Electric vehicle charging system and method, and electric vehicle

Abstract

Charging of an electric vehicle is accomplished using wireless power transfer between a transmit coil of a charging station and a receive coil integrated into a wheel of the vehicle. One aspect is a docking unit for receiving a wheel of a vehicle having a drive arrangement for rotating the received wheel. A relative alignment between the transmit coil and the receive coil is detected, and the drive arrangement is controlled to provide a desired relative alignment between the transmit coil and the receive coil in response to the detected relative alignment. Another aspect is that the wireless charging receive coil is incorporated into the wheel and includes a loop including an arcuate portion of the wheel rim, where the arcuate portion of the wheel rim is intended to be received in a closable opening of a core of a transmit coil of a vehicle charging system. Another aspect is a rotary electrical coupler between the wireless charging receive coil and the battery charging circuit. An actuator is provided for controlling mechanical engagement of the electrical coupler such that the electrical coupler is engaged in preparation for charging.

Description

Technical Field

[0001] This invention relates to electric vehicles, and more particularly to the charging of electric vehicles. The invention especially relates to light electric vehicles, such as bicycles and scooters, or self-balancing unicycles. Background Technology

[0002] It is known that light electric vehicles (LEVs) can be wirelessly charged via wireless charging systems. Figure 1 A basic wireless charging system is shown, including a wireless power transmitter 10 and a wireless power receiver 20.

[0003] The wireless power transmitter 10 includes a transmitter (primary) coil Lp, a resonant network, and an inverter 12. The wireless power receiver 20 includes a receiver (secondary) coil Ls, a resonant network, and a load 22 in the form of a battery.

[0004] Mutual inductive coupling exists between the coils. The level of mutual coupling is represented by a K-factor and is approximately 0.1 to 0.8 in practical systems. Due to the mutual coupling between the coils, the wireless power receiver can receive power to charge the battery (load). Resonant networks on both sides are used to optimize the power transfer efficiency between the two subsystems.

[0005] The advantage of wirelessly charged LEVs is that they eliminate the need for charging cables. Instead, the LEV is simply placed in a charging booth, and it will be charged. LEVs, such as those on e-bikes, are placed in known booth charging systems, with their front wheels positioned between or against the two posts of the booth. The bicycle's wireless power receiver is typically attached to or near the front fork. The wireless power transmitter is attached to one of the posts of the booth.

[0006] The result is that the wireless power receiver on the LEV is visually very prominent. Furthermore, in this arrangement, the magnetic alignment between the wireless power transmitter and receiver is not reliably controlled, but this alignment is necessary for the efficient operation of the wireless charging system.

[0007] A design has been proposed for the front wheel of the LEV, in which the wireless power receiver is hidden, for example, inside the wheel near the outer perimeter. However, this results in a small receiving coil and therefore poor magnetic coupling.

[0008] Furthermore, integrating the wireless power receiver into the wheel requires a rotary electrical coupling to transfer the induced charging current from the receiving coil to the stationary part of the LEV (such as the battery). Typically, a sliding rotary electrical coupling is used, but this is prone to wear. A second wireless power transmission arrangement can be used alternatively to address the wear problem. However, this increases complexity and further reduces efficiency.

[0009] Therefore, an improved electric vehicle charging system is needed to address some or all of these problems. Summary of the Invention

[0010] This invention is defined by the claims.

[0011] According to one aspect of the present invention, an electric vehicle charging system is provided, comprising: A docking unit for receiving the wheels of a vehicle equipped with a wireless charging receiving coil. A drive arrangement structure for rotating the wheels received by the docking unit; A wireless charging transmitting coil, used to transfer charge to the receiving coil of the wheel, which is received by the docking unit; A detection system used to detect the relative alignment between the transmitting and receiving coils; and The controller is configured to: In response to the detected relative alignment, the drive arrangement structure is controlled to provide the desired relative alignment between the transmitting and receiving coils; and Controls wireless charging from the transmitting coil to the receiving coil.

[0012] This charging system drives the receiving wheel until the wheel's receiving coil is correctly aligned with the charging system's transmitting coil. In this way, the magnetic coupling between the coils is improved, thereby improving charging efficiency.

[0013] The docking unit includes, for example, a set of rollers for engaging with the tire of the wheel, wherein at least one roller is driven by a drive arrangement structure.

[0014] Therefore, the drive arrangement allows the received wheels to rotate while the rest of the vehicle is stationary. The drive arrangement is, for example, bidirectional, allowing for fine-tuning of the wheel positions (without having to complete a full rotation for adjustment).

[0015] The detection system includes, for example, a peak detector, which is used to detect the resonant frequency that generates peak current or voltage.

[0016] The primary resonant frequency is generated by the characteristics of the transmitting coil circuit, but the proximity of the receiving coil changes the frequency characteristics, especially the frequency characteristics of the secondary resonant frequency, making it possible to monitor the offset in the secondary resonant frequency to provide measurement results of coil alignment.

[0017] The transmitting coil includes, for example, a core having a loop with a closable opening for receiving a wheel rim, wherein the opening is configured to receive the wheel rim when open and is configured to close around the wheel rim to enable wireless charging.

[0018] Therefore, the core of the transmitting coil is clamped around the wheel rim (once it is in the correct position). This provides close proximity between the two coils (one of which is formed by the wheel rim itself). The transmitting coil, for example, comprises a tightly wound coil around a ferrite core, while the receiving coil is a more open coil, for example, following the shape of a portion of the wheel rim and spokes, but also magnetically coupled to the same ferrite core.

[0019] The transmitting coil may include, for example: Two arc-shaped cores are moved apart and together to open and close the ring; or Two overlapping arc-shaped cores rotate concentrically relative to each other to open and close the ring.

[0020] The core of the transmitting coil can be opened and closed laterally, or it can have portions that slide on each other to open and close openings. Any arrangement structure controllable between the open and closed shapes is feasible, wherein there is a continuous ferrite path around the closed shape.

[0021] The present invention also provides an electric vehicle configured to be charged by the vehicle charging system defined above, and comprising: A wheel with a rim; A wireless charging receiver coil integrated into the wheel; Batteries; and Battery charging circuit.

[0022] The receiving coil includes, for example, a loop that includes an arcuate portion of a wheel rim, wherein the arcuate portion of the wheel rim is used to receive a closed opening in the core of the transmitting coil of the vehicle charging system.

[0023] Therefore, a portion of the wheel rim is received in a closable opening to create a strong magnetic coupling between the transmitting and receiving coils.

[0024] The ring may also include, for example, a connector between the ends of the arcuate portion, wherein the connector is positioned to align with the spokes of the wheel.

[0025] In this way, the receiving coil is made discrete because it matches the shape of the wheel section.

[0026] Electric vehicles include, for example, a rotary electrical connector between a wireless charging receiving coil and a battery charging circuit, wherein the electric vehicle also includes an actuator for controlling the mechanical engagement of the electrical connector such that the electrical connector is engaged in preparation for charging.

[0027] In this way, a rotary electrical connector is used, allowing charge to be delivered to the battery charging circuit from any position on the wheel. For example, sliding electrical contacts can be used. However, these contacts are only used during charging, thus avoiding wear and tear on the contacts during vehicle use. In this way, a mechanical (ohmic contact) electrical connector can be used, which is more efficient than providing a second wireless power transfer coupling.

[0028] Electric vehicles may also include, for example, a load connected to a receiving coil, including when the rotary electrical connector is not engaged.

[0029] In this way, a load still exists in the receiving coil circuit even when the rotary electrical connector is not engaged. This load can be detected at the transmitting coil, allowing measurement of the current or voltage related to the alignment between the receiving and transmitting coils. Therefore, this load enables current sensing for the alignment between the coils.

[0030] The resonant frequency observed when the coil is aligned produces a second resonant peak, which is higher than, for example, the receiver resonant frequency of 200 to 300 kHz. For example, a frequency scan is performed on the transmitter side, starting at 200 kHz and scanning up to a maximum value of 1 MHz. By tracking the current or voltage, it can be determined when the maximum measured value occurs at a certain frequency corresponding to correct alignment. Of course, these frequency values ​​depend on the components used in the circuit, including any added loads.

[0031] Once alignment is achieved, a signal is generated to stop the front wheels from rotating.

[0032] The present invention also provides an electric vehicle system, comprising: Such as the vehicle charging system defined above; and Electric vehicles, as defined above.

[0033] The present invention also provides an electric vehicle, comprising: A wheel with a rim; A wireless charging receiver coil is incorporated into the wheel, comprising a loop that includes the arcuate portion of the wheel rim.

[0034] This type of vehicle uses a portion of the wheel rim as part of a receiving coil for receiving wireless power transfer from the charging system.

[0035] The curved portion of the wheel rim is used, for example, as a closed opening in the core of the transmitting coil of the vehicle charging system.

[0036] The ring also includes, for example, a connector between the ends of the curved portion, wherein the connector is positioned to align with the spokes of the wheel. This gives the receiving coil integrated into the wheel a discrete appearance.

[0037] The present invention also provides a method for charging an electric vehicle, comprising: The electric vehicle charging system receives the vehicle's wheel at the docking unit, the wheel being coupled with a wireless charging receiving coil, and the electric vehicle charging system having a wireless charging transmitting coil for transferring charge to the wireless receiving coil. The rotating wheel, received at the docking unit, simultaneously detects the relative alignment between the transmitting and receiving coils; and Wireless charging is controlled from the transmitting coil to the receiving coil once the wheels have been rotated to the desired relative alignment.

[0038] These and other aspects of the invention will become apparent from the embodiments described below, and will be explained with reference to the embodiments described below. Attached Figure Description

[0039] To better understand the invention and to more clearly illustrate how to implement it, reference will now be made to the accompanying drawings by way of example only, wherein: Figure 1 A basic wireless charging system is shown, including a wireless power transmitter and a wireless power receiver; Figure 2 An electric vehicle system for wireless charging of light electric vehicles (LEVs) is shown. Figure 3 This shows how the receiving coil and transmitting coil are aligned; Figure 4 A schematic diagram of a wireless LEV charging system is shown. Figure 5 The input current is shown as a function of frequency for a coupling factor ranging from 0.1 to 0.8. Figure 6 A block diagram of a wireless LEV charging system is shown, including a search system for rotating a wheel to provide alignment of the receiver and transmitting coils; Figure 7 An example of a feasible coil design is shown; Figure 8 It shows Figure 7 How should the design match the wheel design? Figure 9The bicycle wheel received in the docking unit is shown; Figure 10 An example of a transmitting coil is shown; Figure 11 It shows that it is in the open state. Figure 10 The transmitting coil; Figure 12 This shows that the receiving coil Ls can be configured as part of a wheel design; Figure 13 It shows the components assembled to form a wheel. Figure 12 The structure; Figure 14 A 3D view of the receiving coil is shown; Figure 15 A basic circuit diagram is shown schematically. Figure 16 An example of a rotary electrical connector is shown; Figure 17 An exploded view of a rotary electrical connector is shown; Figure 18 Another view of a stationary printed circuit board is shown; Figure 19 Another design for a rotary electrical connector is shown; Figure 20 It shows Figure 19 Exploded view of a rotary electrical connector; Figure 21 Another exploded view is shown; Figure 22 Another exploded view is shown; and Figure 23 An internal view of a relay used in a rotary electrical connector is shown. Detailed Implementation

[0040] The invention will be described with reference to the accompanying drawings.

[0041] It should be understood that while the detailed description and specific examples indicate exemplary embodiments of the apparatus, system, and method, they are intended for illustrative purposes only and are not intended to limit the scope of the invention. These and other features, aspects, and advantages of the apparatus, system, and method of the present invention will be better understood from the following description, the appended claims, and the accompanying drawings. It should be understood that the drawings are merely schematic and not drawn to scale. It should also be understood that the same reference numerals are used in all the drawings to indicate the same or similar parts.

[0042] This invention relates to charging electric vehicles, and more particularly to the use of wireless power transmission between a transmitting coil at a charging station and a receiving coil integrated into the wheels (typically the front wheels) of the vehicle.

[0043] One design feature is that the docking unit for receiving the vehicle's wheel has a drive arrangement structure for rotating the received wheel. The relative alignment between the transmitting and receiving coils is detected, and the drive mechanism is controlled in response to the detected relative alignment to provide the desired relative alignment between the transmitting and receiving coils. Another design feature is that the wireless charging receiving coil is integrated into the wheel and includes a ring comprising an arcuate portion of the wheel rim, wherein the arcuate portion of the wheel rim is used to receive the core of the transmitting coil in the vehicle charging system, which can be closed. Another design feature is that a rotary electrical connector is provided between the wireless charging receiving coil and the battery charging circuitry. An actuator is provided for controlling the mechanical engagement of the electrical connector, such that the connector is engaged in preparation for charging.

[0044] A system incorporating these and other design features will now be described. However, the various features can be used individually or in combination with other features, and the invention relates to various aspects of the overall design as defined by the claims.

[0045] Figure 2 An electric vehicle system, namely an electric vehicle and a wireless charging system, is shown, particularly for light electric vehicles (LEVs), which provides improved magnetic coupling.

[0046] The electric vehicle system includes a vehicle charging system 30 in the form of a bicycle storage station, in which the front wheel of the LEV can be placed, allowing the front wheel to still rotate when parked.

[0047] The front wheel 40 of the LEV is supported by two rollers 42 and a bidirectional drive roller 44 for driving the front wheel. The front wheel 40 is equipped with a single receiving coil 50, which covers only a small area of ​​the wheel. The receiving coil 50 is designed to be positioned in a fixed location relative to the charging station and placed close to the outer circumference of the front wheel.

[0048] The bicycle storage station is equipped with a wireless power transmitter with a transmitting coil 52. The transmitting coil 52 of the wireless power transmitter has a similar size to the receiving coil and is positioned close to the front wheel.

[0049] The placement of LEVs in the bicycle storage station will be automatically detected by a wireless LEV charging system. This is achieved via a mechanical switch (not shown) that engages when the wheels are docked.

[0050] A controller 54 is present, which is part of a detection system for detecting the relative alignment between the transmitting and receiving coils. Immediately after a stop is detected, the charging system, under the control of the controller 54, begins searching for the receiving coil 50 by rotating the front wheel using the drive roller 44. When the transmitting and receiving coils are aligned, a recognizable signal is generated, and the rotation of the front wheel stops. In this case, the maximum coupling factor between the transmitting and receiving coils is achieved.

[0051] Then, the controller 54 also controls the wireless charging from the transmitting coil to the receiving coil.

[0052] Therefore, the charging system drives the receiving wheel until the wheel's receiving coil is correctly aligned with the charging system's transmitting coil. In this way, the magnetic coupling between the coils is improved, thereby improving charging efficiency.

[0053] The magnetic coupling between the transmitting coil inside the wireless power transmitter and the receiving coil inside the wheel can be optimized by matching the sizes of the transmitting and receiving coils and ensuring proper alignment between the coils.

[0054] Because the receiving coil rotates within the wheel, the received power needs to be transmitted via the wheel axle to the battery and battery charging circuitry within the LEV body. As discussed further below, an electromechanical rotary connector is employed for this purpose.

[0055] Figure 3 The diagram illustrates how the receiving coil 50 and transmitting coil 52 are aligned. Maximum magnetic coupling is shown when the coils are aligned (as shown in the right-hand image) with concentric coil alignment. Optimal magnetic coupling occurs when the diameter ratio of the two coils is 1 (i.e., the coils are the same size). Although magnetic coupling can be automatically adjusted to its maximum level through positional adjustments, disk-shaped, side-by-side transmitting and receiving coils exhibit a maximum coupling factor of approximately 0.3 to 0.5, depending on the degree of alignment and the spacing distance Z. This distance Z results in stray fields, limiting maximum coupling under practical conditions.

[0056] As mentioned above, electricity needs to be transmitted from the receiving coils in the wheels to the stationary parts of the vehicle, namely the battery and battery charging control circuit.

[0057] The problem with rotary mechanical and electrical contacts is the wear of the commutator's sliding contacts or carbon brushes. One option is to use an alternative wireless (contactless) power transmission device, but this reduces the system's efficiency.

[0058] Another aspect of the overall design is the rotary electrical connector, which can be connected and disconnected, for example, using a relay to control the engagement and disengagement of physical (ohmic) contacts. The electrical connector forms physical electrical and mechanical contact when connected, but disconnects when not needed. Specifically, in the case of LEVs such as wireless charging for e-bikes, this charging occurs when the vehicle is stationary. In all other road conditions, during riding, contact is not required. The rotary electrical connector, which closes only during power transmission, avoids contact wear.

[0059] Figure 4 A schematic diagram of a wireless LEV charging system is shown. This circuit is for... Figure 1 The circuit is improved and additionally includes a load capacitor Cd and a rotary electrical connector in the receiving circuit.

[0060] Typically, it is difficult to align the transmitting and receiving coils electronically when no load is connected to the terminals of the wireless power receiver 20. For example, when the transmitting and receiving coils are in their maximum alignment, measuring the current through the transmitting coil will not result in any detectable maximum signal because the current through the wireless power receiver is zero. Therefore, when the rotary electrical connector 24 is still in the "open" state, the (small) load capacitor Cd serves as a non-dissipative preload for the wireless power receiver. This load Cd is connected to the receiving coil, including when the rotary electrical connector is not engaged.

[0061] In this way, a load still exists in the receiving coil circuit when the connector is not engaged. This load can be detected at the transmitting coil, allowing measurement of the current related to the alignment between the receiving and transmitting coils. Therefore, this load enables current or voltage sensing of the alignment between the coils even without a connection to the load.

[0062] Figure 5 The input current I(Lp) is shown as a function of frequency with a K-factor ranging from 0.1 to 0.8. It shows the first primary maximum current (for example) around 80 kHz, primarily attributed to the primary resonant frequency of capacitor Cp and inductor Lp. When the receiving coil is placed near the transmitting coil, the primary resonant frequency will be shifted, but only slightly, due to the proximity effect.

[0063] The presence of the capacitor load Cd, along with the capacitor Cs and inductor Ls, results in a minimum current I(Lp) at a relatively high resonant frequency of approximately 200 to 300 kHz (e.g.), independent of the coupling factor, as can be seen in... Figure 5 This is seen through another peak.

[0064] This is called the "receiver" resonant frequency. Because the receiver resonant frequency of 200 to 300 kHz is relatively high, the added capacitor Cd will have almost no effect on the primary resonant frequency. A factor of 5 to 10 between the primary resonant frequency and the receiver frequency is sufficient to achieve this. It can be seen that the circuit exhibits high impedance for frequencies ranging from 80 kHz to 200 kHz.

[0065] Above 200 to 300 kHz, several resonant frequency peaks become visible. The larger the K-factor between the transmitting and receiving coils, the higher the frequency of the second resonant peak. The location of the second resonant peak is determined by capacitors Cd and Cs, and inductors Lp and Ls.

[0066] When the load on the wireless receiver remains disconnected and the coupling between the transmitting and receiving coils is low, the receiver resonance and the second resonant peaks are closer together. As the coupling between the transmitting and receiving coils increases, the second peak shifts to a higher frequency. Therefore, the better the coupling, the higher the second resonant frequency. A peak detector can be used to detect the resonant frequency that generates the peak current or voltage, and this resonant frequency indicates the coupling quality. Therefore, the second resonant frequency can be used as an alignment metric.

[0067] Figure 6 A block diagram of a wireless LEV charging system is shown, including a search system for rotating a wheel to provide alignment of the receiving and transmitting coils.

[0068] Transmitter 10 includes inverter 12, transmitting coil Lp, and resonant capacitor Cp. Primary current is provided to peak detector 60 via high-pass filter 62, and controller 64 processes the peak detector signal to derive control signals for wheel drive roller 44 and to control inverter 12 to enable wireless power transmission.

[0069] Receiver 20 includes a receiving coil Ls, a resonant capacitor Cs, and a load capacitor Cd. Rectifier 70 converts the received AC power into DC battery charging current, which is then controlled by battery management system 72.

[0070] If the LEV is detected parked in the bicycle storage station (e.g., by a separate mechanical switch engaged when the bicycle wheel is received), it will begin searching for the receiving coil by rotating the front wheel.

[0071] If the transmitting and receiving coils remain misaligned, no second resonant peak will occur. However, if the transmitting and receiving coils become closer, a second resonant frequency will appear. The frequency of the second resonant peak will always be higher than the receiver's resonant frequency of 200 to 300 kHz. Therefore, the inverter's starting frequency can be set to 200 kHz, and it can be scanned up to a maximum value of 1 MHz (in this example). By synchronously increasing the inverter frequency and tracking the current I(Lp) via a high-pass filter and peak detector, it can be determined whether a maximum current I(Lp) occurs at a certain frequency.

[0072] If a maximum current I (Lp) is detected at a given frequency, the transmitting and receiving coils are perfectly aligned. Fine-tuning of the system can be achieved by adjusting the direction of the rotating wheel to get as close as possible to the maximum value.

[0073] If a maximum value is detected, a signal is generated to stop the front wheel rotation. In this case, the maximum coupling factor between the coils is achieved.

[0074] If the search system cannot find a second resonance or impedance change, it knows that a receiving coil has not been found or that the wheel placed in the bicycle storage station does not have a coil at all.

[0075] After the wireless LEV charging system aligns the transmitting and receiving coils, a communication link is established between the inductive power transmitter and the inductive power receiver using a battery management system (BMS).

[0076] This is illustrated by transmitter 80 and receiver 82. This can be achieved via an in-band communication link, Bluetooth, etc. Once communication has been established, inductive power transfer can begin charging the battery.

[0077] For this purpose, a signal is transmitted from the controller 64 of the inductive power transmitter to the inductive power receiver via communication links 80 and 82 to activate the relay switch of the rotary electrical connector 24. The mechanical contacts of the relay switch will be closed only during charging in this way to overcome contact wear during normal use of the LEV.

[0078] An example of a feasible coil design will now be described, such as... Figure 7 As shown.

[0079] The transmitting coil Lp includes a ferrite core and a coil surrounding the ferrite core, the ferrite core forming a closed loop around a portion of the receiving coil Ls.

[0080] In this example, the ferrite core includes two arcuate core portions 92 and 94, which are moved apart and together to open and close the ring, as shown. Figure 7As indicated by the arrows in the diagram. The transmitting coil Lp includes a winding around at least one of the arcuate core portions. In the example shown, each arcuate core portion 92 and 94 has a winding arrangement 96 around each of its two ends.

[0081] In the closed configuration, the transmitting coil Lp comprises a closed ferrite core with a tightly wound coil. The secondary coil can be considered to comprise a loosely wound coil. It is defined by an arcuate portion 90 conforming to the shape of a wheel rim and a spoke portion 92 conforming to the shape of a wheel spoke. The spoke portion provides a connection between the ends of the arcuate portion.

[0082] Therefore, the receiving coil has the shape of an open space between the spokes of a wheel, making it least visible and ultimately not interfering with the bicycle design. The air gap in the ferrite core is kept to a minimum to reduce stray fields.

[0083] In this way, the vehicle has a wheel with a rim, and a wireless charging receiving coil is integrated into the wheel and includes a ring that comprises an arcuate portion of the wheel rim. Therefore, a portion of the wheel rim serves as part of the receiving coil.

[0084] Figure 8 It shows Figure 7 How does the design match the wheel design?

[0085] Figure 9 A bicycle wheel is shown being received in docking unit 30. It shows the curved portion 90 of the wheel rim being received in a closable opening 100 of the core of the transmitting coil Lp.

[0086] By closing the core of the transmitting coil Lp around the wheel rim, the transmitting coil can be designed as a tightly wound coil and achieve a good K-factor. The core of the transmitting coil can be opened and closed to allow the wheel to enter. When the bicycle is placed in the bicycle storage station, the front wheel is moved into the inside of the open core. If the bicycle is detected, the front wheel is rotated as described above. Once the transmitting and receiving coils are aligned, the front wheel stops rotating, and the core is closed to further increase the coupling factor.

[0087] Figure 10 Another example of a transmitting coil Lp is shown. It also includes a ferrite core and a coil wound around the core. The ferrite core in this example includes a first arcuate segment 110 with an opening 100 and a second arcuate segment 112 slidably received within the first segment. It is rotatably driven, allowing it to expose or close the opening to form a continuous ferrite loop. The rotatable actuator includes a drive gear and a worm gear 114.

[0088] Therefore, instead of moving the core portions laterally toward and away from each other, the two overlapping arcuate cores rotate concentrically relative to each other in order to open and close the closed loop defined by the cores.

[0089] In one example, one or more coil arrangements are wound around a stationary arc-shaped segment 110, for example, similar to Figure 7 The method shown involves a coil arrangement structure surrounding both ends of a stationary arcuate segment 110. However, the coil arrangement structure may be present only at one location around the ferrite core. One or more coil arrangements structure induce a magnetic field around the ferrite core, providing magnetic coupling with the receiving coil Ls. Thus, the ferrite core is used to guide the magnetic flux generated by the one or more coil arrangements structure around the ferrite core.

[0090] Figure 11 The transmitting coil with its core in the open state is shown.

[0091] There are various feasible designs for implementing a closable opening in the core of the transmitting coil.

[0092] Figure 10 and 11 The example has two concentric arc-shaped ferrite sections that rotate concentrically relative to each other. When the two cores are fully rotated over each other, a well-defined magnetic flux path is produced. Due to the relatively large overlap area, stray flux is kept to a minimum. The advantage of this configuration with overlapping ferrites is that the coupling factor between the transmitter and receiver coils increases to approximately 0.6.

[0093] Another example is an arc-shaped section forming two semicircles, which move laterally together and apart, such as... Figure 7 As shown. In this way, using two opposing facing surfaces, there exists a traversing path from ferrite core to ferrite core. The construction of the ferrite elements with opposing faces allows the coupling factor between the transmitting and receiving coils to be increased to approximately 0.5.

[0094] Other examples are feasible, provided that the components move relative to each other to open and close the openings, and a continuous ferrite path is formed around the closed shape. In all examples, mechanical and electronic devices can be applied as needed to move the components.

[0095] The closure of the transmitting coil also serves as part of a lock to prevent vehicle theft.

[0096] Figure 12 The receiving coil Ls is shown to be configured as part of a wheel design, including an arcuate portion 90 and a spoke portion 92. Figure 12 The receiving coil section of the wheel design is shown, separate from the rest of the wheel.

[0097] To avoid inducing eddy currents in the wheel rim due to magnetic flux, one option is as follows: Figure 12 The top image shows a partial removal of the wheel rim, and as... Figure 12 The bottom part is shown to be replaced with a non-conductive part.

[0098] Wheel rims are typically aluminum extrusions, rolled into a circle using a profile rolling mill, and then mechanically joined at the two open ends. Therefore, the additional section joined between the rolled ends does not represent a significant additional weakness. The non-conductive portion can simply consist of non-conductive end spacers and a conductive center portion.

[0099] Figure 13 It shows the components assembled to form a wheel. Figure 12 The structure. The curved section extends, for example, around a 36-degree angle, but other angles can certainly be used to match the spoke design.

[0100] Figure 14 A 3D view of the receiving coil Ls is shown. The arcuate portion 90 is housed within a non-conductive housing 120 forming a non-metallic rim section. The non-conductive housing 120 has a connecting pin 122 for connection to the remainder of the wheel rim, which is typically in the form of extruded aluminum, as described above.

[0101] The receiving coil spoke portion 92 includes, for example, a co-molded plastic injection unit. The spoke portion is separate and additional to the structural spokes 124 (and its tension nut 125), but they can be aligned (from the side view). The wire 126 extends from the receiving coil to the hub, in which a rotary electrical contact is housed.

[0102] Tires 128, for example, should avoid having metal reinforcements.

[0103] Figure 15 A basic circuit diagram is schematically shown. It shows a transmitting coil Lp that excites a ferrite core 130, which passes around the wheel rim and thus around the arcuate portion 90 of the secondary coil Ls.

[0104] Figure 15 A separate charging unit 152 is also shown. This could be, for example, a handheld power clip that a user could attach to a wheel at home to perform recharging. The compact clip charger is, for example, mounted around one of the two spoke portions 92 of the receiving coil Ls. The clip charger can have a compact size because it does not require mounting around the rim and tire.

[0105] As mentioned above, one aspect of this design is the rotary electrical contact, which can be opened and closed by an actuator.

[0106] Figure 16An example of a rotary electrical contact is shown. It is formed by a rotating printed circuit board 160 and a stationary printed circuit board 162. An actuator in the form of a relay 164 controls the activation and deactivation of the rotary electrical contact.

[0107] like Figure 17 As shown in the exploded view, the contact bridging assembly 166 is a moving and stationary printed circuit board for the relay. The contact bridging assembly has flexible contacts connected to conductor rails formed as two concentric contact paths 172, 174, which rotate together with the rotating printed circuit board 160. When the relay is engaged, the contact bridging member connects to the concentric contact paths 172, 174. The contact bridging member is positioned about the wheel axle axis, with defined concentricity, contact distance, and parallel alignment.

[0108] Figure 18 Another view of the stationary printed circuit board 162 is shown.

[0109] exist Figures 16 to 18 In this design, the conductor rail comprises a cylindrical surface extending about the axis of rotation of the wheel and in adjacent parallel planes. An actuator (relay) is configured to move a contact bridge radially relative to the axis of rotation of the wheel. Therefore, in this design, two circuit boards are placed side-by-side. The contact bridge spans the outer circumference of the rail, and the rail rotates below the contacts.

[0110] There are other feasible designs.

[0111] Figures 19 to 23 A second design is shown, in which the conductor rail is located in a plane perpendicular to the axis of rotation of the wheel, and the actuator is configured to move the contact bridge in a direction parallel to the axis of rotation of the wheel.

[0112] Figure 19 A stationary printed circuit board 190 and its relay 194 and a rotating printed circuit board 192 are shown.

[0113] Figure 20 The exploded view shows the contact bridging assembly 196 fixed to a stationary printed circuit board.

[0114] Figure 21 The exploded view shows the concentric rails 200 and 202 on the rotating printed circuit board 192.

[0115] In this design, the contact bridging element 196 spans the gap between two parallel and spaced-apart circuit boards. It moves parallel to the axis of rotation, thus moving axially, and the guide rail lies in a plane perpendicular to the axis of rotation.

[0116] Figure 22 Another exploded view of the relay is shown. Figure 23An internal view of the relay is shown. It shows the relay coil 210 and coil isolator 212, as well as the iron core 214 and return spring 216.

[0117] In another design, the conductor rails comprise cylindrical surfaces extending around the axis of rotation of the wheel and axially aligned (thus one radially outward of the other), and actuators are configured to move contact bridging members radially between the two concentric circuit boards relative to the axis of rotation of the wheel. In this design, the two circuit boards can be coplanar, for example, one concentrically surrounding the other, thus occupying less space. The contact bridging members move radially between them.

[0118] The actuator can then be configured to move the contact bridge radially in response to the centrifugal force generated by the rotation of the wheel, thereby disengaging the electrical connector. In this design, wheel rotation automatically breaks the contact established by the contact bridge. Activation of the contact in this manner is achieved by spring force and the absence of centrifugal force due to the inactivity of the wheel. The contacts are, for example, configured with a suitable mass block and hinged to the wheel hub, such that they expand outward as they rotate against the spring force.

[0119] By studying the accompanying drawings, the disclosure, and the appended claims, those skilled in the art can understand and implement variations of the disclosed embodiments in the practice of the claimed invention. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude a plurality.

[0120] The functions implemented by a processor can be implemented by a single processor or by multiple separate processing units, which together can be considered to constitute a "processor". In some cases, such processing units can be located far apart from each other and communicate with each other via wired or wireless means.

[0121] The fact that some measures are described in different dependent claims does not indicate that a combination of these measures cannot be used advantageously.

[0122] If the term "suitable" is used in the claims or description, it should be noted that the term "suitable" is intended to be equivalent to the term "configured as". If the term "arrangement structure" is used in the claims or description, it should be noted that the term "arrangement structure" is intended to be equivalent to the term "system", and vice versa.

[0123] Any reference numerals in the claims should not be construed as limiting the scope.

Claims

1. An electric vehicle, comprising: Wheel with rim (40); Battery (22); Battery charging circuit (72); as well as A wireless charging receiving coil (Ls) incorporated into the wheel includes a loop comprising an arcuate portion (90) of the wheel rim, wherein the arcuate portion (90) of the wheel rim is used to receive in a closable opening in the core of the transmitting coil of the vehicle charging system.

2. The electric vehicle according to claim 1, wherein, The ring also includes a connector (92) between the ends of the arcuate portion (90), wherein the connector is positioned to align with the spokes of the wheel.

3. An electric vehicle system, comprising: Vehicle charging system; as well as The electric vehicle according to claim 1 or 2, The vehicle charging system includes a transmitting coil (Lp) having a core with a loop having a closable opening for receiving the wheel rim, wherein the opening is configured to receive the wheel rim when open and is configured to close around the wheel rim to enable wireless charging.

4. An electric vehicle charging system, comprising: The docking unit (30) is used to receive the wheels of the vehicle that are equipped with wireless charging receiving coils (Ls). A drive arrangement structure (44) for rotating the wheel (40) received by the docking unit. A wireless charging transmitting coil (Lp) is used to transfer charge to the receiving coil (Ls) of the wheel that is received by the docking unit. Detection systems (60, 62) are used to detect the relative alignment between the transmitting coil and the receiving coil; and Controller (54), which is configured to: In response to the detected relative alignment, the drive arrangement structure (44) is controlled to provide the desired relative alignment between the transmitting coil (Lp) and the receiving coil (Ls); as well as Control the wireless charging from the transmitting coil (Lp) to the receiving coil (Ls).

5. The system according to claim 4, wherein, The docking unit includes a set of rollers (42, 44) for engaging with the tire of the wheel, wherein at least one roller (44) is driven by the drive arrangement structure.

6. The system according to any one of claims 4 to 5, wherein, The detection system includes a peak detector (60) for detecting the resonant frequency that generates peak current or voltage.

7. The system according to any one of claims 4 to 6, wherein, The transmitting coil (Lp) includes a core with a loop having a closable opening for receiving a wheel rim, wherein the opening is configured to receive the wheel rim when open and is configured to close around the wheel rim to enable wireless charging.

8. The system according to claim 7, wherein, The transmitting coil (Lp) includes: Two arcuate core portions (92, 94) are moved apart and together to open and close the ring; or Two overlapping arcuate core portions (110, 112) rotate concentrically relative to each other to open and close the ring.

9. An electric vehicle configured for charging by a vehicle charging system according to any one of claims 4 to 8, comprising: Wheel with rim (40); A wireless charging receiver coil (Ls) is incorporated into the wheel. Battery (22); and Battery charging circuit (72). The receiving coil (Ls) includes a ring, which includes an arcuate portion (90) of the wheel rim, wherein the arcuate portion of the wheel rim is used to receive a closed opening in the core of the transmitting coil of the vehicle charging system.

10. The electric vehicle according to claim 9, wherein, The ring also includes a connector (92) between the ends of the arcuate portion, wherein the connector is positioned to align with the spokes of the wheel.

11. The electric vehicle according to claim 9 or 10, wherein, The electric vehicle includes a rotary electrical connector (24) between the wireless charging receiving coil (Ls) and the battery charging circuit (72), wherein the electric vehicle also includes an actuator (64) for controlling the mechanical engagement of the rotary electrical connector (24) such that the rotary electrical connector is engaged in preparation for charging.

12. The electric vehicle according to claim 11, wherein, The electric vehicle also includes a load (Cd) connected to the receiving coil (Ls), including when the rotary electrical connector (24) is not engaged.

13. An electric vehicle system, comprising: The vehicle charging system according to any one of claims 4 to 8; as well as The electric vehicle according to any one of claims 9 to 12.

14. A method for charging an electric vehicle, comprising: The electric vehicle charging system receives the vehicle's wheels at its docking unit, the wheels being coupled with a wireless charging receiving coil, and the electric vehicle charging system having a wireless charging transmitting coil for transferring charge to the wireless receiving coil. The rotation is received at the docking unit by the wheel, while the relative alignment between the transmitting coil and the receiving coil is detected; as well as Wireless charging from the transmitting coil to the receiving coil is controlled once the wheels have been rotated to the desired relative alignment.

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