Wireless power transmission device and wireless power transmission method thereof

Abstract

A wireless power transmission device according to an embodiment of the present application includes a control unit, a power conversion unit that converts power received from a power supply device, and a transmission coil unit to which a current output from the power conversion unit is applied. The transmission coil unit includes a first transmission coil, a second transmission coil, and a third transmission coil. The power conversion unit includes a power factor compensation circuit unit that outputs a DC voltage according to the power received from the power supply device, and an inverter unit that outputs the DC voltage received from the power factor compensation circuit unit as an AC voltage. The inverter unit outputs a first AC voltage, a second AC voltage, and a third AC voltage, wherein at least two of a magnitude of the first AC voltage, a magnitude of the second AC voltage, and a magnitude of the third AC voltage are different from each other, and a duty ratio of the first AC voltage, a duty ratio of the second AC voltage, and a duty ratio of the third AC voltage are the same as each other.

Description

Technical Field

[0001] This invention relates to a wireless power transmission device and a wireless power transmission method for electric vehicles. Background Technology

[0002] Wireless charging systems for electric vehicles include a power supply unit, a ground assembly (GA), and a vehicle assembly (VA). In the case of a static wireless power transmission method, the GA is installed on the ground in a parking lot, and the electric vehicle can be charged via the VA while parked. In the case of a dynamic wireless power transmission method, the GA is installed on the road, and the electric vehicle can be charged via the VA while in motion.

[0003] Power can be wirelessly transmitted from the GA to the VA through magnetic induction or magnetic resonance between the GA's transmitting coil and the VA's receiving coil.

[0004] To shorten charging time for electric vehicles via wireless charging, high-capacity wireless charging systems are required. However, when transmitting power in a high-capacity manner in a wireless charging system that includes a single transmitting coil and a single receiving coil, high electromagnetic waves may be generated due to leakage flux.

[0005] Meanwhile, in wireless charging systems used for electric vehicles, the efficiency of wireless charging can vary depending on the alignment between the transmitting coil of the GA and the receiving coil of the VA. When wireless charging is initiated without alignment between the transmitting coil of the GA and the receiving coil of the VA, overcurrent or overheating may occur in the transmitting coil. Summary of the Invention

[0006] [Technical Issues]

[0007] The technical objective of this invention is to provide a wireless power transmission device and a wireless power transmission method for use in a wireless charging system for electric vehicles.

[0008] Another technical objective of this invention is to provide a wireless power transmission device and method with limited leakage flux and electromagnetic wave generation in a wireless charging system for electric vehicles.

[0009] Another technical objective of this invention is to provide a wireless power transmission device and method that improves the power transmission efficiency between the transmitting coil and the receiving coil in a wireless charging system for electric vehicles.

[0010] [Technical Solutions]

[0011] A wireless power transmission device according to an embodiment of the present invention includes: a control unit; a power conversion unit configured to convert power received from a power supply device; and a transmission coil unit, wherein a current output from the power conversion unit is applied to the transmission coil unit, wherein the transmission coil unit includes a first transmission coil, a second transmission coil, and a third transmission coil, and the current output from the power conversion unit includes a first current applied to the first transmission coil, a second current applied to the second transmission coil, and a third current applied to the third transmission coil, wherein at least two of the amplitudes of the first current, the second current, and the third current are different from each other, or at least two of the phase difference between the first current and the second current, the phase difference between the second current and the third current, and the phase difference between the third current and the first current are different from each other, and at least one of the amplitude and phase of the first current, at least one of the amplitude and phase of the second current, and at least one of the amplitude and phase of the third current are controlled by the control unit.

[0012] The control unit can control the power conversion unit based on the alignment information between the transmission coil unit and the receiving coil unit included in the wireless power receiving device.

[0013] The power conversion unit may include: a power factor correction circuit unit that outputs a DC voltage based on power received from a power supply device; an inverter unit that outputs an AC voltage based on the DC voltage received from the power factor correction circuit unit; and an impedance matching unit disposed between the inverter unit and the transmission coil unit. The control unit may control at least one of the power factor correction circuit unit, the inverter unit, and the impedance matching unit based on alignment information.

[0014] The inverter unit can output a first voltage with phase offset, a second voltage with phase offset, and a third voltage with phase offset, and at least one of the amplitude and phase of the first current, at least one of the amplitude and phase of the second current, and at least one of the amplitude and phase of the third current can be controlled by the first voltage, the second voltage, and the third voltage.

[0015] At least two of the duty cycles of the first voltage, the second voltage, and the third voltage can be different from each other.

[0016] The inverter unit may include a first full-bridge inverter that outputs a first voltage, a second full-bridge inverter that outputs a second voltage, and a third full-bridge inverter that outputs a third voltage.

[0017] It may also include a sensor unit that detects alignment information between the transmitting coil unit and the receiving coil unit.

[0018] The sensor unit may include multiple position sensors disposed around the first transmission coil, the second transmission coil, and the third transmission coil.

[0019] The wireless power transmission method of the wireless power transmission device according to an embodiment of the present invention includes: a power conversion operation of converting power received from a power supply device, and a current application operation of applying the current output in the power conversion operation to a first transmission coil, a second transmission coil, and a third transmission coil, wherein the current output in the power conversion operation includes a first current applied to the first transmission coil, a second current applied to the second transmission coil, and a third current applied to the third transmission coil, and in the power conversion operation, at least two of the amplitudes of the first current, the second current, and the third current are controlled to be different from each other, or at least two of the phase difference between the first current and the second current, the phase difference between the second current and the third current, and the phase difference between the third current and the first current are controlled to be different from each other.

[0020] It may also include the operation of acquiring alignment information between the first, second, and third transmission coils and the first, second, and third receiving coils included in the wireless power receiving device, and may control at least one of the amplitude and phase of the first current, at least one of the amplitude and phase of the second current, and at least one of the amplitude and phase of the third current based on the alignment information.

[0021] In the power conversion operation, the first voltage, the second voltage, and the third voltage of phase shift can be generated based on the power received from the power supply device, and at least one of the amplitude and phase of the first current, at least one of the amplitude and phase of the second current, and at least one of the amplitude and phase of the third current can be controlled by the first voltage, the second voltage, and the third voltage.

[0022] According to another embodiment of the present invention, a wireless power transmission device includes: a control unit; a power conversion unit for converting power received from a power supply device; and a transmission coil unit, wherein current output from the power conversion unit is applied to the transmission coil unit, wherein the transmission coil unit includes a first transmission coil, a second transmission coil, and a third transmission coil, the power conversion unit includes: a power factor correction circuit unit that outputs a DC voltage based on the power received from the power supply device; and an inverter unit that outputs an AC voltage based on the DC voltage received from the power factor correction circuit unit, the inverter unit outputting a first AC voltage, a second AC voltage, and a third AC voltage, at least two of the amplitudes of the first AC voltage, the second AC voltage, and the third AC voltage being different from each other, and the duty cycles of the first AC voltage, the second AC voltage, and the third AC voltage being the same as each other.

[0023] The power factor correction circuit unit may include a first power factor correction circuit, a second power factor correction circuit, and a third power factor correction circuit. The inverter unit may include: a first inverter that receives a first DC voltage output from the first power factor correction circuit; a second inverter that receives a second DC voltage output from the second power factor correction circuit; and a third inverter that receives a third DC voltage output from the third power factor correction circuit. The first AC voltage may be output from the first inverter, the second AC voltage may be output from the second inverter, and the third AC voltage may be output from the third inverter.

[0024] The first power factor correction circuit, the second power factor correction circuit, and the third power factor correction circuit can be controlled by the control unit based on alignment information between the transmission coil unit and the receiving coil unit included in the wireless power receiving device.

[0025] The input to the first power factor correction circuit can be the first phase power received from the power supply device, the input to the second power factor correction circuit can be the second phase power received from the power supply device, and the input to the third power factor correction circuit can be the third phase power received from the power supply device. At least one of the first power factor correction circuit, the second power factor correction circuit, and the third power factor correction circuit can be connected to the neutral point.

[0026] The current output from the power conversion unit includes a first current applied to a first transmission coil, a second current applied to a second transmission coil, and a third current applied to a third transmission coil, and at least one of the amplitude and phase of the first current, at least one of the amplitude and phase of the second current, and at least one of the amplitude and phase of the third current can be controlled by a first AC voltage, a second AC voltage, and a third AC voltage.

[0027] At least two of the amplitudes of the first current, the second current, and the third current may be different from each other, or at least two of the phase differences between the first current and the second current, the phase differences between the second current and the third current, and the phase differences between the third current and the first current may be different from each other.

[0028] Each of the first inverter, the second inverter, and the third inverter can be a full-bridge inverter.

[0029] The power conversion unit may also include an impedance matching unit disposed between the inverter unit and the transmission coil unit.

[0030] According to another embodiment of the present invention, a wireless power transmission device includes: a control unit; a power conversion unit for converting power received from a power supply device; and a transmission coil unit, wherein current output from the power conversion unit is applied to the transmission coil unit, wherein the transmission coil unit includes a first transmission coil, a second transmission coil, and a third transmission coil; the power conversion unit includes: a power factor correction circuit unit that outputs a DC voltage based on the power received from the power supply device; and an inverter unit that outputs an AC voltage based on the DC voltage received from the power factor correction circuit unit; the power factor correction circuit unit includes a first power factor correction circuit that outputs a first DC voltage, a second power factor correction circuit that outputs a second DC voltage, and a third power factor correction circuit that outputs a third DC voltage; the inverter unit includes a first inverter that outputs a first AC voltage based on the first DC voltage, a second inverter that outputs a second AC voltage based on the second DC voltage, and a third inverter that outputs a third AC voltage based on the third DC voltage; and the first power factor correction circuit, the second power factor correction circuit, and the third power factor correction circuit are controlled by the control unit based on alignment information between the transmission coil unit and a receiving coil unit included in the wireless power receiving device.

[0031] A wireless power transmission method of a wireless power transmission device according to another embodiment of the present invention includes: a power conversion operation of converting power received from a power supply device; and a current application operation of applying the current output in the power conversion operation to a first transmission coil, a second transmission coil, and a third transmission coil, wherein the power conversion operation includes: an operation of outputting a first DC voltage, a second DC voltage, and a third DC voltage according to the power received from the power supply device; and an operation of outputting a first AC voltage, a second AC voltage, and a third AC voltage according to the first DC voltage, the second DC voltage, and the third DC voltage, and wherein, in the power conversion operation, at least two of the amplitudes of the first AC voltage, the second AC voltage, and the third AC voltage are controlled to be different from each other, and the duty cycles of the first AC voltage, the second AC voltage, and the third AC voltage are controlled to be the same as each other.

[0032] The first DC voltage, the second DC voltage, and the third DC voltage can be controlled based on alignment information between the first, second, and third transmission coils and the first, second, and third receiving coils in the wireless power receiving device.

[0033] A wireless power transmission method of a wireless power transmission device according to another embodiment of the present invention includes: a position detection operation for acquiring alignment information between a transmission coil unit of the wireless power transmission device and a receiving coil unit of a wireless power receiving device; and a power transmission operation for transmitting power from the transmission coil unit to the receiving coil unit based on the alignment information acquired in the position detection operation, wherein the transmission coil unit includes a first transmission coil, a second transmission coil, and a third transmission coil, the receiving coil unit includes a first receiving coil, a second receiving coil, and a third receiving coil, and in the position detection operation, a current for position detection is applied to the first transmission coil, a current for position detection is applied to the second transmission coil, a current for position detection is applied to the third transmission coil, and the current for position detection is applied sequentially to the first transmission coil, the second transmission coil, and the third transmission coil so as not to overlap with each other.

[0034] In power transmission operation, a first current can be applied to a first transmission coil, a second current can be applied to a second transmission coil, and a third current can be applied to a third transmission coil, and the first current, the second current, and the third current can be applied to the first transmission coil, the second transmission coil, and the third transmission coil simultaneously.

[0035] The amplitude of the current used for position detection can be smaller than the amplitudes of the first current, the second current, and the third current.

[0036] In the position detection operation, the amplitudes of the currents applied to the first, second, and third transmission coils for position detection can be the same, and in the power transmission operation, at least two of the amplitudes of the first, second, and third currents can be different from each other.

[0037] At least two of the phase differences between the first and second currents, the phase differences between the second and third currents, and the phase differences between the third and first currents can be different from each other.

[0038] At least one of the amplitude and phase of the first current, at least one of the amplitude and phase of the second current, and at least one of the amplitude and phase of the third current can be controlled based on alignment information obtained during the position detection operation.

[0039] A standby operation may also be included between the position detection operation and the power transmission operation.

[0040] A wireless charging method for a wireless charging system according to another embodiment of the present invention includes: a position detection operation for acquiring alignment information between a transmission coil unit of a wireless power transmission device and a receiving coil unit of a wireless power receiving device; and a power transmission operation for transmitting power from the transmission coil unit to the receiving coil unit based on the alignment information acquired in the position detection operation, wherein the transmission coil unit includes a first transmission coil, a second transmission coil, and a third transmission coil, the receiving coil unit includes a first receiving coil, a second receiving coil, and a third receiving coil, and the position detection operation includes: an operation for sequentially applying a current for position detection to the first transmission coil, the second transmission coil, and the third transmission coil so that they do not overlap; and an operation for detecting the voltage induced in the first receiving coil, the second receiving coil, and the third receiving coil by the current for position detection.

[0041] The position detection operation may further include: calculating the mutual inductance between the transmission coil unit and the receiving coil unit based on the voltage induced in the first to third receiving coils when the current for position detection is applied to the first transmission coil, the voltage induced in the first to third receiving coils when the current for position detection is applied to the second transmission coil, and the voltage induced in the first to third receiving coils when the current for position detection is applied to the third transmission coil; and detecting the relative position between the transmission coil unit and the receiving coil unit based on the mutual inductance.

[0042] The mutual inductance between the first to third transmitting coils and the first to third receiving coils can be calculated as 3. In the form of a 3-matrix.

[0043] In power transmission operation, a first current can be applied to a first transmission coil, a second current can be applied to a second transmission coil, and a third current can be applied to a third transmission coil, and the first current, the second current, and the third current can be applied to the first transmission coil, the second transmission coil, and the third transmission coil simultaneously.

[0044] The amplitude of the current used for position detection can be smaller than the amplitudes of the first current, the second current, and the third current.

[0045] Beneficial effects

[0046] According to embodiments of the present invention, leakage flux and electromagnetic wave generation in a wireless charging system for electric vehicles can be limited. Furthermore, according to embodiments of the present invention, the power transfer efficiency between the transmitting and receiving coils in a wireless charging system for electric vehicles can be improved. Furthermore, according to embodiments of the present invention, the relative position between the transmitting and receiving coils in a wireless charging system for electric vehicles can be effectively detected. Furthermore, according to embodiments of the present invention, a high-power wireless charging system of 22 kW or greater with limited leakage flux and high charging efficiency can be obtained. Furthermore, according to embodiments of the present invention, even when the transmitting and receiving coils in a wireless charging system for electric vehicles are not precisely aligned, high power transfer efficiency between the transmitting and receiving coils can be achieved without overheating on the transmitting coil side. Attached Figure Description

[0047] Figure 1 This is a block diagram of an electric vehicle and a wireless charging system according to an embodiment of the present invention.

[0048] Figure 2 This is a block diagram of a wireless charging system according to an embodiment of the present invention.

[0049] Figure 3 This is a block diagram of a power supply device included in a wireless charging system according to an embodiment of the present invention.

[0050] Figure 4 This is a schematic diagram of a wireless charging system according to an embodiment of the present invention.

[0051] Figure 5 This is a more detailed schematic diagram of a wireless charging system according to an embodiment of the present invention.

[0052] Figure 6 This is a flowchart of a wireless power transmission method for a wireless power transmission device included in a wireless charging system according to an embodiment of the present invention.

[0053] Figure 7 This is a circuit diagram of a wireless charging system according to an embodiment of the present invention.

[0054] Figure 8 It shows that according to Figure 7 The circuit diagram shows the waveform of the voltage output from the inverter unit.

[0055] Figure 9 It shows that according to Figure 7 The circuit diagram shows the waveform of the current applied to the transmission coil unit.

[0056] Figure 10 This is a circuit diagram of a wireless charging system according to another embodiment of the present invention.

[0057] Figure 11 It shows that according to Figure 10 The circuit diagram shows the waveform of the voltage output from the inverter unit.

[0058] Figure 12 It shows that according to Figure 10 The circuit diagram shows the waveform of the current applied to the transmission coil unit.

[0059] Figure 13 This is a circuit diagram of a wireless charging system according to another embodiment of the present invention.

[0060] Figure 14 It is based on Figure 13 The circuit diagram is a flowchart of a wireless power transmission method.

[0061] Figure 15 It shows that according to Figure 13 The circuit diagram shows the waveform of the voltage output from the inverter unit.

[0062] Figure 16 It shows that according to Figure 13 The circuit diagram shows the waveform of the current applied to the transmission coil unit.

[0063] Figure 17 It shows that according to Figure 13 The circuit diagram shows the waveforms of the voltage output from the inverter unit and the inverter current.

[0064] Figure 18 This is a flowchart of a wireless charging method for a wireless charging system according to an embodiment of the present invention.

[0065] Figure 19 An example of obtaining alignment information between a transmitting coil unit and a receiving coil unit according to an embodiment of the present invention is shown.

[0066] Figure 20 This is a flowchart of a wireless charging method for a wireless charging system according to another embodiment of the present invention.

[0067] Figure 21 shows an example of acquiring alignment information between a transmission coil unit and a receiving coil unit according to another embodiment of the present invention.

[0068] Figure 22 An example is shown of a state in which the transmitting coil unit and the receiving coil unit are misaligned in a wireless charging system according to an embodiment of the present invention.

[0069] Figure 23 It is a reference Figure 20 The implementation flowchart of the wireless charging method is shown in Figure 21.

[0070] Figure 24 It shows in Figure 23 The current applied to the transmission coil unit in each operation.

[0071] Figure 25 It shows in Figure 23 The voltage induced in the receiving coil unit during each operation.

[0072] Figure 26 The waveform of the current applied to the transmission coil unit during the position detection operation of the wireless charging method according to an embodiment of the present invention is shown.

[0073] Figure 27 This illustrates the situation where the transmitting coil unit and the receiving coil unit are aligned, when... Figure 26 The waveform of the voltage induced in the receiving coil unit when a current is applied to the transmitting coil unit.

[0074] Figure 28 This illustrates the situation where the transmitting coil unit and the receiving coil unit are misaligned. Figure 26 The waveform of the voltage induced in the receiving coil unit when a current is applied to the transmitting coil unit. Detailed Implementation

[0075] In the following, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0076] However, it should be understood that the technical spirit of the present invention is not limited to the embodiments disclosed below, but can be implemented in many different forms. It should be understood that, within the scope of the present invention, one or more elements in each embodiment can be selectively combined and substituted.

[0077] Furthermore, the terms (including technical and scientific terms) used in the embodiments of this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms, such as those defined in common dictionaries, should be interpreted as having the same meaning as they have in the context of the relevant art.

[0078] Furthermore, the terminology used in the embodiments of the present invention is provided only for describing the embodiments of the present invention and not for limiting purposes.

[0079] In this specification, unless the context clearly indicates otherwise, the singular form includes the plural form, and the phrase “at least one element (or one or more elements) of element A, element B and element C” should be understood to include at least one of all combinations obtained by combining element A, element B and element C.

[0080] Furthermore, when describing the elements of the present invention, terms such as first, second, A, B, (a) and (b) may be used.

[0081] This term is used to distinguish one element from another, but the nature, order, or sequence of elements is not limited by this term.

[0082] It will be understood that when a component is referred to as “connected” or “coupled” to another component, it can be directly connected or coupled to the other component, there can be an intermediate component, or it can be connected or coupled to the other component through other components.

[0083] Furthermore, when an element is described as being formed "above" or "below" another element, the terms "above" or "below" include both situations where the two elements are in direct contact with each other or where one or more elements are (indirectly) disposed between the two elements. Additionally, the terms "above" or "below" also include situations where the other element is disposed relative to one element in an upward or downward direction.

[0084] In the following description, embodiments will be described in detail with reference to the accompanying drawings. Regardless of the reference numerals, the same or corresponding parts are indicated by the same reference numerals and therefore will not be described again.

[0085] Figure 1 This is a block diagram of an electric vehicle (EV) and a wireless charging system according to an embodiment of the present invention. Figure 2 This is a block diagram of a wireless charging system according to an embodiment of the present invention. Figure 3 This is a block diagram of a power supply device included in a wireless charging system according to an embodiment of the present invention. Figure 4 This is a schematic diagram of a wireless charging system according to an embodiment of the present invention. Figure 5 A more detailed schematic diagram of a wireless charging system according to an embodiment of the present invention, and Figure 6 This is a flowchart of a wireless power transmission method for a wireless power transmission device included in a wireless charging system according to an embodiment of the present invention.

[0086] Reference Figure 1 The EV 10 can be charged by the wireless charging system 20. In this specification, EV 10 refers to a vehicle propelled by an electric motor that draws current from a rechargeable battery or other portable energy storage device.

[0087] According to an embodiment of the present invention, EV 10 can be a vehicle that can be charged using a wireless charging method without the use of physical plugs and sockets.

[0088] Reference Figures 2 to 5The wireless charging system 20 includes a wireless power transmission device 100, a wireless power receiving device 200, and a power supply device 300.

[0089] The wireless power transmission device 100 includes a control unit 110, a power conversion unit 120, and a transmission coil unit 130, while the wireless power receiving device 200 includes a control unit 210, a power conversion unit 220, and a receiving coil unit 230.

[0090] The transmission coil unit 130 of the wireless power transmission device 100 can be disposed on the ground or road of the parking lot, or at least a portion thereof can be embedded in the ground or road of the parking lot, and the receiving coil unit 230 of the wireless power receiving device 200 can be mounted on the EV 10. The receiving coil unit 230 can be mounted on the lower part of the EV 10 and aligned to face the transmission coil unit 130 embedded in the ground or road of the parking lot, and the current applied to the transmission coil unit 130 can induce a voltage in the receiving coil unit 230. Therefore, the transmission coil unit 130 or at least some components of the wireless power transmission device 100 including the transmission coil unit 130 can be referred to as the ground assembly (GA). The receiving coil unit 230 or at least some components of the wireless power receiving device 200 including the receiving coil unit 230 can be referred to as the vehicle assembly (VA).

[0091] In the case of the static wireless power transmission method, the transmission coil unit 130 can be installed on the ground of the parking lot, and the transmission coil unit 130 can be aligned with the receiving coil unit 230 installed on the EV 10 when parked.

[0092] The power supply device 300 controls the wireless power transmission device 100 and / or the wireless power receiving device 200, and supplies power to the wireless power transmission device 100. For this purpose, the power supply device 300 can communicate with the wireless power transmission device 100 and / or the wireless power receiving device 200, and transmit control signals to each of the wireless power transmission device 100 and the wireless power receiving device 200. The power supply device 300 may be an EV power supply equipment (EVSE) or part of an EVSE, or may be used as a power grid, power source, system, etc.

[0093] The power supply unit 300 includes a control unit 310, a communication unit 320, and a power supply unit 330. The control unit 310 can control at least one of the control unit 110, power conversion unit 120, and transmission coil unit 130 of the wireless power transmission device 100. Alternatively, at least some components of the control unit 310 of the power supply unit 300 and the control unit 110 of the wireless power transmission device 100 can be integrated. The communication unit 320 communicates with the EV 10 or an EV communication controller (EVCC) installed on the EV 10, and also communicates with the wireless power transmission device 100. The power supply unit 330 supplies power to a wireless power receiving device 200 installed on the EV 10 via the wireless power transmission device 100. The control unit 310 and communication unit 320 of the power supply unit 300 can be a power supply device communication controller (SECC). Alternatively, a portion of the control unit 110 of the wireless power transmission device 100 and the control unit 310 and communication unit 320 of the power supply unit 300 can be an SECC. The power supply device 300 may be referred to as a wireless charging device or EVSE, and the control unit 310 and communication unit 320 of the power supply device 300 may be referred to as a wireless charging control device.

[0094] Although not shown, each of the wireless power transmission device 100 and the wireless power receiving device 200 may also include a communication unit.

[0095] When the receiving coil unit 230 is aligned with the transmitting coil unit 130, signal exchange can be performed to establish a connection between the communication unit of the wireless power transmission device 100 and the communication unit of the wireless power receiving device 200. For example, the communication unit of the wireless power transmission device 100 can periodically transmit ping signals, and the connection establishment between the communication unit of the wireless power receiving device 200 receiving the ping signals and the communication unit of the wireless power transmission device 100 can be performed through signal exchange.

[0096] The communication units of the wireless power transmission device 100 and the wireless power receiving device 200 can communicate with the power supply device 300. For example, the communication unit of the wireless power transmission device 100 can transmit information about its connection with the wireless power receiving device 200 to the power supply device 300, and the power supply device 300 can transmit control signals for wireless power transmission to the communication unit of the wireless power transmission device 100. The communication unit of the wireless power transmission device 100 can operate the control unit 110 based on the control signals received from the power supply device 300, and can control the transmission coil unit 130 according to the operation of the control unit 110. The communication unit of the wireless power transmission device 100 can be integrated with the control unit 110 of the wireless power transmission device 100, or integrated with the communication unit 320 of the power supply device 300.

[0097] Furthermore, the communication unit of the wireless power receiver 200 can transmit vehicle information to the power supply unit 300, and the power supply unit 300 can transmit control signals for wireless power reception to the communication unit of the wireless power receiver 200. The communication unit of the wireless power receiver 110 can operate the control unit 210 based on the control signals received from the power supply unit 300, and can control the receiving coil unit 230 according to the operation of the control unit 210. At least some components of the communication unit of the wireless power receiver 200 and the control unit 210 can be some components of the EVCC installed on the EV 10.

[0098] In wireless charging technology for EVs, high-power wireless charging systems are needed to reduce charging time, and efforts are being made to address the impact of electromagnetic waves generated in the surrounding environment on the human body during high-power transmission. When the GA and VA each have a single transmitting coil and a single receiving coil, leakage flux can increase significantly during high-power transmission.

[0099] According to an embodiment of the present invention, in order to limit leakage flux during high-power transmission, GA and VA each include a three-phase transmission coil and a three-phase receiving coil. That is, the transmission coil unit 130 of the wireless power transmission device 100 according to an embodiment of the present invention includes a first transmission coil 131, a second transmission coil 132, and a third transmission coil 133, and the receiving coil unit 230 of the wireless power receiving device 200 includes a first receiving coil 231, a second receiving coil 232, and a third receiving coil 233. Therefore, there is magnetic asymmetry between the transmission coil unit 130 and the receiving coil unit 230, and the wireless charging efficiency can vary depending on the relative position between the transmission coil unit 130 and the receiving coil unit 230. High wireless charging efficiency is achieved when the first transmission coil 131, second transmission coil 132, and third transmission coil 133 of the transmission coil unit 130 are precisely aligned with the first receiving coil 231, second receiving coil 232, and third receiving coil 233 of the receiving coil unit 230. However, when these coils are not precisely aligned, overcurrent may flow on one side of the transmission coil unit 130, or one side of the transmission coil unit 130 may overheat, potentially reducing wireless charging efficiency. To precisely align the first transmission coil 131, second transmission coil 132, and third transmission coil 133 of the transmission coil unit 130 with the first receiving coil 231, second receiving coil 232, and third receiving coil 233 of the receiving coil unit 230, either the transmission coil unit 130 side or the receiving coil unit 230 side should be moved; however, precise movement may be difficult.

[0100] According to an embodiment of the invention, the current applied to the transmission coil unit 130 is controlled based on the alignment information between the transmission coil unit 130 and the receiving coil unit 230, and therefore, even when the transmission coil unit 130 and the receiving coil unit 230 are not precisely aligned, it is desirable that the voltage induced in the receiving coil unit 230 is maximized.

[0101] More specifically, refer to Figures 4 to 6The wireless power transmission device 100 includes a control unit 110, a power conversion unit 120, and a transmission coil unit 130, while the wireless power receiving device 200 includes a control unit 210, a power conversion unit 220, and a receiving coil unit 230. As described above, the transmission coil unit 130 includes a first transmission coil 131, a second transmission coil 132, and a third transmission coil 133. The receiving coil unit 230 includes a first receiving coil 231, a second receiving coil 232, and a third receiving coil 233. The control unit 110 controls the wireless power transmission device 100, and the control unit 210 controls the wireless power receiving device 200.

[0102] Wireless power transmission device 100 receives power from power supply device 300. Power supply device 300 supplies power in three phases. Power conversion unit 120 of wireless power transmission device 100 converts the power received from power supply device 300, and the current output from power conversion unit 120 is applied to transmission coil unit 130. Control unit 110 can control the current applied to transmission coil unit 130 via power conversion unit 120. The current applied to transmission coil unit 130 enables the generation of an induced voltage in receiving coil unit 230 of wireless power receiving device 200, and power conversion unit 220 converts the induced voltage received from receiving coil unit 230 and transmits the converted voltage to battery. Control unit 210 can control power conversion unit 220 to meet battery output specifications.

[0103] More specifically, the power conversion unit 120 of the wireless power transmission device 100 includes a power factor correction (PFC) circuit unit 121, an inverter unit 122, and an impedance matching unit 123. The PFC circuit unit 121 performs AC / DC conversion and outputs a DC voltage based on the power received from the power supply device 300. Here, the DC voltage may be referred to as the DC link voltage. The inverter unit 122 performs DC / AC conversion and outputs an AC voltage based on the DC voltage received from the PFC circuit unit 121. The inverter unit 122 may be referred to as a high-frequency (HF) inverter unit. The impedance matching unit 123 is configured to connect the inverter unit 122 and the transmission coil unit 130 to perform impedance matching. The impedance matching unit 123 includes variable passive components or fixed passive components and may be referred to as an impedance matching network (IMN).

[0104] The power conversion unit 220 of the wireless power receiving device 200 includes an impedance matching unit 221 and a rectifier 222. The impedance matching unit 221 is disposed between the receiving coil unit 230 and the rectifier 222 to perform impedance matching. The impedance matching unit 221 includes variable passive components or fixed passive components and may be referred to as an IMN. The rectifier 222 converts AC voltage or AC current into DC voltage or DC current to charge the battery.

[0105] According to an embodiment of the present invention, the wireless power transmission device 100 converts the power received from the power supply device 300 based on the alignment information between the transmission coil unit 130 and the receiving coil unit 230, and applies current to the transmission coil unit 130.

[0106] In other words, the wireless power transmission device 100 acquires alignment information between the first transmission coil 131, the second transmission coil 132, and the third transmission coil 133 included in the transmission coil unit 130 and the first receiving coil 231, the second receiving coil 232, and the third receiving coil 233 included in the receiving coil unit 230 of the wireless power receiving device 200 (S600). For this purpose, the wireless power transmission device 100 may further include an alignment information acquisition unit 140. Here, the alignment information may be information about the relative positions of the first transmission coil 131, the second transmission coil 132, and the third transmission coil 133 with the first receiving coil 231, the second receiving coil 232, and the third receiving coil 233. For example, the alignment information between the first transmission coil 131, the second transmission coil 132, and the third transmission coil 133 and the first receiving coil 231, the second receiving coil 232, and the third receiving coil 233 can vary according to a distance R and an angle θ. Here, R may represent the distance between the center of the transmission coil unit and the center of the receiving coil unit, and θ may represent the angle of offset between the center of the transmission coil unit and the center of the receiving coil unit. Here, the distance between the center of the transmitting coil unit 130 and the center of the receiving coil unit 230 can be the distance between the centers of the transmitting coil unit 130 and the receiving coil unit 230 in the planar direction. This planar distance can be either the distance in the plane in which the transmitting coil unit 130 is positioned, or the distance in the plane in which the receiving coil unit 230 is positioned. That is, when the centers of the transmitting coil unit 130 and the receiving coil unit 230 overlap in the vertical direction, the distance between them can be expressed as 0. Here, the vertical direction is the direction perpendicular to the planar direction, and can be the direction from the transmitting coil unit 130 toward the receiving coil unit 230. Furthermore, the angle θ can be the angle formed by the transmitting coil unit 130 and the receiving coil unit 230 in the planar direction. The specific method for acquiring alignment information for the wireless power transmission device 100 will be described below.

[0107] Next, the power conversion unit 120 of the wireless power transmission device 100 converts the power received from the power supply device 300 based on the alignment information acquired in operation S600 (S610), and applies the current output from the power conversion unit 120 to the transmission coil units 113, namely, the first transmission coil 131, the second transmission coil 132, and the third transmission coil 133 (S620). For this purpose, the control unit 110 controls the power conversion unit 120 based on the alignment information acquired in operation S600, and the power conversion unit 120 outputs the current to be applied to the transmission coil units 130 under the control of the control unit 110.

[0108] The current output by the power conversion unit 120 includes a first current I applied to the first transmission coil 131. a The second current I applied to the second transmission coil 132 b and the third current I applied to the third transmission coil 133 c First current I a Second current I b and the third current I c These are AC currents with their own amplitude and phase.

[0109] According to an embodiment of the present invention, the first current I a At least one of the amplitude and phase, the second current I b At least one of the amplitude and phase, and the third current I c At least one of the amplitude and phase is controlled by the control unit 110 based on alignment information between the transmitting coil unit 130 and the receiving coil unit 230. In this case, the first current I... a amplitude, second current I b The amplitude and the third current I c At least two of the amplitudes can be different from each other, or the first current I a With the second current I b The phase difference between them, the second current I b With the third current I c The phase difference between them and the third current I c With the first current I a At least two of the phase differences between them can be different from each other. In this specification, when the first current I... a amplitude, second current I b The amplitude and the third current I c When at least two of the amplitudes are different from each other, or when the first current I a With the second current I b The phase difference between them, the second current I b With the third current I c The phase difference between them and the third current I c With the first current I a When at least two of the phase differences between them are different from each other, the first current I a Second current I b and the third current I c This can be represented as asymmetrical. For example, the first current I... a amplitude, second current I b The amplitude and the third current I c The amplitudes can all be different from each other, or the first current I a amplitude, second current Ib The amplitude and the third current I c One of the amplitudes can be different from the other two. For example, the first current I a With the second current I b The phase difference between them, the second current I b With the third current I c The phase difference between them and the third current I c With the first current I a The phase difference between them can be different from each other, or the first current I a With the second current I b The phase difference between them, the second current I b With the third current I c The phase difference between them and the third current I c With the first current I a One of the phase differences between them can be different from the other two. For example, the first current I a With the second current I b The phase difference between them, the second current I b With the third current I c The phase difference between them and the third current I c With the first current I a At least one of the phase differences between them may not be 120°.

[0110] In this manner, according to an embodiment of the present invention, the first to third currents I applied to the first to third transmission coils 131, 132, and 133 of the transmission coil unit 130 are controlled based on the alignment information between the transmission coil unit 130 and the receiving coil unit 230. a I b and I c For example, when the transmission coil unit 130 and the receiving coil unit 230 are precisely aligned, the first to third currents I applied to the first to third transmission coils 131, 132, and 133 of the transmission coil unit 130 are... a I b and I c They can be symmetrical to each other. That is, when the transmission coil unit 130 and the receiving coil unit 230 are in a precisely aligned state, the first to third currents I applied to the first to third transmission coils 131, 132 and 133 of the transmission coil unit 130 are... a I b and I cThey can all have the same amplitude and a phase difference of 120°. In contrast, when the transmission coil unit 130 and the receiving coil unit 230 are not precisely aligned, an intentional asymmetry is imparted to the first to third currents I applied to the first to third transmission coils 131, 132, and 133 of the transmission coil unit 130. a I b and I c According to an embodiment of the present invention, asymmetry can be imparted to the first to third currents I. a I b and I c This minimizes the losses between the transmitting coil unit 130 and the receiving coil unit 230. For example, the first to third currents I a I b and I c It can be controlled to a value that minimizes the following loss metrics.

[0111]

[0112] Here, I a,bal I b,bal and I c,bal This represents the current applied to the transmission coil unit 130 under ideal alignment conditions, and I a,opt I b,opt and I c,opt This indicates the current applied to the transmission coil unit 130, controlled by the control unit 110 based on the alignment information.

[0113] Therefore, even when wireless charging is performed with the transmission coil unit 130 and the receiving coil unit 230 not precisely aligned, the power transmission efficiency between the transmission coil unit 130 and the receiving coil unit 230 can be maximized.

[0114] According to an embodiment of the present invention, in order to supply the first to third currents I a I b and I c By incorporating intentional asymmetry, control unit 110 can control PFC circuit unit 121, inverter unit 122, or impedance matching unit 123.

[0115] Figure 7 This is a circuit diagram of a wireless charging system according to an embodiment of the present invention. Figure 8 It shows that according to Figure 7 The circuit diagram shows the waveform of the voltage output from the inverter unit, and Figure 9 It shows that according to Figure 7 The circuit diagram shows the waveform of the current applied to the transmission coil unit.

[0116] Reference Figure 7 The wireless power transmission device 100 includes a control unit 110, a power conversion unit 120, and a transmission coil unit 130. The power conversion unit 120 includes a PFC circuit unit 121, an inverter unit 122, and an impedance matching unit 123. (This will not be repeated in the reference.) Figures 1 to 6 Descriptions of content that are identical to the descriptions provided.

[0117] According to an embodiment of the present invention, the inverter unit 122 includes a first inverter 122a, a second inverter 122b, and a third inverter 122c, and the control unit 110 controls the first inverter 122a, the second inverter 122b, and the third inverter 122c to impart an intentional asymmetry to the first to third currents I. a I b and I c As shown, each of the first inverter 122a, the second inverter 122b, and the third inverter 122c includes a full-bridge inverter, but the invention is not limited thereto, and inverter unit 122 may include a half-bridge inverter.

[0118] First inverter 122a, second inverter 122b, and third inverter 122c are connected to a single PFC circuit unit 121. The PFC circuit unit 121 is a single three-phase PFC circuit and outputs a common DC voltage. The first inverter 122a, second inverter 122b, and third inverter 122c, receiving the common DC voltage output from the PFC circuit unit 121, can output a first AC voltage V. a Second AC voltage V b and the third AC voltage V c The first AC voltage V output by the first inverter 122a, the second inverter 122b, and the third inverter 122c a Second AC voltage V b and the third AC voltage V c It has a waveform controlled by control unit 110 to impart intentional asymmetry to the first to third currents I based on alignment information between the transmission coil unit 130 and the receiving coil unit 230. a I b and I c Since the common DC voltage is input to the first inverter 122a, the second inverter 122b, and the third inverter 122c, the first AC voltage V... a Second AC voltage V b and the third AC voltage V c Although their amplitudes are the same, their duty cycles can be different through phase shift control. For example... Figure 8 As shown, the first AC voltage V a Second AC voltage Vb and the third AC voltage V c The duty cycles can all be different, or the first AC voltage V a Second AC voltage V b and the third AC voltage V c The duty cycle of one of them can be different from the duty cycles of the other two. In this way, when an intentional asymmetry is applied to the first AC voltage V output from inverter unit 122... a Second AC voltage V b and the third AC voltage V c At that time, the first to third currents I applied to the transmission coil unit 130 a I b and I c It can also be generated asymmetrically. That is, such as Figure 9 As shown, the first current I a amplitude, second current I b The amplitude and the third current I c At least two of the amplitudes can be different from each other, or the first current I a With the second current I b The phase difference between them, the second current I b With the third current I c The phase difference between them and the third current I c With the first current I a At least two of the phase differences between them can be different from each other. For example, the first current I a amplitude, second current I b The amplitude and the third current I c The amplitudes can all be different from each other, or the first current I a amplitude, second current I b The amplitude and the third current I c One of the amplitudes can be different from the other two. For example, the first current I a With the second current I b The phase difference between them, the second current I b With the third current I c The phase difference between them and the third current I c With the first current I a The phase difference between them can be different from each other, or the first current I a With the second current I b The phase difference between them, the second current I b With the third current I c The phase difference between them and the third current I c With the first current I a One of the phase differences between the two can be different from the other two.

[0119] In this way, when a current with optimized amplitude and phase is applied to each of the first to third transmission coil units 131, 132 and 133 of the transmission coil unit 130 based on the alignment information between the transmission coil unit 130 and the receiving coil unit 230, even when wireless charging is performed in a state where the transmission coil unit 130 and the receiving coil unit 230 are not precisely aligned, the loss between the transmission coil unit 130 and the receiving coil unit 230 can be minimized, thereby maximizing the power transmission efficiency.

[0120] Figure 10 This is a circuit diagram of a wireless charging system according to another embodiment of the present invention. Figure 11 It shows that according to Figure 10 The circuit diagram shows the waveform of the voltage output from the inverter unit, and Figure 12 It shows that according to Figure 10 The circuit diagram shows the waveform of the current applied to the transmission coil unit.

[0121] Reference Figure 10 The wireless power transmission device 100 includes a control unit 110, a power conversion unit 120, and a transmission coil unit 130. The power conversion unit 120 includes a PFC circuit unit 121, an inverter unit 122, and an impedance matching unit 123. (This will not be repeated in the reference.) Figures 1 to 6 Descriptions of content that are identical to the descriptions provided.

[0122] According to an embodiment of the present invention, the inverter unit 122 includes a first inverter 122a, a second inverter 122b, and a third inverter 122c, and the control unit 110 controls the impedance matching unit 123 to impart an intentional asymmetry to the first to third currents I. a I b and I c As shown, each of the first inverter 122a, the second inverter 122b, and the third inverter 122c includes, but is not limited to, a full-bridge inverter and may include a half-bridge inverter.

[0123] First inverter 122a, second inverter 122b, and third inverter 122c are connected to a single PFC circuit unit 121. PFC circuit unit 121 is a single three-phase PFC circuit and outputs a common DC voltage. First inverter 122a, second inverter 122b, and third inverter 122c can output a first AC voltage V. a Second AC voltage V b and the third AC voltage V c .like Figure 11As shown, the first AC voltage V output by the first inverter 122a, the second inverter 122b, and the third inverter 122c is... a Second AC voltage V b and the third AC voltage V c They all have the same amplitude and are output as waveforms with a 120-degree phase difference. (And...) Figures 7 to 9 The implementation methods shown are different, the first AC voltage V a Second AC voltage V b and the third AC voltage V c The duty cycles are all the same. However, according to Figures 10 to 12 In the illustrated embodiment, due to the variable capacitor included in the impedance matching unit 123, the first to third currents I applied to the transmission coil unit 130 can be asymmetrically generated. a I b and I c In other words, such as Figure 12 As shown, the first current I a amplitude, second current I b The amplitude and the third current I c At least two of the amplitudes can be different from each other, or the first current I a With the second current I b The phase difference between them, the second current I b With the third current I c The phase difference between them and the third current I c With the first current I a At least two of the phase differences between them can be different from each other. For example, the first current I a amplitude, second current I b The amplitude and the third current I c The amplitudes can all be different from each other, or the first current I a amplitude, second current I b The amplitude and the third current I c One of the amplitudes can be different from the other two. For example, the first current I a With the second current I b The phase difference between them, the second current I b With the third current I c The phase difference between them and the third current I c With the first current I a The phase difference between them can be different from each other, or the first current I a With the second current I b The phase difference between them, the second current I b With the third current I c The phase difference between them and the third current I cWith the first current I a One of the phase differences between the two can be different from the other two.

[0124] Figure 13 This is a circuit diagram of a wireless charging system according to another embodiment of the present invention. Figure 14 It is based on Figure 13 The circuit diagram is a flowchart of a wireless power transmission method. Figure 15 It shows that according to Figure 13 The circuit diagram shows the waveform of the voltage output from the inverter unit. Figure 16 It shows that according to Figure 13 The circuit diagram shows the waveform of the current applied to the transmission coil unit, and Figure 17 It shows that according to Figure 13 The circuit diagram shows the waveforms of the voltage output from the inverter unit and the inverter current.

[0125] Reference Figure 13 and Figure 14 The wireless power transmission device 100 includes a control unit 110, a power conversion unit 120, and a transmission coil unit 130. The power conversion unit 120 includes a PFC circuit unit 121, an inverter unit 122, and an impedance matching unit 123. (This will not be repeated in the reference.) Figures 1 to 6 Descriptions of content that are identical to the descriptions provided.

[0126] More specifically, refer to Figure 13 and Figure 14 The power conversion unit 120 of the wireless power transmission device 100 converts the power received from the power supply device 300 (S1400) and applies the current output in operation S1400 to the first transmission coil 131, the second transmission coil 132 and the third transmission coil 133 (S1410).

[0127] In operation S1400, the PFC circuit unit 121 outputs a first DC voltage, a second DC voltage, and a third DC voltage from the power supply device 300 (S1402), and the inverter unit 122 outputs a first AC voltage, a second AC voltage, and a third AC voltage based on the first DC voltage, the second DC voltage, and the third DC voltage output by the PFC circuit unit 121 (S1404).

[0128] Therefore, the PFC circuit unit 121 includes a first PFC circuit 121a, a second PFC circuit 121b, and a third PFC circuit 121c, and the inverter unit 122 includes a first inverter 122a, a second inverter 122b, and a third inverter 122c. The control unit 110 controls the first PFC circuit 121a, the second PFC circuit 121b, and the third PFC circuit 121c based on the alignment information between the transmission coil unit 130 and the receiving coil unit 230. Therefore, the first to third currents I applied to the first to third transmission coils 131, 132, and 133 are... a I b and I c It can be asymmetrically controlled to have the optimal combination that minimizes the loss index.

[0129] Therefore, the first PFC circuit 121a, the second PFC circuit 121b, and the third PFC circuit 121c can output independent DC voltages based on the alignment information between the transmission coil unit 130 and the receiving coil unit 230, so that the first to third currents I applied to the first to third transmission coils 131, 132, and 133 are... a I b and I c It has minimal loss characteristics. That is, the first PFC circuit 121a outputs a first DC voltage, and the first inverter 122a, which receives the first DC voltage, can output a first AC voltage V. a The second PFC circuit 121b outputs a second DC voltage, and the second inverter 122b, which receives the second DC voltage, can output a second AC voltage V. b The third PFC circuit 121c outputs a third DC voltage, and the third inverter 122c, which receives the third DC voltage, can output a third AC voltage V. cHere, at least two of the first DC voltage, second DC voltage, and third DC voltage can be different from each other. Each of the first PFC circuit 121a, second PFC circuit 121b, and third PFC circuit 121c is a single-phase PFC circuit and receives each phase of the three-phase power supply and the neutral point n as input. That is, the input to the first PFC circuit 121a can be the first phase power received from the power supply device 300, the input to the second PFC circuit 121b can be the second phase power received from the power supply device 300, and the input to the third PFC circuit 121c can be the third phase power received from the power supply device 300. At least one of the first PFC circuit 121a, second PFC circuit 121b, and third PFC circuit 121c can be connected to the neutral point n. Therefore, the first to third DC voltages can be controlled independently. As in the embodiment of the present invention, when each of the first PFC circuit 121a, the second PFC circuit 121b, and the third PFC circuit 121c is a single-phase PFC circuit and receives each phase of the three-phase power supply and the neutral point n as input, each phase of the three-phase power supply can be controlled independently, and since an induced voltage is easily generated in the receiving coil unit even when the current applied to the transmission coil unit is small, the size of the transmission coil unit can be reduced.

[0130] Meanwhile, each of the first inverter 122a, the second inverter 122b, and the third inverter 122c may have a fixed duty cycle and includes a full-bridge inverter. The first inverter 122a, the second inverter 122b, and the third inverter 122c may use independently controlled first to third DC voltages to output asymmetrical first to third AC voltages.

[0131] According to an embodiment of the present invention, the control unit 110 controls the first PFC circuit 121a, the second PFC circuit 121b, and the third PFC circuit 121c based on the alignment information between the transmission coil unit 130 and the receiving coil unit 230. The first to third DC voltages output from the first PFC circuit 121a, the second PFC circuit 121b, and the third PFC circuit 121c are input to the first inverter 122a, the second inverter 122b, and the third inverter 122c, and the output is a first AC voltage V. a Second AC voltage V b and the third AC voltage V c .

[0132] Since the independently controlled first to third DC voltages are input to the first inverter 122a, the second inverter 122b, and the third inverter 122c, as... Figure 15 As shown, the first AC voltage V a Second AC voltage V b and the third AC voltage V c The amplitudes can all be different, or the first AC voltage V a Second AC voltage V b and the third AC voltage V c The amplitude of one of them can differ from the amplitudes of the other two. However, since the duty cycles of the first inverter 122a, the second inverter 122b, and the third inverter 122c are fixed, the first AC voltage V a Second AC voltage V b and the third AC voltage V c The duty cycles can all be the same.

[0133] The first current I applied to the first transmission coil 131 a At least one of the amplitude and phase of the second current I applied to the second transmission coil 132 b At least one of the amplitude and phase, and the third current I applied to the third transmission coil 133 c At least one of the amplitude and phase can be determined by the first AC voltage V. a Second AC voltage V b and the third AC voltage V c Control, and therefore, the first to third currents I can also be generated asymmetrically. a I b and I c In other words, such as Figure 16 As shown, the first current I a amplitude, second current I b The amplitude and the third current I c At least two of the amplitudes can be different from each other, or the first current I a With the second current I b The phase difference between them, the second current I b With the third current I c The phase difference between them and the third current I c With the first current I a At least two of the phase differences between them can be different from each other. For example, the first current I a amplitude, second current I b The amplitude and the third current I c The amplitudes can all be different from each other, or the first current I a amplitude, second current I bThe amplitude and the third current I c One of the amplitudes can be different from the other two. For example, the first current I a With the second current I b The phase difference between them, the second current I b With the third current I c The phase difference between them and the third current I c With the first current I a The phase difference between them can be different from each other, or the first current I a With the second current I b The phase difference between them, the second current I b With the third current I c The phase difference between them and the third current I c With the first current I a One of the phase differences between the two can be different from the other two.

[0134] At the same time, refer to Figure 17 It can be seen that when the first to third PFC circuits 121a, 121b and 121c are in Figure 13 When the first to third DC voltages are independently controlled in the circuit diagram, the first to third inverters 122a, 122b, and 122c can output the first to third AC voltages V through soft switching. a V b and V c .

[0135] According to an embodiment of the present invention, the current applied to the transmission coil unit 130 of the wireless power transmission device 100 is controlled based on the alignment information between the transmission coil unit 130 of the wireless power transmission device 100 and the receiving coil unit 230 of the wireless power receiving device 200, and thus the power transmission efficiency between the transmission coil unit 130 and the receiving coil unit 230 can be improved.

[0136] Figure 18 This is a flowchart of a wireless charging method for a wireless charging system according to an embodiment of the present invention, and... Figure 19 An example of obtaining alignment information between a transmitting coil unit and a receiving coil unit according to an embodiment of the present invention is shown.

[0137] Reference Figure 18The wireless charging system 20 uses sensors to acquire alignment information between the transmission coil unit 130 of the wireless power transmission device 100 and the receiving coil unit 230 of the wireless power receiving device 200 (S1800), and transmits power to the receiving coil unit 230 through the transmission coil unit 130 based on the alignment information acquired in operation S1800 (S1810). In operation S1810, the power conversion unit 120 of the wireless power transmission device 100 converts the power received from the power supply device 300, and an asymmetrical current is applied to the first to third transmission coils 131, 132, and 133 included in the transmission coil unit 130. For a detailed description, please refer to Reference Figures 1 to 17 The content described.

[0138] Reference Figure 19 The alignment information acquisition unit 140 included in the wireless power transmission device 100 may include sensors, and the alignment information between the transmission coil unit 130 and the receiving coil unit 230 can be acquired by the sensors included in the wireless power transmission device 100. For example, the sensors may include a plurality of position sensors PS1, PS2, PS3, and PS4 arranged spaced apart from each other between the first to third transmission coils 131, 132, and 133. The plurality of position sensors PS1, PS2, PS3, and PS4 may be ultrasonic sensors. Figure 19 (a) shows an example of multiple position sensors PS1, PS2, PS3, and PS4 arranged on the sides of the first to third transmission coils 131, 132, and 133 transmitting signals to the sides of the first to third receiving coils 231, 232, and 233, with the first to third transmission coils 131, 132, and 133 aligned with the first to third receiving coils 231, 232, and 233. Figure 19 (b) illustrates an example of multiple position sensors PS1, PS2, PS3, and PS4 arranged on the sides of the first to third transmission coils 131, 132, and 133 transmitting signals to the sides of the first to third receiving coils 231, 232, and 233 when the first to third transmission coils 131, 132, and 133 are misaligned. The alignment information acquisition unit 140 can acquire alignment information between the transmission coil unit 130 and the receiving coil unit 230 based on the signals received by the multiple position sensors PS1, PS2, PS3, and PS4 in the aligned state. Here, the alignment information between the transmission coil unit 130 and the receiving coil unit 230 can be information about the relative positions between the transmission coil unit 130 and the receiving coil unit 230, and can be the degree of deviation from a precisely aligned state.

[0139] Figure 20Figure 21 is a flowchart of a wireless charging method for a wireless charging system according to another embodiment of the present invention, and Figure 22 shows an example of acquiring alignment information between a transmitting coil unit and a receiving coil unit according to another embodiment of the present invention.

[0140] Reference Figure 20 The wireless charging system 20 performs a position detection operation S2000, which uses current for position detection to acquire alignment information between the transmission coil unit 130 of the wireless power transmission device 100 and the receiving coil unit 230 of the wireless power receiving device 200. It also performs a power transfer operation S2010, which transfers power from the transmission coil unit 130 to the receiving coil unit 230 based on the alignment information acquired in operation S2000. In operation S2010, the power conversion unit 120 of the wireless power transmission device 100 converts the power received from the power supply device 300, and an asymmetrical current is applied to the first to third transmission coils 131, 132, and 133 included in the transmission coil unit 130. For a detailed description, please refer to Reference 100. Figures 1 to 17 The content described.

[0141] Referring to FIG21, a current for position detection is applied to the first to third transmission coils 131, 132 and 133 of the wireless power transmission device 100, and thus an induced voltage can be generated in the first to third receiving coils 231, 232 and 233 of the wireless power receiving device 200. Figure 21a The diagram illustrates applying current I for position detection to the first to third transmission coils 131, 132, and 133, respectively, with the first to third transmission coils 131, 132, and 133 aligned with the first to third receiving coils 231, 232, and 233. ga I gb and I gc Examples, and Figure 21b The diagram illustrates applying a current I for position detection to the first to third transmission coils 131, 132, and 133, respectively, when the first to third transmission coils 131, 132, and 133 are misaligned with the first to third receiving coils 231, 232, and 233. ga I gb and I gc Example. The alignment information acquisition unit 140 can acquire information based on the voltage V induced in the first to third receiving coils 231, 232 and 233 during the alignment state. va V vb and V vcThis is used to obtain alignment information between the first to third transmission coils 131, 132, and 133 and the first to third receiving coils 231, 232, and 233. Here, the alignment information between the first to third transmission coils 131, 132, and 133 and the first to third receiving coils 231, 232, and 233 can be information about the relative positions of the first to third transmission coils 131, 132, and 133 and the first to third receiving coils 231, 232, and 233, and can be the degree of deviation from a precise alignment.

[0142] Therefore, alignment information between the transmission coil unit 130 and the receiving coil unit 230 can be obtained without adding hardware components such as position sensors or auxiliary coils.

[0143] Figure 22 An example of a misaligned state between the transmitting coil unit and the receiving coil unit in a wireless charging system according to an embodiment of the present invention is shown. Figure 23 It is a reference Figure 20 And the implementation flowchart of the wireless charging method described in Figure 21, Figure 24 It shows in Figure 23 The current applied to the transmission coil unit in each operation, and Figure 25 It shows in Figure 23 The voltage induced in the receiving coil unit during each operation. Figure 26 The waveform of the current applied to the transmission coil unit during the position detection operation of the wireless charging method according to an embodiment of the present invention is shown. Figure 27 This illustrates the state when the transmitting coil unit and the receiving coil unit are aligned. Figure 26 The waveform of the voltage induced in the receiving coil unit when a current is applied to the transmitting coil unit, and Figure 28 This illustrates the situation where the transmitting coil unit and the receiving coil unit are misaligned. Figure 26 The waveform of the voltage induced in the receiving coil unit when a current is applied to the transmitting coil unit. Figure 26 (b) is Figure 26 A magnified view of a portion of (a). Figure 27 (b) is Figure 27 An enlarged view of a portion of (a), and Figure 28 (b) is Figure 28 An enlarged view of a portion of (a). Here, Figure 23 The wireless charging method can be, for example, through the methods described in this instruction manual. Figure 13 This is achieved using a circuit diagram.

[0144] Reference Figure 22The transmission coil unit 130 includes first to third transmission coils as three-phase coils, and the receiving coil unit 230 includes first to third receiving coils as three-phase coils. The misalignment of the transmission coil unit 130 and the receiving coil unit 230 can be represented by (R, θ). Here, R can represent the distance between the centers of the transmission coil unit and the receiving coil unit, and θ can represent the angle of offset between the centers of the transmission coil unit and the receiving coil unit. The distance between the centers of the transmission coil unit 130 and the receiving coil unit 230 can be the distance in the planar direction between their centers. This planar distance can be either the distance in the plane in which the transmission coil unit 130 is located, or the distance in the plane in which the receiving coil unit 230 is located. That is, when the centers of the transmission coil unit 130 and the receiving coil unit 230 overlap in the vertical direction, the distance between their centers can be represented as 0. Here, the vertical direction is the direction perpendicular to the plane direction, and it can be the direction from the transmission coil unit 130 toward the receiving coil unit 230. Additionally, the angle θ can be the angle formed by the transmission coil unit 130 and the receiving coil unit 230 in the plane direction.

[0145] Reference Figures 23 to 25 The wireless charging method according to an embodiment of the present invention includes a position detection operation S2300 for acquiring alignment information between a transmission coil unit 130 of a wireless power transmission device 100 and a receiving coil unit 230 of a wireless power receiving device 200, and a power transmission operation S2320 for transmitting power from the transmission coil unit 130 to the receiving coil unit 230 based on the alignment information acquired in operation S2300. The wireless charging method according to an embodiment of the present invention may further include a standby operation S2310 between the position detection operation S2300 and the power transmission operation S2320.

[0146] In the position detection operation S2300, the wireless power transmission device 100 transmits a first current I for position detection. ga The second current I used for position detection is applied to the first transmission coil 131 (S2301). gb A third current I for position detection is applied to the second transmission coil 132 (S2302). gc Applied to the third transmission coil 133 (S2303). For example... Figure 23 , Figure 24 and Figure 26 As shown, the first to third currents I used for position detection ga I gb and Igc It can be applied sequentially to the first transmission coil 131, the second transmission coil 132, and the third transmission coil 133 so as not to overlap with each other. Figure 13 In the example of the circuit diagram, a first current I for position detection is output from the first PFC circuit 211a and the first inverter 212a. ga Subsequently, a second current I for position detection can be output from the second PFC circuit 211b and the second inverter 212b. gb Then, a third current I for position detection can be output from the third PFC circuit 211c and the third inverter 212c. gc In this case, the first current I used for position detection ga The second current I used for position detection gb and the third current I used for position detection gc They can have the same amplitude. Therefore, each of the first PFC circuit 211a, the second PFC circuit 211b, and the third PFC circuit 211c can output the same magnitude of DC voltage.

[0147] Next, in the position detection operation S2300, the wireless power receiving device 200 uses the first current I applied to the first transmission coil 131 for position detection. ga To detect the voltage induced in the first receiving coil 231, the second receiving coil 232, and the third receiving coil 233 (S2304), a second current I for position detection is applied to the second transmission coil 132. gb The voltage induced in the first receiving coil 231, the second receiving coil 232, and the third receiving coil 233 is detected (S2305), and a third current I applied to the third transmission coil 133 for position detection is used. gc To detect the voltage induced in the first receiving coil 231, the second receiving coil 232, and the third receiving coil 233 (S2306). Figure 23 , Figure 25 , Figure 27 and Figure 28 As shown, when the current I used for position detection g When applied to the first to third transmission coils 131, 132 and 133, an induced voltage E is generated in the first to third receiving coils 231, 232 and 233. v .like Figures 26 to 28 As shown, when the first current I used for position detection ga When applied to the first transmitting coil 131, induced voltages E are generated in the first to third receiving coils 231, 232 and 233 respectively. va E vb and E vcIn this case, such as Figure 27 As shown, when the transmission coil unit 130 and the receiving coil unit 230 are aligned, the first current I used for position detection is applied. ga When applied to the first transmission coil 131, a maximum induced voltage E is generated in the first receiving coil 231 facing the first transmission coil 131. va Furthermore, overlapping induced voltages E with the same amplitude and phase are generated in the second receiving coil 232 and the third receiving coil 233. vb and E vc In contrast, such as Figure 28 As shown, when the transmission coil unit 130 and the receiving coil unit 230 are misaligned, the first current I used for position detection is applied. ga When applied to the first transmission coil 131, a maximum induced voltage E is generated in the first receiving coil 231, which is closest to the first transmission coil 131. va Furthermore, an induced voltage E in offset form with incomplete overlap in amplitude and phase is generated in the second receiving coil 232 and the third receiving coil 233. vb and E vc In the same way, when the second current I used for position detection... gb When applied to the second transmission coil 132, a maximum induced voltage E is generated in the second receiving coil 232, which is located closest to the second transmission coil 132. vb Furthermore, an induced voltage E in offset form with incomplete overlap in amplitude and phase is generated in the first receiving coil 231 and the third receiving coil 233. va and E vc When the third current I used for position detection gc When applied to the third transmission coil 133, a maximum induced voltage E is generated in the third receiving coil 233, which is located closest to the third transmission coil 133. vc Furthermore, an induced voltage E in offset form with incomplete overlap in amplitude and phase is generated in the first receiving coil 231 and the second receiving coil 232. va and E vb .

[0148] Next, in the position detection operation S2300, the wireless power transmission device 100 calculates the mutual inductance between the transmission coil unit 130 and the receiving coil unit 230 (S2307). Here, the mutual inductance between the transmission coil unit 130 and the receiving coil unit 230 can be calculated based on the following: the voltage induced in the first to third receiving coils 231, 232 and 233 when the current for position detection is applied to the first transmission coil 131, the voltage induced in the first to third receiving coils 231, 232 and 233 when the current for position detection is applied to the second transmission coil 132, and the voltage induced in the first to third receiving coils 231, 232 and 233 when the current for position detection is applied to the third transmission coil 133. For this purpose, the wireless power transmission device 100 can receive the induced voltage detected by the wireless power receiving device 200 during operation S2304, S2305 and S2306 from the wireless power receiving device 200, receive the induced voltage through the power supply device 300, or receive the induced voltage through a superior management server (not shown).

[0149] For example, the mutual inductance between the transmitting coil unit 130 and the receiving coil unit 230 can be calculated as follows.

[0150] The current I applied to the first to third transmission coils 131, 132 and 133 for position detection g It can be represented as follows.

[0151]

[0152] The voltage E induced in the first to third receiving coils 231, 232 and 233 v It can be represented as follows.

[0153]

[0154] Current I used for position detection g Induced voltage E v Mutual inductance M vg The relational expression can be represented as follows.

[0155]

[0156] When the current I used for position detection ga When applied to the first transmitting coil 131, the voltage E induced in the first to third receiving coils v1 It can be represented as follows.

[0157]

[0158] When the current I used for position detection gbWhen applied to the second transmission coil 132, the voltage E induced in the first to third receiving coils v2 It can be represented as follows.

[0159]

[0160] When the current I used for position detection gc When applied to the third transmission coil 133, the voltage E induced in the first to third receiving coils v3 It can be represented as follows.

[0161]

[0162] Therefore, the mutual inductance between the first to third transmitting coils 131, 132 and 133 and the first to third receiving coils 231, 232 and 233 can be expressed as follows: 3 3. Represented in matrix form.

[0163]

[0164] Next, in the position detection operation S2300, the wireless power transmission device 100 detects the relative position between the transmission coil unit 130 and the receiving coil unit 230 based on mutual inductance (S2308). The relative position between the transmission coil unit 130 and the receiving coil unit 230 can be determined by referring to the above. Figure 22 The description (R, θ) indicates that when (R, θ) converges to (0, 0), the transmission coil unit 130 and the receiving coil unit 230 are in a precisely aligned state, and when (R, θ) moves away from (0, 0), the transmission coil unit 130 and the receiving coil unit 230 move away from the precisely aligned state and become misaligned.

[0165] In the above description, the wireless power transmission device 100 is described as calculating the mutual inductance between the transmitting coil unit 130 and the receiving coil unit 230, and detecting the relative position between the transmitting coil unit 130 and the receiving coil unit 230, but the invention is not limited thereto. The mutual inductance and relative position between the transmitting coil unit 130 and the receiving coil unit 230 can be detected by the power supply device 300 or a higher-level management server (not shown).

[0166] Subsequently, the wireless charging system performs standby operation S2310 followed by power transfer operation S2320. For a detailed description of power transfer operation S2320, please refer to [reference needed]. Figures 1 to 17 The content being described. That is to say, such as... Figures 23 to 25 As shown, during power transmission operation S2320, the first current I a The second current I is applied to the first transmission coil 131. bThe third current I is applied to the second transmission coil 132. c It is applied to the third transmission coil 133. In this case, the first current I a Second current I b and the third current I c A first current I can be applied simultaneously to the first transmission coil 131, the second transmission coil 132, and the third transmission coil 133. In the power transmission operation S2320, a first current I is applied to the first transmission coil 131, the second transmission coil 132, and the third transmission coil 133. a Second current I b and the third current I c This can be based on the alignment information obtained in the position detection operation S2300. That is, as a result of the position detection operation S2300, when it is determined that the transmission coil unit 130 and the receiving coil unit 230 are misaligned, the asymmetry can be applied to the first current I. a Second current I b and the third current I c .

[0167] In other words, as referenced Figures 13 to 17 As described, the control unit 110 can control the first PFC circuit 121a, the second PFC circuit 121b, and the third PFC circuit 121c based on the alignment information between the transmission coil unit 130 and the receiving coil unit 230. Furthermore, the first to third DC voltages output from the first PFC circuit 121a, the second PFC circuit 121b, and the third PFC circuit 121c can be input to the first inverter 122a, the second inverter 122b, and the third inverter 122c to output as the first AC voltage V. a Second AC voltage V b and the third AC voltage V c .

[0168] Since independently controlled DC voltages are input to the first inverter 122a, the second inverter 122b, and the third inverter 122c, as... Figure 15 As shown, the first AC voltage V a Second AC voltage V b and the third AC voltage V c The amplitudes can all be different, or the first AC voltage V a Second AC voltage V b and the third AC voltage V c The amplitude of one of them can differ from the amplitudes of the other two. However, since the duty cycles of the first inverter 122a, the second inverter 122b, and the third inverter 122c are fixed, the first AC voltage V a Second AC voltage Vb and the third AC voltage V c The duty cycles can all be the same. The first current I applied to the first transmission coil 131 a At least one of the amplitude and phase of the second current I applied to the second transmission coil 132 b At least one of the amplitude and phase, and the third current I applied to the third transmission coil 133 c At least one of the amplitude and phase can be determined by the first AC voltage V. a Second AC voltage V b and the third AC voltage V c Control, and therefore, the first to third currents I can also be generated asymmetrically. a I b and I c In other words, such as Figure 16 As shown, the first current I a amplitude, second current I b The amplitude and the third current I c At least two of the amplitudes can be different from each other, or the first current I a With the second current I b The phase difference between them, the second current I b With the third current I c The phase difference between them and the third current I c With the first current I a At least two of the phase differences between them can be different from each other. For example, the first current I a amplitude, second current I b The amplitude and the third current I c The amplitudes can all be different from each other, or the first current I a amplitude, second current I b The amplitude and the third current I c One of the amplitudes can be different from the other two. For example, the first current I a With the second current I b The phase difference between them, the second current I b With the third current I c The phase difference between them and the third current I c With the first current I a The phase difference between them can be different from each other, or the first current I a With the second current I b The phase difference between them, the second current I b With the third current I c The phase difference between them and the third current I c With the first current I aOne of the phase differences between the two can be different from the other two.

[0169] Therefore, the control unit 110 included in the wireless power transmission device 100 according to an embodiment of the present invention can control the PFC circuit unit 121 differently in the position detection operation S2300 and in the power transmission operation S2320. That is, in the position detection operation S2300, the control unit 110 can control the first to third PFC circuits 121a, 121b and 121c, such that the output is the same as the current I used for position detection. ga I gb and I gc The corresponding DC voltage, and in the power transmission operation S2320, the control unit 110 can control the first to third PFC circuits 121a, 121b and 121c, so that the output based on the alignment information and the first to third currents I a I b and I c The corresponding DC voltage.

[0170] According to embodiments of the present invention, such as Figure 24 As shown, in position detection operation S2300, the current I applied to the first to third transmission coils 131, 132 and 133 for position detection is... ga I gb and I gc The amplitude can be less than the first to third currents I applied to the first to third transmission coils 131, 132 and 133 in the power transmission operation S2320. a I b and I c Therefore, in the position detection operation S2300, alignment information between the transmission coil unit 130 and the receiving coil unit 230 can be obtained using minimal power, thereby reducing unnecessary power consumption.

[0171] Although exemplary embodiments of the invention and their advantages have been described in detail above, those skilled in the art will understand that various changes, substitutions and modifications may be made herein without departing from the scope of the invention as defined by the appended claims.

Claims

1. A wireless power transmission device, comprising: Control unit A power conversion unit configured to convert power received from a power supply device, and The current output from the power conversion unit is applied to the transmission coil unit. The transmission coil unit includes a first transmission coil, a second transmission coil, and a third transmission coil. The power conversion unit includes: a power factor correction circuit unit that outputs a DC voltage based on power received from the power supply device; and an inverter unit that outputs an AC voltage based on the DC voltage received from the power factor correction circuit unit. The inverter unit outputs a first AC voltage, a second AC voltage, and a third AC voltage. Wherein, at least two of the amplitudes of the first AC voltage, the second AC voltage, and the third AC voltage are different from each other, and The duty cycles of the first AC voltage, the second AC voltage, and the third AC voltage are the same.

2. The wireless power transmission device according to claim 1, wherein: The power factor correction circuit unit includes a first power factor correction circuit, a second power factor correction circuit, and a third power factor correction circuit. The inverter unit includes: a first inverter that receives a first DC voltage output from the first power factor correction circuit; a second inverter that receives a second DC voltage output from the second power factor correction circuit; and a third inverter that receives a third DC voltage output from the third power factor correction circuit. The first AC voltage is output from the first inverter. The second AC voltage is output from the second inverter, and The third AC voltage is output from the third inverter.

3. The wireless power transmission device according to claim 2, wherein, The first power factor correction circuit, the second power factor correction circuit, and the third power factor correction circuit are controlled by the control unit based on alignment information between the transmission coil unit and the receiving coil unit included in the wireless power receiving device.

4. The wireless power transmission device according to claim 2, wherein: The input to the first power factor correction circuit is the first phase power received from the power supply device. The input to the second power factor correction circuit is the second-phase power received from the power supply device. The input to the third power factor correction circuit is the third-phase power received from the power supply device, and At least one of the first power factor correction circuit, the second power factor correction circuit, and the third power factor correction circuit is connected to the neutral point.

5. The wireless power transmission device according to claim 2, wherein: The current output from the power conversion unit includes: a first current applied to the first transmission coil, a second current applied to the second transmission coil, and a third current applied to the third transmission coil. At least one of the amplitude and phase of the first current, at least one of the amplitude and phase of the second current, and at least one of the amplitude and phase of the third current are controlled by the first AC voltage, the second AC voltage, and the third AC voltage.

6. The wireless power transmission device according to claim 5, wherein: At least two of the amplitudes of the first current, the second current, and the third current are different from each other, or At least two of the phase differences between the first current and the second current, the phase differences between the second current and the third current, and the phase differences between the third current and the first current are different from each other.

7. The wireless power transmission device according to claim 2, wherein, Each of the first inverter, the second inverter, and the third inverter is a full-bridge inverter.

8. The wireless power transmission device according to claim 1, wherein, The power conversion unit further includes an impedance matching unit disposed between the inverter unit and the transmission coil unit.

9. A wireless power transmission device, comprising: Control unit A power conversion unit configured to convert power received from a power supply device, and The current output from the power conversion unit is applied to the transmission coil unit. The transmission coil unit includes a first transmission coil, a second transmission coil, and a third transmission coil. The power conversion unit includes: a power factor correction circuit unit that outputs a DC voltage based on power received from the power supply device; and an inverter unit that outputs an AC voltage based on the DC voltage received from the power factor correction circuit unit. The power factor correction circuit unit includes: a first power factor correction circuit that outputs a first DC voltage; a second power factor correction circuit that outputs a second DC voltage; and a third power factor correction circuit that outputs a third DC voltage. The inverter unit includes: a first inverter that outputs a first AC voltage based on the first DC voltage; a second inverter that outputs a second AC voltage based on the second DC voltage; and a third inverter that outputs a third AC voltage based on the third DC voltage. The first power factor correction circuit, the second power factor correction circuit, and the third power factor correction circuit are controlled by the control unit based on alignment information between the transmission coil unit and the receiving coil unit included in the wireless power receiving device.

10. A wireless power transmission method for a wireless power transmission device, comprising: Power conversion operation, converting the power received from the power supply unit; as well as The current application operation applies the current output in the power conversion operation to the first transmission coil, the second transmission coil, and the third transmission coil. The power conversion operation includes: outputting a first DC voltage, a second DC voltage, and a third DC voltage based on power received from the power supply device; and outputting a first AC voltage, a second AC voltage, and a third AC voltage based on the first DC voltage, the second DC voltage, and the third DC voltage. In the power conversion operation, at least two of the amplitudes of the first AC voltage, the second AC voltage, and the third AC voltage are controlled to be different from each other, and the duty cycles of the first AC voltage, the second AC voltage, and the third AC voltage are controlled to be the same as each other.

Images