Method and for protecting against high voltage at a vehicle assembly communicating with a ground assembly

Abstract

A circuitry for protecting against overvoltage in a vehicle assembly 120 of an electric vehicle. The vehicle assembly is in communication with a ground assembly 110 as a part of a wireless power trans

Description

[0001] The present invention relates generally to wireless power transmission in electric vehicles and more specifically to protecting the receiver of electric vehicle from over voltage. BACKGROUND OF THE INVENTION

[0002] Prior to setting forth the background of the invention, it would be advantageous to provide some term definitions as follows:

[0003] The term ‘electric vehicle’ refers generally to a vehicle powered solely, or in part, by electrical energy stored (e.g., chemically) in a battery, or the like. In the present context, an ‘electric vehicle’ operates as part of a wireless power transfer (WPT) system and has provision for receiving (e.g., at coils disposed on the underside of the vehicle) a wirelessly induced electromotive force (i.e., voltage) that may be stored, or otherwise utilized to recharge the battery. For an electromagnetically induced voltage to occur, the vehicle (i.e., the ‘conductor’) may be moving relative to a magnetic field which is, for example, projected about the road upon which the vehicle is travelling. Alternatively, the magnetic field may be periodically varied (e.g., through use of alternating current) thereby inducing a voltage at the vehicle in its static form.

[0004] The term ‘ground assembly” refers generally to a portion of, for example, a road, a highway or motorway which has been modified to comprise a medium for wirelessly transmitting power (i.e., a ‘power transmitter’). This may mean that the road comprises a plurality of coils embedded beneath the surface of the road section which are operable to emit a magnetic field. In typical arrangements, the medium (coils) may be connected to an alternating current source, e.g. an electrical grid, and may generate a varying magnetic field, thereby inducing a voltage in any proximate conductor.

[0005] The term ‘vehicle assembly” refers generally to circuitry on board of the electric vehicle which include a receiver to receive the power transmitted from the ground assembly, an energy regulator, as well as other circuitries as needed to ensure the battery of the electric vehicle and then the motor of the electric vehicle receive the energy per their requirements.

[0006] Charging the battery of the electric vehicle either while the electric vehicle is static when the vehicle is parked or dynamic when the vehicle is moving may involve incidents of overvoltage which may cause several safety issues and may damage the battery and the motor.

[0007] These undesirable overvoltage incidents may occur whenever the voltage across the output of the vehicle assembly goes beyond an acceptable voltage level or alternatively , whenever the gradient of the voltage increase level at the output of the vehicle assembly goes beyond an acceptable gradient level. SUMMARY OF THE PRESENT INVENTION

[0008] The present invention addresses undesirable overvoltage events in a vehicle assembly of an electric vehicle operating as a part of a wireless power transfer system by a combination of a quick response of a controlled switch and a unidirectional communication mechanism between the vehicle assembly and the power assembly which upon detection of the overvoltage, divert the energy into a bypass and stop the power request from the ground assembly, respectively.

[0009] Embodiments of the present invention provide a circuitry for protecting against an overvoltage event at a vehicle assembly of an electric vehicle, being in communication with a ground assembly as a part of a wireless power transfer system for electric vehicles. The circuitry for protecting against overvoltage event may include: a radio frequency transmitter to repeatedly transmit a power request signal to the ground assembly, being a modulated signal having a unique identifier of the electric vehicle; a detection circuitry to detect an overvoltage event, across an output of the vehicle assembly; a controlled switch to divert current off the output of the vehicle assembly, into a by-pass circuitry, upon detection of the overvoltage event, wherein upon receiving an indication from the detection circuitry of overvoltage event, the radio frequency transmitter stops transmitting the power request signal to the ground assembly.

[0010] These and other advantages of the present invention are set forth in detail in the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] For a better understanding of the invention and in order to show how it may be implemented, references are made, purely by way of example, to the accompanying drawings in which, like-numerals designate corresponding elements or sections. In the accompanying drawings:

[0012] Figure 1 is a block diagram in accordance with some embodiments of the present invention;

[0013] Figure 2 is a block diagram in accordance with some embodiments of the present invention; and

[0014] Figure 3 is a block diagram in accordance with some embodiments of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] With specific reference now to the drawings in detail, it is stressed that the particulars shown are for the purpose of example and solely for discussing the preferred embodiments of the present invention and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention. The description taken with the drawings makes apparent to those skilled in the art how the several forms of the invention may be embodied in practice.

[0016] Before explaining the embodiments of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following descriptions or illustrated in the drawings. The invention is applicable to other embodiments and may be practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting.

[0017] According to some embodiments of the present invention the vehicle assembly which charges the battery in the vehicle acts as current source. As opposed to a voltage source which can be disconnected using a simple series circuit breaker, the current source can be disabled by a shortcut.

[0018] These are the situations that require disabling the output of the vehicle assembly: a) The receiver is not connected to the load, the output connector is not connected. b) The vehicle initiates disconnection for any reason. c) A malfunction while working that disconnects the receiver from the battery.

[0019] In all these situations the current source tries to continue the current and since it does not see a load, the voltage will rise. The outcome may lead eventually to a destruction of the vehicle assembly circuitry.

[0020] Embodiments of the present invention have been designed to operate under the following conditions: a) Power transmission at a working frequency of at least 85kHz b) Currents flowing though the vehicle assembly of up to 150A c) Fast response time of less than 0. ImS for disconnecting the ground assembly. d) Working voltage of 1000V

[0021] Figure 1 is a block diagram of a vehicle assembly 120 with an overvoltage protection circuitry according to some embodiments of the present invention designed to address an overvoltage event in accordance with the aforementioned conditions. Ground assembly 110 may include a ground assembly power circuitry 112 which is controlled by ground assembly controller 113 and may be configured to feed transmitter coils 111 with the electrical power required to create the magnetic needed for the wireless power transfer with vehicle assembly 120. Ground assembly 110 further includes an RF receiver 14 having an output connected to an input of ground assembly controller 113.

[0022] According to some embodiments of the present invention, vehicle assembly 120 may be placed on board an electric vehicle (not shown) and may include receiver coils 121 which may be coupled to transmitter coils 111. Receiver coils 121 may feed the input of a rectifier 122 configured to rectify the alternating current into direct current. Rectifier 122 in turn feeds the input of a direct current (DC) filter 123 which reduces the harmonies of the power signal passing through it. The output of DC filter 123 is also effectively the output of vehicle assembly 120 which may feed the EV battery 130 via contactor 132 and EV battery 130 in turn feeds the motor (not shown) of the EV.

[0023] According to some embodiments of the present invention, detection circuitry 124 may receive as an input, the voltage across the output of vehicle assembly 120 and the output of detection circuitry 124 may be connected to a vehicle assembly controller 127.

[0024] The input of controlled switch circuitry 125 is connected to the output of vehicle assembly 120 and the output of controlled switch circuitry 125 is connected to an input of a bypass circuitry 126.

[0025] According to some embodiments of the present invention, one of the outputs of vehicle assembly controller 127 is connected to a control input of the controlled switch circuitry 125.

[0026] Vehicle assembly 120 further includes an RF transmitter 128 which is controlled by vehicle assembly controller 127 and is also fed by modulator 129 which may ne controlled in turn by vehicle assembly controller 127.

[0027] In operation, when charging is needed, either static or dynamic, vehicle assembly controller 127 instructs RF transmitter to transmit a power request signal to RF receiver 114 of ground assembly 110. The power request signal is a modulated signal such that the modulating signal is a series of pulses where the duty cycle of the pulse may indicate the level of power needed and the carrier signal is an RF signal, so the modulated signal is a pulsed RF signal. The modulating signal may also include a unique identification of the EV associated with vehicle assembly 120. On the ground assembly 110 side, RF receiver 114 receives and demodulate the modulate signal and ground assembly controller 113 may be configured to set ground assembly power circuitry 112 accordingly so that the power applied by ground assembly power circuitry 112 to transmitter coils 111 match the power request signal initiated by vehicle assembly controller 127 and transmitted by RF transmitter 128.

[0028] The communication between vehicle assembly 120 and ground assembly 110 is unidirectional in nature and may issue power requests but is not receiving any communication from ground assembly 110.

[0029] According to some embodiments of the present invention, RF transmitter 12 at the vehicle assembly 120 repeatedly transmits a power request signal to the ground assembly, wherein the power request signal is a modulated signal wherein the modulating signal comprises a unique identifier of the electric vehicle.

[0030] According to some embodiments of the present invention, a sensor 134 may be configured to sense whether contactor 132 is open or closes. In case it is open there is a risk of an overvoltage developing at the output of the vehicle assembly and vehicle assembly controller instructs RF transmitter to stop requesting any power request.

[0031] According to some embodiments of the present invention, detection circuitry 124 detects an overvoltage event across the output of vehicle assembly 120.

[0032] In some embodiments both aforementioned protection circuity for stopping the communication may be implemented and according to other embodiments, only one of the aforementioned solutions is implemented.

[0033] According to some embodiments of the present invention, an overvoltage event may occur whenever voltage level across an output of the vehicle assembly goes beyond a specific level, or when the voltage gradient across an output of the vehicle assembly goes beyond a specific voltage gradient.

[0034] According to some embodiments of the present invention, controlled switch circuitry 12 diverts current off the output of the vehicle assembly 120, into by-pass circuitry 126, upon detection of an overvoltage event by detection circuitry 124 across the output of the vehicle assembly.

[0035] According to some embodiments of the present invention, controlled switch circuitry may be operated directly by detection circuitry 124 or via vehicle assembly controller 127.

[0036] According to some embodiments of the present invention, upon receiving an indication from the detection circuitry of an overvoltage event, RF transmitter 128 stops transmitting the power request signal to the ground assembly.

[0037] The stopping of the communication by RF transmitter 128 may be instructed by vehicle assembly controller 127 by shutting down the power to RF transmitter 128, disabling the carrier signal or by controlling modulator 129 to adjust modulating signal to have a zero duty-cycle hence stopping any power request signal to ground signal 110.

[0038] According to some embodiments of the present invention, bypass circuitry 126 may be implemented as a rectifier having two sets positive-side diodes and negative-side diodes and once an overvoltage event has been detected by detection circuitry 124 the switch in controlled switch circuitry 125 divert the current from output of vehicle assembly 120 into the rectifier having two sets positive-side diodes and negative-side diodes which is in turn grounded to earth.

[0039] Advantageously, embodiments of the present invention provide a two-stage solution or addressing an overvoltage event. The first stage occurs when the controlled switch circuitry 125 diverts the excessive energy at the output of vehicle assembly 120 into the bypass circuity 126. This stage occurs very fast but is limited in duration. Then the second stage takes over by stopping the power request signal by RF transmitter 128 which takes effect as soon as the next pulse of the modulating signal turns off.

[0040] According to some embodiments of the present invention, controlled switch circuitry 126 may include a silicon-controlled rectifier (SCR). The controlled switch can also be implemented as a power metal-oxide-semiconductor field-effect transistor (MOSFET) or insulated-gate bipolar transistor (IGBT) and bypass circuitry 126 may be implemented one or more sets of power diodes connected in series to the ground.

[0041] According to some embodiments of the present invention, vehicle assembly controller 127 may be connected via a bus to detection circuitry 124 and to RF transmitter 128, to receive an indication from detection circuitry 124 out the overvoltage event, and in response, to disable RF transmitter 128 thereby disabling the transmitting of the power request signal to the ground assembly 120. In other embodiments, no controller is used for this purpose and detection circuitry 124 is connected directly to both controlled switch circuitry 125 and RF transmitter 128 for enabling controlled switch circuitry 125 and at the same time disabling RF transmitter 128.

[0042] Figure 2 is a block diagram of a vehicle assembly 120 with an overvoltage protection circuitry according to some embodiments of the present invention designed reduce the number of power electronics elements used in the circuits. Ground assembly 110 may include a ground assembly power circuitry 112 which is controlled by ground assembly controller 113 and may be configured to feed transmitter coils 111 with the electrical power required to create the magnetic needed for the wireless power transfer with vehicle assembly 120. Ground assembly 110 further includes an RF receiver 14 having an output connected to an input of ground assembly controller 113.

[0043] According to some embodiments of the present invention, vehicle assembly 120 may be placed on board an electric vehicle (not shown) and may include receiver coils 121 which may be coupled to transmitter coils 111. Receiver coils 121 may feed the input of a rectifier 122 configured to rectify the alternating current into direct current.

[0044] Rectifier 122 may include positive-side diodes 226 as well as matching negative-side diodes 224 which in operation rectify the incoming AC signal coming from receiver coils 121. Typically, positive-side diodes 226 as well as matching negative-side diodes 224 include 4 power diodes in each branch but other numbers of diodes may be used in accordance with the design of rectifier 122.

[0045] Rectifier 122 in turn feeds the input of a direct current (DC) filter 123 which reduces the harmonies of the power signal passing through it. The output of DC filter 123 is also effectively the output of vehicle assembly 120 which may feed the EV battery 130 which in turn feeds the motor (not shown) of the EV.

[0046] According to some embodiments of the present invention, detection circuitry 124 may receive as an input, the voltage across the output of vehicle assembly 120 and the output of detection circuitry 124 may be connected to a vehicle assembly controller 127.

[0047] The input of controlled switch circuitry 125 is connected to the output of vehicle assembly 120 and the output of controlled switch circuitry 125 is connected to an input of a bypass circuitry 126.

[0048] In accordance with some embodiments of the present invention bypass circuitry 126 typically include, similarly to rectifier 122 one branch of positive-side diodes as well as matching branch of negative-side diodes which typically include 4 power diodes in each branch but other numbers of diodes may be used. In order to reduce the number of diodes used in the circuitry it is suggested by the inventor of the present invention to use the negative side diodes 224 as the negative side diodes of bypass circuitry 126 together with positive-side diodes 228 of bypass circuitry 126 so bypass circuitry 126 shares negative side diodes 224 with rectifier 122. This suggestion saves the use of a branch of negative side diodes. In order to implement this solution, the branch of negative side diodes 224 connected in parallel to positive side diodes 226 of rectifier 122 is further connected is parallel to the branch of positive side diodes 228 of bypass circuitry 126.

[0049] According to some embodiments of the present invention, one of the outputs of vehicle assembly controller 127 is connected to a control input of the controlled switch circuitry.

[0050] Vehicle assembly 120 further includes an RF transmitter 128 which is controlled by vehicle assembly controller 127 and is also fed by modulator 129 which may be controlled in turn by vehicle assembly controller 127.

[0051] In operation, when charging is needed, either static or dynamic, vehicle assembly controller 127 instructs RF transmitter to transmit a power request signal to RF receiver 114 of ground assembly 110. The power request signal is a modulated signal such that the modulating signal is a series of pulses where the duty cycle of the pulse may indicate the level of power needed and the carrier signal is an RF signal, so the modulated signal is a pulsed RF signal. The modulating signal may also include a unique identification of the EV associated with vehicle assembly 120. On the ground assembly 110 side, RF receiver 114 receives and demodulate the modulate signal and ground assembly controller 113 may be configured to set ground assembly power circuitry 112 accordingly so that the power applied by ground assembly power circuitry 112 to transmitter coils 111 match the power request signal initiated by vehicle assembly controller 127 and transmitted by RF transmitter 128.

[0052] The communication between vehicle assembly 120 and ground assembly 110 is unidirectional in nature and may issue power requests but is not receiving any communication from ground assembly 110.

[0053] According to some embodiments of the present invention, RF transmitter 12 at the vehicle assembly 120 repeatedly transmits a power request signal to the ground assembly, wherein the power request signal is a modulated signal wherein the modulating signal comprises a unique identifier of the electric vehicle (or of the vehicle assembly).

[0054] According to some embodiments of the present invention, a sensor 134 may be configured to sense whether contactor 132 is open or closes. In case it is open there is a risk of an overvoltage developing at the output of the vehicle assembly and vehicle assembly controller 127 instructs RF transmitter 128 to stop requesting any power request. The sensor can be integrated as part of the Controller Area Network (CAN) bus of the electric vehicle.

[0055] According to some embodiments of the present invention, detection circuitry 124 detects an overvoltage event across the output of vehicle assembly 120.

[0056] In some embodiments both aforementioned protection circuity for stopping the communication may be implemented and according to other embodiments, only one of the aforementioned solutions is implemented.

[0057] According to some embodiments of the present invention, an overvoltage event may occur whenever voltage level across an output of the vehicle assembly goes beyond a specific level, or when the voltage gradient across an output of the vehicle assembly goes beyond a specific voltage gradient.

[0058] According to some embodiments of the present invention, controlled switch circuitry 12 diverts current off the output of the vehicle assembly 120, into by-pass circuitry 126, upon detection of an overvoltage event by detection circuitry 124 across the output of the vehicle assembly.

[0059] According to some embodiments of the present invention, controlled switch circuitry may be operated directly by detection circuitry 124 or via vehicle assembly controller 127.

[0060] According to some embodiments of the present invention, upon receiving an indication from the detection circuitry of an overvoltage event, RF transmitter 128 stops transmitting the power request signal to the ground assembly.

[0061] The stopping of the communication by RF transmitter 128 may be instructed by vehicle assembly controller 127 by shutting down the power to RF transmitter 128, disabling the carrier signal or by controlling modulator 129 to adjust modulating signal to have a zero duty-cycle hence stopping any power request signal to ground signal 110.

[0062] Figure 3 is a block diagram of a vehicle assembly 120 with an overvoltage protection circuitry according to some embodiments of the present invention designed to provide further safety measures to the protection circuitry. Ground assembly 110 may include a ground assembly power circuitry 112 which is controlled by ground assembly controller 113 and may be configured to feed transmitter coils 111 with the electrical power required to create the magnetic needed for the wireless power transfer with vehicle assembly 120. Ground assembly 110 further includes an RF receiver 14 having an output connected to an input of ground assembly controller 113.

[0063] According to some embodiments of the present invention, vehicle assembly 120 may be placed on board an electric vehicle (not shown) and may include receiver coils 121 which may be coupled to transmitter coils 111. Receiver coils 121 may feed the input of a rectifier 122 configured to rectify the alternating current into direct current. Rectifier 122 in turn feeds the input of a direct current (DC) filter 123 which reduces the harmonies of the power signal passing through it. The output of DC filter 123 is also effectively the output of vehicle assembly 120 which may feed the EV battery 130 which in turn feeds the motor (not shown) of the EV.

[0064] According to some embodiments of the present invention a pulse resistor 314 is connected to the output of vehicle assembly 120 and then via a fuse 316 to controlled switch circuitry 125.

[0065] According to some embodiments of the present invention, detection circuitry 124 may receive as an input, the voltage across the output of vehicle assembly 120 and the output of detection circuitry 124 may be connected to a vehicle assembly controller 127.

[0066] The input of controlled switch circuitry 125 is connected to the output of vehicle assembly 120 and the output of controlled switch circuitry 125 is connected to an input of a bypass circuitry 126.

[0067] According to some embodiments of the present invention, one of the outputs of vehicle assembly controller 127 is connected to a control input of the controlled switch circuitry.

[0068] Vehicle assembly 120 further includes an RF transmitter 128 which is controlled by vehicle assembly controller 127 and is also fed by modulator 129 which may ne controlled in turn by vehicle assembly controller 127.

[0069] In operation, when charging is needed, either static or dynamic, vehicle assembly controller 127 instructs RF transmitter to transmit a power request signal to RF receiver 114 of ground assembly 110. The power request signal is a modulated signal such that the modulating signal is a series of pulses where the duty cycle of the pulse may indicate the level of power needed and the carrier signal is an RF signal, so the modulated signal is a pulsed RF signal. The modulating signal may also include a unique identification of the EV associated with vehicle assembly 120. On the ground assembly 110 side, RF receiver 114 receives and demodulate the modulate signal and ground assembly controller 113 may be configured to set ground assembly power circuitry 112 accordingly so that the power applied by ground assembly power circuitry 112 to transmitter coils 111 match the power request signal initiated by vehicle assembly controller 127 and transmitted by RF transmitter 128.

[0070] The communication between vehicle assembly 120 and ground assembly 110 is unidirectional in nature and may issue power requests but is not receiving any communication from ground assembly 110.

[0071] According to some embodiments of the present invention, RF transmitter 12 at the vehicle assembly 120 repeatedly transmits a power request signal to the ground assembly, wherein the power request signal is a modulated signal wherein the modulating signal comprises a unique identifier of the electric vehicle.

[0072] According to some embodiments of the present invention, detection circuitry 124 detects an overvoltage event across the output of vehicle assembly 120. Pulse resistor 314 resists a change in the current flowing through the output of vehicle assembly 120 towards controlled switch circuity 125. By doing so, it attenuates the gradient of the voltage across the output of vehicle assembly 120 which serves as slowing down the occurrence of the overvoltage event thereby improving the reaction time of controlled switch circuitry 125. Fuse 316 forms a circuit break if current goes above a certain level. The break level is set to a level of overvoltage that cannot be managed by controlled switch circuitry 125 hence protecting it in case of a sever overvoltage which cannot be managed by controlled switch 125

[0073] According to some embodiments of the present invention, an overvoltage event may occur whenever voltage level across an output of the vehicle assembly goes beyond a specific level, or when the voltage gradient across an output of the vehicle assembly goes beyond a specific voltage gradient.

[0074] According to some embodiments of the present invention, controlled switch circuitry 12 diverts current off the output of the vehicle assembly 120, into by-pass circuitry 126, upon detection of an overvoltage event by detection circuitry 124 across the output of the vehicle assembly.

[0075] According to some embodiments of the present invention, controlled switch circuitry may be operated directly by detection circuitry 124 or via vehicle assembly controller 127.

[0076] According to some embodiments of the present invention, upon receiving an indication from the detection circuitry of an overvoltage event, RF transmitter 128 stops transmitting the power request signal to the ground assembly.

[0077] The stopping of the communication by RF transmitter 128 may be instructed by vehicle assembly controller 127 by shutting down the power to RF transmitter 128, disabling the carrier signal or by controlling modulator 129 to adjust modulating signal to have a zero duty-cycle hence stopping any power request signal to ground signal 110.

[0078] According to some embodiments of the present invention, bypass circuitry 126 may be implemented as a rectifier having two sets positive-side diodes and negative-side diodes and once an overvoltage event has been detected by detection circuitry 124 the switch in controlled switch circuitry 125 divert the current from output of vehicle assembly 120 into the rectifier having two sets positive-side diodes and negative-side diodes which is in turn grounded to earth.

[0079] Advantageously, the circuitry for protecting against overvoltage described above can be used at two or more of the vehicle assemblies such as vehicle assembly 120 on a same vehicle, wherein upon receiving an indication from at least one of the detection circuitries such as 124 of the two or more vehicle assemblies such as vehicle assembly 120 of an overvoltage event, the RF transmitters such as RF transmitter 128 of the two or more vehicle assemblies may stop transmitting the power request signals to the ground assembly 110. It is noted that in this embodiment the power request signal includes the unique identifier of the vehicle assembly rather than the unique identifier of the electric vehicle.

[0080] The aforementioned flowchart and diagrams illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each portion in the flowchart or portion diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the portion may occur out of the order noted in the figures. For example, two portions shown in succession may, in fact, be executed substantially concurrently, or the portions may sometimes be executed in the reverse order, depending upon the functionality involved, It will also be noted that each portion of the portion diagrams and / or flowchart illustration, and combinations of portions in the portion diagrams and / or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

[0081] As will be appreciated by one skilled in the art, aspects of the present invention may be embodied as a system or an apparatus. Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit”, “module” or “system”.

[0082] The aforementioned figures illustrate the architecture, functionality, and operation of possible implementations of systems and apparatus according to various embodiments of the present invention. Where referred to in the above description, an embodiment is an example or implementation of the invention. The various appearances of “one embodiment,” “an embodiment” or “some embodiments” do not necessarily all refer to the same embodiments.

[0083] Although various features of the invention may be described in the context of a single embodiment, the features may also be provided separately or in any suitable combination. Conversely, although the invention may be described herein in the context of separate embodiments for clarity, the invention may also be implemented in a single embodiment.

[0084] Reference in the specification to “some embodiments”, “an embodiment”, “one embodiment” or “other embodiments” means that a particular feature, structure, or characteristic described in connection with the embodiments is included in at least some embodiments, but not necessarily all embodiments, of the inventions. It will further be recognized that the aspects of the invention described hereinabove may be combined or otherwise coexist in embodiments of the invention.

[0085] It is to be understood that the phraseology and terminology employed herein is not to be construed as limiting and are for descriptive purpose only.

[0086] The principles and uses of the teachings of the present invention may be better understood with reference to the accompanying description, figures and examples.

[0087] It is to be understood that the details set forth herein do not construe a limitation to an application of the invention.

[0088] Furthermore, it is to be understood that the invention can be carried out or practiced in various ways and that the invention can be implemented in embodiments other than the ones outlined in the description above.

[0089] It is to be understood that the terms “including”, “comprising”, “consisting of’ and grammatical variants thereof do not preclude the addition of one or more components, features, steps, or integers or groups thereof and that the terms are to be construed as specifying components, features, steps or integers.

[0090] If the specification or claims refer to “an additional” element, that does not preclude there being more than one of the additional element.

[0091] It is to be understood that where the claims or specification refer to “a” or “an” element, such reference is not construed that there is only one of that element.

[0092] It is to be understood that where the specification states that a component, feature, structure, or characteristic “may”, “might”, “can” or “could” be included, that particular component, feature, structure, or characteristic is not required to be included.

[0093] Where applicable, although state diagrams, flow diagrams or both may be used to describe embodiments, the invention is not limited to those diagrams or to the corresponding descriptions. For example, flow need not move through each illustrated box or state, or in exactly the same order as illustrated and described.

[0094] Methods of the present invention may be implemented by performing or completing manually, automatically, or a combination thereof, selected steps or tasks.

[0095] The term “method” may refer to manners, means, techniques and procedures for accomplishing a given task including, but not limited to, those manners, means, techniques and procedures either known to, or readily developed from known manners, means, techniques and procedures by practitioners of the art to which the invention belongs.

[0096] The descriptions, examples and materials presented in the claims and the specification are not to be construed as limiting but rather as illustrative only.

[0097] Meanings of technical and scientific terms used herein are to be commonly understood as by one of ordinary skill in the art to which the invention belongs, unless otherwise defined.

[0098] The present invention may be implemented in the testing or practice with materials equivalent or similar to those described herein.

[0099] While the invention has been described with respect to a limited number of embodiments, these should not be construed as limitations on the scope of the invention, but rather as exemplifications of some of the preferred embodiments. Other or equivalent variations, modifications, and applications are also within the scope of the invention. Accordingly, the scope of the invention should not be limited by what has thus far been described, but by the appended claims and their legal equivalents.

Claims

1. A circuitry for protecting against overvoltage in a vehicle assembly of an electric vehicle, said vehicle assembly being in communication with a ground assembly as a part of a wireless power transfer system for electric vehicles, said circuitry comprising:a radio frequency (RF) transmitter in the vehicle assembly to repeatedly transmit a power request signal to the ground assembly, wherein the power request signal is a modulated signal wherein the modulating signal comprises a unique identifier of the vehicle assembly;a detection circuitry to detect an overvoltage event across an output of the vehicle assembly;a controlled switch to divert current off the output of the vehicle assembly, into a bypass circuitry, upon detection of the overvoltage event,wherein upon receiving an indication from the detection circuitry of the overvoltage event, the RF transmitter stops transmitting the power request signal to the ground assembly.

2. The circuitry according to claim 1, wherein the overvoltage event comprises a voltage level across the output of the vehicle assembly going beyond the predefined level, or a voltage gradient across the output of the vehicle assembly going above the predefined voltage gradient.

3. The circuitry of claim 1, wherein the controlled switch comprises a si 1 icon-control led rectifier (SCR).

4. The circuitry of claim 1, further comprising a controller connected via a bus to the detection circuitry and to the RF transmitter, to receive an indication from the detection circuitry of the overvoltage event, and in response, to disable the RF transmitter thereby disabling the transmitting of the power request signal to the ground assembly.

5. The circuitry of claim 4, further comprising a sensor adapted to sense a contactor located between the output of the vehicle assembly and the battery, and wherein the controller is adapted, upon sensing by the sensor that the contactor is open, to disable the RF transmitter thereby disabling the transmitting of the power request signal to the ground assembly.

6. A circuitry for protecting against high voltage at two or more of the vehicle assemblies of claim 1 installed on a same vehicle, wherein upon receiving an indication from at least one of the detection circuitries of the two or more vehicle assemblies of the overvoltage event, the RF transmitters of the two or more vehicle assemblies stop transmitting the power request signals to the ground assembly.

7. The circuitry of claim 1, the rectifier comprises a branch of positive-side diodes and branch of negative-side diodes and wherein the by-pass circuity comprises a branch of positive-side diodes and wherein the branch of negative-side diodes of the rectifier is further used by the by-pass circuitry as a branch of negative-side diodes of the by-pass circuitry.

8. The circuitry of claim 1, further comprising a pulse resistor connected in parallel to the output of the vehicle assembly and a fuse connected in series to the pulse resistor.Application No: GB2414233.3Examiner:Jonathan MarlowClaims searched: 1-8 Date of search: 19 March 2025Patents Act 1977: Search Report under Section 17Documents considered to be relevant:Category Relevant to claims Identity of document and passage or figure of particular relevance X 1 -4 US 2022 / 0278554 Al (MISHIMA et al.) Figures 22 &26 and paragraphs [0098], [0193] &[0215], X 1-4 EP 3166203 Al (IHI) Figures 1 &2 and paragraphs [0015], [0023], [0040] &[0042], A - JP 7518674 B2 (LECIP HOLDINGS) Paragraphs [0008], [0022] &[0085], A - US 2024 / 0266881 Al (GREENE et al.) Paragraphs [0088] &[0101],Categories:X Document indicating lack of novelty or inventive A Document indicating technological background and / or state step of the art. Y Document indicating lack of inventive step if P Document published on or after the declared priority date but combined with one or more other documents of same category'. before the filing date of this invention. & Member of the same patent family E Patent document published on or after, but with priority date earlier than, the filing date of this application.Field of Search:International Classification:Subclass Subgroup Valid From B60L 0003 / 04 01 / 01 / 2006 B60L 0053 / 12 01 / 01 / 2019 0009 / 04 01 / 01 / 2006 H02J 0007 / 00 01 / 01 / 2006 H02J 0050 / 00 01 / 01 / 2016

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