Patent Application
20250174382
The present application is based upon and claims the right of priority to CN Patent Application No. 202311583427.4, filed Nov. 24, 2023, the disclosure of which is hereby incorporated by reference herein in its entirety for all purposes.
This invention relates to inductive power transfer (IPT) systems, and in particular to laminated cores in such systems.
IPT technology has attracted significant attention from industries and researchers.
The wireless transmission of energy offers numerous advantages for electric vehicles (EVs), enabling autonomous charging and dynamic charging with minimal effort in terms of wiring and maintenance [1], [2], [3], [4].
However, as the demand for charging power and the power density of the chargers has dramatically increased in recent years, IPT faces imminent challenges to enhance its competitiveness. One of the main obstacles is the use of soft magnetic materials (SMCs) in the technology. SMCs are essential for commercial and industrial IPT applications as they provide a low-reluctance path for magnetic flux, thereby effectively improving the power transfer efficiency by increasing the coupling coefficient and quality factors of the magnetic coupler [5]. Furthermore, the high permeability of SMCs helps in reducing the leakage stray field, which is tightly regulated by the standards. For the moment, the most commonly used SMCs for inductive power transfer are soft MnZn ferrites. The materials dominate the market due to their affordability and sufficient magnetic properties.
However, soft ferrites have certain limitations. They exhibit relatively low saturation flux density, and their properties vary significantly at different temperatures [6], [7]. Moreover, the assembly of ferrite blocks can introduce unwanted air gaps, leading to hotspots and posing a threat to the stability of the system [8], [9].
An alternative type of SMC commonly applied in transformers is the laminated core. The core materials are typically made with highly conductive and permeable materials like silicon steel and nanocrystalline alloys [10], [11], [12]. By utilizing thin laminations, the effective paths for eddy currents along the ribbon directions are reduced, thereby minimizing eddy current losses. The adoption of laminated cores offers several advantages. Firstly, these materials exhibit high saturation flux density, typically exceeding 1 T, allowing high power density. Additionally, the relative permeabilities of laminated cores are often higher than that of ferrite, with silicon steel reaching values of over 5000 and nanocrystalline materials surpassing 10000. Finally, the thermal stability of the materials outperforms MnZn ferrite [13], benefiting applications operating in different ambient temperatures. Silicon steel is laminated in layer thicknesses ranging from 100 to 300 μm and finds extensive application in low-frequency AC scenarios such as grid transformers and electrical machines. While the nanocrystalline material can be laminated as thin as 18 μm, enabling its utilization in high-frequency applications over 100 kHz.
In the field of IPT research, investigations have also been conducted on the potential utilization of laminated cores. Typically, two different lamination directions are employed: horizontally laminated cores (H-cores) and vertically laminated cores (V-cores), relative to the winding planes. In [14], [15], the authors explore the use of thin, horizontally laminated nanocrystalline ribbons to enhance the efficiency of inductive power transfer. The magnetic coupler design exhibited an approximate 2% increase in efficiency. However, the study did not address the issue of the non-uniform distribution of flux density in the horizontal lamination. Research in [16], [17], [18] involves the use of crushed nanocrystalline cores. These cores have the same material composition but undergo an additional crushing process to reduce eddy current losses. Vertical laminations become possible to implement. However, the crushing process also compromises permeability and introduces larger hysteresis losses due to the presence of distributed air gaps, thereby degrading the potential benefits of the highly permeable materials [19], [20]. Hybrid core design with vertical lamination and ferrite proposed in [21], [22], results show that the efficiency can be improved drastically by mitigating the eddy current loss of the laminated cores. The primary reason for the degraded performance of the laminated cores in IPT is the dominant leakage field, which typically accounts for a relatively small proportion compared to the total flux of the tightly coupled transformers. During the operations in IPT, the leakage flux enters the cores from different directions. The norm flux, oriented perpendicular to the sheets, induces substantial eddy current losses.
All referenced literatures throughout this disclosure are incorporated herein by reference in their entirety, which include the following references:
In one aspect of the invention, there is provided a magnetic flux device configured to transmit or receive magnetic flux to or from a space beyond the magnetic flux device. The magnetic flux device includes a first electrically conductive coil and a magnetically permeable core. The magnetically permeable core includes a plurality of first laminated cores each laminated along a first direction, and a plurality of second laminated cores each laminated along a second direction substantially perpendicular to the first direction.
In some embodiments, the magnetic flux device further includes a second electrically conductive coil which is configured side-by-side with the first electrically conductive coil to form a double-D winding structure.
In some embodiments, both the first direction and the second direction are parallel to a virtual plane in which the first electrically conductive coil is located.
In some embodiments, the second direction is parallel to a virtual line that connects a centre of the first electrically conductive coil and a centre of the second electrically conductive coil. The second direction and the first direction are parallel to a virtual plane in which the first electrically conductive coil and the second electrically conductive coil are located.
In some embodiments, each first laminated core includes a plurality of first laminations, and each second laminated core includes a plurality of second laminations.
The first laminations and the second laminations are co-planar.
In some embodiments, the plurality of the first laminated cores is placed on one side of the plurality of the second laminated cores, as a magnetic flux balancer, to reduce flux concentration.
In some embodiments, the plurality of the first laminations includes a plurality of insulation layers and a plurality of first soft magnetic core (SMC) layers that are interlaced.
In some embodiments, both the plurality of insulation layers and the plurality of first SMC layers extend along the first direction.
In some embodiments, the plurality of the second laminations contains a plurality of insulation layers and a plurality of second SMC layers that are interlaced.
In some embodiments, both the plurality of insulation layers and the plurality of second SMC layers extend along the second direction.
In some embodiments, the plurality of first SMC layers has higher permeability in directions along a layer surface than the plurality of the second SMC layers.
In some embodiments, the plurality of first SMC layers has lower permeability in a direction perpendicular to a layer surface than the plurality of the second SMC layers.
In some embodiments, the plurality of first SMC layers has higher conductivity than the plurality of the second SMC layers.
In some embodiments, the plurality of first SMC layers is made of a Fe-based nanocrystalline material. The plurality of second SMC layers is made of a nanocrystalline flake ribbons (NFR) material.
In some embodiments, the magnetic flux device further includes a base plate on which a plurality of core clamps is configured. The core clamps secure the plurality of first laminations and/or the plurality of second laminations to the base plate.
In some embodiments, the magnetic flux device further includes an insulation film arranged between the first electrically conductive coil and the magnetically permeable core.
Exemplary embodiments of the invention therefore provide a cross-lamination structure that combines the advantages of both vertical and parallel laminations, effectively mitigating thermal imbalances and enhancing the efficiency. The cross-lamination contains at least two variations. The cross-laminated cores significantly reduce eddy currents, which are loops of electrical currents induced within conductors by changing magnetic fields, which if unchecked, can cause substantial power losses and generate excessive heat. By minimizing these currents, the cores ensure more efficient transfer of magnetic flux, which is critical for the energy transfer in wireless charging as an example of the applications of the invention. Secondly, the cross-laminated cores help maintain high magnetic permeability. This property is crucial for achieving strong magnetic coupling between the transmitter and receiver coils—the primary pathway through which energy is transferred wirelessly. High permeability allows for the generation of a strong magnetic field with less energy, thereby boosting the system's overall efficiency. Furthermore, the cross-lamination helps to balance the flux density distributions within the core. Laminated cores typically exhibit high anisotropy, resulting in an uneven flux density distribution. However, by combining vertical and horizontal laminations, the anisotropic permeability can be effectively balanced, leading to a more uniform flux density distribution. This, in turn, reduces core loss by eliminating flux concentration, ultimately resulting in improved efficiency. Moreover, the cross-laminated cores help increase the power density. Due to the fact that most of the lamination materials exhibit high saturation flux density, the cores can be designed very thin, reducing the overall dimension of the wireless charging device, for example a wireless charging pad.
The foregoing and further features of the present invention will be apparent from the following description of embodiments which are provided by way of example only in connection with the accompanying figures, of which:
In the claims which follow and in the preceding description, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.
As used herein and in the claims, “couple” or “connect” refers to electrical coupling or connection either directly or indirectly via one or more electrical means unless otherwise stated.
Terms such as “top”, “bottom”, “horizontal”, “vertical”, “upwards”, “downwards”, “above”, “below” and similar terms as used herein are for the purpose of describing the invention in its normal in-use orientation. However, they should not be interpreted as imposing any strict limitation to the claims regarding orientation or relation positions of the relevant components.
Embodiments of the invention are related to the field of IPT systems, specifically focusing on the implementation of laminated cores to enhance system performance. In some embodiments, lamination structures including vertical and parallel configurations, employing Fe-based nanocrystalline materials and NFR respectively, are chosen for their superior core loss characteristics. In the detailed exposition, the disclosure introduces material modeling and loss analysis methodologies that integrate toroidal measurements with assessments of eddy current losses induced by norm flux. Utilizing the Finite Element Method (FEM) under this modeling framework, it has been determined that both lamination structures exhibit notable flux density and thermal imbalances, which present significant operational challenges for IPT systems.
In response to these findings, the cross-lamination structure is proposed which combines the advantages of both vertical and parallel laminations, effectively mitigating the aforementioned thermal imbalances. Experimental simulations, as delineated herein, demonstrate an enhancement in system performance, which is further corroborated by empirical testing. The results of implementing the integrated lamination approach are profound, extending the operational duration of IPT systems, reducing the maximum operational temperature by approximately 40° C., and achieving an efficiency increase of over 0.4% at a power output of 10.8 kW. The core design not only offers a practical solution for the deployment of laminated cores in IPT applications but also significantly augments their efficiency and thermal management capabilities.
Right underneath the top plate 20 is the coil structure of the wireless charging pad 21, which includes two identical electrically conductive coils 22. Each coil 22 has a substantially stadium shape. The two coils 22 are arranged side-by-side, and they are located in a same virtual plane (not shown, which is the winding plane) that is parallel to the planar part 20a of the top plate 20. For the purpose of easy reference, define the direction along which a virtual line (not shown) connecting centers (not shown) of the two coils 22 to be the y direction. In other words, the two coils 22 are positioned one after another along the y direction. However, for each coil 22 its dimension along a x direction is larger than that along the y direction, because of the stadium shape. The x direction is perpendicular to the y direction, whereas a z direction is defined as the stacking direction of the top plate 20, the coils 22, the bottom plate 34, etc. The three directions x, y and z are shown in
At the center of the wireless charging pad 21 there is a magnetically permeable core which includes a plurality of V-cores 26 and a plurality of H-cores 28. The V-core 26 is named since laminations in the V-core 26 contain layers that extend along a vertical direction that is defined to be the y direction. The H-core 28 is named since laminations in the H-core 28 contain layers that extend along a horizontal direction, which is defined to be the x direction. The laminations in the V-cores 26 and the H-cores 28 will be described in more detail later. Note that although in the exploded view of
Between the magnetically permeable core and the two coils 22, there is an insulation film 24 placed, which insulates the magnetically permeable core from the coils 22. Next, underneath the magnetically permeable core there is an aluminum plate 30, on which there are multiple core clamps 32 configured. The core clamps 32 are used to fix laminations 26a, 28a in the magnetically permeable core on the aluminum plate 30. As shown in
Turning to
For the second variation as shown in
As mentioned above, for a H-core 28 the laminations contain layers that extend along the horizontal direction, which is defined to be the x direction in
Similarly, for the V-core 26 the laminations contain layers that extend along the vertical direction, which is defined to be the y direction in
The SMC layers 42 in the V-cores 26 and the SMC layers 40 in the H-cores 28 can be made of the same materials or different materials. In a preferred embodiment, the H-cores 28 should use materials with medium permeability between 3000-8000 to ensure effectiveness, and the V-cores 26 should use materials with high saturation flux density over 1 T and high permeability over 10000, such as silicon steel and nanocrystalline alloy. In one exemplary embodiment, the core material for vertical lamination has a permeability of 17710. Preferably, as will be described in more details below, in one preferred implementation the Finemet® nanocrystalline alloy (which can be obtained from Proterial, Ltd.) is configured with horizontal laminations, while NFR is configured as vertical laminations.
The width of the vertical lamination shall be in the range of 20-30 mm, while the parallel laminations shall remain below 15 mm. In this case, the main flux is conducted primarily with the vertical laminations, due to their high permeability and low core loss. The parallel laminations behave as shielding to reduce the edge loss of the vertical laminations. Meanwhile, as the permeability of parallel laminations increases, the flux density distribution becomes more uniform, as shown in
Having described the structure of the wireless charging pad 21, the descriptions will now come to the working principle of the wireless charging pad 21. In particular, in the following sections the flux density distribution and core loss behavior of the laminated cores in the IPT (i.e., the wireless charging pad 21) are first analyzed. Due to the dominating leakage flux, the mathematical model of the equivalent magnetic circuit in IPT cannot be precisely described. Therefore, finite element simulation is used as the tool for macroscopic analysis. Experiments are performed to compare and verify the performances.
As mentioned above, in the wireless charging pad 21 a double-D winding structure is utilized, due to its superior performance in minimizing leakage fields when compared to rectangular and circular windings [23], [24]. Moreover, the use of this structure complies with the SAE standards (from SAE International) for EVs. As shown in
A stacking factor of Fs=1 leads to a solid core composition. A higher stacking factor is preferred, given that the material of the insulation layers 38 offers sufficient insulation to reduce eddy currents. A thinner SMC layer 40, 42 would lead to lower eddy current loss. Nonetheless, this imposes limitations on the stacking factor as the insulation layer 38 must maintain a thickness that ensures adequate insulation.
The orientation of the lamination can be determined relative to the winding plane (e.g. the plane in which the coils 22 are wound). In V-core configurations, the lamination direction aligns parallel to the winding plane, whereas in H-core configurations, it aligns perpendicular to the winding plane. Intuitively, vertical lamination leads to higher core loss because the normal flux from the windings enters a larger surface area of the sheets, resulting in a larger eddy current path and increased Joule losses. On the other hand, H-cores 28 result in a significant increase in the length-width ratio of the core, which raises manufacturing costs and lowers the yield rate [15].
For laminated cores in transformers and inductors, the magnetic path forms a closed loop filled with material that has a much higher permeability than air. As a result, the leakage flux can be ignored other than in the area of the cut gaps. The material in the unidirectional path can be assumed to be isotropic. Nevertheless, in an IPT operating situation, leakage flux dominates. Therefore, the anisotropic characteristic of the material must be considered. The homogenization method is typically used to evaluate anisotropic behavior [25]. With the assumption that the adhesive layer is non-conductive and has relative air permeability μ0, the permeability and conductivity along the ribbon and lamination directions can be expressed as in (2).
where □l and □c are the permeabilities in the lamination and ribbon directions (the definitions of which are shown in
Since both horizontal and vertical laminated cores are uniaxially anisotropic, the homogenized permeability and conductivity can be modeled as rank-2 diagonal tensors in (3).
The horizontal and vertical lamination exhibit different tensors.
Based on the permeability and conductivity tensor setup, the distribution of flux density and core loss can be simulated with FEM. In this case, both losses occurred in ribbon and lamination directions are included.
The famous Bertotti model proposed in [26] separates the core loss Pv into hysteresis loss Ph, eddy current loss Pe, and excess loss Pc based on their mathematical characteristics in response to the flux density Bm and frequency fsw.
where kh, ke, and kc are the coefficients for the hysteresis loss Ph, eddy current loss Pe, and excess loss Pc respectively. In particular, the eddy current loss coefficient ke is determined by (5).
However, Eqn. (5) assumes that the majority of the flux remains along the sheet direction, and the induced eddy currents on the sheet surface can be neglected. This is true in transformer and inductor design where only a small controlled air gap is present. Nevertheless, in IPT applications, the eddy current loss caused by the normal flux is present for both vertical and horizontal laminations, as illustrated in
where Jn is the eddy current density, induced by the norm flux. The norm flux Bn is the subcomponent of the flux density vector at the specific position that is perpendicular to the SMC surface. Jn can be further represented by the Maxwell equations and Ohm's Law in (7).
The equations can be numerically solved with the FEM using T−Ω formulation to separate the regions and taking boundary conditions into consideration [29].
The total of laminated cores in IPT can be eventually obtained as (8).
The first term, Pv, represents the core loss when the flux direction is aligned with the sheet direction. It is determined experimentally, as physically separating different types of core loss during measurement is not practical. The second term, Pn, cannot be directly measured; however, it can be estimated using FEM simulations by calculating Bn and Jn. Therefore, in this disclosure, the two methods are combined for the laminated core loss analysis.
Since Pn only accounts for the eddy current loss caused by the norm flux, and the eddy current loss due to the parallel flux is already included in Pv. Therefore, σl can be set to 0 to avoid duplicate calculations of the eddy current loss.
Several types of core materials are available in the market and can be used for laminated cores for IPT applications. Table I in
NFR are created by further crushing Fe-based nanocrystalline ribbons, resulting in decreased conductivity and permeability. This lower conductivity allows for the use of NFR in vertical lamination configurations, as Pn is inversely proportional to the conductivity. Therefore, as mentioned above for the magnetically permeable core the Finemet® nanocrystalline alloy is configured with horizontal laminations, while NFR is configured as vertical laminations. Optimization details will be provided below.
To evaluate the core loss Pv of the nanocrystalline materials, core samples are made to perform the measurements. The horizontally laminated nanocrystalline ribbon core sample, as depicted in
The core loss measurement setup is shown in
where N1 and N2 are the winding numbers of the primary and secondary sides of the cores under test. The magnetic length lc and cross-sectional area Ac are calculated based on the core geometry. T is the period of the excitation. Based on the loss definition with magnetic field intensity and flux density in (10), the core loss Pv can be calculated accordingly.
The calculated loss does not account for winding loss as it utilizes the open secondary voltage.
Among the materials evaluated, the Finemet® core exhibits the lowest core loss under identical flux density conditions across all tested frequencies. For NFR materials, there is a noticeable increase in core loss as their permeability decreases in the core loss measurement of toroidal core. For instance, at an excitation frequency of 85 kHz and a flux density of 0.3 T, the measured core losses for NFR1, NFR2, and NFR3 materials are 1367.8 kW/m3, 886.6 kW/m3, and 633.8 kW/m3, respectively. These figures are significantly higher than those for the Finemet® core, which is 405.5 kW/m3, even though the Finemet® has smaller stacking factors.
This reveals that for toroidal cores where the majority of the flux aligns with the sheet direction, the crushing process of the NFR material cannot improve the loss performance. Nevertheless, the additional eddy current loss Pn, which is highly geometry-dependent, can vary significantly in IPT applications. The results of the measurements, which represent the core loss model for Pv, are utilized in the FEM simulation which will now be described.
The evaluation and optimization of the magnetic core is performed with FEM simulation.
The air gap between the primary and secondary pads is 120 mm. To pursue higher power density, the target core thickness is set to 4 mm, while the magnetic core area covers only an area of 200 mm×460 mm. The primary and secondary windings are symmetric, with 10 turns on each winding. A series-series compensation network for the coupler is assumed. 15-A current excitations are assigned for the primary and secondary sides. The anisotropic material characteristics of the horizontally and vertically laminated core are modelled with (4) and (5), with the former one laminated along the x direction, and the latter laminated along the z direction.
The FEM simulations with horizontally laminated NRC cores are performed first.
where Bi and Beddy are the resulting flux densities from the excitations and induced eddy current respectively.
The superimposed flux density of the NRC cores reaches over 1.1 T on the center edge, close to the saturation flux density. Excessive loss will be generated on the edge, despite a relatively low overall core loss. The hot spot can create severe thermal issues. Even though the nanocrystalline material has a high Curie temperature over 600° C., the high temperature of the core material can potentially melt the adhesive layers and the insulations. In addition, the inner cores are conducting few flux densities despite the high permeability, resulting in low utilization of the core material.
The problem of vertical lamination is different. Simulation with vertically laminated NFR3 material is shown in
Saturation does not occur in the vertically laminated NFR cores, allowing for the proper operation of the magnetic coupler. However, when taking into account the norm flux density, the presence of additional induced eddy current loss Pn results in an increase in the overall core loss. As a consequence, the efficiency of the magnetic coupler is reduced.
For the cross-lamination structures shown in
The performance of the cross-lamination structure is further verified experimentally.
To facilitate a direct and fair comparison, the primary side employs Finemet® core material, whereas variations are made only to the secondary side. The inductance measurements are conducted using an LCR meter set to an excitation frequency of 85 kHz and an amplitude of 0.5 Vrms. Results regarding self and mutual inductance values are presented in Table II. Here, L1 and L2 represent the self-inductances of the primary and secondary pads, respectively, M denotes the mutual inductance, and k is the coupling coefficient. Notably, the cross-lamination structure exhibits increased self-inductance but reduced mutual inductance. This behavior is attributed to the flux linkage primarily traversing the window area of the double-D windings in the z-axis direction. This finding is consistent with the anisotropic modeling of the material, which indicates that NFR cores exhibit significantly lower permeability in the z-axis due to their vertical lamination structure, resulting in decreased coupling in the cross-lamination structure.
The tests are performed first with horizontal laminations.
Lowering the output current can mitigate the temperature disparity, as demonstrated in
Consistent with flux density distributions, the cross-lamination structure enhances both the temperature distribution and the peak temperature. Notably, as the permeability of the NFR material increases, these improvements become more evident. In terms of operational duration, Finemet® & NFR1 and Finemet® & NFR2 configurations extend to 2 minutes 40 seconds and 5 minutes 50 seconds, respectively, compared to single horizontally laminated Finemet® cores. The Finemet® & NFR3 setup can operate continuously without triggering over-temperature protections.
The temperature difference, Tm-m, is reduced from 10.6° C. to 4.2° C. at a 5 A output, and from 43.7° C. to 15° C. at a 10 A output with the Finemet® & NFR. These enhancements not only increase the operation times but also reduce thermal stress on the magnetic cores, thereby reducing the need for cooling efforts.
The innovative cross-lamination structure also simplifies the construction by reducing the number of horizontal laminations required. Typically, H-cores necessitate the assembly of thousands of thin magnetic and adhesive layers to achieve a core width of 25 mm, significantly increasing manufacturing costs. In contrast, vertical laminations involve fewer than 200 layers due to the core bar's thickness, which generally ranges from 3 to 5 mm in the WPT3 wireless charging system, thereby reducing production expenses.
The experimental results with cross-lamination indicate that configuring V-cores with higher permeability materials is more effective. The improvement with Finemet® & NFR3 is more evident than the other two. The reason is that the permeability of NFR1 material is only about 10% of that of horizontally laminated Finemet®. The reluctance of the material is much higher, resulting in a limited ability to redirect flux. The maximum relative permeability of the selected NFR materials reaches up to 7000. However, the impact of even higher permeability in vertical laminations is yet to be determined, as it is anticipated that conductivity might significantly increase due to reduced crushing. Consequently, the increase in norm flux eddy current losses Pn might outweigh the benefits.
In summary, the analysis above begins with anisotropic modelling of the laminated cores, followed by toroidal measurements using a power amplifier to determine core losses when flux aligns with the lamination sheet direction. By distinguishing losses from toroidal measurements and eddy current losses due to normal flux, finite element models are developed. The following simulations reveal that horizontal laminations exhibit a significant imbalance in flux distribution, whereas vertical laminations incur substantial additional eddy current losses. By alternating horizontal and vertical laminations, the flux distribution imbalance along the thickness direction can be evened out, and peak flux density at the edges can be reduced. Subsequent experimental results validate these simulations. Using single horizontal laminations, thermal camera observations of temperature distribution coincide with the simulated flux density distribution. The maximum temperature rapidly reaches the over-temperature limit at an output current of 15 A. In contrast, the cross-lamination structure enhances performance, reducing the maximum temperature by over 40° C. and increasing efficiency by over 0.4% at an output power of 10.8 kW. The proposed cross-lamination structure provides a viable approach to implement laminated cores in high-power IPT applications for EVs, enhancing saturation capacity and thermal stability with higher power density. The novel structure alleviates the inhomogeneous distribution of the flux density and core loss.
One can see that preferred embodiments of the invention provide a cross-lamination structure for laminated cores in double-D winding inductive power transfer applications. The cross-lamination structure cores can be used in the construction of inductive coils used in wireless charging systems. These cores are structured from multiple thin layers of metal, typically electrical steel, separated by insulating material. The combination of vertical and parallel laminations enhances the efficiency as well as thermal uniformity. The function of the structure includes firstly, the cross-laminated cores significantly reduce eddy currents. These are loops of electrical currents induced within conductors by changing magnetic fields, which if unchecked, can cause substantial power losses and generate excessive heat. By minimizing these currents, the cores ensure more efficient transfer of magnetic flux, which is critical for the energy transfer in wireless charging. Secondly, the design of cross-laminated cores helps maintain high magnetic permeability. This property is crucial for achieving strong magnetic coupling between the transmitter and receiver coils—the primary pathway through which energy is transferred wirelessly. High permeability allows for the generation of a strong magnetic field with less energy, thereby boosting the system's overall efficiency. Moreover, the cross-laminated cores help to increase the power density. Due to the fact that most of the lamination materials exhibit high saturation flux density, the cores can be designed very thin, reducing the overall thickness of the wireless charging pad.
The cross-laminated cores offer several advantages over solid ferrite cores in wireless charging systems, particularly due to their structural and material characteristics.
They can handle higher flux density with lower losses compared to ferrite cores, which have lower saturation magnetization, limiting their effectiveness in high-power applications.
These benefits make laminated cores particularly suitable for high-performance wireless charging applications where efficiency, heat management, and power handling are paramount.
In practical applications, wireless charging utilizing cross-laminated cores is employed in various sectors. It is prominently used in consumer electronics, such as smartphones and laptops, to provide a convenient, cable-free charging solution. Additionally, it's increasingly being adopted in automotive industries for charging electric vehicles and in healthcare for powering medical devices. The use of the cross-laminated core structures in these applications not only increases the efficiency of charging but also extends the longevity and reliability of the devices being charged.
Moreover, a novel application of wireless charging technology is emerging in the maritime sector, specifically for charging electric ships. This development aims to reduce dependency on traditional fossil fuels and enhance the sustainability of maritime transport. Wireless charging for ships involves creating a charging station, either at the dock or embedded in the port's infrastructure, where ships equipped with compatible wireless charging receivers can charge without the need to physically plug in. This system can significantly streamline the process of recharging electric vessels, making operations more efficient and less labor-intensive. The adoption of cross-laminated cores in such systems could further optimize the efficiency and reliability of wireless charging in harsh marine environments, ensuring strong magnetic coupling despite the challenging conditions. This expansion into marine applications not only broadens the market for wireless charging solutions but also contributes to the green transformation of the shipping industry.
The exemplary embodiments are thus fully described. Although the description referred to particular embodiments, it will be clear to one skilled in the art that the invention may be practiced with variation of these specific details. Hence this invention should not be construed as limited to the embodiments set forth herein.
While the embodiments have been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only exemplary embodiments have been shown and described and do not limit the scope of the invention in any manner. It can be appreciated that any of the features described herein may be used with any embodiment. The illustrative embodiments are not exclusive of each other or of other embodiments not recited herein. Accordingly, the invention also provides embodiments that comprise combinations of one or more of the illustrative embodiments described above. Modifications and variations of the invention as herein set forth can be made without departing from the spirit and scope thereof, and, therefore, only such limitations should be imposed as are indicated by the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202311583427.4 | Nov 2023 | CN | national |
