a coil made from such wire is that the coil can be used in high voltage applications and that the insulation adheres well enough to the conductors of the conductors to select and use one of a variety of insulation materials, e.g., KRAFT, THERMAL UPGRADE KRAFT, NOMEX, DENNISON, KAPTON, MICA, and CONDUCTOFOL.

If the insulation problem is solved in this way, the number of turns can be increased compared to existing litz wire coils, and the increase in the number of turns can enable an increased magnetic flux to be established and to enhance the power transmission efficiency.

Furthermore, because it is essentially a single cylindrical metal structure when viewed from the outside, heat can be rapidly transferred from the inside to the outside without any discontinuity.

Further, the litz wire has a structure in which the inner strands are surrounded by the outer strands as described above. Therefore, when an internal short circuit or insulation deformation or deterioration occurs, it is difficult to identify the location of the fault, and the electric wire cannot be partially maintained and the entire coil must be replaced, which results in an increase in maintenance cost. However, the coil structure employing the flat wire or the planar wire proposed in the present disclosure is more durable than litz wire, and thus a failure such as a short circuit in the wire is less likely to occur. In addition, even if a failure occurs, the position where the failure occurs can be easily determined. Therefore, the fault can be repaired immediately, and even if the coil itself is replaced, the replacement cost is low. Thus, the coil structure according to the present disclosure requires much less resources for maintenance.

Referring to the structure of the coil shown in fig. 11, a power transmitting device/pad and a power receiving device/pad that can be easily cooled and reduce cooling costs can be realized.

According to embodiments of the present disclosure, the power transmission device/pad and the power reception device/pad may be implemented with less space limitations when arranging the ferrite pad to be magnetically coupled to the coil.

According to the embodiments of the present disclosure, a power transmission device/pad and a power reception device/pad that impose fewer restrictions on the space for placing a ferrite core inside a coil to magnetically couple to the coil can be realized.

Accordingly, the embodiments of the present disclosure enable relatively free setting of the size and shape of the power transmission pad or the power reception pad for wireless power transmission.

Furthermore, the structure of fig. 11 has advantages of high heat transfer efficiency and high degree of freedom of arrangement, which enables selective application of different cooling techniques such as dry self-cooling, dry air cooling, dry seal self-cooling, inflow air cooling, oil flow water cooling, oil flow air cooling, and refrigerant cooling. Because various cooling techniques may be selectively applied or applied in combination, embodiments of the present disclosure may have a very advantageous effect in cooling heat generated during power transmission.

The exemplary embodiments of the present disclosure shown in fig. 12 to 32, which will be described below, are directed to a coil for transmitting or receiving 22kW or more of electric power to an electric vehicle through wireless power transmission, and include a coil structure using the flat or planar electric wire of fig. 11 together with a power circuit.

According to the embodiments shown in fig. 7 to 10, litz wire is used as the primary coil and the secondary coil to wirelessly transmit electric power to the electric vehicle. However, the usability of the electric wire may be limited for 22kW or more of power transmission due to the cost and heat generated when transmitting high power.

In order to solve this problem, alternative embodiments have been proposed that employ flat wires or planar wires as the primary coil and the secondary coil.

Fig. 12 to 14 show embodiments in which the secondary coil or the receiving coil is implemented using a flat wire, and fig. 15 to 20 show three embodiments in which the transmitting coil or the primary coil is implemented using a flat wire. According to an exemplary embodiment, for convenience of explanation, both the primary coil and the secondary coil may be implemented using flat wires, but the scope of the present disclosure is not limited thereto. For example, in alternative embodiments of the present disclosure, the secondary coil may be implemented using any other shape of coil instead of a flat wire.

The flat wire shown in fig. 11 may be implemented using at least one material selected from copper and copper alloy, but the scope of the present disclosure is not limited thereto, and different conductors may also be used for the flat wire.

The aspect ratio of the cross section of the electric wire shown in fig. 11 is not limited to the embodiment shown in fig. 11. For convenience of explanation, it may be assumed that specific dimensions show fig. 11 and fig. 11 may be enlarged, and an aspect ratio of a cross section of an electric wire for forming the coil of the exemplary embodiment of the present disclosure may be determined in consideration of power transmission efficiency, a shape of the coil, and the like.

At the same time, it may be advantageous to establish an electromagnetic field in the vicinity of the coil to at least partially round the corners of the coil. The curvature at which the corners are rounded may also be determined in consideration of power transmission efficiency, the shape of the coil, and the like.

In an exemplary embodiment, the coil of fig. 11 may be implemented by determining the aspect ratio of the cross-section of the wire and the numerical range of curvature of the rounded corners based on the shape and material of the bus bar forming the conductor connected to the battery within the electric vehicle 10.

Further, an embodiment employing litz wire will be compared with an alternative embodiment, although litz wire is a technique designed to increase the ratio of surface area (i.e., current path) to cross-sectional area or volume, interference between strands of litz wire in the central region of the litz wire harness (where the litz wire is dense) can reduce power transmission efficiency and increase heat generation.

Since current flows through the surface of the conductor, the ratio of surface area to cross-sectional area can be understood to correspond to the ratio of current path to total volume.

Exemplary embodiments of the present disclosure may improve power transmission efficiency by proposing a flat wire and coil structure shown in fig. 11 to increase a ratio of a surface area to a cross-sectional area and improve a space factor.

The rounded corners may facilitate the formation of an electromagnetic field, resulting in more advantageous electromagnetic properties of the coil.

Fig. 12 to 14 are diagrams of conceptual structures of wireless power receiving pads according to exemplary embodiments of the present disclosure. Fig. 12 is a top/bottom view of the power receiving pad 11, fig. 13 is an exploded perspective view of the power receiving pad 11, and fig. 14 is an enlarged view of rounded corners of the secondary coil 101c of the power receiving pad 11.

For example, the power receiving pad 11 may be provided at the bottom of the electric vehicle 10.

Referring to fig. 12 and 13, the power receiving pad 11 may include: an aluminum shield 101a forming a part of the housing and having a shape of a flat plate; an aluminum plate 101d disposed below the aluminum shield 101 a; a flat ferrite pad 101b disposed under the aluminum plate 101 d; and a secondary coil 101c disposed under the flat ferrite pad 101 b. Here, the term "below" refers to a downward direction of a virtual horizontal plane of the vehicle on which the power receiving pad 11 is mounted.

A housing including an aluminum shield 101a may be implemented to support at least the secondary coil 101c and the flat ferrite pad 101b.

The secondary coil 101c may be implemented using the flat wire of fig. 11. The secondary coil 101c may be of a circular type and may be wound 18 times, but the scope of the present disclosure is not limited by the number of turns of this embodiment.

The secondary coil 101c may be implemented in a form surrounding the central space. The secondary coil 101c may include a plurality of coil elements surrounding a central space. For ease of illustration, it is assumed that one coil element surrounds the central space only once. In some exemplary embodiments, a flat wire element comprising a bundle of a plurality of coil elements may form the secondary coil 101c. For example, the secondary coil 101c having a total number of turns of 18 may be implemented by one flat wire element including 18 coil elements. Alternatively, the secondary coil 101c may be formed using two flat wire elements each including nine coil elements. In this case, the two flat wire elements may be electrically connected to each other. However, each of these flat wire elements may be arranged to be spatially separated in the direction of at least one of X, Y and Z-axis. The flat wire elements may be arranged in a concentric shape sharing the central axis of the secondary coil 101c.

The corners of the cross section of the flat wire forming the secondary coil 101c may be at least partially rounded in order to establish an electromagnetic field that facilitates wireless power transmission in the vicinity of the wire.

Referring to fig. 14, an embodiment in which corners in a top view of the secondary coil 101c are rounded to have a radius of curvature of 6mm is shown. Such a shape of the secondary coil 101c, which is at least partially rounded, may help to establish an electromagnetic field that facilitates wireless power transmission in the vicinity of the wire.

Referring to fig. 14, a virtual extension line extending in the X-axis direction of the coil element of the secondary coil 101c and a virtual extension line extending in the Y-axis direction may be perpendicular to each other.

Since the secondary coil 101c is made of a flat wire, the cross section of the coil element of the secondary coil 101c may have a long axis and a short axis. In the case where the long axis is arranged parallel to the central axis of the secondary coil 101c, the flat electric wire is arranged perpendicular to the ground, and the coil may be referred to as a vertical coil. In the case where the long axis is arranged perpendicular to the central axis of the secondary coil 101c, the flat electric wire is arranged parallel to the ground and the coil may be referred to as a horizontal coil. The secondary coil 101c may have a vertical type structure or a horizontal type structure.

In the case where the secondary coil 101c has a vertical structure, for example, the long axis of the cross section of the flat electric wire may be designated as 10mm with a tolerance of 1%.

In the case where the secondary coil 101c includes two or more flat wire elements, each of the flat wire elements may be arranged to be spaced apart by a spacing distance of at least 4.5 mm. At this time, the error of the separation distance may be designated as less than 1%.

A flat ferrite pad 101b may be disposed between the aluminum plate 101d and the secondary coil 101 c. Assuming a virtual horizontal plane perpendicular to the central axis of the secondary coil 101c, the flat ferrite pad 101b may be arranged such that a first area on which the secondary coil 101c is projected on the virtual horizontal plane is included in a second area on which the flat ferrite pad 101c is projected.

A central portion of the flat ferrite pad 101b may protrude toward the central space of the secondary coil 101c to face the inner surface of the secondary coil 101 c. Further, in some exemplary embodiments of the various embodiments of the present disclosure, the edge portion of the ferrite pad 101b may be bent downward so as to form a shape of a wall surrounding the outer surface of the secondary coil 101 c. However, in alternative embodiments, the edge portion of the ferrite pad 101b may not be bent downward and maintain a planar shape. In the case where the flat ferrite pad 101b protrudes toward the central space of the secondary coil 101c, the protruding portion of the flat ferrite pad 101b may be designated to have a height of 10mm from the non-protruding portion and to have a fault tolerance of 1%.

Fig. 15 and 16 are diagrams of conceptual structures of wireless power transmission pads according to exemplary embodiments of the present disclosure.

Fig. 15 is a top view of the power transmission pad 21, and fig. 16 is an exploded perspective view of the power transmission pad 21. The power transmission pad 21 may be placed on the ground, partially buried, or placed under the ground.

Referring to fig. 15 and 16, the power transmission pad 21 may include: a bottom cover 201a forming a part of the case and partially having a flat plate form; an aluminum plate 201b disposed on top of the bottom cover 201 a; a flat ferrite pad 201c disposed on top of the aluminum plate 201 b; and a primary coil 201d arranged on top of the flat ferrite pad 201c. Here, the term "on top" refers to an upward direction of a virtual horizontal plane on which the power transmission pad 21 is mounted.

The case including the bottom cover 201a may be implemented to support at least the primary coil 201d and the flat ferrite pad 201c.

The primary coil 201d may be implemented using the flat wire of fig. 11. The primary coil 201d may be of a circular type and may be wound 15 times, but the scope of the present disclosure is not limited by the number of turns in the present embodiment.

The primary coil 201d may be implemented in a form surrounding a central space. The primary coil 201d may include a plurality of coil elements surrounding a central space. For ease of illustration, it is assumed that one coil element surrounds the central space only once. In some exemplary embodiments, a flat wire element comprising a bundle of a plurality of coil elements may form the primary coil 201d. For example, the primary coil 201d having a total number of turns of 15 may be realized by one flat wire element including 15 coil elements. Alternatively, the primary coil 201d may be formed using three flat wire elements each including five coil elements. In this case, three flat wire elements may be electrically connected to each other. However, each of these flat wire elements may be arranged to be spatially separated in the direction of at least one of X, Y and Z-axis. The flat wire elements may be arranged in a concentric shape sharing the central axis of the primary coil 201d. In the exemplary embodiment shown in fig. 15 and 16, the primary coil 201d is implemented by a single flat wire element including fifteen coil elements.

The corners of the cross section of the flat wire forming the primary coil 201d may be at least partially rounded to establish an electromagnetic field that facilitates wireless power transmission in the vicinity of the wire.

The configuration of the secondary coil 101c in which the corners of the secondary coil 101c are rounded as shown in fig. 14 is also applicable to the primary coil 201d. In this case, the radius of curvature of the corner portion may be adapted to the characteristics of the primary coil 201d. This shape of the at least partially rounded primary coil 201d may help establish an electromagnetic field that facilitates wireless power transmission in the vicinity of the wire.

Similar to the secondary coil 101c shown in fig. 14, a virtual extension line extending in the X-axis direction and a virtual extension line extending in the Y-axis direction of the coil element of the primary coil 201d may be perpendicular to each other.

Since the primary coil 201d is constituted by a flat electric wire, the cross section of the coil element of the primary coil 201d may have a long axis and a short axis. In the case where the long axis is arranged parallel to the central axis of the primary coil 201d, the flat electric wire is arranged perpendicular to the ground, and the coil may be referred to as a vertical coil. In the case where the long axis is arranged perpendicular to the central axis of the primary coil 201d, the flat electric wire is arranged parallel to the ground, and the coil may be referred to as a horizontal coil. An exemplary embodiment of a primary coil 201d having a horizontal type arrangement is shown in fig. 15 and 16.

The long axis of the cross section of the flat electric wire in the primary coil 201d is designated as 5mm, for example, with a tolerance of 1%. The horizontal separation distance between the coil elements of the primary coil 201d may be designated as 1.25mm with a tolerance of 1%. The short axis of the cross section of the flat electric wire in the primary coil 201d may be designated as 1mm, with a tolerance of, for example, 1%. Thus, the aspect ratio of the cross section is 5:1, but the present disclosure is not limited thereto.

A flat ferrite pad 201c may be disposed between the aluminum plate 201b and the primary coil 201 d. Assuming a virtual horizontal plane perpendicular to the central axis of the primary coil 201d, the flat ferrite pad 201c may be arranged such that a first area on the virtual horizontal plane where the primary coil 201d is projected is included in a second area on the virtual horizontal plane where the flat ferrite pad 201c is projected.

The central portion of the flat ferrite pad 201c may be implemented as a void corresponding to at least a portion of the central space of the primary coil 201 d. For example, when the central space of the primary coil 201d has a size of 331mm×170mm in the xy plane, the void in the central space of the flat ferrite pad 201c may have a size of 320mm×160 mm. At this time, the error of each length may be designated as less than 1%.

When the size of the primary coil 201d in the xy plane is 568mm×407.5mm, the flat ferrite pad 201c may have a size of 600mm×440mm in the xy plane. At this time, the error of each length may be designated as less than 1%.

Fig. 17 and 18 are diagrams of conceptual structures of a wireless power transmission pad according to another exemplary embodiment of the present disclosure.

Fig. 17 is a top view of the power transmission pad 21, and fig. 18 is an exploded perspective view of the power transmission pad 21. The power transmission pad 21 may be placed on the ground, partially buried, or placed under the ground.

Referring to fig. 17 and 18, the power transmission pad 21 may include: a bottom cover 202a forming a part of the housing and partially having a flat plate form; an aluminum plate 202b disposed on top of the bottom cover 202 a; a flat ferrite pad 202c disposed on top of the aluminum plate 202 b; and a primary coil 202d disposed on top of the flat ferrite pad 202 c. Here, the term "on top" refers to an upward direction of a virtual horizontal plane on which the power transmission pad 21 is mounted.

A housing including a bottom cover 202a may be implemented to support at least the primary coil 202d and the flat ferrite pad 201c.

The primary coil 202d may be implemented using the flat wire of fig. 11. The primary coil 202d may be of a circular type and may be wound 15 times, but the scope of the present disclosure is not limited by the number of turns in the present embodiment.

The primary coil 202d may be implemented in a form surrounding a central space. The primary coil 202d may include a plurality of coil elements surrounding a central space. For ease of illustration, it is assumed that one coil element surrounds the central space only once. In some exemplary embodiments, a flat wire element comprising a bundle of multiple coil elements may form the primary coil 202d. For example, the primary coil 202d having 15 turns may be implemented by one flat wire element including 15 coil elements. Alternatively, three flat wire elements (each including five coil elements) may be used to form the primary coil 202d. In this case, three flat wire elements may be electrically connected to each other. However, each of these flat wire elements may be arranged to be spatially separated in the direction of at least one of the x, y and z axes. The flat wire elements may be arranged in a concentric shape sharing the central axis of the primary coil 202d. In the exemplary embodiment shown in fig. 17 and 18, the primary coil 202d is implemented by a single flat wire element including fifteen coil elements.

The corners of the cross section of the flat wire forming the primary coil 202d may be at least partially rounded in order to establish an electromagnetic field that facilitates wireless power transfer in the vicinity of the wire.

The configuration of the secondary coil 101c in which the corners of the secondary coil 101c are rounded as shown in fig. 14 is also applicable to the primary coil 202d. In this case, the radius of curvature of the corner portion can be adapted to the characteristics of the primary coil 202d. Such a shape of the primary coil 202d, which is at least partially rounded, may help to establish an electromagnetic field that facilitates wireless power transmission in the vicinity of the wire.

Similar to the secondary coil 101c shown in fig. 14, a virtual extension line extending in the X-axis direction and a virtual extension line extending in the Y-axis direction of the coil element of the primary coil 202d may be perpendicular to each other.

Because the primary coil 202d is made of a flat wire, the cross section of the coil element of the primary coil 202d may have a long axis and a short axis. In the case where the long axis is arranged parallel to the central axis of the primary coil 202d, the flat electric wire is arranged perpendicular to the ground, and the coil may be referred to as a vertical coil. In the case where the long axis is set to be perpendicular to the central axis of the primary coil 202d, the flat wire is set to be parallel to the ground, and the coil may be referred to as a horizontal coil. An exemplary embodiment of a primary coil 202d having a horizontal type configuration is shown in fig. 17 and 18.

The long axis of the cross section of the flat wire in the primary coil 202d may be designated as 10mm with, for example, a tolerance of 1%. The horizontal separation distance between each coil element of the primary coil 202d may be designated 4.24mm with a fault tolerance of 1%. The short axis of the cross section of the flat wire in the primary coil 202d may be designated as 2mm with, for example, a tolerance of 1%. Thus, the aspect ratio of the cross section is 5:1, but the present disclosure is not limited thereto.

A flat ferrite pad 202c may be disposed between the aluminum plate 202b and the primary coil 202 d. Assuming a virtual horizontal plane perpendicular to the central axis of the primary coil 202d, the flat ferrite pad 202c may be arranged such that a first area on the virtual horizontal plane where the primary coil 202d is projected is included in a second area on the virtual horizontal plane where the flat ferrite pad 202c is projected.

The central portion of the flat ferrite pad 202c may be implemented as a void corresponding to at least a portion of the central space of the primary coil 202 d. For example, when the central space of the primary coil 202d has a size of 331mm×170mm in the xy plane, the void in the central space of the flat ferrite pad 202c may have a size of 320mm×160 mm. At this time, the error of each length may be designated as less than 1%.

When the primary coil 202d has dimensions 568mm×407.5mm in the xy plane, the flat ferrite pad 202c may have dimensions 600mm×440mm in the xy plane. At this time, the error of each length may be designated as less than 1%.

Fig. 19 and 20 are diagrams of conceptual structures of a wireless power transmission pad according to another exemplary embodiment of the present disclosure.

Fig. 19 is a top view of the power transmission pad 21, and fig. 20 is an exploded perspective view of the power transmission pad 21. The power transmission pad 21 may be placed on the ground, partially buried, or placed under the ground.

Referring to fig. 19 and 20, the power transmission pad 21 may include: a bottom cover 203a forming a part of the housing and partially in the form of a flat plate; an aluminum plate 203b disposed on top of the bottom cover 203 a; a flat ferrite pad 203c disposed on top of the aluminum plate 203 b; and a primary coil 203d arranged on top of the flat ferrite pad 203c. Here, the term "on top" refers to an upward direction of a virtual horizontal plane on which the power transmission pad 21 is mounted.

A housing including a bottom cover 203a may be implemented to support at least the primary coil 203d and the flat ferrite pad 203c.

The primary coil 203d may be implemented using the flat wire of fig. 11. The primary coil 203d may be of a circular type and may be wound 30 times, but the scope of the present disclosure is not limited to the number of turns in this embodiment.

The primary coil 203d may be implemented in a form surrounding a central space. The primary coil 203d may include a plurality of coil elements surrounding a central space. For ease of illustration, it is assumed that one coil element surrounds the central space only once. In some exemplary embodiments, a flat wire element comprising a bundle of a plurality of coil elements may form the primary coil 203d. For example, the primary coil 203d having a total number of turns of 30 may be implemented by one flat wire element including 30 coil elements. Alternatively, two flat wire elements (each including fifteen coil elements) may be used to form the primary coil 203d. In this case, the two flat wire elements may or may not be electrically connected to each other. However, each of these flat wire elements may be arranged to be spatially separated in the direction of at least one of the x, y and z axes. The flat wire elements may be arranged in a concentric shape sharing the central axis of the primary coil 203d. In the exemplary embodiment shown in fig. 19 and 20, the primary coil 203d is implemented by two flat wire elements each including 15 coil elements.

The corners of the cross section of the flat wire forming the primary coil 203d may be at least partially rounded in order to establish an electromagnetic field that facilitates wireless power transmission in the vicinity of the wire.

The configuration of the secondary coil 101c in which the corners of the secondary coil 101c are rounded as shown in fig. 14 is also applicable to the primary coil 203d. In this case, the radius of curvature of the corner portion may be adapted to the characteristics of the primary coil 203d. This shape of the at least partially rounded primary coil 203d may help to establish an electromagnetic field that facilitates wireless power transmission in the vicinity of the wire.

Similar to the secondary coil 101c shown in fig. 14, a virtual extension line extending in the X-axis direction and a virtual extension line extending in the Y-axis direction of the coil element of the primary coil 203d may be perpendicular to each other.

Since the primary coil 203d is made of a flat wire, the cross section of the coil element of the primary coil 203d may have a long axis and a short axis. In the case where the long axis is set parallel to the central axis of the primary coil 203d, the flat electric wire is set perpendicular to the ground, and the coil may be referred to as a vertical coil. In the case where the long axis is set to be perpendicular to the central axis of the primary coil 203d, the flat wire is set to be parallel to the ground, and the coil may be referred to as a horizontal coil. An exemplary embodiment of a primary coil 203d having a horizontal type configuration and implemented to include two flat wire elements is shown in fig. 19 and 20. In this case, each of the two flat wire elements may be arranged around the central space or the central axis. According to the embodiment shown in the top view of fig. 19, two horizontal flat wire elements may form a concentric structure sharing the center axis thereof with each other, and may be arranged at the same position on the xy plane.

For example, the long axis of the cross section of the flat electric wire in the primary coil 203d may be designated as 5mm with, for example, a tolerance of 1%. The horizontal separation distance between each coil element of the primary coil 203d may be designated as 1.25mm, with a tolerance of 1%. For example, the short axis of the cross section of the flat wire in the primary coil 203d may be designated as-mm, with a tolerance of 1%. Thus, the aspect ratio of the cross section is 5:1, but the present disclosure is not limited thereto.

In the case where the primary coil 203d includes two or more flat wire elements, each of the flat wire elements may be arranged to be spaced apart by a spacing distance of at least 4 mm. At this time, the error of the separation distance may be designated as less than 1%.

A flat ferrite pad 203c may be disposed between the aluminum plate 203b and the primary coil 203 d. Assuming a virtual horizontal plane perpendicular to the central axis of the primary coil 203d, the flat ferrite pad 203c may be arranged such that a first area on the virtual horizontal plane where the primary coil 203d is projected is included in a second area on the virtual horizontal plane where the flat ferrite pad 203c is projected.

The central portion of the flat ferrite pad 203c may be implemented as a void corresponding to at least a portion of the central space of the primary coil 203 d. For example, when the central space of the primary coil 203d has a size of 331mm×170mm in the xy plane, the void in the central space of the flat ferrite pad 203c may have a size of 320mm×160 mm. At this time, the error of each length may be designated as less than 1%.

When the size of the primary coil 203d in the xy plane is 568mm×407.5mm, the flat ferrite pad 203c may have a size of 600mm×440mm in the xy plane. At this time, the error of each length may be designated as less than 1%.

In the exemplary embodiments shown in fig. 15 to 20, the separation distances in the Z-axis direction between the primary coils 201d, 202d, and 203d and the flat ferrite pads 201c, 202c, and 203c may be designated as 3mm, respectively, with a tolerance of, for example, 1%.

In the exemplary embodiment shown in fig. 15 to 20, the thicknesses of the flat ferrite pads 201c, 202c and 203c in the Z-axis direction may be designated as 2mm, with a tolerance of, for example, 1%.

In the exemplary embodiments shown in fig. 15 to 20, the spacing distances between the flat ferrite pads 201c, 202c and 203c and the aluminum plates 201b, 202b and 203b in the Z-axis direction may be designated as 2.7mm, respectively, with a tolerance of, for example, 1%.

Fig. 21 is a block diagram illustrating a conceptual structure of a power transmission circuit for wireless power transmission according to an exemplary embodiment of the present disclosure.

The magnetic/inductive coupling or resonance structure formed between the primary coils 201d, 202d, and 203d and the secondary coil 101c shown in fig. 12 to 20 can be equivalently represented by the transformer shown in fig. 21.

Referring to fig. 21, a three-phase AC-DC rectifier circuit 210 and a Sinusoidal Pulse Width Modulation (SPWM) inverter 220 for applying alternating current power to primary coils may be disposed at one side of the primary coils 201d, 202d, and 203 d.

Referring also to fig. 21, a rectifier 110 and a charger 120 for transmitting power from the secondary coil 101c to the load/battery may be disposed on one side of the secondary coil.

A first technical feature of the power transmission circuit according to the exemplary embodiment of the present disclosure is the structure that it includes the three-phase AC-DC rectifier circuit 210 and the SPWM inverter 220 on the primary coils 201d, 202d, and 203d sides.

A second technical feature of the power transmission circuit according to the exemplary embodiment of the present disclosure is a proportional-integral (PI) control structure based on measurement of the three-phase AC-DC rectifier circuit 210 to control the three-phase AC-DC rectifier circuit 210 and the SPWM inverter 220 to apply AC power to the primary coil.

Fig. 22 is a circuit diagram showing a conceptual structure of an embodiment of the three-phase AC-DC rectifier circuit 210 shown in fig. 21.

Referring to fig. 22, peak voltage, rms current, and peak current of each phase of the three-phase input may be adjusted to 700V, 33.6A, and 50.4A, respectively.

The peak voltage, rms current and peak current formed at each switch pair constituting each phase of the rectifier can be adjusted to 700V, 23.8A and 48.3A, respectively.

The peak voltage, rms current and peak current developed at capacitor Cdc by the combination of three phases can be adjusted to 700V, 25.7A and 53A, respectively. Due to the rectifying operation, a peak voltage equal to the peak voltage of each phase of the three-phase input may be applied between the two terminals of the capacitor Cdc. By rectifying, a unidirectional current flows through the capacitor Cdc, and when the voltage in the three-phase input reaches a peak value, the current in the capacitor Cdc reaches a peak value. The three-phase AC-DC rectifier circuit 210 may generate a voltage across the terminals of the capacitor Cdc as an output voltage to provide an input to the SPWM inverter 220.

Fig. 23 is a circuit diagram showing a conceptual configuration of an embodiment of the SPWM inverter 220 shown in fig. 21.

Referring to fig. 23, the peak voltage, rms current, and peak current formed at each switch pair may be adjusted to 700V, 25.3A, and 52.6A, respectively.

The rms current and peak current formed at the LC network including the inductor Lr and the capacitor can be adjusted to 35.8A and 52.6A, respectively. The peak voltage across capacitor Cr may be adjusted to 509V and the peak voltage across inductor Lr may be adjusted to 290V.

The SPWM inverter 220 may receive the output of the three-phase AC-DC rectifier circuit 210, generate an alternating voltage signal, and output the alternating voltage as an output to the primary coils 201d, 202d, and 203d.

Fig. 24 is a circuit diagram showing a conceptual structure of the embodiment of the rectifier 110 shown in fig. 21. Fig. 25 is a circuit diagram illustrating a conceptual configuration of the embodiment of the charger 120 shown in fig. 21.

The inductor Lr, the capacitor Cr, and the diode shown in fig. 24, and the capacitors Cf and Co and the inductor Lb shown in fig. 25 may be implemented by lumped elements as shown in the drawings, or may be implemented by an equivalent circuit.

The direct current voltage may be supplied to the battery to charge the battery through the operation of the rectifier 110 and the charger 120.

Fig. 26 is a circuit diagram showing a conceptual structure of a three-phase AC-DC rectifier circuit 210 according to an embodiment of the present disclosure. The circuit shown in fig. 26 has a similar configuration to the circuit shown in fig. 22, but phase currents iga, igb, and igc corresponding to each of the phases a, b, and c, respectively, and a real-time voltage Vdc after rectification are additionally indicated in the figure.

Fig. 27 is a block diagram showing a conceptual structure of an embodiment of a controller suitable for controlling the circuit of fig. 22 or 26 using the voltage and/or current values measured in the circuit of fig. 22 or 26.

Referring to fig. 27, the controller mayIncluding a Phase Locked Loop (PLL) circuit 310, a grid current conversion circuit 320, an output voltage (Vdc) controller 330, I based on the grid phase information of fig. 22 or 26 _L A current controller 340, DQ-abc reverse conversion circuitry 350, and Pulse Width Modulation (PWM) output circuitry 360.

PLL circuit 310 may detect the input of each phase, i.e., grid voltages vg, a, vg, b, and vg, c, and extract a grid phase value based on the grid voltages using a phase-locked loop. The grid voltage information is firstly converted into q-axis grid voltages vg and q through an abc-DQ domain conversion circuit, and then the q-axis grid voltages vg and q are provided for a feedback loop through a PI controller.

Grid current conversion circuit 320 may receive grid current in the abc domain using the grid phase value from PLL circuit 310 to convert to current in the DQ domain. The process of converting current into the DQ domain may be understood to correspond to the process of converting an ac signal into a dc signal or converting a three-phase signal into a single-phase signal in order to use PI control technology in the controllers 330 and 340 later.

Vdc voltage controller 330 forms an outer loop and is capable of controlling the Vdc voltage of the output stage. At this time, the input signal of the internal PI controller may be generated using the output voltage Vdc and the voltage reference Vdc measured in the circuit of fig. 26.

Vdc voltage controller 330 may use PI control techniques to generate current references iL, d, and iq, d reflecting the states of output voltage Vdc and voltage reference Vdc.

IL current controller 340 may control the grid voltage and/or the grid current (i.e., generate a control reference) via an internal PI control module based on the d-axis current and the q-axis current of the grid current converted to a direct current signal or a single phase signal. The d-axis current and q-axis current of the grid current may be values obtained by the grid current conversion circuit 320 from the three-phase grid current measured in the circuit of fig. 26.

IL current controller 340 may include parallel control paths provided for the d-axis and q-axis. The inputs to the internal PI control module may include a d-axis current reference, a converted d-axis current measurement, a q-axis current reference, and a converted q-axis current measurement.

The signal converted by the impedance calculation for each of the d-axis current and the q-axis current is supplied to the output terminal of the internal PI control module, and the voltage reference vff may be additionally supplied to the d-axis control path. An output reference signal supplied by IL current controller 340 to DQ-abc reverse conversion circuit 350 may be generated for each of the d-axis and q-axis, which may be labeled VIref, d and VIref, q, respectively.

The DQ-abc inverse conversion circuit 350 may perform inverse conversion of control information of DQ domain to three-phase (abc) signals using the grid phase information obtained by the PLL circuit 310. In addition, DQ-abc inverse conversion circuit 350 may perform inverse conversion of the DC signal from IL current controller 340 into an AC signal. This reverse conversion process is necessary to generate the reference signal required to generate the AC-DC rectifier PWM signal.

The PWM output circuit 360 may include a comparator that compares a reference signal obtained through inverse conversion with a triangular wave. The PWM output circuit 360 may output the PWM signal derived by the comparator as an AC-DC rectifier PWM signal.

Although only grid current conversion circuit 320 is depicted in fig. 27, the grid voltage conversion circuit may also be implemented using a similar conceptual configuration, and conversion circuits may be provided in the controller circuit for each of the grid current and the grid voltage, according to an embodiment. If the output signals of the grid current conversion circuit 320 are iL, d and iL, q, the output signals of the grid voltage conversion circuit may be labeled vg, d and vg, q.

Fig. 28 is a schematic diagram of a coil structure and a magnetic field simulation result of a power transmission pad according to an exemplary embodiment of the present disclosure.

Fig. 28 depicts the shape of a transmitting coil using the litz wire shown in fig. 7 to 10 and a magnetic field (H-field) simulation result for the transmitting coil.

Fig. 29 is a diagram of a coil structure and a magnetic field simulation result of a power transmission pad according to another exemplary embodiment of the present disclosure.

Fig. 29 depicts the shape of a transmitting coil using the horizontal type flat wire structure shown in fig. 15 to 16 and a magnetic field (H-field) simulation result for the transmitting coil.

Fig. 30 is a diagram of a coil structure and a magnetic field simulation result of a power transmission pad according to another exemplary embodiment of the present disclosure.

Fig. 30 depicts the shape of a transmitting coil using the vertical type flat wire structure shown in fig. 17 to 18 and a magnetic field (H-field) simulation result for the transmitting coil.

Fig. 31 is a diagram of a coil structure and a magnetic field simulation result of a power transmission pad according to another exemplary embodiment of the present disclosure.

Fig. 31 depicts the shape of a transmitting coil using the horizontal type two-stage flat wire structure shown in fig. 19 to 20 and a magnetic field (H-field) simulation result for the transmitting coil.

The magnetic field simulation results shown in fig. 28 to 31 are depicted with respect to a virtual y-z plane. A magnetic field (H-field) of up to 90dbA/m is formed in the region close to the coil, and the H-field gradually decreases as the detection position moves away from the coil. The magnetic field simulation results of fig. 28 to 31 generally show similar magnetic field distributions, and it should be understood from the drawings that the power transmission pad employing the coil structure of fig. 11 according to the alternative embodiment of fig. 15 to 20 reveals electromagnetic characteristics equivalent to those of the power transmission pad based on the coil structure of fig. 7 to 10.

Fig. 32 is a graph showing that the magnetic field simulation results of the power transmission pad according to the embodiments of fig. 28 to 31 may be at a level equal to each other.

The graphs of magnetic field simulation results for the four embodiments of the coil structure of the transmitting pad in fig. 32 are plotted to represent the magnitude of the H-field along the vertical axis relative to the horizontal axis, which represents the horizontal distance from the origin (i.e., the distance along the y-axis) in the structure including the coil structure, with the center point of the coil of the transmitting pad set as the origin.

The coordinates where the magnitude of the magnetic field is greatest represent the location where the magnetic field of the coil windings is most concentrated. The magnetic field distribution of fig. 32 shows that in all four embodiments of the coil structure of the transmitting pad, the magnetic field is smallest at the center of the coil (i.e., the central space) and the magnetic field is largest at the location where the coil windings are densely concentrated.

Referring to fig. 28 to 32, it can be seen that the shapes of the magnetic fields obtained by simulation for the four coil structures and the flat ferrite structure are very similar to each other. In other words, the electromagnetic properties of the four coil structures and the flat ferrite structure are equivalent, and one skilled in the art can expect that the four coil structures and the flat ferrite structure will exhibit similar performance and efficiency in wireless power transmission.

While the above description focuses on an embodiment having a flat ferrite structure, it will be apparent to those skilled in the art that an embodiment in which a ferrite core is formed in the central space of the coil falls within the scope of the present disclosure.

Fig. 33 is a block diagram showing an overall configuration of hardware included in or associated with a wireless power transmitting pad and/or a wireless power receiving pad to control a sequence for wireless power transmission. For convenience of explanation, hardware that controls a sequence for wireless power transmission may be referred to as a controller 1000.

The controller 1000 may be disposed on one side of the electric vehicle 10, one side of an Electric Vehicle Supply Equipment (EVSE), or one side of the power transmission device or pad 210.

The controller 1000 may include at least one processor 1100, a memory 1200 storing at least one instruction for performing the above-described operations by the processor 1100, and a communication interface 1300 connected to a network to perform communication. The controller 1000 for wireless power transmission may further include a storage 1400 capable of storing at least one instruction for performing the above-described operations or data generated during execution of the instruction. The controller 1000 for wireless power transfer may further include an input user interface 1500 and an output user interface 1600 for interacting with a user. Components of the controller 1000 for wireless power transmission may be connected to each other through the system bus 1700 to communicate with each other.

The processor 1100 executing program instructions or commands stored in the memory 1200 may include a Central Processing Unit (CPU) or a Graphics Processing Unit (GPU), or may be implemented by another special purpose processor suitable for performing the methods of the present disclosure.

Each of the memory 1200 and the storage 1400 may include at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory 1200 may include at least one of Read Only Memory (ROM) and Random Access Memory (RAM).

Here, the at least one instruction may include at least one of: a sequence adapted to identify at least one of the electric vehicle 10, the Electric Vehicle Supply Equipment (EVSE) 20, and the power transmission pad 21, a sequence adapted to associate two or more devices among the electric vehicle 10, the Electric Vehicle Supply Equipment (EVSE) 20, the power transmission pad 21 by wireless communication, a sequence adapted to perform alignment and/or pairing by positioning of the counterpart device, and a sequence adapted to allow provision of ac power for power transmission after alignment and/or pairing.

Methods of controlling and operating a WPT system according to exemplary embodiments of the present disclosure may be implemented as computer instructions executable by various computer devices and recorded on a non-transitory computer-readable medium. The computer readable medium may include program instructions, data files, data structures, or combinations thereof. Program instructions recorded on the medium may be specially designed and constructed for the inventive concepts or may be available to those having ordinary skill in the computer software arts. Examples of the computer readable medium may include hardware devices specifically configured to store program instructions, such as magnetic media (such as hard disks, floppy disks, and magnetic tapes), optical media (such as compact disk read-only memories (CD-ROMs), and Digital Video Disks (DVDs)), magneto-optical media (such as floppy disks), and semiconductor memory (such as ROMs, RAMs, and flash memories). The program instructions may include not only machine language code generated by a compiler but also high-level language code executable by a computer using an interpreter or the like. The hardware means may be replaced by software modules executable to perform the operations of the exemplary embodiments and vice versa.

Some aspects of the disclosure described above in the context of a device may indicate corresponding descriptions of methods according to the disclosure, and the blocks or devices may correspond to operations of the methods or features of the operations. Similarly, some aspects described in the context of the method may be expressed by features of a block, an item, or an apparatus corresponding thereto. For example, some or all of the operations of the method may be performed by (or using) a hardware device such as a microprocessor, a programmable computer, or electronic circuitry. In some exemplary embodiments, one or more of the most important operations of the method may be performed by such an apparatus.

In some example embodiments, a programmable logic device, such as a field-programmable gate array (field-programmable gate array), may be used to perform some or all of the functions of the methods described herein. In some example embodiments, a field-programmable gate array (field-programmable gate array) can be operated with a microprocessor to perform one of the methods described herein. In general, the method is preferably performed by some hardware device.

The present disclosure is not limited to the exemplary embodiments. Like reference numerals in the drawings may refer to like elements. The length, height, dimensions, widths, etc. introduced in the embodiments and figures may have been exaggerated to aid in the understanding of exemplary embodiments of the present disclosure.

The description of the disclosure may be merely exemplary in nature and, thus, variations that do not depart from the gist of the disclosure are intended to be within the scope of the disclosure. Such variations may not be regarded as a departure from the spirit and scope of the disclosure. Accordingly, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims.

Thus, the scope of the present disclosure should not be limited by the exemplary embodiments, but should be construed in accordance with the appended claims and their equivalents.

Claims (20)

1. A wireless power transmission pad prepared to wirelessly transmit power to a receiving pad including a secondary coil, the power transmission pad comprising:

a primary coil disposed around the central space;

a ferrite member configured to form a magnetic coupling with the primary coil; and

a housing configured to support the primary coil and the ferrite member,

wherein the primary coil includes a flat wire wound at least once.

2. The power transmission pad of claim 1, wherein corners of the primary coil are at least partially rounded.

3. The power transmission pad of claim 1, wherein corners of a cross section of the flat wire of the primary coil are at least partially rounded.

4. The power transmission pad of claim 1, wherein the primary coil has a planar structure in which a long axis of a cross section of the flat wire is perpendicular to a central axis of the primary coil.

5. The power transmission pad according to claim 1, wherein the primary coil has a vertical type structure in which a long axis of a cross section of the flat electric wire is parallel to a central axis of the primary coil.

6. The power transmission pad of claim 1, wherein the primary coil has a shape in which each of a plurality of flat wire elements is wound to surround the central space.

7. The power transmission pad of claim 6, wherein the plurality of flat wire elements are arranged in a concentric shape sharing a central axis of the primary coil.

8. The power transmission pad of claim 1, wherein the ferrite member is arranged such that: a first region on which the primary coil is projected on a virtual horizontal plane perpendicular to a central axis of the primary coil is included in a second region on which the ferrite member is projected on the virtual horizontal plane.

9. The power transmission pad of claim 8, wherein the ferrite member is formed to include a void corresponding to at least a portion of the central space of the primary coil.

10. A wireless power receiving pad prepared to wirelessly receive power from a transmitting pad including a primary coil, the power receiving pad comprising:

a secondary coil disposed around the central space;

a ferrite member configured to form a magnetic coupling with the secondary coil; and

a housing configured to support the secondary coil and the ferrite member,

wherein the secondary coil includes a flat wire wound at least once.

11. The power receiving pad of claim 10, wherein corners of the secondary coil are at least partially rounded.

12. The power receiving pad of claim 10, wherein corners of a cross section of the flat wire of the secondary coil are at least partially rounded.

13. The power receiving pad of claim 10, wherein the ferrite member is arranged such that: a first region on which the secondary coil is projected on a virtual horizontal plane perpendicular to a central axis of the secondary coil is included in a second region on which the ferrite member is projected on the virtual horizontal plane.

14. A wireless power transfer system prepared to wirelessly transmit power from a transmitting pad to a receiving pad, the wireless power transfer system comprising:

a transmitting pad including a primary coil; and

a receiving pad, comprising a secondary coil,

wherein the transmitting pad includes:

the primary coil is arranged around the central space;

a ferrite member configured to form a magnetic coupling with the primary coil; and

a housing configured to support the primary coil and the ferrite member,

wherein the primary coil includes a flat wire wound at least once.

15. The wireless power transfer system of claim 14, wherein corners of the primary coil are at least partially rounded.

16. The wireless power transfer system of claim 14, wherein corners of a cross section of the flat wire of the primary coil are at least partially rounded.

17. The wireless power transfer system of claim 14, wherein the primary coil has a planar structure in which a long axis of a cross section of the flat wire is perpendicular to a central axis of the primary coil.

18. The wireless power transfer system of claim 14, wherein the primary coil has a vertical-type structure in which a long axis of a cross section of the flat wire is parallel to a central axis of the primary coil.

19. The wireless power transfer system of claim 14, wherein the primary coil has a shape in which each of a plurality of flat wire elements is wound to surround the central space.

20. The wireless power transfer system of claim 14, wherein the ferrite member is arranged such that: a first region on which the primary coil is projected on a virtual horizontal plane perpendicular to a central axis of the primary coil is included in a second region on which the ferrite member is projected on the virtual horizontal plane.