Patent Description:
Generally, the current charging technology for electric vehicles (EVs) may be classified as on-board charging (OBC), off-board charging, and wireless charging (WC). In many ways, the current topologies used in one or more conventional OBC and WC systems are quite similar. To some extent, one could say that a conventional WC is a conventional OBC with a loosely coupled isolation transformer. The integration of the conventional WC and the conventional OBC is preferred as the integration can lead to a partial improvement in power density and a partial reduction in the overall cost of the conventional OBC and WC system.

Currently, various methods have been proposed for the integration of the OBC and the WC. A conventional method of direct current (DC) link sharing has been proposed for integrating the conventional OBC and the conventional WC. In the conventional method of DC-link integration, the conventional OBC and the conventional WC both are connected at the DC-link level resulting in a very low level of integration and higher components count. However, the conventional method of DC-link integration requires no reconfigurable switches. Another conventional method of connection at power factor correction (PFC) level has been proposed for integrating the conventional OBC and the conventional WC. The conventional WC is integrated at the PFC level. When using the conventional WC, the energy is processed by several stages resulting in reduced efficiency. Additionally, the conventional method of connection at the PFC level does not reuse converters, such as conventional alternating current-to-direct current (AC-to-DC) or DC-to-AC converters, and hence, results in higher components count, which further results in a low level of integration.

Thereafter, different methods have been proposed for integrating the conventional OBC and the conventional WC by use of a conventional AC-to-DC converter with or without switches. In a conventional method of connection at the AC-to-DC converter with switches, the AC-to-DC (e.g., a diode bridge) stage is common for both the conventional WC and the conventional OBC systems. In this method, relays and connectors are used to isolate the conventional OBC from the conventional WC during operation. In a conventional method of connection at the AC-to-DC converter without switches, one of the AC-to-DC stages is common to both the conventional WC and the conventional OBC systems. However, the conventional method of connection at the AC-to-DC converter without switches does not require reconfiguration switches, hence, does not offer magnetic integration of the conventional WC and the conventional OBC systems. Further after, a conventional method of magnetic integration of the conventional WC and the conventional OBC is also proposed. In the conventional method of magnetic integration, a conventional WC pad serves as the transformer of the conventional OBC system. The conventional method of magnetic integration requires additional resonant components, such as external inductance, external capacitance, and two AC switches to isolate the OBC. The conventional method of connection at the AC-to-DC converter without switches and the conventional method of magnetic integration reuse only one of the two AC-to-DC converters of the conventional OBC and hence, result in lower power ratings, lower power densities, and lower utilization factors. Thus, there exists a technical problem of inefficient integration of the conventional WC and the conventional OBC systems.

Therefore, in light of the foregoing discussion, there exists a need to overcome the aforementioned drawbacks associated with the conventional methods of integrating the conventional WC and the conventional OBC systems. The <CIT> refers to a charging system for both plug-in charging systems and contactless charging systems.

The present disclosure provides an on-board charging (OBC) device for an electric vehicle, an electric vehicle, a system and methods for wirelessly charging the electric vehicle. The present disclosure provides a solution to the existing problem of inefficient integration of a conventional WC and a conventional OBC system. An objective of the present disclosure is to provide a solution that overcomes at least partially the problems encountered in the prior art and provides an improved on-board charging (OBC) device for an electric vehicle, an electric vehicle, a system, and methods for wirelessly charging the electric vehicle. Further implementations are disclosed in the dependent claims. In the following, implementations not falling within the scope of the claims are to be understood as examples useful for understanding the claims.

Advantageous implementations of the present disclosure are further defined in the dependent claims.

In one aspect, the present disclosure provides an on-board charging (OBC) device for an electric vehicle, comprising a mains input comprising a power factor correction (PFC) converter, a mains-side DC/AC converter, a transformer having a mains-side coil, and a battery-side coil, a battery-side AC/DC converter, a battery connector and one or more bypass switches configured to galvanically connecting the mains-side converter to the battery-side converter when closed. The transformer is configured to be magnetically coupled to a TX pad of an external wireless power transmitter, WPT, such that power is received by the mains-side coil and the battery side coil. When the bypass switches are closed, and the transformer is magnetically coupled to a WPT, power is sent to the battery connector through both the battery-side converter and the mains-side converter.

The present disclosure provides an improved OBC device which is configured to function as the OBC device as well as a wireless charger (or a wireless charging device) for wirelessly charging the electric vehicle. The disclosed OBC device is configured to function according to the mains input as well as the external wireless power transmitter at two independent frequencies. The disclosed OBC device manifests a higher power density at a significantly reduced cost. The disclosed OBC device requires no additional resonant components (e.g., inductors or capacitors) apart from the two standard resonant capacitors.

According to the invention, the OBC device further comprises a mains-side resonant tank having a first capacitance and a first inductance, and a battery-side resonant tank having a second capacitance and a second inductance and wherein values of the first capacitance and the first inductance of the mains-side resonant tank and the second capacitance and the second inductance of the battery-side resonant tank are selected to adapt the OBC device for operation with the mains input and operation with the WPT.

By virtue of selecting the values of the first capacitance and the first inductance of the mains-side resonant tank and the second capacitance and the second inductance of the battery-side resonant tank, the performance of the operation of the OBC device is adapted according to the mains input as well as to the external WPT.

According to the invention, the values of the first capacitance and the first inductance of the mains-side resonant tank and the second capacitance and the second inductance of the battery-side resonant tank are selected to correspond to a first resonant frequency for operation with the mains input and a second resonant frequency for operation with the WPT.

By virtue of selecting the values of the first capacitance and the first inductance of the mains-side resonant tank and the second capacitance and the second inductance of the battery-side resonant tank, the first resonant frequency and the second resonant frequency of the OBC device can be defined for operation with the mains input and with the external WPT, respectively.

In a further implementation form, the transformer is configured to operate with the mains input at the first resonant frequency commonly in the range of <NUM>-<NUM> (or higher) and operate with the WPT at the second resonant frequency in the range of <NUM>-<NUM>.

The transformer is configured to operate at two independent frequencies that are the first resonant frequency and the second resonant frequency, without any additional resonant components.

In a further implementation form, the mains-side resonant tank comprises a first capacitor configured to generate the first capacitance, and the battery-side resonant tank comprises a second capacitor configured to generate the second capacitance.

The use of the first capacitor to generate the first capacitance and the second capacitor to generate the second capacitance simplifies the structure of the OBC device.

According to the invention, the mains-side coil and the battery-side coil are arranged with an offset overlap to generate the first inductance of the mains-side resonant tank and the second inductance of the battery-side resonant tank simultaneously.

By virtue of the offset overlap between the mains-side coil and the battery-side coil, the OBC device manifests the first inductance and the second inductance; hence, the OBC device requires no additional magnetic components.

In a further implementation form, the bypass switches are direct current switches.

The use of the bypass switches as the direct current switches results in a reduced cost of the OBC device.

In a further implementation form, each of the mains-side converter and the battery-side converter comprises one of a full bridge, a half-bridge, or a diode bridge.

The use of the mains-side converter and the battery-side converter as the full-bridge, the half-bridge, and the diode bridge provides efficient conversion of power from DC domain to AC domain and vice-versa.

In another aspect, the present disclosure provides an electric vehicle comprising the on-board charging (OBC) device and at least one battery.

The electric vehicle achieves all the advantages and effects of the OBC device of the present disclosure.

In yet another aspect, the present disclosure provides a system for wirelessly charging an electric vehicle comprising the electric vehicle and an external wireless power transmitter, WPT, comprising a TX pad configured to deliver wireless power to the transformer of the OBC in the electric vehicle.

The system for wirelessly charging the electric vehicle manifests all the advantages and effects of the OBC device as well as the electric vehicle of the present disclosure. The system manifests an improved power density, copper utilization, low current stress, and losses as well.

In yet another aspect, the present disclosure provides a method of charging the electric vehicle, comprising magnetically coupling the transformer to a TX pad of an external wireless power transmitter (WPT), such that power is received by the mains-side coil and the battery side coil and closing the one or more bypass switches to galvanically connect the mains-side converter to the battery-side converter such that power is sent to the battery connector through both the battery-side converter and the mains-side converter.

The disclosed method provides bi-directional power flow and enables the electric vehicle to manifest high power density at a reduced cost.

In yet another aspect, the present disclosure provides a method of charging the electric vehicle, comprising connecting the mains input with an external mains supply and opening the one or more bypass switches to galvanically disconnect the mains-side converter from the battery-side converter such that power is sent to the mains-side coil of the transformer.

The disclosed method provides an on-board charging of the electric vehicle.

It is to be appreciated that all the aforementioned implementation forms can be combined.

It has to be noted that all devices, elements, circuitry, units, and means described in the present disclosure could be implemented in the software or hardware elements or any kind of combination thereof. All steps which are performed by the various entities described in the present disclosure, as well as the functionalities described to be performed by the various entities, are intended to mean that the respective entity is adapted to or configured to perform the respective steps and functionalities. Even if, in the following description of specific embodiments, a specific functionality or step to be performed by external entities is not reflected in the description of a specific detailed element of that entity that performs that specific step or functionality, it should be clear for a skilled person that these methods and functionalities can be implemented in respective software or hardware elements, or any kind of combination thereof.

Additional aspects, advantages, features, and objects of the present disclosure would be made apparent from the drawings and the detailed description of the illustrative implementations construed in conjunction with the appended claims that follow.

<FIG> is a block diagram that illustrates various exemplary components of an on-board charging (OBC) device for an electric vehicle, in accordance with an embodiment of the present disclosure. With reference to <FIG>, there is shown a block diagram <NUM> of an on-board charging (OBC) device <NUM> that includes a mains input <NUM>, a mains-side DC-to-AC converter <NUM>, a transformer <NUM>, a battery-side AC-to-DC converter <NUM>, a battery connector <NUM>, one or more bypass switches <NUM>, a mains-side resonant tank <NUM> and a battery-side resonant tank <NUM>. There is further shown an external wireless power transmitter (WPT) <NUM> that includes a transmitter (TX) pad 120A. The mains input <NUM> includes a power factor correction (PFC) converter 104A. The transformer <NUM> includes a mains-side coil 108A and a battery-side coil 108B. The main-side resonant tank <NUM> includes a first capacitor 116A, and the battery-side resonant tank <NUM> includes a second capacitor 118A.

An on-board charging, OBC, device <NUM> for an electric vehicle, comprising:.

The OBC device <NUM> includes suitable logic, circuitry, interfaces, or code that is configured for use in an electric vehicle for charging a battery through the battery connector <NUM>. The OBC device <NUM> is configured to operate with the mains input <NUM> as well as with the external WPT (or simply WPT) <NUM>. When the one or more bypass switches <NUM> are open, the OBC device <NUM> is configured to operate with the mains input <NUM> and charge the battery through the battery connector <NUM> depending on the mains input <NUM>. When the one or more bypass switches <NUM> are closed, the OBC device <NUM> is configured to operate with the WPT <NUM> and charge the battery through the battery connector <NUM> depending on power received from the WPT <NUM>. The operation of the OBC device <NUM> with the mains input <NUM> as well as the WPT <NUM> is described in more detail, for example, in <FIG>.

The mains input <NUM> includes suitable logic, circuitry, interfaces, or code that is configured to provide direct current (DC) power in output. The mains input <NUM> may be a grid.

The PFC converter 104A includes suitable logic, circuitry, interfaces, or code that is configured to regulate the power factor of the DC power provided by the mains input <NUM>. Generally, a PFC converter is used to make the power factor of the DC power closer to <NUM>. Alternatively stated, the PFC converter is used to bring the power factor angle (or phase angle) of the DC power closer to <NUM>° in order to reduce phase difference between the voltage and current so that maximum power can be drawn from the mains input <NUM>. Examples of the PFC converter 104A includes but are not limited to a PFC boost converter, an active PFC converter, and the like.

The mains-side DC-to-AC converter <NUM> includes suitable logic, circuitry, interfaces, or code that is configured to convert the DC power into an AC power.

The transformer <NUM> includes suitable logic, circuitry, interfaces, or code that is configured to be magnetically coupled to the TX pad 120A of the external wireless power transmitter (WPT) <NUM> such that the power is received by the mains-side coil 108A and the battery-side coil 108B.

The battery-side AC-to-DC converter <NUM> includes suitable logic, circuitry, interfaces, or code that is configured to convert the AC power into DC power.

The battery connector <NUM> includes suitable logic, circuitry, interfaces, or code that is configured to provide the DC power to the battery.

The one or more bypass switches <NUM> includes suitable logic, circuitry, interfaces, or code that is configured to galvanically connect the mains-side converter (i.e., the mains-side DC-to-AC converter <NUM>) to the battery-side converter (i.e., the battery-side AC-to-DC converter <NUM>) when closed. Each of the one or more bypass switches <NUM> may be a DC switch. The structural and functional connections between various components of the OBC device <NUM> are described in more detail, for example, in <FIG>.

In operation, when the bypass switches <NUM> are closed and the transformer <NUM> is magnetically coupled to a WPT <NUM>, power is sent to the battery connector <NUM> through both the battery-side converter (i.e., the battery-side AC-to-DC converter <NUM>) and the mains-side converter (i.e., the mains-side DC-to-AC converter <NUM>). When the one or more bypass switches <NUM> are closed and the transformer <NUM> is magnetically coupled to the TX pad 120A of the WPT <NUM>, the OBC device <NUM> is configured to operate as a wireless charger (WC). In this configuration, the transformer <NUM> is configured to operate as a receiver (RX) pad of the WC. The mains-side coil 108A and the battery-side coil 108B operate in parallel and feed their energy to their respective power converters, such as the mains-side coil 108A feeds the energy to the mains-side DC-to-AC converter <NUM> and the battery-side coil 108B feeds the energy to the battery-side AC-to-DC converter <NUM>. In such configuration, both the converters that are the mains-side DC-to-AC converter <NUM> and the battery-side AC-to-DC converter <NUM>, are used simultaneously and resulting in an improved power rating. The WC is configured for wireless charging of the battery, which may be used in an electric vehicle.

According to the invention, the OBC device <NUM> further comprises the mains-side resonant tank <NUM> having a first capacitance and a first inductance, and the battery-side resonant tank <NUM> having a second capacitance and a second inductance and wherein values of the first capacitance and the first inductance of the mains-side resonant tank <NUM> and the second capacitance and the second inductance of the battery-side resonant tank <NUM> are selected to adapt the OBC device <NUM> for operation with the mains input <NUM> and operation with the WPT <NUM>. The mains-side resonant tank <NUM> and the battery-side resonant tank <NUM> together act as a CLLC resonant tank. The CLLC resonant tank refers to a capacitor (C)-inductor (L)-inductor (L)-capacitor (C) resonant tank. The first inductance of the mains-side resonant tank <NUM> and the second inductance of the battery-side resonant tank <NUM> act as leakage inductances of the CLLC resonant tank. The first capacitance of the mains-side resonant tank <NUM> and the second capacitance of the battery-side resonant tank <NUM> are described in detail, for example, in <FIG>.

According to the invention, the values of the first capacitance and the first inductance of the mains-side resonant tank <NUM> and the second capacitance and the second inductance of the battery-side resonant tank <NUM> are selected to correspond to a first resonant frequency for operation with the mains input <NUM> and a second resonant frequency for operation with the WPT <NUM>. The values of the first capacitance and the first inductance of the mains-side resonant tank <NUM> and the second capacitance and the second inductance of the battery-side resonant tank <NUM> are selected in order to define the first resonant frequency of the CLLC resonant tank (i.e., the combination of the mains-side resonant tank <NUM> and the battery-side resonant tank <NUM>) for operation with the mains input <NUM> as well as the second resonant frequency for operation with the WPT <NUM>.

In accordance with an embodiment, the transformer <NUM> is configured to operate with the mains input <NUM> at the first resonant frequency usually in the range of <NUM>-<NUM> (higher frequencies are also possible) and operate with the WPT <NUM> at the second resonant frequency in the range of <NUM>-<NUM>. In a case when the one or more bypass switches <NUM> are open, the transformer <NUM> is configured to operate with the mains input <NUM> at the first resonant frequency usually in the range of <NUM>-<NUM>. The first resonant frequency higher than the range of <NUM>-<NUM> may also be used. Alternatively stated, when the one or more bypass switches <NUM> are open, the OBC device <NUM> is configured to operate according to the mains input <NUM> at the first resonant frequency. In another case, when the one or more bypass switches <NUM> are closed, the transformer <NUM> is configured to operate with the WPT <NUM> at the second resonant frequency in the range of <NUM>-<NUM>. Alternatively stated, when the one or more bypass switches <NUM> are closed, the OBC device <NUM> is configured to operate with the WPT <NUM> at the second resonant frequency in the range of <NUM>-<NUM>.

In accordance with an embodiment, the mains-side resonant tank <NUM> comprises a first capacitor 116A configured to generate the first capacitance, and the battery-side resonant tank <NUM> comprises a second capacitor 118A configured to generate the second capacitance. The mains-side resonant tank <NUM> comprises the first capacitor 116A that is configured to generate the first capacitance. Similarly, the battery-side resonant tank <NUM> comprises the second capacitor 118A that is configured to generate the second capacitance. This is described in more detail, for example, in <FIG>.

According to the invention, the mains-side coil 108A and the battery-side coil 108B are arranged with an offset overlap to generate the first inductance of the mains-side resonant tank <NUM> and the second inductance of the battery-side resonant tank <NUM> simultaneously. The mains-side coil 108A and the battery-side coil 108B of the transformer <NUM> are arranged with the offset (i.e., a partial) overlap to generate the first inductance of the mains-side resonant tank <NUM> and the second inductance of the battery-side resonant tank <NUM>, simultaneously. The mains-side coil 108A and the battery-side coil 108B are configured to have a partial overlap (i.e., the offset overlap) which induces a large mutual inductance as well as a small leakage inductance. The partial overlap between the mains-side coil 108A and the battery-side coil 108B may be obtained in various ways. For example, in one configuration, the mains-side coil 108A and the battery-side coil 108B may be displaced from their center points, or in a second configuration, the mains-side coil 108A and the battery-side coil 108B may be stretched sideways to create the partial overlap, or in a third configuration, the mains-side coil 108A and the battery-side coil 108B may be stretched in different axes to create the partial overlap. All such configurations are described in detail, for example, in <FIG>, <FIG>, and <FIG>. In accordance with an embodiment, the bypass switches (i.e., the one or more bypass switches <NUM>) are direct current switches. The one or more bypass switches <NUM> are direct current (DC) switches that are configured to regulate the operation of the OBC device <NUM> with the mains input <NUM> as well as with the WPT <NUM>.

In accordance with an embodiment, each of the mains-side converter (i.e., the mains-side DC-to-AC converter <NUM>) and the battery-side converter (i.e., the battery-side AC-to-DC converter <NUM>) comprises one of a full bridge, a half-bridge, or a diode bridge. Each of the mains-side DC-to-AC converter <NUM> and the battery-side AC-to-DC converter <NUM> may be one of an active full-bridge converter or a half-bridge converter. In a case, if bi-directional power flow is not required, then, in that case, the battery-side AC-to-DC converter <NUM> may be a passive converter, such as a diode bridge.

Thus, the OBC device <NUM> is configured to function as the on-board charging device as well as wireless charging device for the battery. When the one or more bypass switches <NUM> are open, then the OBC device <NUM> is configured to function as the on-board charging device for the battery. When the one or more bypass switches <NUM> are closed, then, the OBC device <NUM> is configured to function as the wireless charging device for the battery. In this way, the OBC device may function as the on-board charging device as well as the wireless charging device for the battery resulting into higher power density with a significant cost reduction.

<FIG> is a block diagram that illustrates various exemplary components of an electric vehicle, in accordance with an embodiment of the present disclosure. <FIG> is described in conjunction with elements from <FIG>. With reference to <FIG>, there is shown a block diagram <NUM> of an electric vehicle <NUM> that includes the on-board charging (OBC) device <NUM> (of <FIG>) and a battery <NUM>.

The electric vehicle <NUM> includes suitable logic, circuitry, interfaces, or code that is configured either partially or fully powered by use of the battery <NUM>. As the electric vehicle <NUM> includes the OBC device <NUM>, therefore, the electric vehicle <NUM> manifests on-board charging as well as wireless charging of the battery <NUM>. The electric vehicle <NUM> manifests an improved power rating as well as reduced cost. Examples of the electric vehicle <NUM> include, but are not limited to, a battery-electric vehicle, a plugin hybrid electric vehicle, a hybrid electric vehicle, and the like.

<FIG> is a block diagram that illustrates various exemplary components of a system for wirelessly charging an electric vehicle, in accordance with an embodiment of the present disclosure. <FIG> is described in conjunction with elements from <FIG> and <FIG>. With reference to <FIG>, there is shown a block diagram <NUM> of a system <NUM> that includes the electric vehicle <NUM> (of <FIG>) and the external wireless power transmitter (WPT) <NUM> (of <FIG>). The external WPT <NUM> includes the TX pad 120A.

The system <NUM> is configured for wirelessly charging an electric vehicle, such as the electric vehicle <NUM> (of <FIG>). In a case, the system <NUM> is configured to function as the OBC device <NUM> for charging the battery <NUM> of the electric vehicle <NUM>. In this case, the system <NUM> is configured to operate depending on a mains input, such as the mains input <NUM>.

In another case, the system <NUM> is configured to function as a wireless charger (WC) for charging the battery <NUM> of the electric vehicle <NUM>. In this case, the system <NUM> is configured to operate depending on an external power source, for this, the external WPT <NUM> including with the TX pad 120A that is configured to deliver wireless power to the transformer <NUM> of the OBC device <NUM> in the electric vehicle <NUM>. In this case, the OBC device <NUM> functions as the WC.

In an implementation form, the WPT <NUM> is configured to operate at resonant frequency in the range of <NUM>-<NUM>. In a case, when the system <NUM> is configured to operate as the WC, the WPT <NUM> is configured to operate at the resonant frequency in the range of <NUM>-<NUM>.

In this way, the system <NUM> is configured to adapt the operation of the OBC device <NUM> and the WC at two independent frequencies without having to add or remove resonant components (e.g., inductors or capacitors). Thus, the system <NUM> provides a higher power density with a significantly reduced cost.

<FIG> is a circuit diagram of a system that depicts the operation of an on-board charging (OBC) device with a mains input and an external wireless power transmitter (WPT), in accordance with an embodiment of the present disclosure. <FIG> is described in conjunction with elements from <FIG>, <FIG>. With reference to <FIG>, there is shown a system <NUM> that depicts the operation of an OBC device, such as the OBC device <NUM> (of <FIG>) with the mains input <NUM> as well as with the external WPT <NUM>.

The external WPT <NUM> includes a power factor correction (PFC) converter 120B that corresponds to the PFC converter 104A of the OBC device <NUM>.

In a case, the OBC device <NUM> is configured to operate with the mains input <NUM> when the one or more bypass switches <NUM> (also represented as S1) are open. In another case, the OBC device <NUM> is configured to operate with the external WPT <NUM> when the one or more bypass switches <NUM> (i.e., S1) are closed. In the other case, the OBC device <NUM> may operate as a wireless charger (WC) which may be configured for wirelessly charging the battery <NUM> of the electric vehicle <NUM> (of <FIG>). In the other case, the transformer <NUM> of the OBC device <NUM> is configured to operate as a RX pad of the WC which is configured to receive wireless power from the TX pad 120A of the external WPT <NUM>. In this case, the RX pad of the WC and the TX pad 120A of the external WPT <NUM> are magnetically coupled and this magnetic coupling is represented by a dotted circle <NUM>. Therefore, in a case when the one or more bypass switches <NUM> (i.e., S1) are closed, and the RX pad of the WC is magnetically coupled to the TX pad 120A of the external WPT <NUM>, the OBC device <NUM> operates as the WC. Due to the magnetic coupling between the TX pad 120A of the external WPT <NUM> and the RX pad of the WC, magnetic inductance comes into play. In this case, the mains-side coil 108A and the battery-side coil 108B of the RX pad (i.e., the transformer <NUM>) of the WC are configured to operate in parallel, feeding the energy to their respective power converters. That means the mains-side coil 108A is configured to feed the energy to the mains-side DC-to-AC converter <NUM>, and the battery-side coil 108B is configured to feed the energy to the battery-side AC-to-DC converter <NUM>. In this case, both the converters that are the mains-side DC-to-AC converter <NUM> and the battery-side AC-to-DC converter <NUM>, are simultaneously used, resulting in an improved power rating, for example, twice that of the OBC device <NUM>. The mains-side coil 108A and the battery-side coil 108B of the RX pad (i.e., the transformer <NUM>) of the WC are galvanically isolated. In comparison to conventional methods, each of the mains-side coil 108A and the battery-side coil 108B is simultaneously used to transmit power to the battery <NUM> when the OBC device <NUM> operates as the WC. This way, each of the mains-side DC-to-AC converter <NUM> and the battery-side AC-to-DC converter <NUM>, and each of the mains-side coil 108A and the battery-side coil 108B is simultaneously used that result in higher power ratings and utilization factors. Moreover, the current and the power get split into the two converters (i.e., the mains-side coil 108A and the battery-side coil 108B) and the two coils (i.e., the mains-side coil 108A and the battery-side coil 108B), hence, an improved copper utilization, lower current stress, and losses are attained.

In the case, when the OBC device <NUM> is configured to operate with the mains input <NUM>, the RX pad of the WC is configured to serve as the transformer <NUM> (e.g., an isolation transformer) of the OBC device <NUM>. The OBC device <NUM> includes the CLLC resonant tank induced by the mains-side resonant tank <NUM> and the battery-side resonant tank <NUM>. The mains-side resonant tank <NUM> includes the first capacitor 116A (also represented as Cr1) that is configured to generate the first capacitance. Moreover, the mains-side resonant tank <NUM> includes the first inductance (also represented as Lr1). Similarly, the battery-side resonant tank <NUM> includes the second capacitor 118A (also represented as Cr2) that is configured to generate the second capacitance. Moreover, the battery-side resonant tank <NUM> includes the second inductance (also represented as Lr2). The first inductance (i.e., Lr1) and the second inductance (i.e., Lr2) may act as the leakage inductances of the CLLC resonant tank. Therefore, no additional magnetic components are required in comparison to conventional methods in which more inductors and capacitors are required. Additionally, the ratio between the leakage inductance and the magnetizing inductance can be controlled by regulating the offset overlap between the two coils (i.e., the mains-side coil 108A and the battery-side coil 108B) forming the transformer <NUM> of the OBC device <NUM>.

The operation of the OBC device <NUM> with the mains input <NUM> as well as the WPT <NUM> allows a bi-directional power flow. Furthermore, the system <NUM> adapts the operation of the OBC device <NUM> and the WC at two independent frequencies without having to add or remove resonant components (i.e., inductors or capacitors). In comparison to the conventional approach, the system <NUM> provides higher power densities and cost reduction as well. The power density is increased due to removal of a conventional OBC transformer and resonant tank inductors, removal of AC-to-DC converter of a conventional WC system, and increase in power rating when the OBC device <NUM> is used as the WC. The cost of the system <NUM> is reduced due to removal of the conventional OBC transformer and additional resonant tank inductors, removal of the AC-to-DC converter of the conventional WC system, and integration of the system <NUM> into one single printed circuit board (PCB) with share housing and cooling system. Further, shared controller and gate drives circuits also reduce the cost of the system <NUM>.

<FIG> is a schematic diagram that depicts coil structure of a transformer of an OBC device, in accordance with an embodiment of the present disclosure. <FIG> is described in conjunction with elements from <FIG> and <FIG>. With reference to <FIG>, there is shown a coil structure 500A of the transformer <NUM> of the OBC device <NUM> (of <FIG>). The transformer <NUM> includes the mains-side coil 108A and the battery-side coil 108B.

Each of the mains-side coil 108A and the battery-side coil 108B is displaced from its center point to induce a partial overlap between the two. The partial overlap between the mains-side coil 108A and the battery-side coil 108B introduces a large mutual inductance and a small leakage inductance in the CLLC resonant tank. Conventionally, the coils of a WC system are designed to have either a zero overlap or a large overlap to cancel the mutual inductance. In contrast to the conventional coils, the mains-side coil 108A and the battery-side coil 108B introduces a large mutual inductance (i.e., magnetizing inductance) and a small leakage inductance in the CLLC resonant tank. Therefore, no additional magnetic components are required in comparison to conventional methods in which more inductors and capacitors are required. Additionally, the ratio between the leakage inductance and the magnetizing inductance can be controlled by regulating the partial overlap between the two coils (i.e., the mains-side coil 108A and the battery-side coil 108B) forming the transformer <NUM> of the OBC device <NUM>. A different arrangement of the mains-side coil 108A and the battery-side coil 108B allows the integration of the leakage as well as a magnetizing inductance in the RX pad of the WC and described in detail, for example, in <FIG>, <FIG>, and <FIG>. The mains-side coil 108A and the battery-side coil 108B of the transformer <NUM> may also be referred to as the mains-side coil 108A and the battery-side coil 108B of the RX pad of the WC when the OBC device <NUM> is configured to operate with the external WPT <NUM>.

<FIG> is a graphical representation that illustrates variation of a ratio between leakage and magnetizing inductances with an increase in overlap between the two coils of the transformer of the OBC device, in accordance with an embodiment of the present disclosure. <FIG> is described in conjunction with elements from <FIG>, <FIG>, and <FIG>. With reference to <FIG>, there is shown a graphical representation 500B that depicts a variation of a ratio between leakage and magnetizing inductances with an increase in overlap between the two coils (i.e., the mains-side coil 108A and the battery-side coil 108B) of the transformer <NUM> of the OBC device <NUM>.

The graphical representation 500B includes an X-axis <NUM> that depicts an overlap in centimeters (cm) between the mains-side coil 108A and the battery-side coil 108B of the transformer <NUM> of the OBC device <NUM>. The graphical representation 500B further includes a Y-axis <NUM> that depicts a ratio (k=Lm/Lr) between the leakage and magnetizing inductances induced by the overlap between the mains-side coil 108A and the battery-side coil 108B of the transformer <NUM> of the OBC device <NUM>. In the graphical representation 500B, a first line <NUM> represents the variation of the ratio (k=Lm/Lr) between leakage and magnetizing inductances with an increase in overlap between the mains-side coil 108A and the battery-side coil 108B of the transformer <NUM> of the OBC device <NUM>. The first line <NUM> signifies that as the overlap between the mains-side coil 108A and the battery-side coil 108B increases, the ratio between leakage and magnetizing inductances decreases.

<FIG> is a block diagram that illustrates various exemplary components of a system for wirelessly charging an electric vehicle, in accordance with an embodiment of the present disclosure. <FIG> is described in conjunction with elements from <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>. With reference to <FIG>, there is shown a block diagram of a system <NUM> for wirelessly charging an electric vehicle, such as the electric vehicle <NUM> (of <FIG>).

The system <NUM> corresponds to the system <NUM> (of <FIG>) and the system <NUM> (of <FIG>). The system <NUM> is configured to function as the OBC device <NUM> for charging the battery <NUM> of the electric vehicle <NUM>. Additionally, the system <NUM> is configured to function as a wireless charger (WC) for charging the battery <NUM> of the electric vehicle <NUM>. In this way, the system <NUM> is arranged to allow two operating modes (i.e., the OBC device <NUM> and the WC) and to allow for the use of both AC-to-DC converters when operating as the WC. Furthermore, in addition to the TX pad 120A, the external WPT <NUM> includes a PFC converter 120B, a DC-to-AC converter 120C, and a resonant tank 120D. Each of the PFC converter 120B, the DC-to-AC converter 120C, and the resonant tank 120D of the external WPT <NUM> corresponds to the PFC converter 104A, the mains-side DC-to-AC converter <NUM> and the mains-side resonant tank <NUM> of the OBC device <NUM>, respectively.

When the one or more bypass switches <NUM> (i.e., S1) are open and the system <NUM> is configured to function as the OBC device <NUM>, the mains input <NUM> is used. The mains input <NUM> may be a power grid to supply the power to the PFC converter 104A. The PFC converter 104A is used to regulate the power factor of the power supplied by the mains input <NUM>. After regulating the power factor, the power is converted from DC domain to AC domain by use of the mains-side DC-to-AC converter <NUM>. The mains-side DC-to-AC converter <NUM> is also configured to excite the power with higher frequency currents. Similarly, the battery-side AC-to-DC converter <NUM> is used for conversion of the power from the AC domain to the DC domain. Each of the mains-side DC-to-AC converter <NUM> and the battery-side AC-to-DC converter <NUM> is an active full-bridge converter (or rectifier). However, a half-bridge rectifier may also be used as the mains-side DC-to-AC converter <NUM> and the battery-side AC-to-DC converter <NUM>. If bi-directional power flow is not required, then, the battery-side AC-to-DC converter <NUM> may be a diode bridge. Furthermore, between the transformer <NUM> and the mains-side DC-to-AC converter <NUM>, the mains-side resonant tank <NUM> is placed. In order to maintain symmetry in the system <NUM>, between the transformer <NUM> and the battery side AC-to-DC converter <NUM>, the battery-side resonant tank <NUM> is placed. The mains-side resonant tank <NUM> and the battery-side resonant tank <NUM> are configured to define a first resonant frequency of the OBC device <NUM> usually in the range of <NUM>-<NUM>. The first resonant frequency higher than the range of <NUM>-<NUM> may also be used. In order to define the first resonant frequency of the OBC device <NUM>, the values of the first capacitance and the first inductance of the mains-side resonant tank <NUM> and the second capacitance and the second inductance of the battery-side resonant tank <NUM> are adjusted accordingly. The first capacitance of the mains-side resonant tank <NUM> is adjusted by use of the first capacitor 116A (i.e., Cr1), and the second capacitance of the battery-side resonant tank <NUM> is adjusted by use of the second capacitor 118A (i.e., Cr2). The use of the first capacitor 116A and the second capacitor 118A simplifies the structure of the system <NUM>. Moreover, the first inductance (i.e., Lr1) of the mains-side resonant tank <NUM> and the second inductance (i.e., Lr2) of the battery-side resonant tank <NUM> is adjusted by regulating the overlap between the mains-side coil 108A and the battery-side coil 108B of the transformer <NUM>. The power converted to the DC domain by use of the battery-side AC-to-DC converter <NUM> is provided to the battery <NUM> through the battery connector <NUM>. In this way, the system <NUM> is configured to operate as the OBC device <NUM> when the one or more bypass switches <NUM> (i.e., S1) are open.

When the one or more bypass switches <NUM> (i.e., S1) are closed and the system <NUM> is configured to function as the WC, hence, the external WPT <NUM> is used. In this case, the transformer <NUM> of the OBC device <NUM> is configured to operate as the RX pad of the WC. The TX pad 120A of the external WPT <NUM> is magnetically coupled to the RX pad of the WC. The external WPT <NUM> including the TX pad 120A is configured to deliver wireless power to the RX pad (i.e., the transformer <NUM>) of the WC. The mains-side coil 108A and the battery-side coil 108B of the RX pad (i.e., the transformer <NUM>) of the WC are configured to operate in parallel, feeding the energy to their respective power converters. That means the mains-side coil 108A is configured to feed the energy to the mains-side DC-to-AC converter <NUM> and the battery-side coil 108B is configured to feed the energy to the battery-side AC-to-DC converter <NUM>. In this case, both the converters that are the mains-side DC-to-AC converter <NUM> and the battery-side AC-to-DC converter <NUM>, are simultaneously used resulting in a higher power rating in comparison to the OBC device <NUM>.

Thus, the system <NUM> provides a higher power rating due to an increase in the power rating of the WC and a significant cost reduction due to the integration of the system <NUM> into one single PCB with share housing and a cooling system as well.

<FIG> is a circuit diagram of a system configured to operate as an OBC device, in accordance with an embodiment of the present disclosure. <FIG> is described in conjunction with elements from <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>. With reference to <FIG>, there is shown a system <NUM> that is configured to operate as the OBC device <NUM> (of <FIG>).

When the one or more bypass switches <NUM> (i.e., S1) are open, the system <NUM> is split into two galvanically isolated sections. Therefore, the system <NUM> is configured to operate as the OBC device <NUM>, whose the first resonant frequency is given by equation <NUM> <MAT>.

The first resonant frequency of the OBC device <NUM> can be designed to operate at frequency usually in a range of <NUM>-<NUM> (or higher) by virtue of selecting the values of the capacitances (Crx) and the inductances (Lrx), accordingly. Alternatively stated, the first resonant frequency of the OBC device <NUM> can be designed depending on an application scenario by virtue of selecting the values of the first capacitance (Cr1) and the first inductance (Lr1) of the mains-side resonant tank <NUM> and the second capacitance (Cr2) and the second inductance (Lr2) of the battery-side resonant tank <NUM>. There is further shown a power flow direction in the system <NUM> during charging a battery (e.g., the battery <NUM> of the electric vehicle <NUM>) by use of an arrow <NUM>. The arrow <NUM> indicates the power flow direction from the mains input <NUM> to the battery <NUM> (not shown here). However, the power flow direction can be reversed if vehicle to everything (V2X) operation is required.

<FIG> is a graphical representation that illustrates voltage waveforms of an OBC device under sub-resonant frequencies, in accordance with an embodiment of the present disclosure. <FIG> is described in conjunction with elements from <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>. With reference to <FIG>, there is shown a graphical representation 800A that depicts voltage waveforms of the OBC device <NUM> (of <FIG>) under sub-resonant frequencies. The system <NUM> (of <FIG>) is configured to operate as the OBC device <NUM>.

The graphical representation 800A includes an X-axis <NUM> that depicts time. The graphical representation 800A further includes a Y-axis <NUM> that depicts an amplitude of voltage waveforms of the OBC device <NUM>. A first waveform <NUM> represents an input voltage waveform of the OBC device <NUM> under sub-resonant frequencies. Alternatively stated, the first waveform <NUM> represents a voltage waveform (Vcon1) of the mains-side DC-to-AC converter <NUM> of the OBC device <NUM>. A second waveform <NUM> represents an output voltage waveform of the OBC device <NUM> under sub-resonant frequencies. Alternatively stated, the second waveform <NUM> represents a voltage waveform (Vcon2) of the battery-side AC-to-DC converter <NUM>.

<FIG> is a graphical representation that illustrates current waveforms of an OBC device under sub-resonant frequencies, in accordance with an embodiment of the present disclosure. <FIG> is described in conjunction with elements from <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>. With reference to <FIG>, there is shown a graphical representation 800B that depicts current waveforms of the OBC device <NUM> (of <FIG>) under sub-resonant frequencies. The system <NUM> (of <FIG>) is configured to operate as the OBC device <NUM>.

The graphical representation 800B includes an X-axis <NUM> that depicts time. The graphical representation 800B further includes a Y-axis <NUM> that depicts an amplitude of current waveforms of the OBC device <NUM>. A first waveform <NUM> represents a current waveform (ilr1) flowing through the first inductance (lr1) of the mains-side resonant tank <NUM> of the OBC device <NUM> under sub-resonant frequencies. A second waveform <NUM> represents a current waveform (ilr2) flowing through the second inductance (lr2) of the battery-side resonant tank <NUM> of the OBC device <NUM> under sub-resonant frequencies.

<FIG> is a graphical representation that illustrates voltage waveforms of an OBC device at resonant frequencies, in accordance with an embodiment of the present disclosure. <FIG> is described in conjunction with elements from <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>. With reference to <FIG>, there is shown a graphical representation 800C that depicts voltage waveforms of the OBC device <NUM> (of <FIG>) at resonant frequencies (e.g., the first resonant frequency). The system <NUM> (of <FIG>) is configured to operate as the OBC device <NUM>. The resonant frequencies (i.e., the first resonant frequency) of the OBC device <NUM> usually lie in the range of <NUM>-<NUM>. The first resonant frequency higher than the range of <NUM>-<NUM> may also be used.

The graphical representation 800C includes an X-axis <NUM> that depicts time. The graphical representation 800C further includes a Y-axis <NUM> that depicts an amplitude of voltage waveforms of the OBC device <NUM>. A first waveform <NUM> represents a voltage waveform of the OBC device <NUM> at the resonant frequencies (i.e., the first resonant frequency). Alternatively stated, the first waveform <NUM> represents a voltage waveform (Vcon2) of the battery-side AC-to-DC converter <NUM> of the OBC device <NUM>.

<FIG> is a graphical representation that illustrates current waveforms of an OBC device at resonant frequencies, in accordance with an embodiment of the present disclosure. <FIG> is described in conjunction with elements from <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>. With reference to <FIG>, there is shown a graphical representation 800D that depicts current waveforms of the OBC device <NUM> (of <FIG>) at resonant frequencies. The system <NUM> (of <FIG>) is configured to operate as the OBC device <NUM>.

The graphical representation 800D includes an X-axis <NUM> that depicts time. The graphical representation 800D further includes a Y-axis <NUM> that depicts an amplitude of current waveforms of the OBC device <NUM>. A first waveform <NUM> represents a current waveform (ilr1) flowing through the first inductance (lr1) of the mains-side resonant tank <NUM> of the OBC device <NUM> at resonant frequencies. A second waveform <NUM> represents a current waveform (ilr2) flowing through the second inductance (lr2) of the battery-side resonant tank <NUM> of the OBC device <NUM> at resonant frequencies.

<FIG> is a circuit diagram of a system configured to operate as a wireless charger (WC), in accordance with an embodiment of the present disclosure. <FIG> is described in conjunction with elements from <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>. With reference to <FIG>, there is shown a system <NUM> that is configured to operate as a wireless charger.

When the one or more bypass switches <NUM> (i.e., S1) are closed, and the transformer <NUM> is magnetically coupled to the TX pad 120A of the external WPT <NUM>, then the OBC device <NUM> is configured to operate as the wireless charger (WC) and hence, the system <NUM> is configured to operate as the wireless charger (WC). In such a configuration, the transformer <NUM> of the OBC device <NUM> operates as the RX pad of the WC. The two isolated coils (i.e., the mains-side coil 108A and the battery-side coil 108B) of the RX pad of the WC operate in parallel. The system <NUM> resembles a series-series compensated inductive power transfer system. The first capacitor 116A (Cr1) and the second capacitor 118A (Cr2) form a resonant circuit with the leakage and magnetizing inductance. The second resonant frequency of the system <NUM> is given by equation <NUM> <MAT>.

The second resonant frequency of the WC can be designed approximately <NUM> according to a standard J2954, which regulates the frequency of operation of the WC for electric vehicles (EVs), such as the electric vehicle <NUM> (of <FIG>). Moreover, the directions of power flow are shown in the system <NUM> by use of three arrows. However, the directions of power flow can be reversed on an application basis.

<FIG> is a graphical representation that illustrates voltage waveforms of the WC at a second resonant frequency, in accordance with an embodiment of the present disclosure. <FIG> is described in conjunction with elements from <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>. With reference to <FIG>, there is shown a graphical representation 1000A that depicts voltage waveforms of the WC at a second resonant frequency. The system <NUM> (of <FIG>) is configured to operate as the WC. The second resonant frequency of the WC can be designed, approximately <NUM>.

The graphical representation 1000A includes an X-axis <NUM> that depicts time. The graphical representation 1000A further includes a Y-axis <NUM> that depicts an amplitude of voltage waveforms of the WC. A first waveform <NUM> represents a voltage waveform of the WC at the second resonant frequency. Alternatively stated, the first waveform <NUM> represents a voltage waveform (Vcon2) of the battery-side AC-to-DC converter <NUM> of the WC.

<FIG> is a graphical representation that illustrates current waveforms of the WC at a second resonant frequency, in accordance with an embodiment of the present disclosure. <FIG> is described in conjunction with elements from <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>. With reference to <FIG>, there is shown a graphical representation 1000B that depicts current waveforms of the WC at a second resonant frequency. The system <NUM> (of <FIG>) is configured to operate as the WC.

The graphical representation 1000B includes an X-axis <NUM> that depicts time. The graphical representation 1000B further includes a Y-axis <NUM> that depicts amplitude of current waveforms of the WC. A first waveform <NUM> represents a current waveform (ilr2) flowing through the second inductance (lr2) of the battery-side resonant tank <NUM> of the WC at the resonant frequency. A second waveform <NUM> represents a current waveform (Itx_coil) flowing through the TX pad 120A of the external WPT <NUM>. The second waveform <NUM> (Itx_coil) flowing through the TX pad 120A indicates a varying current which signifies that the external WPT <NUM> is in use when the system <NUM> operates as the WC.

<FIG> is a schematic diagram that depicts coil structure of a transformer of an OBC device, in accordance with an embodiment of the present disclosure. <FIG> is described in conjunction with elements from <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>. With reference to <FIG>, there is shown a coil structure 1100A of the transformer <NUM> of the OBC device <NUM> (of <FIG>). The transformer <NUM> includes the mains-side coil 108A and the battery-side coil 108B. Each of the mains-side coil 108A and the battery-side coil 108B may also be referred to as two galvanically isolated coils of the RX pad of the WC when the OBC device <NUM> is configured to operate with the external WPT <NUM>.

Each of the mains-side coil 108A and the battery-side coil 108B is used to induce an embedded leakage inductance and a magnetizing inductance in the OBC device <NUM> and the WC as well. The ratio (k) between the magnetizing inductance and the embedded leakage inductance is controlled by adjusting the overlap between each of the mains-side coil 108A and the battery-side coil 108B. The overlapping of each of the mains-side coil 108A and the battery-side coil 108B can be done in different ways. For example, in the coil structure 1100A, each of the mains-side coil 108A and the battery-side coil 108B is displaced from its center point to create a partial overlap between the two coils.

<FIG> is a graphical representation that illustrates leakage and mutual inductances induced by two coils of a transformer of an OBC device, in accordance with an embodiment of the present disclosure. <FIG> is described in conjunction with elements from <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>. With reference to <FIG>, there is shown a graphical representation 1100B that illustrates the embedded leakage and the mutual inductances induced by each of the mains-side coil 108A and the battery-side coil 108B of the transformer <NUM> of the OBC device <NUM>.

The graphical representation 1100B includes an X-axis <NUM> that depicts an overlap in centimeters (cm) between each of the mains-side coil 108A and the battery-side coil 108B. The graphical representation 1100B further includes a Y-axis <NUM> that depicts inductances in microhenry (µH) induced by an overlap between each of the mains-side coil 108A and the battery-side coil 108B. A first line <NUM> and a second line <NUM> depict self inductances (µH) of the mains-side coil 108A and the battery-side coil 108B, respectively. A third line <NUM> and a fourth line <NUM> depict mutual inductances (µH) or magnetizing inductances (µH) of the mains-side coil 108A and the battery-side coil 108B, respectively. A fifth line <NUM> and a sixth line <NUM> depict embedded leakage inductances (µH) of the mains-side coil 108A and the battery-side coil 108B, respectively. In the graphical representation 1100B, each of the mutual inductances and the embedded leakage inductances is obtained when each of the mains-side coil 108A and the battery-side coil 108B is displaced from their center points. The self inductances, the mutual inductances and the embedded leakage inductances may be generated as a part of the WC as well.

<FIG> is a schematic diagram that depicts coil structure of a transformer of an OBC device, in accordance with another embodiment of the present disclosure. <FIG> is described in conjunction with elements from <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>. With reference to <FIG>, there is shown a coil structure 1200A of the transformer <NUM> of the OBC device <NUM> (of <FIG>). The transformer <NUM> includes the mains-side coil 108A and the battery-side coil 108B.

In the coil structure 1200A, each of the mains-side coil 108A and the battery-side coil 108B is stretched sideways to create a partial overlap between the two coils. Alternatively stated, edges of each of the mains-side coil 108A and the battery-side coil 108B are extended in one direction to create the partial overlap between the two coils. The partial overlap between each of the mains-side coil 108A and the battery-side coil 108B is used to regulate the ratio (k) between the magnetizing inductance and the embedded leakage inductances of the WC (i.e., the system <NUM>).

<FIG> is a graphical representation that illustrates leakage and mutual inductances induced by two coils of a transformer of an OBC device, in accordance with another embodiment of the present disclosure. <FIG> is described in conjunction with elements from <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>. With reference to <FIG>, there is shown a graphical representation 1200B that illustrates the embedded leakage and the mutual inductances induced by each of the mains-side coil 108A and the battery-side coil 108B of the transformer <NUM> of the OBC device <NUM>.

The graphical representation 1200B includes an X-axis <NUM> that depicts an overlap in centimeters (cm) between each of the mains-side coil 108A and the battery-side coil 108B. The graphical representation 1200B further includes a Y-axis <NUM> that depicts inductances in microhenry (µH) induced by an overlap between each of the mains-side coil 108A and the battery-side coil 108B. A first line <NUM> and a second line <NUM> depict self inductances (µH) of the mains-side coil 108A and the battery-side coil 108B, respectively. A third line <NUM> and a fourth line <NUM> depict mutual inductances (µH) or magnetizing inductances of the mains-side coil 108A and the battery-side coil 108B, respectively. A fifth line <NUM> and a sixth line <NUM> depict embedded leakage inductances (µH) of the mains-side coil 108A and the battery-side coil 108B, respectively. In the graphical representation 1200B, each of the mutual inductances and the embedded leakage inductances is obtained when each of the mains-side coil 108A and the battery-side coil 108B is stretched sideways. Each of the self inductances, the mutual inductances and the embedded leakage inductances may be generated as a part of the WC as well.

<FIG> is a schematic diagram that depicts coil structure of a transformer of an OBC device, in accordance with yet another embodiment of the present disclosure. <FIG> is described in conjunction with elements from <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>. With reference to <FIG>, there is shown a coil structure 1300A of the transformer <NUM> of the OBC device <NUM> (of <FIG>). The transformer <NUM> includes the mains-side coil 108A and the battery-side coil 108B.

In the coil structure 1300A, each of the mains-side coil 108A and the battery-side coil 108B is stretched in different axes to create a partial overlap between the two coils. Alternatively stated, edges of each of the mains-side coil 108A and the battery-side coil 108B are extended in two different directions to create the partial overlap between the two coils. The partial overlap between each of the mains-side coil 108A and the battery-side coil 108B is used to regulate the ratio (k) between the magnetizing inductance and the embedded leakage inductances of the WC (i.e., the system <NUM>).

<FIG> is a graphical representation that illustrates leakage and mutual inductances induced by two coils of a transformer of an OBC device, in accordance with yet another embodiment of the present disclosure. <FIG> is described in conjunction with elements from <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>. With reference to <FIG>, there is shown a graphical representation 1300B that illustrates the embedded leakage and the mutual inductances induced by each of the mains-side coil 108A and the battery-side coil 108B of the transformer <NUM> of the OBC device <NUM>.

The graphical representation 1300B includes an X-axis <NUM> that depicts an overlap in centimeters (cm) between each of the mains-side coil 108A and the battery-side coil 108B. The graphical representation 1300B further includes a Y-axis <NUM> that depicts inductances in microhenry (µH) induced by an overlap between each of the mains-side coil 108A and the battery-side coil 108B. A first line <NUM> and a second line <NUM> depict self inductances (µH) of the mains-side coil 108A and the battery-side coil 108B, respectively. A third line <NUM> and a fourth line <NUM> depict mutual inductances (µH) or magnetizing inductances of the mains-side coil 108A and the battery-side coil 108B, respectively. A fifth line <NUM> and a sixth line <NUM> depict embedded leakage inductances (µH) of the mains-side coil 108A and the battery-side coil 108B, respectively. In the graphical representation 1300B, each of the mutual inductances and the embedded leakage inductances is obtained when each of the mains-side coil 108A and the battery-side coil 108B is stretched in two different directions. Each of the coil inductances, the mutual inductances and the embedded leakage inductances may be generated as a part of the WC as well.

<FIG> is a flowchart of a method of charging an electric vehicle, in accordance with an embodiment of the present disclosure. <FIG> is described in conjunction with elements from <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>. With reference to <FIG>, there is shown a method <NUM> of charging an electric vehicle, such as the electric vehicle <NUM> (of <FIG>). The method <NUM> includes <NUM> and <NUM> steps. The method <NUM> is executed by the OBC device <NUM> (of <FIG>) when the OBC device <NUM> is configured to operate with the WPT <NUM>. Moreover, the method <NUM> is also executed by the system <NUM> (of <FIG>).

A method (i.e., the method <NUM>) of charging the electric vehicle <NUM>, comprising:
magnetically coupling the transformer <NUM> to a TX pad 120A of an external wireless power transmitter (WPT) <NUM>, such that power is received by the mains-side coil 108A and the battery-side coil 108B; and closing the one or more bypass switches <NUM> (i.e., S1) to galvanically connect the mains-side converter (i.e., the mains-side DC-to-AC converter <NUM>) to the battery-side converter (i.e., the battery side AC-to-DC converter <NUM>) such that power is sent to the battery connector <NUM> through both the battery-side converter (i.e., the battery side AC-to-DC converter <NUM>) and the mains-side converter (i.e., the mains-side DC-to-AC converter <NUM>).

At step <NUM>, the method <NUM> comprises magnetically coupling the transformer <NUM> to a TX pad 120A of an external wireless power transmitter (WPT) <NUM>, such that power is received by the mains-side coil 108A and the battery-side coil 108B. When the OBC device <NUM> comprised by the electric vehicle <NUM> is configured to operate as wireless charger (WC), the transformer <NUM> is magnetically coupled to the TX pad 120A of the external WPT <NUM> in order to receive the power. The power is received by the mains-side coil 108A and the battery-side coil 108B of the transformer <NUM> in order to feed the energy to the mains-side DC-to-AC converter <NUM> and the battery-side AC-to-DC converter <NUM>, simultaneously.

At step <NUM>, the method <NUM> further comprises closing the one or more bypass switches <NUM> (i.e., S1) to galvanically connect the mains-side converter (i.e., the mains-side DC-to-AC converter <NUM>) to the battery-side converter (i.e., the battery side AC-to-DC converter <NUM>) such that power is sent to the battery connector <NUM> through both the battery-side converter (i.e., the battery side AC-to-DC converter <NUM>) and the mains-side converter (i.e., the mains-side DC-to-AC converter <NUM>). When the one or more bypass switches <NUM> (i.e., S1) are closed, and the transformer <NUM> is magnetically coupled to the TX pad 120A of the WPT <NUM>, the mains-side DC-to-AC converter <NUM> and the battery-side AC-to-DC converter <NUM> are galvanically connected and together charge the battery <NUM> of the electric vehicle <NUM> through the battery connector <NUM>.

In accordance with an embodiment, the WPT <NUM> is configured to operate at a resonant frequency in the range of <NUM>-<NUM>. When the OBC device <NUM> is configured to operate as the WC, the WPT <NUM> is configured to operate at the resonant frequency in the range of <NUM>-<NUM>.

The steps <NUM> and <NUM> are only illustrative and other alternatives can also be provided where one or more steps are added, one or more steps are removed, or one or more steps are provided in a different sequence without departing from the scope of the claims herein.

<FIG> is a flowchart of a method of charging an electric vehicle, in accordance with another embodiment of the present disclosure. <FIG> is described in conjunction with elements from <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>. With reference to <FIG>, there is shown a method <NUM> of charging an electric vehicle, such as the electric vehicle <NUM> (of <FIG>). The method <NUM> includes <NUM> and <NUM> steps. The method <NUM> is executed by the OBC device <NUM> (of <FIG>), when the OBC device <NUM> is configured to operate with the mains input <NUM>. Moreover, the method <NUM> is also executed by the system <NUM> (of <FIG>).

A method (i.e., the method <NUM>) of charging the electric vehicle <NUM>, comprising:.

At step <NUM>, the method <NUM> comprises connecting the mains input <NUM> with an external mains supply. The OBC device <NUM> comprised by the electric vehicle <NUM> is configured to operate depending on the mains input <NUM>. For this, the mains input <NUM> is connected with the external mains supply.

At step <NUM>, the method <NUM> further comprises opening the one or more bypass switches <NUM> (i.e., S1) to galvanically disconnect the mains-side converter (i.e., the mains-side DC-to-AC converter <NUM>) from the battery-side converter (i.e., the battery side AC-to-DC converter <NUM>) such that power is sent to the mains-side coil 108A of the transformer <NUM>. When the one or more bypass switches <NUM> are open and the OBC device <NUM> is configured to operate with the mains input <NUM>, the mains-side DC-to-AC converter <NUM> and the battery-side AC-to-DC converter <NUM> are galvanically disconnected from each other. In such configuration, the power from the mains input <NUM> is sent to the mains-side coil 108A of the transformer <NUM> and further, power is sent to the battery <NUM> of the electric vehicle <NUM> through the battery connector <NUM>.

In accordance with an embodiment, the mains supply is configured to operate at a resonant frequency usually in the range of <NUM>-<NUM>. The resonant frequency higher than the range of <NUM>-<NUM> may also be used. The mains input <NUM> is connected with the external mains supply which is configured to operate at the resonant frequency in the range usually of <NUM>-<NUM>.

The steps <NUM> and <NUM> are only illustrative, and other alternatives can also be provided where one or more steps are added, one or more steps are removed, or one or more steps are provided in a different sequence without departing from the scope of the claims herein.

Claim 1:
An on-board charging, OBC, device (<NUM>) for an electric vehicle (<NUM>), comprising:
a mains input (<NUM>) comprising a power factor correction, PFC, converter (104A);
a mains-side DC/AC converter (<NUM>);
a transformer (<NUM>) having a mains-side coil (108A) and a battery-side coil (108B);
a battery-side AC/DC converter (<NUM>);
a battery connector (<NUM>); and
one or more bypass switches (<NUM>) configured to galvanically connect the mains-side converter (<NUM>) to the battery-side converter (<NUM>) when closed;
wherein the transformer (<NUM>) is configured to be magnetically coupled to a TX pad (120A) of an external wireless power transmitter, WPT (<NUM>), such that power is received by the mains-side coil (108A) and the battery-side coil (108B);
wherein when the bypass switches (<NUM>) are closed and the transformer (<NUM>) is magnetically coupled to a WPT (<NUM>), power is sent to the battery connector (<NUM>) through both the battery-side converter (<NUM>) and the mains-side converter (<NUM>), the OBC device (<NUM>) further comprises a mains-side resonant tank (<NUM>) having a first capacitance and a first inductance, and a battery-side resonant tank (<NUM>) having a second capacitance and a second inductance; and wherein values of the first capacitance and the first inductance of the mains-side resonant tank (<NUM>) and the second capacitance and the second inductance of the battery-side resonant tank (<NUM>) are selected to adapt the OBC device (<NUM>) for operation with the mains input (<NUM>) and operation with the WPT (<NUM>), wherein the values of the first capacitance and the first inductance of the mains-side resonant tank (<NUM>) and the second capacitance and the second inductance of the battery-side resonant tank (<NUM>) are selected in order to define the first resonant frequency of a CLLC resonant tank which is a combination of the mains-side resonant tank (<NUM>) and the battery-side resonant tank (<NUM>) for operation with the mains input (<NUM>) as well as the second resonant frequency for operation with the WPT (<NUM>), and characterized in that the mains-side coil (108A) and the battery-side coil (108B) are arranged with a partial overlap to generate the first inductance of the mains-side resonant tank (<NUM>) and the second inductance of the battery-side resonant tank (<NUM>) simultaneously.