Integrated wireless and onboard charging systems

Abstract

A family of integrated onboard and wireless chargers are proposed in a number of embodiments. The chargers are adapted to utilize the same rectifier for both on board charging and wireless charging, providing significant cost, weight, and volume savings, which are important considerations for improving the adoption of electric technology where energy storage devices need to be charged. Variations are also proposed with respect to other shared resonant components and connection variants.

Description

INTEGRATED WIRELESS AND ONBOARD CHARGING SYSTEMSCROSS-REFERENCE

[0001] This application is a non-provisional of, and claims all benefit to, including priority from, US Application No. 63 / 447033, entitled INTEGRATED WIRELESS AND ONBOARD CHARGING SYSTEMS, filed 20-Feb-2023, incorporated herein by reference in its entirety.FIELD

[0002] Embodiments of the present disclosure relate to the field of charging electronics, and more specifically, embodiments relate to devices, systems and methods for integrating wireless and onboard charging systems.INTRODUCTION

[0003] Wireless Power Transfer (WPT) and the wired Onboard Charger (OBC) are the two most prominent methods for level 1 and level 2 EV charging, i.e., charging the traction battery at powers under 20 kW. WPT is a useful mechanism to provide a convenient mechanism for charging (e.g., without having to plug in), and for example, WPT can be embedded into a parking spot. OBC infrastructure allows a vehicle to perform charging operations and reduces some need for certain charging infrastructure components.

[0004] Conventionally, the OBC is a converter that is fully embedded into the vehicle and comprises two stages. The first stage is a Power Factor Correction (PFC) converter, responsible for meeting the Total Harmonic Distortion (THD) requirements for interconnection with the electric grid while converting the input’s Alternate Current (AC) into Direct Current (DC). The second stage is conventionally a galvanically isolated DC-to-DC conversion stage. In the DC-to-DC stage, the DC voltage produced by the PFC stage is converted back into AC, conducted through a galvanic isolation transformer, and then rectified into DC once more to feed the traction battery.

[0005] WPT solutions can be described with the same stages as an OBC, with the difference that the PFC stage and the DC-to-AC conversion within the isolated DC-to-DC converter are located outside the vehicle. Furthermore, instead of a galvanic isolation transformer, galvanic isolation is substituted by a combination of components within andwithout the vehicle. The transmitter coil operates analogously to the primary coil of the transformer, whereas the receiver coil is analogous to the secondary side of the transformer. As OBCs, WPT schemes also have a rectifier connected downstream from the galvanic isolation stage.

[0006] A technical drawback with WPT and OBC systems is that they contribute to weight, complexity, and expense, as various electronic components are necessary.

[0007] Accordingly, improved approaches are desirable.SUMMARY

[0008] A family of integrated onboard and wireless charger circuits and corresponding electronic systems are proposed in a number of embodiments. The chargers are adapted to utilize the same rectifier for both on board charging (OBC mode charging) and wireless charging (WC mode charging), providing significant cost, weight, and volume savings, which are important considerations for improving the adoption of electric technology where energy storage devices need to be charged. For example, charging infrastructure and component complexity is a major consideration for the development of electric vehicles, as cost, weight, and volume can impact vehicle range and operational characteristics, and savings can improve or accelerate adoption of “green” technologies that can have environmental benefits, such as reducing climate impacts by reducing reliance on combustion-based technologies.

[0009] Using the same rectifier for both OBC mode charging and WC mode charging can be challenging due to technical issues that arise relating to undesired interaction of the OBC and WC, which results in performance and safety issues.

[0010] One of the major challenges of integrating the OBC and WC is an objective of not generating any magnetic field on the wireless receiver coil while the system is operating in OBC mode. From the performance side view, circulating current in the coils while the system is operating in OBC mode results in more conduction and core losses.

[0011] Similarly, when the system is operating in WC mode, the OBC transformer current and voltages should be taken into account to avoid introducing additional losses. Therefore,additional circuitry, such as relays, can be considered to disconnect the two systems.However, this may impact the reliability and cost of the system.

[0012] A good integrated solution would operate in OBC mode without generating a magnetic field on the wireless charger coils and minimize circulating current in the wireless charger circuitry. Moreover, while it is operating in WC mode, the losses of the transformer and OBC inverter would not be increased. Furthermore, an ideal integrated solution should be commercially competitive with a conventional solution. Therefore, minor changes in the circuit topology with no additional components are desired to minimize the cost.

[0013] While a number of other solutions have been proposed to combine onboard charging and wireless charging, other solutions have required undesirable modifications to topologies of the onboard charger to prevent deleterious interactions. Accordingly, these approaches have had challenges with practical viability.

[0014] A proposed solution is described herein that uses the common-mode current path on the secondary side of the isolating transformer of the onboard charger as a path for wireless charging. In other words, the wireless charger output current is divided into two or more parallel paths to the load (i.e., the currents are in phase). These parallel paths are seen as common-mode current paths from the OBC circuit point of view.

[0015] The proposed solution uses a differential mode power transfer path for the onboard charger (i.e., the currents leaving the transformer’s winding terminals are out of phase). In an alternate embodiment, the common-mode current path is utilized for WC, and the differential mode path is used for OBC. In yet another further embodiment, the assignment of common-mode or differential mode paths can be conducted dynamically to optimize, for example, an efficiency of power transfer.

[0016] For example, in a single-phase OBC with a single-phase transformer, the power of the OBC circuit transfers to the load through a differential mode current. This differential mode current circulates in the transformer's secondary side winding. In other words, the current leaves the top terminal of the transformer winding, circulates through the load, and returns back to the secondary side winding from the bottom terminal. If the wireless chargeris connected to the middle terminal of the transformer's secondary side winding and the middle point of the output DC link. In this case, the output current of the wireless charger will split into two equal currents and flow in opposite directions to the transformer’s secondary side winding. In other words, the wireless charger current leaves from both ends of the secondary side windings and returns from the middle point of the DC link. Therefore, it can be said that the power of the wireless charger passes through a common-mode path from the perspective of the OBC circuit. As noted, in alternate embodiments, the common-mode and differential mode can be swapped as between the WC and OBC circuitry.

[0017] The isolating transformer can be either a single-phase or a multi-phase configuration. Moreover, the proposed topology can, in some embodiments (but not necessarily in all embodiments), integrate the resonant components of the receiver side of the wireless charging system into the OBC circuit. The integrated circuit can be configured to ensure soft switching conditions over a wide range of the load. Integrating the resonant elements into the onboard charger can be conducted to utilize the leakage inductance of the transformer. Therefore, the proposed integrated solution shares resonant components and I or a rectifier stage between the onboard and wireless charger to save cost and space. As described herein, in some proposed variants, is possible to integrate resonant components, but not all embodiments necessarily have this feature. In some proposed variants, only the rectifier is shared.

[0018] Specifically, the rectifier downstream from the galvanic isolation transformer of the OBC is used as a rectifier of the wireless charger (WC), eliminating the necessity for a dedicated rectifier. The approach is adapted to utilize fundamental symmetries to ensure decoupling between both systems to aid with safe operation. A symmetrical circuit is formed by connecting the wireless charger output terminals to the middle point of the OBC transformer's secondary side winding or its neutral point and the middle point of the DC link capacitors. The OBC circuit operates in differential mode, and the WC operates in commonmode (or vice versa). Therefore, there is no parasitic interaction between the two systems. The proposed approaches are additionally beneficial as there is no need for significant modifications of the OBC, such as the inclusion of additional relays or challenging fine- tuning.

[0019] A number of variant embodiments are proposed in approaches herein.

[0020] In some embodiments, there are variations with an APU integrated to the transformer. The output of the APU is connected to the auxiliary battery of the vehicle, e.g., a 12 V lead-acid battery, which typically has its negative terminal connected to the chassis, whereas the input of the APU is connected to the main traction battery. Thus, galvanic isolation is often sought as a feature of APU, which is achieved by the presence of a galvanic isolation transformer in the circuit, with the objective of preventing the traction battery from being connected to the vehicle chassis, thereby improving safety.

[0021] Given the cost associated with an additional transformer, it may be advantageous to leverage the transformer present in the OBC also to avoid the need for a dedicated transformer within the APU, thus reducing overall system cost. This can be achieved by using a transformer with three ports, as shown in a proposed circuit, which could be an active bridge with integrated low voltage auxiliary circuit, with one port connecting to the output of the PFC, one port connecting to the OBC rectifier and WC, and the third port connecting to the rectification stage of the APU.

[0022] In some embodiments, there are variations without an APU integrated to the transformer. These embodiments may be suitable for a given application because, by separating APU and OBC implementations, they result in relaxed constraints by not having to simultaneously meet the requirements of the APU and OBC in a single component, in exchange for the higher bill-of-materials cost, e.g., additional galvanic isolation transformer. In these embodiments, the OBC and APU are integrated and work in such a way to not interfere with one another. The APU can be separated from both OBC and WC implementations in some embodiments.

[0023] In some embodiments, there are variations using a single phase transformer. A single phase transformer is used in low power applications where the wire diameter and switches current ratings are in a reasonable range. Moreover, single phase transformers are easier to build and manufacture.

[0024] In some embodiments, there are variations using a multi-phase (e.g., three phase) transformer. A multi-phase transformer is typically adopted for higher power applications to reduce the current rating of the transformer windings and inverter switches. Moreover, it can improve fault-tolerant capabilities of the system.

[0025] In some embodiments, the wireless coil can be connected directly to the rectifier. Connecting the wireless coil directly means that the receiver circuit of the wireless charger is in parallel with the onboard charger secondary side circuit. A benefit of direct connection is that it can be a simpler implementation and does not require any changes in the circuit. However, when the onboard charger is working, the current will flow through the wireless charging circuit in the parallel path and generates magnetic field on the receiver coil. This can cause safety issues for the live objects and metal objects around the receiver coil.

[0026] Moreover, the circulating current results in more losses and reduction of the OBC efficiency. Similarly, when the wireless charger is operating, it can induce a voltage on the primary side of the OBC transformer and generate a high voltage on the DC link that can damage the inverter switches and capacitors.

[0027] In some embodiments, the wireless coil can be connected indirectly to the rectifier but independently from galvanic isolation transformer. Connecting the wireless coil indirectly means that a disconnection circuit, such as a relay, may be included between the wireless coil and the rectifier. A benefit of connecting the wireless coil to the rectifier via a relay is that the relay can be actuated to ensure the wireless coil is not inadvertently energized as a result of OBC operation.

[0028] In some embodiments, the wireless coil can be connected directly or indirectly to the galvanic isolation transformer and another point in the system. Connection to the galvanic isolation transformer without using the terminals that are coupled to the rectifier allows for the functional decoupling between the WC and OBC, e.g., OBC power is associated with the differential-mode current on the secondary coil of the OBC whereas the WPT is associated with the common-mode current on the secondary.

[0029] For clarity of terminology, both solutions connect to the transformer, and the difference is that one of the solutions doesn’t directly connect to the rectifier and thus the solution does not need a relay disconnector. As a result, connecting the coil to the system without using the terminals that are coupled to the rectifier allows for the operation of the OBC while the WC coil is connected to the system, and therefore the wireless coil may be connected without requiring a relay for disconnection.

[0030] In some embodiments, the wireless receiver coil can be connected to the rectifier via a relay, which enables the disconnection of the WC from the system. These embodiments have the drawback of requiring the aforementioned relay as well as the advantage of ensuring the wireless coil, by virtue of being disconnected, is not energized during OBC operation, i.e., wired power transfer.

[0031] In some embodiments, the wired and wireless power are decoupled (e.g., don’t interfere with one another). The decoupling is accomplished by designing the system to have each one of the powers (wired and wireless) associated with (e.g., indicative of) a mode of current in a given pair of coils or windings, differential-mode and common-mode. As a matter of example, the secondary side of the galvanic isolation transformer of the OBC may be comprised of two windings, where the sum of current in the windings in the direction of causing magnetic flux through the magnetic core is termed differential-mode, whereas the difference of the current in the windings is termed common-mode.

[0032] In some embodiments, the wired power is associated with differential-mode (DM) at transformer and wireless power is associated with common-mode (CM) at transformer. Differential-mode means the currents of each secondary side winding section are in the opposite direction. Common-mode means the currents of each secondary side winding section are in the same direction. In this topology, an example configuration includes connecting the wireless charging coil to a point (e.g., the middle point of the secondary side but other points are possible) of the OBC transformer and a point of the load side capacitors (e.g., the middle point of the load capacitor voltage divider resulting in equal capacitance split between the middle point and rectifier, but connections resulting in unequal capacitance split are possible). For this embodiment, the benefits of having the wired power associated with DM at the transformer while the wireless power is associated with CM at the transformerstems from the fact that DM and CM are decoupled. Thus, in some embodiments, it may be possible to process wired charging power with the DM current without causing any CM currents, consequently without exciting the wireless coil. Furthermore, the CM currents through the secondary of the transformer, which are used to operate the wireless charger, do not produce flux and do not interfere with the primary-side coil of the OBC’s galvanic isolation transformer, and transformer current rating remains unchanged.

[0033] In some embodiments, the wired power is associated with common-mode at transformer and wireless power is associated with differential-mode at transformer. For this embodiment, the benefits of connecting wired with CM at the transformer means that one terminal of the secondary side of the transformer is connected to a point (e.g. the middle point but other points are possible) of the receiver coil and the other terminal is connected to the a point of the load side capacitors (e.g. the middle point of a capacitor voltage divider resulting in equal split of load side capacitance, but connection resulting in unequal capacitance are possible) and connecting wireless with DM at the transformer means that the receiver circuit of the wireless charger is connected to a rectifier. In this embodiment, during WPT operation, the receiver WC does not produce CM currents or voltages and therefore does not excite the OBC circuitry. This is a result of the decoupling between CM and DM currents.

[0034] Wired power associated with differential-mode at transformer and wireless power associates with common-mode at transformer can refer to structures where the galvanic isolation transformer has a split-coil connection and the wireless coil connects there, such as the solutions that are referred to as Type I for single-phase. In contrast, the expression “wired power associated with common-mode at wireless coil and wireless power associated with differential-mode at wireless coil” refers to structure where the coil has a split-point connection, such as what is termed Type III in the description below.

[0035] Practical examples of the combined charger can be contemplated for use as onboard components of a vehicle, such as a retrofit for an existing vehicle, a charging system upgrade, or a complete vehicle having the requisite components. A retrofit is contemplated where a vehicle has an OBC and is not manufactured with a wireless charging circuitry. An improved charging system, implemented by adding charging capability, iscontemplated where the added WPT circuitry does not include a rectifier and, instead, leverages the existing OBC’s rectifier to reduce the retrofitting cost. An improved vehicle is contemplated where, during the initial design phase, the WPT circuitry is designed to not require a dedicated rectifier, instead leveraging the OBC’s rectifier thereby reducing cost. Vehicles can include cars, trucks, ships, airplanes, autonomous vehicles such as autonomous aerial vehicles (e.g., flying drones), and otherwise any equipment that is responsible to move itself and / or potentially additional load, e.g., persons, cargo.

[0036] Furthermore, additional embodiments are considered that can include without limitation any portable device that includes an energy storage device such as a battery that needs to be charged, and can benefit from a combination OBC and WPT. This can include, for example, a large portable battery pack for camping or emergencies that could benefit from improved charging.

[0037] Control approaches and methods are also contemplated in relation to operating the above devices, along with machine instruction products I articles of manufacture, such as a non-transitory machine readable media storing machine instructions which can be executed on a processor or control circuit of the above devices for performing a method of operation.DESCRIPTION OF THE FIGURES

[0038] In the figures, embodiments are illustrated by way of example. It is to be expressly understood that the description and figures are only for the purpose of illustration and as an aid to understanding.

[0039] Embodiments will now be described, by way of example only, with reference to the attached figures, wherein in the figures:

[0040] FIG. 1 is a block diagram of an example device having an energy storage device and components thereon, according to some embodiments.

[0041] FIG. 2 is a schematic illustration of an electric vehicle (EV) charging system, according to some embodiments.

[0042] FIG. 3A and FIG. 3B are circuit diagrams that show an example OBC with and without a resonant network, according to some embodiments. FIG. 3C is a circuit diagram that shows a topology of the OBC that leverages a single-phase transformer and a passive diode bridge rectifier, according to some embodiments. In FIG. 3E, FIG. 3F, FIG. 3G, and FIG. 3H, the DC-to-DC stage leverages a three-phase galvanic isolation transformer, according to some embodiments.

[0043] FIG. 4A and FIG. 4B are circuit diagrams showing the operation of the system in different modes, according to some embodiments. FIG. 4A shows the operation of the system in OBC mode, and FIG. 4B shows the operation of the system in WC mode, according to some embodiments.

[0044] FIG. 5A and FIG. 5B are circuit diagrams showing a YY type variant of the proposed system, according to some embodiments. FIG. 5A shows the system in OBC mode, and FIG. 5B shows the system in WC mode.

[0045] FIG. 6A and FIG. 6B is a set of waveform diagrams showing example simulation results, according to some embodiments.

[0046] FIG. 7 is a schematic diagram 700 showing a depiction of the experimental setup showing the integrated system and control, according to some embodiments.

[0047] FIG. 8A AND FIG. 8B shows reference tracking performance (Io) at different loading conditions.

[0048] FIG. 9A AND FIG. 9B shows reference tracking performance (Io) at different loading conditions.

[0049] FIG. 10A AND FIG. 10B shows reference tracking performance (Io) at different loading conditions.

[0050] FIG. 11 and FIG. 12 show the closed-loop system measured efficiency versus output current at different load (battery) voltages, according to some embodiments.

[0051] FIG. 13A, FIG. 13B, FIG. 13C, FIG. 13D, FIG. 13E shows leakage current on the wireless charging coil (Iro) at different loading conditions, according to some embodiments.

[0052] FIG. 14A, FIG. 14B, FIG. 14C, FIG. 14D, FIG. 14E shows leakage current on the wireless charging coil (ro) at different loading conditions, according to some embodiments.

[0053] FIG. 15A, FIG. 15B shows closed-loop waveforms of the wireless charging system connected to a 420 V load, according to some embodiments.DETAILED DESCRIPTION

[0054] As described in more detail below, approaches are proposed where combination Wireless Power Transfer (WPT) and Onboard Charger (OBC) are provided. The proposed approaches overcome certain problems associated with combining the two approaches together, for example, by using the same rectifier for both OBC and WPT. A number of variants and sub-variants are also proposed herein, for example, using different combinations of connection types, coupling, and common-mode and differential mode (or dynamically assigning modes I paths thereof in an effort to reduce losses or improve efficiency).

[0055] All of these variations are different contemplated approaches to improve the operation of the combined charger mechanism, and the combined charger can be practically implemented by either retrofitting existing drivetrains or configuring new drivetrains for incorporation into improved vehicles. The improved drivetrains can provide increased wireless charging functionality, which is a convenient and desirable feature that can, for example, improve the adoption rate of green technologies.

[0056] Experimental results are also provided to illustrate the operation of an example embodiment, where the OBC includes a full-bridge inverter, a single-phase transformer, and a diode bridge. In the example provided, wireless charger receiver circuit is connected to the center tap of the secondary side of the transformer. The input of OBC is fed with a constant DC voltage, and an inverter phase shift or frequency is used to regulate the output. The wireless charging circuit is fed with a variable DC voltage instead of a variable voltage PFC. The system's output is connected to an electronic load (or resistive load) and tested inconstant resistance and voltage modes. The WPT operates during a wireless charging mode (WC mode), and on board charging mode (OBC mode). Efficiency of operation is an important performance metric, and the proposed integration of WC and OBC mode ideally should be designed to reduce impacts on either WC or OBC mode operational efficiency. For example, a proposed symmetric design of some embodiments may assist in preventing the operation of one mode impacting the efficiency of the other mode.

[0057] FIG. 1 is a block diagram of an example device having an energy storage device and components thereon, according to some embodiments.

[0058] In FIG. 1 , the example device 100 is a vehicle 150 for illustrative purposes, but not all embodiments require that the device being adapted for wireless charging and onboard charging is a vehicle 150 that can be part of drivetrain 120. A non-vehicle example device that is not a vehicle that can use a combined wireless charging and onboard charging, for example, is a portable battery pack. The device 100 can include an onboard charger 102 and a wireless charging circuit 104, and these can be configured to charge energy storage devices, such as energy storage device 106 and auxiliary energy storage 108. Standalone devices 100, devices 100 incorporated into additional portable electronics, such as, but not limited to, drivetrain 120 and vehicle 150 are contemplated. As shown in FIG. 1 , there can be shared components between onboard charger circuit 102 and wireless charging circuit 104.

[0059] In some embodiments, an additional control switch or control circuit is provided that manages electrical charge characteristics and is configured to dynamically assign either the common-mode current path or the differential mode power transfer path for either the onboard charger or the wireless charger. It can switch assignments based on an interrogation (e.g., polling) of both approaches and selecting the path that is maximally efficient (e.g., highest power transfer), or it can be configured to attempt another path upon efficiency falling below a pre-defined threshold. This provides for a flexible approach to handle for non-idealities and is contemplated in a variation.

[0060] An example approach utilizes a common-mode current path on the secondary side of an isolated transformer of an onboard charger as a path for wireless charging of the device.

[0061] Wireless Power Transfer (WPT) and the wired Onboard Charger (OBC) are the two most prominent methods for level 1 and level 2 EV charging, i.e., charging the traction battery at powers under 20 kW. Conventionally, the OBC is a converter fully embedded into the vehicle and comprises two stages. The first stage is a Power Factor Correction (PFC) converter, responsible for meeting the Total Harmonic Distortion (THD) requirements for interconnection with the electric grid while converting the input’s Alternate Current (AC) into Direct Current (DC). The second stage is conventionally a galvanically isolated DC-to-DC conversion stage. In the DC-to-DC stage, the DC voltage produced by the PFC stage is converted back into AC, conducted through a galvanic isolation transformer, and then rectified into DC once more to feed the traction battery.

[0062] WPT solutions can be described with the same stages as an OBC, with the difference that the PFC stage and the DC-to-AC conversion within the isolated DC-to-DC converter are located outside the vehicle. Furthermore, instead of a galvanic isolation transformer, galvanic isolation is substituted by a combination of components within and without the vehicle. The transmitter coil operates analogously to the primary coil of the transformer, whereas the receiver coil is analogous to the secondary side of the transformer. As OBCs, WPT schemes also have a rectifier connected downstream from the galvanic isolation stage.

[0063] Given the similarity of components, solutions have been proposed to leverage OBC or other pre-existing components to implement a part of the Wireless Charger (WC), thereby decreasing the capital costs associated with the WC.

[0064] In [1] an integrated boost converter and WC solution is proposed. However, this method requires relays to switch between the operation modes which can increase production costs. In [2, 3], integration of the receiver side of the wireless charging system with the secondary side of the OBC transformer is presented. In this method, frequency tunning is used to decouple the OBC circuit and WC circuit.

[0065] The solution presented in [2, 3] requires fundamental changes in the topology of the OBC to prevent deleterious interaction between the OBC and the receiver coil, and the solution is highly sensitive to nominal parameter variation, making the system impractical.

[0066] In [4], a new integration of WC and OBC based on the magnetic coupler of the wireless charging system is proposed. However, this method requires using relays and generating magnetic fields while the system is operating in OBC mode.

[0067] Similarly, in [5], the receiver circuit is shared between the OBC and WC. In this method, the receiver coil acts as a tightly coupled transformer with the OBC primary side and a loosely coupled transformer with the transmitter side of the WC system.

[0068] The main drawback of the topology of [5] is the requirement of a relay on the primary side of the OBC to open the circuit while the system is running in WC mode; and magnetic field generation on the wireless receiver coil while running in OBC mode.

[0069] As described herein in various embodiments, a family of WC solutions are proposed that leverage components present in the OBC to reduce the WC’s capital cost. Specifically, the rectifier downstream from the galvanic isolation transformer of the OBC is used as a rectifier of the WC, eliminating the necessity for a dedicated rectifier. The solutions presented herein advance the current state of technology by not needing significant modifications of the OBC such as the inclusion of additional relays or challenging fine-tuning.

[0070] Instead, the solution leverages fundamental symmetries to ensure decoupling between both systems, thus ensuring safe operation. In the context of this disclosure, fundamental symmetries means either the OBC or WC systems uses the CM or DM, and this specifically allows decoupling by ensuring no circulating current or minimal current flows to each system caused by the other system, and thus safe operation is enabled due to no magnetic field generation while the OBC system is operating or damaging the OBC inverter switches and capacitors.

[0071] A schematic illustration of an electric vehicle (EV) charging system is displayed in FIG. 2. The (OBC) and the receiver side of the wireless charger (WC) share several common components, owing to the similar high switching frequency (50-150 kHz) in bothsystems. Integrating and optimizing these components for both wired and wireless charging modes results in cost and volume savings when compared to a traditional system. In the following sections, a concise overview of the system's operational characteristics and variations will be presented. The two diagrams 200 of FIG. 2 are shown as illustrations. In the top diagram of FIG. 2, a practical variant is shown where there are shared components.

[0072] As mentioned above, the OBC connection to the grid is done via a PFC stage. The solutions presented within this report are agnostic to the PFC configuration. A dividing line is shown between off-board and onboard components.

[0073] The DC-to-DC stage includes an inverter, a galvanic isolation transformer, and a rectifier. Several topologies are available for the galvanic isolation transformer, as well as the inverter and rectifier. In some OBC embodiments, the transformer may have a single-phase, thus constraining the inverter and rectifier to accordingly be single-phase. In some other embodiments, the isolation transformer may be three-phase, in a YY, YA, AY, or AA configuration, constraining the inverter and rectifier to be three-phase. The different phase variations are provided because at higher power levels, it is preferable to move to multiphase systems. Moreover, different configurations of a three phase transformer are useful to reduce the current rating of the windings or resonant capacitor values depending on the application requirements.

[0074] Another source of variation among OBC solutions is found in the rectifier downstream from the isolation transformer. If unidirectional charging capability suffices, the rectifier can be implemented using passive diodes, which are cheaper than active semiconductor switches and do not require gate-driving circuitry. In contrast, if bidirectional power transfer is required, active switches may be employed as the semiconductor, and control costs are justified by the additional functionality. Explicitly, different topologies for the rectification stage such as diode full-bridge

[0016] , centered-tap

[0018] , voltage doubler [19, 20], current doubler [21-25], and active full bridge rectifier [26, 27] or semi-active bridge rectifier can be used. The main difference between full-bridge and centered-tap rectifier topologies is the component rating and number of the semiconductor devices. Depending on the application a trade-off between these parameters should be done. A voltage doubler circuit can supply a load with twice the voltage of the secondary side of the OBC transformer; thus,the primary side voltage can be lower. Moreover, it saves two semiconductors from the rectifier compared to a full-bridge rectifier. However, the current rating of the transformer secondary side windings will be twice of a full-bridge configuration. Similarly, a current doubler circuit can supply the load with twice the current rating of the windings but it requires two extra inductors. In an active rectifier, the diodes are replaced by active switches such as MOSFETs or IGBTs. This adds more degree of freedom to control the load and improves the system efficiency. However, it increases the overall cost of the system. To save cost, in a semi-active rectifier instead of replacing all the diodes with an active switch half of them are replaced with an active switch. However, this configuration is only suitable for unidirectional power transfer.

[0075] In the interest of providing examples, some embodiments of the proposed solution are shown along with sample OBC topologies with which the specific integrated WPT solution is compatible.

[0076] FIG. 3A shows a single-phase OBC (both active and passive rectifier) without a resonant network, for which the rectifier is implemented as a diode bridge. The proposed solution is embodied as the WPT coil, along with its associated capacitive resonant network, connecting between the center point of a capacitive voltage divider associated with the traction battery and a middle point connection on the secondary coil of the OBC’s galvanic isolation transformer. The only modification required in the OBC is the introduction of said midpoint connection in the secondary coil.

[0077] FIG. 3B shows a single-phase OBC with a capacitive resonant network. As it was with FIG. 3A, the rectifier downstream of the galvanic isolation transformer is implemented with a passive diode bridge. Differently from what is seen in FIG. 3A, the OBC exemplified in FIG. 3B includes a capacitive network. Here, the same set of capacitors, with capacitance Crs, is used as a resonant network for both OBC and WPT, thus reducing the impedance during both wired and wireless charging operations and improving efficiency by providing soft switching.

[0078] Both choices of approach are contemplated in different proposed embodiments. In particular, the approach can further include a selection as between the different approachesthat can occur, for example, during configuration, or manufacturing. The selection depends on design of the WC system. Typically, an LCC topology is preferred for wireless charging in EV applications. Because it offers better efficiency and is more tolerant against load and mutual inductance variations. So, FIG. 3A is better in EV applications, (it is important to note that under other assumptions it can be challenging to compare them, so other approaches and / or experimental approaches are contemplated).

[0079] In both FIG. 3A and FIG. 3B, the wireless charging power is associated with the common-mode current flowing through the galvanic isolation secondary coil. In contrast, the OBC charging power is associated with the differential current flowing through the galvanic isolation secondary coil. The decoupled nature of the differential-mode and common-mode degrees-of-freedom of the coil enables the decoupled, and thus safe, operation of either wired or wireless charging without interfering with the portions of the circuits not utilized.

[0080] When the system operates in OBC mode, the current will leave the top terminal of the secondary side winding and return from the bottom terminal. Therefore, according to Kirchhoff’s law, no current will flow to the mid-point connection of the winding that is connected to the wireless charging circuit. In this case, the currents of the transformer's secondary side windings are in opposite directions; thus, this power transfer method is called differential mode operation. Since the current going to the wireless charger circuit is zero, no magnetic field will be generated on the receiver coil, which ensures the safe operation of the system in OBC mode.

[0081] When the system operates in WC mode, the wireless charger current enters the middle point of the transformer's secondary side winding and leaves from both the bottom and top terminals of the transformer's secondary side winding. Therefore, the currents are in phase; thus, this power transfer method is called common mode operation. In this mode, the currents in each section of the secondary side winding of the OBC transformer generate opposite but equal amplitude voltages induced on the primary side of the transformer winding. Therefore, ideally, the total induced voltage on the primary side of the transformer would be zero which is desirable. Therefore, the proposed system can operate in WC mode without interfering and damaging the OBC circuit.

[0082] In FIG. 3C, the OBC leverages a single-phase transformer and a passive diode bridge rectifier, as in the cases depicted in FIG. 3A and FIG. 3B. The OBC secondary coil is connected between the mid-point connection of the receiver coil of the wireless charging system and the mid-point of a capacitive voltage divider associated with the traction battery. As noted above, mid-point is shown as an illustrative example but other points are contemplated. This applies to all references below in respect of the mid-point.

[0083] In this case, the wired charging power is associated with the common-mode current flowing through the WC, whereas the wireless power transfer is associated with the differential-mode current flowing through the WC. The decoupled nature of the differentialmode and common-mode deg rees-of- freedom of the coil enables the decoupled, and thus safe, operation of either wired or wireless charging without interfering with the portions of the circuits not utilized. Decoupled operation is safer and produces fewer losses because it ensures that only the system intended to operate at any given moment (e.g., wired or wireless) is energized, whereas the system that is not intended to operate is not energized, despite systems sharing components.

[0084] In FIG. 3E, FIG. 3F, FIG. 3G, and FIG. 3H, the DC-to-DC stage leverages a three- phase galvanic isolation transformer. In these cases, the secondary side of the galvanic isolation transformer is connected in Y, such that a neutral point is available. The wire power transfer in the three-phase cases is associated with the differential-mode currents flowing through the secondary side of the galvanic isolation transformer. In contrast, wireless power is associated with the common-mode current flowing through the secondary side of the transformer, i.e. , the neutral current of the transformer.

[0085] In the remaining of this section, the operation principle is illustrated.Single Phase Type I

[0086] One variation of the proposed integration method is shown in FIG. 3A.

[0087] In this system, the OBC is made by a full-bridge inverter, a single-phase transformer, and a diode bridge. The wireless charger receiver circuit is connected to the center tap of the secondary side of the transformer. In this configuration, the leakageinductance of the secondary side windings of the OBC transformer can be used to form an LCC compensation network for the wireless charging system. Therefore, the diode bridge and resonant inductor are shared in this integrated configuration.

[0088] FIG. 4A shows the operation of the system in OBC mode. In this condition, the induced voltage on the secondary side of the transformer is symmetrical, and there is a balance between the center tap of the transformer and the middle point of the load side de capacitors. Therefore, no current flows through the WC path (i.e., lw=0 and la=lb) and no magnetic field will be generated on the WC receiver side coil.

[0089] FIG. 4B shows the operation of the system in WC mode. In this case, the wireless charger generates a voltage on the secondary side windings of the transformer in the opposite direction. Therefore, the current in the secondary side windings is in the opposite directions and their amplitude is half of the wireless charging path current (i.e., Ia=-lb =lw / 2). In this case, the induced voltage on the primary side of the transformer is almost zero.Single Phase Type II

[0090] In this configuration, the series resonant of the wireless charging system is shared with the OBC circuit. In this way, the resonant capacitors can also help to provide zero voltage switching (ZVS) for the inverter switches. Therefore, the rectifier stage and resonant capacitors are shared between both OBC and WC to save cost.Single Phase Type III

[0091] The topology of a single-phase OBC with an integrated wireless charger is shown in FIG. 3C. In this system, the receiver coil of the wireless charger is divided into two sections and one of the terminals of the secondary side of the OBC transformer is connected to the middle point. The other terminal of the OBC transformer is connected to the middle point of the DC link capacitor. The OBC utilizes the LCC resonant network of the wireless charger which can provide different voltage gains (at different frequencies) and soft- switching capabilities. In this configuration, the OBC charges the battery through the voltagedoubler rectifier and the wireless charger uses the full-bridge rectifier. The advantage of thismethod is that the current rating of the receiver coil of the wireless charger is half of the current rating of Single-Phase Type I and II topologies.

[0092] When the OBC is operating, the current flowing in the wireless coil sections is in opposite directions. Therefore, the sum of the generated magnetic field will be zero on the receiver coil (under the vehicle). When the WC is operating, the current in the receiver coil sections is in the same direction. Therefore, no current will flow through the middle point of the WC receiver coil to the OBC circuit. Therefore, these two systems are decoupled from each other in both operating points. In FIG. 3C, resonant inductor is added to form an LCC compensation network instead of a series-parallel compensation network. The LCC network behaves differently; it operates as a current source suitable for battery charging applications. This provides an improvement as having a current source behavior limits the output current. Therefore, in the event of a short circuit in the output, the converter output current will be limited to the designed value. Thus, the circuit will not be damaged by a short- circuit fault. Operating as a current source limits the output current according to the tuning of the resonant network. Moreover, it helps the operation of the battery charger converter in constant current charging mode.YY Type I

[0093] In this system, the receiver coil of the wireless charger (Lr) is connected to an LCC compensation network. The two resonant capacitors are not integrated into the onboard charger, but the resonant inductor is integrated with the leakage inductance of the secondary side of the OBC transformer. Moreover, the diode bridge is also shared between both systems.

[0094] In FIG. 3D, the OBC circuit is similar to any conventional isolated dual active bridge (DAB) or an isolated phase-shifted DC-DC converter. In this circuit, when the OBC circuit is operating, the energy is transferred from the AC grid to the circuit by a power factor correction (PFC) converter. The PFC stage creates a stable DC voltage to supply a high frequency inverter. The inverter configuration can be either a full-bridge or half-bridge) as shown in FIG. 3A). Moreover, different numbers of legs can be considered for the inverter to build an interleaved circuit.

[0095] It should be noted that any number of legs that can provide a balanced multi-phase system can be considered (single, 3, 6, 9, 12, etc.).

[0096] There are several advantages to using an interleaved configuration including using lower rating devices, better thermal management, better fault tolerance, voltage, and current ripple reduction, etc. In this figure, a three-leg interleaved inverter (with a phase shift of 120 degrees) is shown as an example.

[0097] The operation of the proposed system shown in FIG. 3D, in OBC and WC mode are shown in FIG. 5A and FIG. 5B, respectively. Looking at FIG. 5A and FIG. 5B, the wired power transfer is associated with a linear combination of the differences in currents between any given two windings of the secondary, which magnetically couple the primary and secondary coils. In contrast, the wireless power is associated with the neutral current on the secondary side of the transformer, i.e. , the sum of the currents in all three-windings of the secondary side of the transformer, i.e., the CM current. As a result, the wired and wireless power transfers are magnetically decoupled. Specifically, there’s no reasonable expectation that the operation of one system should energize the other system.

[0098] When the circuit is running at OBC mode, the sum of the currents on the neutral point of the transformer's secondary side is zero; therefore, no current will pass through the WC receiver circuit (i.e., / w=0). Whenever the system is working in WC mode, there is a voltage induced on the wireless charger receiver coil (Lr) that generates a current that flows to the neutral point of the secondary side of the OBC transformer ( / w). Then this current will be divided into three branches ( / a= lb= lc=lw / 3), going to the rectifier and charging the battery.

[0099] It should be noted that flowing the currents in the secondary side windings of the OBC transformer results in generating induced voltages on the primary side of the OBC transformer. If the switches of the OBC inverter are in the open-circuit mode, the primary side voltages will charge up the PFC DC link capacitor through the body diodes of the inverter switches. However, this condition is only persisted until the DC link voltage reaches the induced voltage on the transformer primary side windings. After reaching the steady state, the currents flowing in the primary side of the transformer will reach zero (i.e., IA= IB= lc=0).

[0100] The main advantage of this configuration is that the topology is compatible with existing conventional OBC topologies. Moreover, the control of this circuit can be done similarly to any conventional OBC and WC. However, more components can be integrated to save more costs. Moreover, due to the usage of a phase-shifted OBC, the ZVS is limited. ZVS limitation is important because ZVS reduces the switching losses and thus improve the inverter efficiency. Moreover, ZVS helps reducing the EMI noises generated by the inverter.YY Type ll-Y

[0101] The YY Type II configuration is shown in FIG. 3E; in this circuit, a series compensation is used for the wireless charging system. The series capacitor also moved from the neutral point path to each of the branches. When the system is running in OBC mode, the circuit is a secondary side compensated resonant converter. This circuit can be useful to offer ZVS operation in a wider range of loads compared to the phase-shifted topology. Moreover, soft switching results in better efficiency and lower EMI noises. The operating principle of this circuit is similar to the YY Type I configuration. This configuration can be helpful to reduce the size of the required capacitor bank. It should be noted that the voltage rating of the resonant capacitor bank will remain the same as a conventional series compensated WC.Y-Y connection Type ll-A

[0102] The YY Type ll-A configuration is shown in FIG. 3F. In this topology, the capacitors are connected in a A configuration. Therefore, the required capacitance (C ) is equal to 1 / 3 of the size of a Y-type compensation

[0016] , Of course, the voltage rating of this configuration is higher than the Y connection. However, based on the application requirements, optimization results, and part availability any of these topologies can be chosen. In FIG. 3F, resonant capacitor Cris added in series with Lrto form a series LC compensation network for the wireless receiver circuit. Without the resonant capacitor, Cr, the efficiency of the wireless power transfer system would be significantly reduced. The approach described in FIG. 3F improves the efficiency and maximum transferable power and reduces the coil current.A-Y connection Type I

[0103] The AY Type III configuration is shown in FIG. 3G. In this topology, the primary side winding of the transformer is connected in A configuration. This helps to reduce the primary winding current by a factor of V3. This is useful because a lower wire diameter (cheaper) can be used in the primary side winding. Moreover, it is possible to use PCB winding in planar transformer design.Simulation Results

[0104] In demonstrative simulation examples in respect of practical applications, it is assumed that both the OBC and WC are rated for a 6.6 kW load. The wireless charging system is operating at 85 kHz (according to SAE2954). The wireless charging coils are the rectangular type with a dimension of 640x508 mm2. Ferrite blocks are placed underneath the transmitter coil to reduce magnetic field leakage and improve the efficiency of the system. As an example, a few of the proposed integrated topologies are simulated and the results are presented in this section. Other variations are possible, and these are shown as non-limiting illustrative guides.

[0105] FIG. 6A and FIG. 6B shows the simulation results of the single-phase Type I integrated system. The compensation network is a double-sided LCC resonant network tuned at 85 kHz. It can be seen that the OBC primary side winding current ( / p) is zero when the system is operating in wireless charging mode as shown in FIG. 6A. Moreover, it can be seen that the current of the secondary side of the OBC transformer is balanced and equal to half of the wireless circuit output current ( / w=2x / a=2x / / ?). Similarly, when the OBC mode is running, no current flows through the path of the wireless charging circuit ( / w=0) as shown in FIG. 6B. In this case, the current on the secondary side windings is dependent on the load current and transformer turns ratio.

[0106] In some embodiments the DC-to-DC stage of the OBC may employ a single-phase transformer, wherein the transformer secondary coil is comprised of two windings wound around the same magnetic core, wherein a terminal of each winding is connected together and to a conductor whose current is indicative of the wireless receiver coil current and / orvoltage, wherein the other two terminals of the two windings comprising the single-phase transformer secondary coil are connected to a rectifier, wherein the traction battery is connected in parallel with a capacitive voltage divider, wherein the other terminal of the combined wireless receiver coil and compensation network is connected to the mid point of the capacitive voltage divider.

[0107] In some embodiments the DC-to-DC stage of the OBC may employ a single-phase transformer, wherein the transformer secondary coil is comprised of two windings wound around the same magnetic core, wherein a terminal of each winding is connected together and to a conductor whose current is indicative of the wireless receiver coil current and / or voltage, wherein the other two terminals of the two windings comprising the single-phase transformer secondary coil are connected to a rectifier, wherein the traction battery is connected in parallel with a capacitive voltage divider, wherein the other terminal of the combined wireless receiver coil and compensation network is connected to the mid point of the capacitive voltage divider, wherein a tertiary coil of the single-phase transformer is used as part of the APU.

[0108] In some embodiments the DC-to-DC stage of the OBC may employ a three-phase transformer, wherein the transformer secondary coil is comprised of three windings wound around the same magnetic core, wherein a terminal of each winding is connected together and to a conductor whose current is indicative of the wireless receiver coil current and / or voltage, wherein the other three remaining terminals of the three windings comprising the three-phase transformer secondary coil are connected to a three-phase rectifier, wherein the traction battery is connected in parallel with a capacitive voltage divider, wherein the other terminal of the combined wireless receiver coil and compensation network is connected to the mid point of the capacitive voltage divider.

[0109] The following section describes experimental results for an example experimental setup.

[0110] A variation of the proposed integration method is the single-phase Type I topology that is being examined. In this system, the OBC is made by a full-bridge inverter, a singlephase transformer, and a diode bridge.

[0111] The wireless charger receiver circuit is connected to the center tap of the secondary side of the transformer. A 6.6 kW integrated wireless and onboard charger is built, and the overall setup for this experiment is shown in FIG. 7; the experimental setup specifications are listed in Table I.

[0112] FIG. 7 is a schematic diagram 700 showing a depiction of the experimental setup showing the integrated system and control, according to some embodiments.

[0113] Table I. Integrated wireless and onboard charging system specification.Symbol Description RangePnRated power 6.6 kW fsw _wc Wireless charger switching frequency 85 kHz fsw _OBC Onboard charger switching frequency 90 - 300 kHzVdd Input DC voltage of the onboard charging system 400 VVdc2 Input DC voltage of the wireless charging system 250 - 850 VVbat Battery voltage 280 - 420 VXmisX-axis misalignment between TX and RX 75 mmYmisY-axis misalignment between TX and RX 100 mmZ The air gap between TX and RX 140 mm

[0114] The input of OBC is fed with a constant DC voltage, and an inverter phase shift or frequency is used to regulate the output. The wireless charging circuit is fed with a variable DC voltage instead of a variable voltage PFC.

[0115] The system's output is connected to an electronic load (or resistive load) and tested in constant resistance and voltage modes.

[0116] Onboard Charging (OBC Mode) and Wireless Charging will now be described in relation to the experimental setup.

[0117] OBC Mode

[0118] In this experiment, the closed-loop reference tracking of the OBC is studied. In this system, the controller regulates the output current according to the reference by changing the inverter phase shift (0) and switching frequency (fsw_oBc). The requested reference current values are 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, and 18 A. The input DC voltagehas been set to 400 V, and the load voltage is set to 280 V, 350 V, and 420 V. The waveforms and efficiency measurements from a power analyzer are presented in FIG. 8A, FIG. 8B, FIG. 9A, FIG. 9B, and FIG. 10A, FIG. 10B.

[0119] In these figures 800A, 800B, 900A, 900B, and 1000A, 1000B, the oscilloscope CH1 is OBC inverter voltage (Vin), CH2 is OBC inverter current ( / „), CH3 is load voltage (Voor Vbat), and CH4 is load current ( / 0or lbat). Udd and ldcirepresent the input DC voltage and current in the power analyzer figures, while U c2 and I c2 represent the output voltage and current. It can be seen that the OBC inverter current has a lagging phase angle compared to the OBC inverter voltage, which indicates zero voltage switching (ZVS). Moreover, the closed-loop system could track the reference output current, and the system showed good efficiency at different operating points, as expected.

[0120] FIG. 8A and FIG. 8B shows reference tracking performance (Io) at different loading conditions (280 V - 1A, 280 V - 10A).

[0121] FIG. 9A and FIG. 9B shows reference tracking performance (Io) at different loading conditions (350 V - 2A, 350 V - 12A).

[0122] FIG. 10A and FIG. 10B shows reference tracking performance (Io) at different loading conditions (420V - 4 A, 420 V - 8 A).

[0123] FIG. 11 and FIG. 12 are graphs 1100 and 1200 showing the closed-loop system measured efficiency versus output current at different load (battery) voltages, according to some embodiments (280 V, 350 V, 420 V).

[0124] It should be noted that the actual measurements are shown as dots on the graph, and the dashed line is a calculated curve of best fit. It can be seen that the efficiency of the proposed integrated system is above 94% in full-load conditions at different load voltages (Vbat). Moreover, the system achieved a peak efficiency of 98.3% with a 420 V load. It can be concluded that the OBC efficiency is not affected by the proposed integration.

[0125] FIG. 11 shows closed-loop system efficiency versus output current (Io) at different load voltages, according to some embodiments (280 V, 350 V, 420 V).

[0126] FIG. 12 shows closed-loop system efficiency versus output power (Pout) at different load voltages, according to some embodiments (280 V, 350 V, 420 V).

[0127] To measure the wireless receiver coil leakage current in OBC mode and capture relevant waveforms, the wireless coils are placed in fully aligned and 100 mm misaligned conditions. The input DC voltage is set to 400 V, and the load voltage is between 280, 350, and 420V. The output reference current is adjusted from 9 to 18 A. To capture the necessary waveforms, an oscilloscope can be used with CH1 measuring OBC inverter voltage, CH2 measuring OBC inverter current, CH3 measuring load current, and CH4 measuring wireless coil current.

[0128] The experimental results while the receiver is fully aligned and the receiver coil is placed at 110 mm misaligned in the Y direction are presented in FIG. 13A, FIG. 13B, FIG. 13C, FIG. 13D, FIG. 13E and FIG. 14A, FIG. 14B, FIG. 14C, FIG. 14D, FIG. 14E, respectively. It can be observed that the leakage current is low at different loading conditions.

[0129] FIG. 13A, FIG. 13B, FIG. 13C, FIG. 13D, FIG. 13E shows leakage current on the wireless charging coil (Iro) at different loading conditions, according to some embodiments (280 V - 9 A, 280 V - 18 A, 350 V - 9 A, 350 V - 15 A, 420 V - 9 A). Diagrams 1300A, 1300B, 1300C, 1300D, 1300E are shown.

[0130] FIG. 14A, FIG. 14B, FIG. 14C, FIG. 14D, FIG. 14E shows leakage current on the wireless charging coil (Iro) at different loading conditions, according to some embodiments (280 V - 9 A, 280 V - 18 A, 350 V - 9 A, 350 V - 15 A, 420 V - 9 A). Diagrams 1400A, 1400B, 1400C, 1400D, 1400E are shown.

[0131] Wireless Charging Mode (WC Mode) is now described. In this experiment, the ground assembly (GA) of the wireless charger input DC voltage is set to 550 V, and a power of 3.3 kW or 6.6 kW for a 420 V load is requested. When working in WC mode, the waveforms of the system are shown in FIG. 15A, FIG. 15B. It can be observed that the OBC DC link voltage remains almost zero, indicating that the OBC is not affected by the operation of the wireless charging system due to the symmetrical design of the transformer windings.The four channels of the waveforms include the WC inverter voltage, WC inverter current, OBC DC voltage, and load current.

[0132] FIG. 15A, FIG. 15B are diagrams 1500A and 1500B that show closed-loop waveforms of the wireless charging system connected to a 420 V load, according to some embodiments (3.3 kW and 6.6 kWwhen connected to a 420 V load).

[0133] Applicant notes that the described embodiments and examples are illustrative and non-limiting. Practical implementation of the features may incorporate a combination of some or all of the aspects, and features described herein should not be taken as indications of future or existing product plans. Applicant partakes in both foundational and applied research, and in some cases, the features described are developed on an exploratory basis.

[0134] The term “connected” or "coupled to" may include both direct coupling (in which two elements that are coupled to each other contact each other) and indirect coupling (in which at least one additional element is located between the two elements).

[0135] Although the embodiments have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the scope. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification.

[0136] As one of ordinary skill in the art will readily appreciate from the disclosure, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed, that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.

[0137] As can be understood, the examples described above and illustrated are intended to be exemplary only.References

[0138] [1] M. Chinthavali, O. C. Onar, S. L. Campbell, and L. M. Tolbert, "Integrated charger with wireless charging and boost functions for PHEV and EV applications," in 2015 IEEE Transportation Electrification Conference and Expo (ITEC), 14-17 June 20152015, pp. 1-8, doi: 10.1109 / ITEC.2015.7165813.

[0139] [2] M. Elshaer, C. Bell, A. Hamid, and J. Wang, "DC-DC Topology for Interfacing a Wireless Power Transfer System to an On-Board Conductive Charger for Plug-in Electric Vehicles," IEEE Transactions on Industry Applications, pp. 1-1 , 2021 , doi: 10.1109 / TIA.2021.3103700.

[0140] [3] M. Elshaer, C. Bell, A. Hamid, and J. Wang, "Wireless Power Transfer System Integration with an On-Board Conductive Charger for Plug-in Electric Vehicles," in 2020 IEEE Energy Conversion Congress and Exposition (ECCE), 11-15 Oct. 2020 2020, pp. 5177-5184, doi: 10.1109 / ECCE44975.2020.9235852.

[0141] [4] B. Vu, J. M. Gonzalez-Gonzalez, V. Pickert, M. Dahidah, and A. Trivino, "A hybrid charger of conductive and inductive modes for Electric Vehicles," IEEE Trans. Ind. Electron., pp. 1-1 , 2020, doi: 10.1109 / TIE.2020.3042162.

[0142] [5] Y. Zhang, Y. Wu, Z. Shen, W. Pan, H. Wang, J. Dong, X. Mao, and X. Liu, "Integration of Onboard Charger and Wireless Charging System for Electric Vehicles with Shared Coupler, Compensation, and Rectifier," IEEE Trans. Ind. Electron., pp. 1-4, 2022, doi: 10.1109 / TIE.2022.3204857.

[0143] [6] A. Khaligh and M. D' Antonio, "Global Trends in High-Power On-Board Chargers for Electric Vehicles," IEEE Trans. Veh. Technol., vol. 68, no. 4, pp. 3306-3324, 2019, doi: 10.1109 / TVT.2019.2897050.

[0144] [7] S. Jeong, Y. Jeong, J. Kwon, and B. Kwon, "A Soft-Switching Single-Stage Converter With High Efficiency for a 3.3-kW On-Board Charger," IEEE Trans. Ind. Electron., vol. 66, no. 9, pp. 6959-6967, 2019, doi: 10.1109 / TIE.2018.2877093.

[0145] [8] Stefan Ditze, Stefan Ehrlich, Nikolai Weitz, Marco Sauer, Frank ABmus, Anne Sacher, Christopher Joffe, Christoph Seller, and Patrick MeiBner, "A High-Efficiency High-Power-Density SiC-Based Portable Charger for Electric Vehicles," Electronics, vol. 11, no.12, p. 1818, 2022. [Online], Available: https: / / www.mdpi.com / 2079-9292 / 11 / 12 / 1818.

[0146] [9] Z. Fang, T. Cai, S. Duan, and C. Chen, "Optimal Design Methodology for LLC Resonant Converter in Battery Charging Applications Based on Time-Weighted Average Efficiency," IEEE Trans. Power Electron., vol. 30, no. 10, pp. 5469-5483, 2015, doi: 10.1109 / TPEL.2014.2379278.

[0147]

[0010] Tiago J. C. Sousa, Delfim Pedrosa, Vitor Monteiro, and Joao L. Afonso, "A Review on Integrated Battery Chargers for Electric Vehicles," Energies, vol. 15, no. 8, p. 2756, 2022. [Online], Available: https: / / www.mdpi.eom / 1996-1073 / 15 / 8 / 2756.

[0148]

[0011] C. D. Viana, S. Semsar, M. Pathmanathan, and P. W. Lehn, "Integrated Transformerless EV Charger with Symmetrical Modulation," IEEE Trans. Ind. Electron., pp. 1-1, 2021 , doi: 10.1109 / TIE.2021.3127032.

[0149]

[0012] S. Semsar, T. Soong, and P. W. Lehn, "On-Board Single-Phase Integrated Electric Vehicle Charger With V2G Functionality," IEEE Trans. Power Electron., vol. 35, no. 11 , pp. 12072-12084, 2020, doi: 10.1109 / TPEL.2020.2982326.

[0150]

[0013] Ruoyun Shi, Sepehr Semsar, and Peter W. Lehn, "Constant Current Fast Charging of Electric Vehicles via a DC Grid Using a Dual-Inverter Drive," IEEE Trans. Ind. Electron., vol. 64, no. 9, pp. 6940-6949, 2017, doi: 10.1109 / tie.2017.2686362.

[0151]

[0014] R. Hou and A. Emadi, "Applied Integrated Active Filter Auxiliary Power Module for Electrified Vehicles With Single-Phase Onboard Chargers," IEEE Trans. Power Electron., vol. 32, no. 3, pp. 1860-1871 , 2017, doi: 10.1109 / TPEL.2016.2569486.

[0152]

[0015] R. Hou and A. Emadi, "A Primary Full-Integrated Active Filter Auxiliary Power Module in Electrified Vehicles With Single-Phase Onboard Chargers," IEEE Trans. Power Electron., vol. 32, no. 11, pp. 8393-8405, 2017, doi: 10.1109 / TPEL.2017.2650482.

[0153]

[0016] C. Fei, R. Gadelrab, Q. Li, and F. C. Lee, "High-Frequency Three-Phase Interleaved LLC Resonant Converter with GaN Devices and Integrated Planar Magnetics," IEEE J. Sei. Topics Power Electron., pp. 1-1, 2019, doi: 10.1109 / JESTPE.2019.2891317.

[0154]

[0017] C. Fei, F. C. Lee, and Q. Li, "High-Efficiency High-Power-Density LLC Converter With an Integrated Planar Matrix Transformer for High-Output Current Applications," IEEE Trans. Ind. Electron., vol. 64, no. 11, pp. 9072-9082, 2017, doi: 10.1109 / TIE.2017.2674599.

[0155]

[0018] E. Orietti, P. Mattavelli, G. Spiazzi, C. Adragna, and G. Gattavari, "Current sharing in three-phase LLC interleaved resonant converter," in 2009 IEEE Energy Conversion Congress and Exposition, 20-24 Sept. 2009 2009, pp. 1145-1152, doi: 10.1109 / ECCE.2009.5316510.

[0156]

[0019] S. Kim, B. Kim, B. Kwon, and M. Kim, "An Active Voltage-Doubler Rectifier Based Hybrid Resonant DC / DC Converter for Wide-Input-Range Thermoelectric Power Generation," IEEE Trans. Power Electron., vol. 33, no. 11, pp. 9470-9481, 2018, doi: 10.1109 / TPEL.2017.2788923.

[0157]

[0020] M. Abbasi, R. Emamalipour, M. A. M. Cheema, and J. Lam, "A Constant Frequency High Voltage Gain Resonant Converter Module With Semi-Active Phase-Shifted Voltage Multiplier For MVDC Distribution," IEEE J. Sei. Topics Power Electron., pp. 1-1, 2021 , doi: 10.1109 / JESTPE.2021.3088120.

[0158]

[0021] U. Badstuebner, J. Biela, D. Christen, and J. W. Kolar, "Optimization of a 5- kW Telecom Phase-Shift DC-DC Converter With Magnetically Integrated Current Doubler," IEEE Trans. Ind. Electron., vol. 58, no. 10, pp. 4736-4745, 2011 , doi: 10.1109 / TIE.2010.2103536.

[0159]

[0022] F. Grazian, T. B. Soeiro, and P. Bauer, "Voltage / Current Doubler Converter for an Efficient Wireless Charging of Electric Vehicles With 400 V and 800 V Battery Voltages," IEEE Trans. Ind. Electron., pp. 1-11 , 2022, doi: 10.1109 / TIE.2022.3208582.

[0160]

[0023] M. Xiong, H. Dai, Q. Li, Z. Jiang, Z. Luo, and X. Wei, "Design of the LCC-SP Topology with a Current Doubler for 11 kW Wireless Charging System of Electric Vehicles," IEEE Trans. Transport. Electrific., pp. 1-1, 2021 , doi: 10.1109 / TTE.2021.3074007.

[0161]

[0024] Lixin Shi, Alberto Delgado, Regina Ramos, and Pedro Alou, "A Wireless Power Transfer System with Inverse Coupled Current Doubler Rectifier for High Output Current Applications," IEEE Trans. Ind. Electron., pp. 1-1 , 2021, doi:10.1109 / tie.2021.3078350.

[0162]

[0025] H. Z. Z. Beh, M. J. Neath, J. T. Boys, and G. A. Covic, "An Alternative IPTPickup Controller for Materials Handling using a Current Doubler," IEEE Trans. Power Electron., vol. PP, no. 99, pp. 1-1 , 2018, doi: 10.1109 / TPEL.2018.2801247.

[0163]

[0026] P. Amiri, C. Botting, M. Craciun, W. Eberle, and L. Wang, "Analytic-Adaptive LLC Resonant Converter Synchronous Rectifier Control," IEEE Trans. Power Electron., vol. 36, no. 5, pp. 5941-5953, 2021 , doi: 10.1109 / TPEL.2020.3026374.

[0164]

[0027] C. Fei, Q. Li, and F. C. Lee, "Digital Implementation of Adaptive Synchronous Rectifier (SR) Driving Scheme for High-Frequency LLC Converters With Microcontroller," IEEE Trans. Power Electron., vol. 33, no. 6, pp. 5351-5361, 2018, doi: 10.1109 / TPEL.2017.2731942.

Claims

WHAT IS CLAIMED IS:

1. A device for charging an energy storage device, the device comprising: an onboard charger circuit; a wireless charger circuit; wherein the onboard charger circuit and the wireless charger circuit share a rectifier stage.

2. The device of claim 1 , wherein the onboard charger circuit and the wireless charger circuit share resonant components.

3. The device of claim 2, wherein the resonant components of a receiver side of the wireless charging circuit are integrated into the onboard charger circuit.

4. The device of claims 2 or 3, wherein the resonant components include at least a shared resonant network, and the shared resonant network reduces impedance during both wired and wireless charging operations.

5. The device of any one of claims 1-3, wherein the onboard charger circuit includes an isolating transformer having a secondary side, and a common-mode current path on the secondary side is used as a path for wireless charging by the wireless charger circuit.

6. The device of any one of claims 1-3, wherein the onboard charger circuit includes an isolating transformer having a secondary side, and a differential mode current path on the secondary side is used as a path for wireless charging by the wireless charger circuit.

7. The device of claim 5, wherein the isolating transformer is three-phase.

8. The device of any one of claims 6 and 7, further comprising an auxiliary power circuit that is also integrated to the isolating transformer.

9. The device of claim 1, wherein the wireless charger circuit is directly connected to the rectifier stage.

10. The device of claim 5, wherein the wireless charger circuit is indirectly connected to the rectifier stage and also independent from the isolating transformer.

11. The device of claim 5, wherein the wireless charger circuit is directly or indirectly connected to the isolating transformer and another point in the system.

12. The device of claim 11 , wherein the wired and wireless power of the device are decoupled.

13. The device of claim 12, wherein wired power transfer is associated with differentialmode connections at the isolating transformer, and wireless power transfer is associated with common-mode connections at the isolating transformer.

14. The device of claim 12, wherein wireless power transfer is associated with differentialmode connections at the isolating transformer, and wired power transfer is associated with common-mode connections at the isolating transformer.

15. The device of claim 13, wherein the isolating transformer has a split-coil connection.

16. The device of claim 15, wherein a wireless coil of the wireless charger circuit connects to the isolating transformer at the split-coil connection.

17. The device of claim 15, wherein a conductor whose current is indicative of the current and / or voltage produced by the receiver wireless coil connects to the isolating transformer at the split coil connection.

18. The device of claim 12, wherein wired power transfer is associated with common-mode connections at the wireless coil, and wireless power transfer is associated with differentialmode connections at the wireless coil.

19. The device of claim 18, wherein the wireless coil has a split-coil connection.

20. The device of claim 19, wherein a conductor whose current is indicative of the current and / or voltage produced by the secondary side of the galvanic isolation transformer connects to the wireless coil at the split coil connection.

21. A method for charging an energy storage device comprising an onboard charger circuit and a wireless charger circuit that share a rectifier stage; the method comprising: using at least one of a common-mode conduction path and a differential mode conduction path for onboard charging, and using the other of the at least one of the common-mode conduction path and the differential mode conduction for wireless charging.

22. The method of claim 21 , wherein the common-mode conduction path and the differential mode conduction path are dynamically assigned based on a detected electrical characteristic of the charging of the energy storage device.

23. The method of claim 22, wherein the detected electrical characteristic is based at least on a charge efficiency of the charging of the energy storage device being greater than or less than a predefined efficiency threshold.

24. The method of claim 21 , wherein the common-mode conduction path is utilized for wireless charging.

25. The method of claim 21 , wherein the differential mode conduction path is utilized for wireless charging.

26. The method of claim 21, wherein during operation of the onboard charger circuit, there is no magnetic field being generated on coils of and circulating current is minimized on the wireless charger circuit.

27. The method of claim 21 , wherein during operation of the wireless charger circuit, electrical losses on the onboard charger circuit are not increased.

28. The method of claim 24, wherein a wireless charger output current is divided into two or more parallel paths to a load, the one or more parallel paths being used for the common-mode conduction path.

29. The method of claim 21, wherein for the common-mode conduction path, the currents leaving a transformer’s winding terminals are in phase, and for the differential mode conduction path, the currents leaving the transformer’s winding terminals are out of phase.

30. A non-transitory machine readable medium storing instructions, which when executed by a processor, cause the processor to perform a method of charging an energy storage device according to any one of claims 21-29.

31. A drivetrain comprising the device of any one of claims 1-20.

32. A vehicle comprising the drivetrain of claim 31.

33. The vehicle of claim 32, wherein the vehicle is any one of a car, a ship, an airplane, an autonomous aerial vehicle.

34. A portable energy storage device comprising the device of any one of claims 1-20.

35. The portable energy storage device of claim 34, wherein the portable energy storage device is any one of a portable battery pack, a portable electronic device.

Images