Wireless charging device and method corresponding to battery voltage range
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-19
- Publication Date
- 2026-04-10
Smart Images
Figure CN121822178A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present disclosure relates to a wireless charging device. BACKGROUND
[0002] An inductive power transfer (IPT) system is a system that transmits power using an electromagnetic induction phenomenon between a transmitting coil and a receiving coil.
[0003] A high-voltage battery pack, which is a load of a wireless charging system for an electric vehicle, generally requires a wide charging voltage range, and has a characteristic that a fluctuation range of a battery equivalent load resistance is wide.
[0004] An output voltage of an IPT system varies depending on a coupling coefficient of a transmitting power coil and a receiving power coil. In the case of a wireless charger for an electric vehicle, since the coupling coefficient k varies depending on a vehicle position and an operation frequency is limited, various ground assembly (GA) / vehicle assembly (VA) side compensation circuit methods and complex optimization control methods are required to satisfy a wide charging voltage and charging power range of a battery pack.
[0005] According to a vehicle wireless charging standard J2954 document, a frequency control range of a GA / VA wireless charging unit needs to be from 79 kHz to 90 kHz (nominal value: 85 kHz). In addition, the coupling coefficient k varies depending on a vehicle position, and the operation frequency is limited. Therefore, in order to satisfy a wide charging voltage and charging power range of a battery pack, there is also a method of configuring a wireless charging system by adding a battery management (BM) circuit unit.
[0006] Such a BM circuit unit has a problem of being configured of a boost circuit, that is, a boost converter, as a DC-DC converter.
[0007] In addition, a three-stage wireless charging system has a problem of a material cost and / or a size being excessively large compared to a two-stage wireless charging system.
[0008] In addition, a converter can be classified into a BM converter of a VA side series or parallel compensation circuit depending on whether an input capacitor exists or not. SUMMARY
[0009] The present disclosure relates to a wireless charging technology, and more particularly, to a fast wireless charging device and method using a vehicle motor system, which can correspond to a wide battery voltage range.
[0010] Embodiments of the present disclosure can solve the above problems, and can aim to provide a device and method for fast wireless charging by configuring a boost / buck converter without adding a separate converter.
[0011] Embodiments of the disclosure can provide an apparatus and method capable of fast wireless charging in a wide range of battery voltage.
[0012] Embodiments of the disclosure can provide an apparatus and method for fast wireless charging by implementing a vehicle assembly (VA) side series or parallel compensation circuit.
[0013] Embodiments of the disclosure can provide an apparatus for fast wireless charging without the need to add a separate converter.
[0014] In embodiments of the disclosure, an apparatus can include a voltage power supply unit configured to supply DC voltage power, a filter unit configured to generate a certain level of DC voltage power from the DC voltage power, a conversion operation unit configured to convert the certain level of DC voltage power into one of boosted charging power, stepped-down charging power, and bypass charging power using a preset level of DC voltage power, or drive a vehicle during vehicle charging, and an inverter configured to perform one of a boosted converter operation mode for the boosted charging power, a stepped-down converter operation mode for the stepped-down charging power, a bypass operation mode for the bypass charging power, and a vehicle drive mode for driving the vehicle in combination with the filter unit, the conversion operation unit, and the drive motor during charging.
[0015] The filter unit can include a capacitor connected in parallel with an external terminal of the voltage power supply unit, and a switching element connected in series with the capacitor in a manner to activate or deactivate a function of the capacitor.
[0016] The capacitor can be an input capacitor, and when the voltage power supply unit is a vehicle assembly (VA) side series compensation circuit, the capacitor can filter a current ripple applied to an input terminal through a full ON operation of the switching element, and maintain a certain level of DC voltage power.
[0017] The switching element can be OFF in the vehicle drive mode or when the voltage power supply unit is a VA side parallel compensation circuit, and can be fully ON when the voltage power supply unit is a VA side series compensation circuit.
[0018] The conversion operation unit can include a plurality of switching units arranged in parallel with each other in a manner to operate in a complementary relationship.
[0019] In the case of the stepped-down converter operation mode, one of the plurality of switching units can repeatedly turn ON and OFF, and the remaining switching units can repeatedly turn OFF and ON in a manner to correspond to the one switching unit in a complementary manner.
[0020] The plurality of switching units can each include a single switching element.
[0021] The plurality of switching units can each include a plurality of switching elements arranged in parallel with each other.
[0022] In a step-down converter operation mode, one of the plurality of switching units can repeatedly turn on and turn off with a phase difference of a certain angle.
[0023] The inverter can include a lower switching block and an upper switching block operating in a complementary relationship.
[0024] In the case of a step-up converter operation mode, the lower switching block can repeatedly turn on and turn off, and the upper switching block can repeatedly turn off and turn on in a manner corresponding to the lower switching block in a complementary manner.
[0025] The lower switching block can repeatedly turn on and turn off with a phase difference of a certain angle.
[0026] In the case of a step-down converter operation mode, the upper switching block can be completely turned on to secure a bypass path.
[0027] According to an embodiment of the disclosure, a wireless charging device that can correspond to a battery voltage range can include a voltage power supply unit configured to supply DC voltage power, a filter unit configured to generate a certain level of DC voltage power from the DC voltage power, a first inverter configured to convert the certain level of DC voltage power into one of a step-up charging power, a step-down charging power, and a bypass charging power using a preset level of DC voltage power, or drive a vehicle during vehicle charging, a drive motor serving as a coupling inductance during vehicle charging, and a second inverter configured to perform one of a step-up converter operation mode for the step-up charging power, a step-down converter operation mode for the step-down charging power, a bypass operation mode for the bypass charging power, and a vehicle drive mode for driving the vehicle in conjunction with the filter unit, the conversion operation unit, and the drive motor during charging.
[0028] The first inverter can include a first switching unit connected to an output terminal of the filter unit, a second switching unit connected in parallel with the first switching unit and disposed at a bottom, a third switching unit connected in parallel with the first switching unit, connected in series with the second switching unit with respect to a neutral point, and disposed at a top, and a fourth switching unit connected in series with the third switching unit.
[0029] In a closed end winding (CEW) operation mode among the vehicle drive mode or in the step-up converter operation mode, the first switching unit can be completely turned on to secure a bypass path.
[0030] In the step-down converter operation mode, the first switching unit can repeatedly turn on and turn off the switching element with a certain angle of phase difference.
[0031] In the open end winding (OEW) operation mode among the vehicle drive modes, the second switching unit can repeatedly turn on and turn off the switching element, and in the step-down converter operation mode, the second switching unit can repeatedly turn off and turn on in a complementary relationship with the first switching unit.
[0032] The fourth switching unit can be fully turned on in the vehicle drive mode, and prevent the voltage of the input terminal from being bypassed to the battery side in the step-down converter operation mode.
[0033] According to an embodiment of the disclosure, a wireless charging method that can correspond to a battery voltage range can include receiving, by a controller, a wireless charging operation request, performing, by the controller, a switching operation for boosting or step-down according to whether a vehicle assembly (VA) side compensation circuit is a series compensation circuit or a parallel compensation circuit, estimating, by the controller, a coupling coefficient through an input voltage of a VA side boost converter or a step-down converter or a current value flowing through a rectifier after a GA side inverter operation, calculating an optimal point for each battery state according to the coupling coefficient, and performing a boost converter operation mode or a step-down converter operation mode according to the optimal point to charge the battery.
[0034] According to an embodiment of the disclosure, using a conventional motor system of a vehicle, a fast wireless charging system can be implemented by adding some elements without adding a separate converter.
[0035] According to an embodiment of the disclosure, a charging operation can be performed with optimal efficiency in a wide battery voltage range.
[0036] According to an embodiment of the disclosure, a VA side series compensation circuit or a parallel compensation circuit can be implemented. BRIEF DESCRIPTION OF DRAWINGS
[0037] Figure 1 FIG. 1 is a circuit diagram of a wireless charging device using a single-stage inverter structure according to an example embodiment of the disclosure.
[0038] Figure 2 FIG. 2 is a circuit diagram of a wireless charging device using a single-stage inverter structure according to an example embodiment of the disclosure.
[0039] Figure 3 FIG. 3 is a circuit diagram of a wireless charging device using a two-stage inverter structure according to an example embodiment of the disclosure.
[0040] Figure 4A FIG. 4 is a circuit diagram of a series compensation circuit according to an example embodiment of the disclosure.
[0041] Figure 4B is a circuit diagram of a parallel compensation circuit according to an example embodiment of the present disclosure.
[0042] Figure 5 is a flowchart of an operation mechanism according to an example embodiment of the present disclosure.
[0043] Figure 6 and Figure 7 is a graph of simulation results according to an example embodiment of the present disclosure. DETAILED DESCRIPTION
[0044] The above features and advantages of the example embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings, so that those skilled in the art to which the present disclosure belongs can easily implement the technical spirit of the present disclosure. In describing the example embodiments of the present disclosure, when it is determined that a detailed description of the known technology related to the present disclosure can cause the gist of the present disclosure to be unnecessarily obscured, the detailed description can be omitted.
[0045] The example embodiments according to the present disclosure will be described in detail below with reference to the accompanying drawings. In the drawings, the same reference numerals can be used to denote the same or similar components.
[0046] Figure 1 is a circuit diagram of a wireless charging device 100 using a single-stage inverter structure according to an example embodiment of the present disclosure. Referring to Figure 1 , the wireless charging device 100 can include a voltage power supply unit 110, a filter unit 120, a conversion operation unit 130, a driving motor 140, an inverter 150, a battery 160, a controller 170, etc.
[0047] The voltage power supply unit 110 can include a VA-side compensation circuit 111 and a rectifier 112 to supply AC voltage power. The VA-side compensation circuit 111 can be a series compensation circuit or a parallel compensation circuit connected to an output end of a transformer (not shown). Figure 1 Examples of such a series compensation circuit or a parallel compensation circuit are illustrated. This will be described below.
[0048] The rectifier 112 can function to convert the AC voltage power into DC voltage power. To this end, the rectifier 112 can include a rectification circuit.
[0049] The filter unit 120 can function to filter the DC voltage power from the rectifier 112 and generate a certain level of DC voltage power. To this end, the DC power generation unit 120 can include a capacitor A 101 connected in parallel to an output end of the voltage power supply unit 110 and a switching element B 102 connected in series to the capacitor A 101.
[0050] When the VA-side series compensation circuit is configured as an input capacitor of a step-up or step-down converter, the capacitor A 101 can be used to filter a current ripple applied to an input terminal through full ON operation of the switching element B and maintain a certain level of voltage. Full ON can refer to an ON state that is maintained without change for an infinite time.
[0051] The switching element B 102 can be a switch for activating / deactivating the function of the capacitor, and can be turned OFF when the vehicle is in a driving mode and when configured as a VA-side parallel compensation circuit, and the switching element B 102 can be fully ON when configured as a series compensation circuit.
[0052] As the switching element 102, a semiconductor switching element such as a field effect transistor (FET), a metal oxide semiconductor field effect transistor (MOSFET), an insulated gate bipolar transistor (IGBT), and a power rectifier diode, a thyristor, a gate turn-off (GTO) thyristor, a triode for alternating current (TRIAC), a silicon controlled rectifier (SCR), an integrated circuit (IC), etc. can be used.
[0053] Specifically, in the case of a semiconductor switching element, a bipolar or power MOSFET element, etc. can be used. The power MOSFET element can operate at high voltage and high current, and unlike a general MOSFET, the power MOSFET element can have a double-diffused metal oxide semiconductor (DMOS) structure.
[0054] The conversion operation unit 130 can be used to perform a conversion operation to step down and convert a DC voltage power to a buck charging power, or step up and convert a DC voltage power to a boost charging power. The conversion operation unit 130 can include a switching unit C connected to an output terminal of the filter unit 120 and a switching unit D connected in parallel to the switching unit C.
[0055] The drive motor 140 can perform a motor driving function when the vehicle is driven using a mutual inductance component of a motor winding. When expressed in an equivalent circuit, the drive motor 140 can include three inductors E arranged in parallel to each other. Accordingly, the drive motor 140 can perform a driving function when the vehicle is driven, and can be used as a coupled inductance during charging. That is, electric energy can be stored in the inductors E and used to perform a step-up voltage.
[0056] The inverter 150 can perform a motor control operation when the vehicle is driven, and perform a step-up or step-down converter operation during charging. That is, a step-up converter operation mode or a step-down converter operation mode can be performed through the conversion operation unit 130 and the drive motor 140. To this end, the inverter 150 can include a lower switch block F and an upper switch block G.
[0057] Generally, in an inverter, two switching elements can be connected to one phase, and the direction of phase current can be controlled according to whether the switching element located at the top is turned on or the switching element located at the bottom is turned on.
[0058] The battery 160 can include battery cells (not shown in the drawings) configured in series and / or in parallel, which can be high-voltage battery cells for an electric vehicle, such as a nickel-metal battery cell, a lithium-ion battery cell, a lithium polymer battery cell, a lithium-sulfur battery cell, a sodium-sulfur battery cell, and a full-solid-state battery cell. In general, a high-voltage battery can be a battery used as a power source for driving an electric vehicle, and the voltage can be 100 V or more. However, embodiments of the present disclosure are not necessarily limited thereto, and a low-voltage battery is also possible.
[0059] The controller 170 can be connected to the filter unit 120, the conversion operation unit 130, and the inverter 150 to control the turn-on / off of the switching elements. The controller 170 can be used to execute a charging command after receiving the charging command from a superior controller (not shown), and transmit a processed signal to the superior controller. The turn-on / off control of the switching elements can use a pulse width modulation (PWM) control method, and generally uses this control method, but a pulse frequency modulation (PFM) control method or a combination method thereof can also be used.
[0060] To this end, the controller 170 can include a microprocessor, an electronic circuit, a memory, a voltage sensor, a current sensor, etc.
[0061] Figure 1 The illustrated circuit diagram is a circuit diagram of a single-phase step-down inverter and a three-phase step-up converter using a single-stage inverter. Therefore, the operation and role according to the use case can be as described below.
[0062] Vehicle driving mode condition:
[0063] A: not used; B: OFF; C: OFF; D: OFF; E: used as a drive motor; F: motor control using a PWM control method; G: motor control using a PWM control method.
[0064] Connected to the VA side series compensation circuit, and step-up use condition:
[0065] A: filters current and generates DC voltage power; B: ON; C: OFF; D: OFF; E: used as coupling inductor; F: three-phase interleaved PWM operation; G: complementary operation to F (i.e., synchronous control) or OFF operation (i.e., diode mode).
[0066] wherein the three-phase interleaved PWM operation can be an operation in which phases are shifted by 120° covering 360°. The PWM operation can be an operation in which a switching element is repeatedly turned on / off.
[0067] The complementary operation can refer to an operation in which the phases are alternately turned on / off. For further explanation, when F is OFF, G is ON, and when F is ON, G is OFF.
[0068] For Figure 1 The circuit shown as used as a boost converter can perform the interleaved PWM operation and the complementary operation.
[0069] Connected to the VA-side series compensation circuit, and step-down use condition:
[0070] A: filters current and generates DC voltage power; B: ON; C: PWM operation; D: complementary operation to C or OFF operation (i.e., diode mode); E: used as coupling inductor; F: OFF; G: ON.
[0071] The switching element of the switching unit D and the switching element of the switching unit C can be operated complementarily, the lower switching block F can be turned off and the upper switching block G can be turned on, and the circuit can be used as a step-down inverter. That is, the upper switching block G can be fully turned on to ensure a bypass path.
[0072] Connected to the VA-side series compensation circuit, and wireless charging bypass use condition:
[0073] A: filters current and generates DC voltage power; B: ON; C: ON; D: OFF; E: used as coupling inductor (i.e., used as output filter); F: OFF; G: ON.
[0074] In the case, the circuit can be executed in a bypass operation mode. By this, the certain level of DC voltage power generated by the filter unit 120 can be supplied to the battery 160 as charging power without voltage lowering or voltage raising.
[0075] Connected to the VA-side parallel compensation circuit, and wireless charging boost use condition:
[0076] A: not used; B: OFF; C: ON; D: OFF; E: used as coupling inductance (i.e., used as output filter); F: OFF; G: ON.
[0077] As such, the only difference is that the VA-side compensation circuit 111 of the voltage power supply unit 110 is a parallel compensation circuit.
[0078] Connected to the VA-side parallel compensation circuit, and step-down use condition:
[0079] Connected to the VA-side parallel compensation circuit, and wireless charging bypass use condition: As such, the only difference is that the VA-side compensation circuit 111 of the voltage power supply unit 110 is a parallel compensation circuit.
[0080] Connected to the VA-side parallel compensation circuit, and step-down use condition:
[0081] A: not used; B: OFF; C: ON; D: OFF; E: used as coupling inductance (i.e., used as output filter); F: OFF; G: ON.
[0082] Connected to the VA-side parallel compensation circuit, and step-down use condition:
[0083] As such, the only difference is that the VA-side compensation circuit 111 of the voltage power supply unit 110 is a parallel compensation circuit. Figure 2 Figure 2 Figure 1 is a circuit diagram of a wireless charging apparatus 200 using a single-stage inverter structure according to an example embodiment of the disclosure. Referring to , the wireless charging apparatus 200 can include a voltage power supply unit 210, a filter unit 220, a conversion operation unit 230, a driving motor 240, an inverter 250, a battery 260, a controller 270, etc. These components can perform similar functions to
[0084] the voltage power supply unit 110, the filter unit 120, the conversion operation unit 130, the driving motor 140, the inverter 150, the battery 160, the controller 170, etc. shown.
[0085] The switching unit D can also have three switching elements arranged in parallel to each other, and the three switching elements can be connected in parallel to the three switching elements arranged in the switching unit C.
[0086] Figure 2 The illustrated circuit diagrams are those of a three-phase step-down inverter and a three-phase step-up converter using a single-stage inverter. Thus, the operation and role according to the use case can be as described below.
[0087] Vehicle drive mode condition:
[0088] A: not used; B: OFF; C: OFF; D: OFF; E: used as a drive motor; F: motor control using a PWM control method; G: motor control using a PWM control method.
[0089] Connected to the VA-side series compensation circuit, and step-up use condition:
[0090] A: filters current and generates DC voltage power; B: ON; C: OFF; D: OFF; E: used as a coupling inductor; F: three-phase interleaved PWM operation; G: complementary operation to F (i.e., synchronous control) or OFF operation (i.e., diode mode).
[0091] Here, the three-phase interleaved PWM operation can be an operation in which phases are shifted by 120° covering 360°. The PWM operation can be an operation in which a switching element is repeatedly turned on / off.
[0092] The complementary operation can refer to an alternating turn-on / off. Supplementary explanation is as follows: when F is OFF, G is ON, and when F is ON, G is OFF.
[0093] For Figure 2 The illustrated circuit used as a step-up converter can perform an interleaved PWM operation and a complementary operation.
[0094] Connected to the VA-side series compensation circuit, and step-down use condition:
[0095] A: filters current and generates DC voltage power; B: ON; C: three-phase interleaved PWM operation; D: complementary operation to C or OFF operation (i.e., diode mode); E: used as a coupling inductor; F: OFF; G: ON.
[0096] The three switching elements of the switching unit D and the three switching elements of the switching unit C can repeatedly perform a complementary operation, the lower switching block F can be turned off and the upper switching block G can be turned on, and the circuit can be used as a step-down inverter.
[0097] Connected to the VA side series compensation circuit, and wireless charging bypass usage conditions:
[0098] A: Filters the current and generates DC voltage power; B: ON; C: ON; D: OFF; E: Used as a coupling inductor (i.e., used as an output filter); F: OFF; G: ON.
[0099] exist In this case, the circuit can operate in bypass mode. Therefore, the DC voltage generated by the filter unit 220 can be supplied to the battery 160 as charging power without needing to reduce or increase the voltage.
[0100] Connect to the parallel compensation circuit on the VA side, and the conditions for wireless charging boost operation are as follows:
[0101] A: Not used; B: OFF; C: ON; D: OFF; E: Used as a coupling inductor; F: Three-phase interleaved PWM operation; G: Complementary operation to F (synchronous control) or OFF operation (i.e., diode mode).
[0102] and Similarly, the only difference is that the VA-side compensation circuit 111 of the voltage power supply unit 110 is a parallel compensation circuit.
[0103] Connect to the parallel compensation circuit on the VA side, and use the step-down voltage under the following conditions:
[0104] and Similarly, the only difference is that the VA-side compensation circuit 111 of the voltage power supply unit 110 is a parallel compensation circuit.
[0105] Connect to the parallel compensation circuit on the VA side, and use conditions for wireless charging bypass:
[0106] A: Not used; B: OFF; C: ON; D: OFF; E: Used as a coupling inductor (i.e., used as an output filter); F: OFF; G: ON.
[0107] and Similarly, the only difference is that the VA-side compensation circuit 111 of the voltage power supply unit 110 is a parallel compensation circuit.
[0108] Figure 3 This is a circuit diagram of a wireless charging device 300 using a two-stage inverter structure according to an exemplary embodiment of this disclosure. (Refer to...) Figure 3The wireless charging device 300 can include a voltage power supply unit 310, a filter unit 320, a first inverter 330, a driving motor 340, a second inverter 350, a battery 360, a controller 370, etc. These components can perform functions similar to those of the voltage power supply unit 210, the filter unit 220, the conversion operation unit 230, the driving motor 240, the inverter 250, the battery 260, the controller 270, etc. illustrated in FIG. 2. Figure 2 The voltage power supply unit 210, the filter unit 220, the conversion operation unit 230, the driving motor 240, the inverter 250, the battery 260, the controller 270, etc. illustrated in FIG. 2 can perform functions similar to those of the voltage power supply unit 310, the filter unit 320, the first inverter 330, the driving motor 340, the second inverter 350, the battery 360, the controller 370, etc. illustrated in FIG. 3.
[0109] However, the difference is that a two-stage inverter structure including the first inverter 330 and the second inverter 350 is provided. The first inverter 330 can have functions of the inverter in addition to the functions of the conversion operation unit 230. Figure 2
[0110] That is, the first inverter 330 can include first to fourth switching units C, D, H, and I. That is, the first inverter 330 can include a first switching unit C connected to an output terminal of the filter unit 320, a second switching unit D connected in parallel with the first switching unit C and provided at a bottom, a third switching unit H connected in parallel with the first switching unit C, connected in series with the second switching unit D with respect to a neutral point 30, and provided at a top, and a fourth switching unit I connected in series with the third switching unit H.
[0111] In the first switching unit C, three switching elements can be configured in parallel with each other, and the three switching elements can be connected to the output terminal of the filter unit 320.
[0112] In a closed end winding (CEW) operation mode among the vehicle driving modes or in a step-up converter operation mode, the first switching unit C can be fully on to secure a bypass path. In a step-down converter operation mode, the first switching unit C can perform a three-phase interleaved PWM operation with a phase difference of 120°.
[0113] In an open end winding (OEW) operation mode among the vehicle driving modes, the second switching unit D can be used to perform a motor control PWM operation, and in a step-down converter operation mode, the second switching unit D performs a PWM operation in a complementary relationship with the first switching unit C.
[0114] The second switching unit D and the third switching unit H can each have three switching elements configured in parallel with each other, and the three switching elements can be connected in parallel with the three switching elements configured in the first switching unit C.
[0115] The second switching unit D and the third switching unit H can correspond to a lower switching block F and an upper switching block G, respectively, configured in the second inverter 350. That is, the neutral point 30 can be connected.
[0116] Accordingly, the controller 370 can perform a CEW operation mode in which the motor 340 is driven by one inverter 330 or 350 or an OEW operation mode in which the motor 340 is driven by both inverters 330 and 350. The CEW operation mode and the OEW operation mode can have different inverter voltage utilization rates.
[0117] The fourth switching unit I can be connected in series with the third switching unit H and can be fully turned on in the vehicle drive mode to configure a two-stage motor system. In the converter operation mode, the fourth switching unit I can be turned off. Specifically, in the step-down converter operation mode, the fourth switching unit I can be used to prevent the input terminal voltage from being bypassed to the battery 360 side.
[0118] The switching element of the fourth switching unit I can be an N-channel MOSFET, and the switching element of the third switching unit H can be an IGBT. Of course, this is only exemplary and can be combined in various ways.
[0119] Figure 3 The illustrated circuit diagram is a circuit diagram of a three-phase step-down inverter using a two-stage inverter and a three-phase step-up converter. Accordingly, the operation and role according to the use case can be as described below.
[0120] Vehicle drive mode conditions:
[0121] A: not used; B: OFF; C: ON in the CEW operation mode and OFF in the OEW operation mode; D: OFF in the CEW operation mode and motor control PWM in the OEW operation mode; E: used as a drive motor; F: motor control using a PWM control method; G: motor control using a PWM control method; H: OFF in the CEW operation mode and motor control PWM in the OEW operation mode; I: ON.
[0122] Connected to the VA side series compensation circuit, and step-up use conditions:
[0123] A: filters current and generates DC voltage power; B: ON; C: OFF; D: OFF; E: used as a coupling inductor; F: three-phase interleaved PWM operation; G: complementary operation (i.e., synchronous control) or OFF operation (i.e., diode mode) to F; H: OFF; I: OFF.
[0124] Here, the three-phase interleaved PWM operation can be an operation in which phases are shifted by 120° covering 360°. The PWM operation can be an operation in which a switching element is repeatedly turned on / off.
[0125] The complementary operation can refer to the alternate turn-on / off. The supplementary explanation is as follows: when F is OFF, G is ON, and when F is ON, G is OFF.
[0126] For Figure 3 The circuit shown as a boost converter can perform the interleaved PWM operation and the complementary operation.
[0127] Connected to the VA-side series compensation circuit, and the step-down use condition:
[0128] A: filters the current and generates a DC voltage power; B: ON; C: three-phase interleaved PWM operation; D: complementary operation to C or OFF operation (i.e., diode mode); E: used as a coupling inductor; F: OFF; G: ON; H: OFF; I: OFF.
[0129] The three switching elements of the switching unit D and the three switching elements of the switching unit C can repeat the complementary operation, the lower switching block F can be turned off and the upper switching block G can be turned on, and the circuit can be used as a step-down inverter.
[0130] Connected to the VA-side series compensation circuit, and the wireless charging bypass use condition:
[0131] A: filters the current and generates a DC voltage power; B: ON; C: ON; D: OFF; E: used as a coupling inductor (i.e., used as an output filter); F: OFF, G: ON, H: OFF, I: OFF.
[0132] In The case, the circuit can be executed in the bypass operation mode. Thus, the certain level of DC voltage power generated by the filter unit 320 can be supplied to the battery 360 as a charging power without voltage reduction or voltage increase. In the bypass operation, the bypass charging power using the certain level of DC voltage power can be supplied to the battery 360.
[0133] Connected to the VA-side parallel compensation circuit, and the wireless charging boost use condition:
[0134] A: not used; B: OFF; C: ON; D: OFF; E: used as a coupling inductor; F: three-phase interleaved PWM operation; G: complementary operation to F (synchronous control) or OFF operation (i.e., diode mode); H: OFF; I: OFF.
[0135] Similar to , the only difference is that the VA-side compensation circuit 111 of the voltage power supply unit 110 is a parallel compensation circuit.
[0136] Connected to the VA-side shunt compensation circuit, and step-down use condition:
[0137] With Similarly, the only difference is that the VA-side compensation circuit 111 of the voltage power supply unit 110 is a shunt compensation circuit.
[0138] Connected to the VA-side shunt compensation circuit, and wireless charging bypass use condition:
[0139] A: not used; B: OFF; C: ON; D: OFF; E: used as a coupling inductor (i.e., used as an output filter); F: OFF; G: ON; H: OFF; I: OFF.
[0140] With Similarly, the only difference is that the VA-side compensation circuit 111 of the voltage power supply unit 110 is a shunt compensation circuit.
[0141] Figure 4A is a circuit diagram of a series compensation circuit according to an example embodiment of the present disclosure. Figure 4B is a circuit diagram of a shunt compensation circuit according to an example embodiment of the present disclosure.
[0142] Figure 4A The transformer 410 shown includes a primary coil inductance L1 and a secondary coil inductance L2, and the capacitor 420 is connected in parallel with the secondary coil inductance L2. Figure 4B The capacitor shown is connected in series with the secondary coil inductance. The coupling coefficient k refers to the ratio of magnetic flux coupling with different coils.
[0143] The primary coil inductance L1 side of the transformer 410 can include a GA-side inverter (not shown) and a GA-side compensation circuit.
[0144] Figure 5 is a flowchart of an operating mechanism according to an example embodiment of the present disclosure. Referring to Figure 5 When the driver makes a wireless charging operation request, the controllers 170, 270, and 370 can perform a wireless charging operation (operation S510).
[0145] After that, the controllers 170, 270, and 370 can operate the switches according to the structure of the VA-side compensation circuit to perform step-up (i.e., increase voltage) or step-down (i.e., decrease voltage) (operation S520). That is, in the case of a series compensation circuit, switch B can be turned on, thereby performing a bypass operation mode. In the case of a shunt compensation circuit, switch B can be turned off, thereby performing a bypass operation mode.
[0146] Afterwards, the wireless charging GA side inverter operates in V link,min under the condition, the VA side V in oltage or I con current value estimates the coupling coefficient k value (operation S530). That is, the V link,min ondition can be that when the controllable link voltage V link anges from about 500 V to 800 V, the V link,min alue is about 500 V.
[0147] The coupling coefficient k value can be estimated by the input voltage V in or the average current I con flowing through the rectifiers 112, 212, and 312, which are input to the input terminal of the step-up converter or step-down converter. That is, when the power transfer operation is performed at a certain frequency (for example, 85 kHz) at V link,min , the coupling coefficient k of the transformer can be estimated by the measured values and phases of the voltages / currents of the input and output terminals.
[0148] Afterwards, after the optimal point of each battery state is calculated, the step-up converter operation mode or the step-down converter operation mode can be performed, and the V link may be changed (operation S540). That is, the step-up / step-down ratio of the step-up / step-down converter that can be operated at the optimal efficiency point can be determined according to the coupling coefficient k. The step-up / step-down ratio of the step-up / step-down converter can be determined by referring to the estimated k value, the battery voltage, the battery required power, etc., and the step-up / step-down converter can be operated to perform the battery charging operation.
[0149] Afterwards, it can be checked whether the battery charging is completed (operation S560). The battery can be checked whether it is fully charged using the state of charge (SoC). To this end, the batteries 160, 260, and 360 can include a battery management system (BMS) (not shown).
[0150] The BMS can improve energy efficiency and prolong the life by optimizing the management of the eco-friendly vehicle battery. By monitoring the voltage, current, and temperature of the battery in real time and preventing overcharging and discharging, the stability and reliability of the battery can be improved. To this end, the BMS can include various sensors, microprocessors, switching elements, cell balancers, etc.
[0151] In operation S560, when the check result is that the battery charging is completed, the charging can be completed (operation S570).
[0152] On the contrary, in operation S560, when the check result is that the battery charging is not completed, operations S540 to S560 can be continuously performed.
[0153] In the configuration of the wireless charging device 100, 200, and 300, the output load resistance RL can be calculated by the relationship between the output voltage and the output current, and the load resistance is one of important variables that determine the overall efficiency of the wireless power transfer system.
[0154] The input power and the output power of an ideal boost / buck converter are the same, and the input impedance can be converted according to the relationship expression between the input and the output terminal. When the output load resistance is RL, the output voltage is Vo, and the input voltage is Vin, Figures 1 to 3 The input impedance of the boost converter or the buck converter shown is Rin=(Vin / Vo) 2 ×RL.
[0155] Figure 6 And Figure 7 is a graph of simulation results according to an embodiment of the disclosure. Figure 6 And Figure 7 is an operating simulation example of a boost converter, in which the motor system is converted into a single-phase equivalent converter.
[0156] In Figure 6 and Figure 7 , V link represents a link voltage, I link represents a link current, V bat represents a battery voltage, and I bat represents a battery current.
[0157] The operations of the methods or algorithms described with respect to the example embodiments disclosed herein can be implemented in the form of program commands that can be executed by various computer means such as a microprocessor, a processor, and a CPU and stored in a computer readable medium. The computer readable medium can include program (command) codes, data files, data structures, etc., alone or in combination.
Claims
1. A wireless charging device, comprising: a voltage power supply unit supplying DC voltage power; a filter unit generating a first level of DC voltage power from the DC voltage power; a conversion operation unit converting the first level of DC voltage power into one of a step-up charging power, a step-down charging power, and a bypass charging power using the first level of DC voltage power, or driving a vehicle during charging of the vehicle; a drive motor serving as a coupling inductance during charging; and an inverter, in conjunction with the filter unit, the conversion operation unit, and the drive motor, performing one of a step-up converter operation mode for the step-up charging power, a step-down converter operation mode for the step-down charging power, a bypass operation mode for the bypass charging power, and a vehicle drive mode for driving the vehicle during the charging. The filter unit includes:
2. The wireless charging device of claim 1, wherein, a capacitor connected in parallel with an external terminal of the voltage power supply unit; and a switching element connected in series with the capacitor in a configuration to activate or deactivate a function of the capacitor. The capacitor includes an input capacitor, based on the voltage power supply unit being configured as a vehicle assembly (VA) side series compensation circuit, the wireless charging device causing the capacitor to filter a current ripple applied to an input terminal through a full conduction operation of the switching element and to maintain the first level of DC voltage power.
3. The wireless charging device of claim 2, wherein, In the vehicle drive mode or based on the voltage power supply unit being configured as a VA side parallel compensation circuit, the wireless charging device causing the switching element to be turned off, and based on the voltage power supply unit being configured as the VA side series compensation circuit, the wireless charging device causing the switching element to be fully turned on.
4. The wireless charging device of claim 2, wherein, The conversion operation unit includes a plurality of switching units arranged in parallel with each other in a configuration to operate in a complementary relationship.
5. The wireless charging device of claim 1, wherein, In the step-down converter operation mode, the wireless charging device causing one of the plurality of switching units to repeatedly turn on and turn off, and the remaining switching units of the plurality of switching units to repeatedly turn off and turn on in a manner corresponding to the one switching unit complementarily.
6. The wireless charging device of claim 5, wherein, Each of the plurality of switching units includes a single switching element.
7. The wireless charging device of claim 5, wherein, Each of the plurality of switching units includes a plurality of switching elements arranged in parallel with each other.
8. The wireless charging device of claim 5, wherein, In the step-down converter operation mode, the wireless charging device causing one of the plurality of switching units to repeatedly turn on and turn off with a phase difference of a preset angle.
9. The wireless charging device of claim 8, wherein, The inverter includes a lower switching block and an upper switching block operating in a complementary relationship.
10. The wireless charging device of claim 1, wherein, In the step-up converter operation mode, the wireless charging device causing the lower switching block to repeatedly turn on and turn off, and the upper switching block to repeatedly turn off and turn on in a manner corresponding to the lower switching block complementarily.
11. The wireless charging device of claim 10, wherein, The wireless charging device causing the lower switching block to repeatedly turn on and turn off with a phase difference of a preset angle.
12. The wireless charging device of claim 11, wherein, 13. The wireless charging device of claim 10, wherein, In the step-up converter operation mode, the wireless charging device makes the upper switch block fully conductive to ensure a bypass path. 14.A wireless charging device comprising: a voltage power supply unit supplying DC voltage power; a filter unit generating a first level of DC voltage power from the DC voltage power; a first inverter converting the first level of DC voltage power into one of a step-up charging power, a step-down charging power, and a bypass charging power using the first level of DC voltage power, or driving the vehicle using a two-stage inverter structure to charge the vehicle; a drive motor serving as a coupling inductance during charging of the vehicle; and a second inverter, in combination with the filter unit, the conversion operation unit, and the drive motor, performing one of a step-up converter operation mode for the step-up charging power, a step-down converter operation mode for the step-down charging power, a bypass operation mode for the bypass charging power, and a vehicle drive mode for driving the vehicle during charging. The first inverter includes:
15. The wireless charging device of claim 14, wherein, a first switch unit connected to an output terminal of the filter unit; a second switch unit connected in parallel with the first switch unit; a third switch unit connected in parallel with the first switch unit and connected in series with the second switch unit with respect to a neutral point; and a fourth switch unit connected in series with the third switch unit. In the closed-end winding (CEW) operation mode among the vehicle drive modes or in the step-up converter operation mode, the first switch unit is fully conductive to ensure a bypass path.
16. The wireless charging device of claim 15, wherein, In the step-down converter operation mode, the first switch unit repeatedly conducts and turns off a switching element with a phase difference of a preset angle.
17. The wireless charging device of claim 15, wherein, In the open-end winding (OEW) operation mode among the vehicle drive modes, the second switch unit repeatedly conducts and turns off, and in the step-down converter operation mode, the second switch unit repeatedly turns off and conducts in a complementary relationship with the first switch unit.
18. The wireless charging device of claim 15, wherein, In the vehicle drive mode, the fourth switch unit is fully conductive, and in the step-down converter operation mode, the fourth switch unit prevents a voltage of an input terminal from being bypassed to a battery side.
19. The wireless charging device of claim 15, wherein, 20.A wireless charging method comprising: receiving a wireless charging operation request; performing a switching operation of step-up or step-down according to whether a vehicle assembly side (VA) compensation circuit is a series compensation circuit or a parallel compensation circuit; estimating a coupling coefficient through an input voltage of a VA side step-up converter or a VA side step-down converter or a current value flowing through a rectifier after a ground assembly (GA) side inverter operation; determining an optimal point for each battery state according to the coupling coefficient; and performing a step-up converter operation mode or a step-down converter operation mode to charge a battery according to the optimal point.