Wireless power transfer system with data communication and method

Abstract

A wireless power transfer system with data communication is provided. The system comprises a transmitter for transferring electrical power via a power signal. The transmitter comprises: a signal generator for generating a power signal; a directional antenna module for transmitting the power signal to a receiver of the wireless power transfer system; a beamforming circuit for directing the power signal based on a position of the receiver; a controller for controlling the directional antenna module based on an output of the beamforming circuit; and a safety system comprising a shell signal generator and antenna for generating and transmitting a shell signal encasing the power signal. The wireless power transfer system further comprises a receiver for receiving electrical power from the transmitter via the transmitted power signal. The receiver comprises a directional antenna module for receiving the power signal from the transmitter.

Description

[0001] Wireless Power Transfer System with Data Communication and Method

[0002] Technical Field

[0003] The subject disclosure generally relates to wireless power transfer, and in particular to a wireless power transfer via a directed signal transmission with data communication.

[0004] Background

[0005] Long range wireless power transfer may eliminate a need for physical connections for a transfer of electricity. Accordingly, long range wireless power transfer may mobilise power transfer providing opportunities for electrification that are not feasible or possible with conventional wired connections, for example, in remote or hostile locations. In this way, long range wireless power transfer may be a break-through technology in the fields of transportation, health, renewable energy, oil and gas and others.

[0006] Taking the example of electric vehicle charging, electric vehicles are currently charged by plugging a cable from a vehicle into a local grid, inductive coupling or resonant inductive coupling. Despite being wireless, inductive coupling and resonant inductive coupling only transfer power a short distance. Accordingly, a vehicle must remain in a fixed location to be charged. Existing forms of electric vehicle charging are not fast, mobile, efficient or sustainable. In addition, there is no bi-directional exchange of data between the charger and the charged vehicle at long range.

[0007] Existing wireless power transfer solutions have been deployed at short range, known as non-radiative power transfer, while long range, known as radiative wireless power transfer, is an active area of research. A serious concern associated with the implementation of long range wireless power transfer is safety and interference with nearby electronic systems. Safety concerns range from preventing harm to people, animals and plants, to avoiding damage to property and infrastructure. In addition, damage to a long range wireless power transfer system itself must be avoided. Further, there is concern that an efficiency of a power transfer may be reduced by implementing safety measures such that when all risks are mitigated the power transfer may be unviable. Accordingly, there is a need for a wireless power transfer system that is safe and efficient, over long ranges or otherwise. Objects and aspects of the subject disclosure seek to alleviate at least the above discussed problems.

[0008] This background serves only to set a scene to allow a person skilled in the art to better appreciate the following description. Therefore, none of the above discussion should necessarily be taken as an acknowledgement that the discussion is part of the state of the art or is common general knowledge. One or more aspects / embodiments of the invention may or may not address one or more of the background issues.

[0009] Summary

[0010] The subject disclosure provides a wireless power transfer system configured to perform long-range wireless power transfer, also known as power beaming. The system may also communicate data. The system may communicate data wirelessly. The system may use electromagnetic or acoustic waves to transfer power wirelessly over long distances.

[0011] For the purposes of the subject disclosure, short-range wireless power transfer is understood to be wireless power transfer of a few meters, while long-range wireless power transfer ranges from a few metres to several kilometres.

[0012] Long-range wireless power transfer with data communication may provide power to devices while at the same time receiving data communicated from the devices being charged in real-time. For example, a wireless power transmitter of a wireless power transfer system may transfer power to a receiver (e.g., medical implant), wirelessly while at the same time receiving data from the receiver (e.g., patient monitoring data from the implant.

[0013] The system may comprise a transmitter and a receiver. The transmitter may transfer power wirelessly to the receiver. The transmitter and receiver may also communicate data between each other. The transmitter may convert electrical energy into high- electromagnetic or acoustic waves, which are transmitted to the receiver. The receiver converts the received electromagnetic or acoustic waves back into electrical energy, which can be applied to a load. Likewise, the transmitter can transmit and receive data from the receiver, and vice versa. As will be described, the electromagnetic or acoustic waves transmitted by the transmitter may be protected from the local environment, including plant and animal interaction, by various technologies. These technologies may include object detection, beam monitoring, beam steering, an active interference cancellation system, a safety shutdown system, and control technology. Additional technologies, e.g., encryption and decryption, may protect transmitted electromagnetic and acoustic waves from external interception, both at rest and while in transmit. These technologies may ensure safety and efficiency.

[0014] According to an aspect of the disclosure, there is provided a wireless power transfer system comprising: a transmitter for transferring electrical power via a power signal, the transmitter comprising: a signal generator for generating a power signal; a power amplifier electrically connected to the signal generator; a directional antenna module for transmitting the power signal to a receiver of the wireless power transfer system; a beamforming circuit for directing the power signal based on a position of the receiver; a controller for controlling the directional antenna module based on an output of the beamforming circuit; and a safety system comprising a shell signal generator for generating a shell signal encasing the power signal; and a receiver for receiving electrical power from the transmitter via the transmitted power signal, the receiver comprising a directional antenna module for receiving the power signal from the transmitter.

[0015] The wireless power transfer system may be a long range wireless power transfer system.

[0016] The power signal may comprise an electromagnetic signal, an optical signal, and an acoustic signal. Exemplary power signals include a microwave signal, a millimetre wave (mmWave) signal, an ultrasonic, a lightwave, and a radio frequency signal. The directional antenna module at the transmitter and / or receiver may comprise a high- gain directional antenna. While a directional antenna module is described, the transmitter and receiver may alternatively comprise an acoustic transducer. The directional antenna module may be for transmitting a power signal having a narrow beam width.

[0017] The directional antenna module at the transmitter and / or receiver may comprise a dipole antenna; a microstrip patch antenna; a phased array antenna.

[0018] The directional antenna module of the transmitter and / or receiver may comprise a dielectric substrate. The dielectric substrate or other components of the transmitter and / or receiver may be impregnated with metamaterials. The use of metamaterials may enhance beam steering, increase efficiency and / or provide a more compact design. The directional antenna module of the transmitter and / or receiver may comprise metamaterials or patterns of metamaterials. The directional antenna module of the transmitter and / or receiver may be impregnated with metamaterials or patterns of metamaterials. Generally, metamaterials are engineered materials with properties not found in naturally occurring substances.

[0019] The directional antenna module at the transmitter and / or receiver may comprise a metasurface-based phased array antenna. A metasurface may be formed by two- dimensional metamaterials. The use of a metasurface-based phased array antenna may improve performance of the transmitter and / or receiver. In particular, the transmitter and / or receiver may have a more compact design. The metasurface-based phased array antenna may provide for more efficient wireless power transfer.

[0020] The directional antenna module at the transmitter and / or receiver may comprise an antenna array.

[0021] The directional antenna module at the transmitter may be for generating a directionally focused beam of wireless power. The beam may comprise the power (e.g., microwave) signal and the shell signal together.

[0022] The shell signal may be envisaged as a substantially hollow cross-sectional shape configured to house and protect the power signal. A frequency of the shell signal may be less than a frequency of the power signal. Even long exposure to the shell signal may be harmless to people, animals, property, etc. The shell signal may guard the power signal by completely covering the power signal. For example, the shell signal may be a radio signal having a frequency less than 300 kHz whilst the power (e.g., microwave) signal may have a frequency of approximately 2.5 GHz.

[0023] The beamforming circuit may be for steering the power signal.

[0024] The beamforming circuit may utilise a beamforming algorithm such as adaptive beamforming, phased array beamforming, retrodirective beamforming, hybrid beamforming, or a combination of such algorithms. The adaptive beamforming algorithm, for example uses a constant modulus algorithm (CMA) or least mean squares (LMS) to adjust antenna weights of each antenna of the transmitter to form a beam directed towards the receiver. The adjustments made to antenna weights may be adjustments of a phase and amplitude of signals, or beams, transmitted by the antenna module. The beamforming circuit may adjust the antenna weights in response to signals received from sensors of the transmitter (which will be described) to optimise an efficiency of power transfer. Further, the beamforming circuit may adjust the antenna weights in response to external input. In these ways, the beamforming circuit may be controlled to steer the beam so that the beam may be accurately directed to the receiver while avoiding obstacles and / or interference in real-time.

[0025] While the beamforming circuit is described as directing the power signal based on a position of the receiver, it may be based on other parameters. For example, the beamforming circuit may direct the power signal based on a speed of the receiver, distance of the receiver from the transmitter, etc.

[0026] The controller may also control the signal generator. The controller may control the signal generator to start or stop generating a power signal. Further, the controller may control the signal generator to vary a power level, voltage, current, frequency, and / or phase of the power signal.

[0027] The safety system may be configured to inhibit the power signal from adversely impacting a local environment, i.e., an environment along a signal path between the transmitter and receiver. The safety system may be an Electromagnetic Beam Control and Safety System or (EBCSS). The safety system may be configured to actively control, manage, protect and / or shield the power signal transmitted by the transmitter from a surrounding environment on a path towards the receiver.

[0028] The safety system may be configured to detect objects and obstacles in or near the beam to ensure that the beam does not harm living things or damage property. The safety system may also detect the receiver. Accordingly, the safety system may assisting in steering the beam to the receiver while avoiding obstacles and interference, whilst also tracking the receiver, even while in motion. The safety system may detect objects and obstacles using sensors, by monitoring a property of the beam, by monitoring a property of an accompanying shell beam, and / or using image recognition as will be described.

[0029] The safety system may comprise an antenna for transmitting the generated shell signal. The antenna may comprise a plurality of antenna or antenna array. The antennae of the safety system may physically surround the directional antenna module of the transmitter. The antennae may physically surround the directional antenna module such that the shell signal encasing the power signal.

[0030] Encasing the power signal in the shell signal may promote safety of the power signal. Encasing may comprise the shell signal surrounding the power signal such that objects are impacted or perturb the shell signal along the signal path between the transmitter and receiver prior to impacting or perturbing the power signal.

[0031] The receiver may comprise circuitry for converting the received power signal into an electrical signal. The electrical signal may be a DC signal. The DC signal may be applied to a load. The receiver may comprise a load to which the electrical signal is applied. The circuitry may comprise a rectifier and DC / DC converter.

[0032] The safety system which may ensure wireless power is transferred safely. In this way, the wireless transfer of power may be implemented in populated areas to provide the advantages described below. Operation of the wireless power transfer system may be protected by beam steering technology, camera, sensors (e.g., radar and / or LiDAR sensors), beam property monitoring, the shell signal, an active interference cancellation system, object recognition, a safety shutdown system, and control technology to ensure as will be described to ensure high levels of safety.

[0033] The safety system may comprise a sensor for a detecting a parameter. The sensor may be configured to detect an object in a vicinity of the power signal, e.g., along the signal path between the transmitter and receiver. The sensor may detect the parameter at all times during beam transmission. Alternatively, the sensor may detect the parameter at intervals. A duration of the intervals may be selected to minimise a power consumption of the sensor while providing an adequate monitoring frequency. Further, the sensor may monitor an area prior to beam transmission to ensure a safe start-up of the transmission. An exemplary interval duration may be evert 5 s, 10 s, 30 s, 1 minutes, 5minutes, 15 minutes, 30 minutes and 1 hour.

[0034] The parameter may comprise at least one of a distance of the object from the power signal (i.e. , a range); and a direction of the object relative to the power signal.

[0035] The sensor may comprise a radar sensor; a LiDAR sensor; and a camera. The sensor may detect an object, a distance of the object from the power signal, a direction of the object relative to the power signal, and characteristics of the object, e.g., size, weight, velocity and acceleration. The sensor may be disposed on an outer surface of housing enclosing components of transmitter. For example, the signal generator, beamforming circuit and controller may be housed in a housing while the sensor and the antenna module are disposed on an outer surface of the housing.

[0036] The sensor may emit electromagnetic (EM) signals and detect reflections indicative of objects in the path of the EM signals. In this way, the sensor may measure a distance to a detected object by calculating a time-of-flight of a received reflection and multiplying the time-of-flight by a speed of light. Alternatively, the sensor may measure a distance to a detected object by measuring a received power of a reflected signal and calculating a distance using a radar equation. Alternatively, the sensor may provide visual information about a vicinity of the beam, and detect objects in or near a vicinity of the beam using computer vision techniques, such as object detection algorithms.

[0037] The sensor may detect reflection from the shell signal. Based on the detected reflection, the controller may trigger a response (as will be described) to be taken to ensure the safety of the impinging object or target. The sensor may comprise LiDAR sensors may detect a scattering or a reflection from the shell signal when an object impinges on the shell signal.

[0038] The controller may be configured to process data acquired by the sensor and estimate a trajectory of a detected object. The controller may be comprise an embedded control system embedded as part of the safety system. Alternatively, two controller may be present, e.g., a main controller for the transmitter and a controller for the safety system. The safety system controller may comprise an embedded control system (or embedded controller).

[0039] The controller may be configured to predict whether the object will interfere with the power signal. The controller may be configured to process the data acquired by the sensor to estimate a trajectory of a detected object and predict whether the object will interfere with the power signal, and / or when the object will interfere the shell signal. In this way, the controller may determine if the detected object poses a risk to power transfer. The controller may quantify the risk.

[0040] The controller may be configured to trigger a response based on an output of the safety system. The response may comprise at least one of: activating a deterrent alarm; redirecting the power signal; lowering a power level of the power signal; pausing transmission of the power signal; and terminating transmission of the power signal. The response may comprise a plurality of stages. For example, a first stage of a response may comprise triggering a deterrent. Should the deterrent mitigate the risk, no further response may be triggered. Should the risk persist, a second stage of a response may be triggered. A second stage may comprise redirecting the beam. Should a further response be triggered, a third stage may comprise terminating a transmission entirely.

[0041] To lower a power level of the power signal the controller may reduce a power delivered to the signal generator. In this case, although the power of the power signal is reduced, the system continues to transmit the beam.

[0042] The controller may be configured to control the power signal such that a power of the power signal is maintained below a pre-determined threshold. The controller may control the signal generator to ensure a power of the power signal is maintained below a pre-determined threshold. The pre-determined threshold may indicate a power of the power signal at which operation of the wireless power transfer system becomes dangerous. Alternatively, the pre-determined threshold may indicate a power of the power signal at which operation of the wireless power transfer system becomes inefficient.

[0043] The controller may be configured to control the power signal such that a power of the power signal is maintained above a second pre-determined threshold. In this way, the controller may control the power signal to be maintained between the first and second pre-determined thresholds to maintain optimal operation of the wireless power transfer system.

[0044] The controller may be programmed with safety protocols to ensure that a power and intensity of the power signal (beam) are maintained within safe limits to minimise a risk of harm or damage caused by the beam. The safety protocols may comprise a further pre-determined threshold which a power of the beam may not exceed without triggering a response (i.e., the described response) from the safety system.

[0045] The controller may store safety margins which indicate an operating range of the wireless power transfer system associated with a risk level. For example, an ideal operating range may be associated with a low risk level, an acceptable operating range may be higher than an ideal operating range and may be associated with a medium risk level. An unacceptable operating range may be higher than an acceptable operating range and may be associated with a high risk level. Pre-determined thresholds may be disposed between each safety margin such that the safety system may respond to an operating range and risk level of the wireless power transfer system in real-time. The pre-determined threshold(s) may be determined based on a measured parameter, for example, an ambient temperature (i.e., a parameter detected by the sensor). In this way, the pre-determined thresholds may vary according to environmental conditions.

[0046] The safety system may be configured to monitor a property of the power signal to detect obstruction or deviation of the power signal. The property of the power signal may be monitored via the previously sensor. The property of the power signal may comprise: power density; signal distortion; signal delay; amplitude modulation; polarisation; and signal strength.

[0047] The safety system may be configured to monitor a property of the shell signal to detect obstruction or deviation of the shell signal. The property of the shell signal may be monitored via the previously sensor. The property of the shell signal may comprise signal strength; power density; phase shift; signal delay; and frequency shift. The property may be calculated, for example the property may be a difference between a measurement taken at the transmitter and a measurement taken at the receiver.

[0048] The sensor may comprise a power meter, a microwave sensor and radio frequency sensor. Power density may be measured using a plurality of power meters, microwave sensors or radio frequency sensors. When an object encounters the beam, the beam may be absorbed, reflected and / or scattered, leading to a change in a measured power in at least a portion of the receiver, causing a change in measured power density of the beam at the receiver. Signal strength may be calculated from measured power and antenna gain. The measured power at the receiver may be highly sensitive to changes in a propagation path of the power signal. Even small perturbations of the power signal cause measurable changes in measured power, and thereby signal strength and power density. Signal distortion may also be monitored by measuring a power of the power signal at the receiver.

[0049] Signal delay may be calculated from time-of-f light measurements. For example, a time taken for the power signal to reach the receiver from the transmitter may be recorded and compared with a reference value. A difference between the recorded time and the reference value may indicate a signal delay. Signal delay measurement may be highly sensitive to minor perturbations of the power signal. Signal delay measurements may be used to detect objects that do not cause significant absorption reflection and / or scattering of the power signal. Therefore, signal delay may be used to detect perturbations undetectable by monitoring power density or signal strength.

[0050] If an object intersects the shell signal, a power density of the shell signal at the receiver may be reduced. The power density of the shell signal may be monitored at the receiver and may be communicated to the transmitter. A measured power density below a predetermined threshold may indicate an obstruction in the shell signal. Further, if an object intersects the shell signal, a time for a signal to travel from the transmitter to the receiver may increase due to the scattering and reflection of the signal. If a signal delay is detected, an obstruction in the shell signal may be indicated. Finally, if the object passes through the shell signal at a high velocity, a Doppler shift in the frequency of the shell signal may be detected at the receiver and communicated to the transmitter.

[0051] In order to detect a deviation of the property of the power signal or shell signal, a standard value of the property and a threshold value of the property are provided for comparison with the real-time measured property. The standard value and threshold value may be used to calibrate the microwave and / or shell signals. An object impinging on the power signal may cause a detectable deviation of the measured value of the property from the standard value and / or threshold value.

[0052] The plurality of properties of the power and / or shell signals may be monitored by the sensor. The plurality of properties may be monitored concurrently. This may provide a fail-safe if one or more properties of the plurality of properties cannot be detected. Further, a detection of an obstruction of the power signal may be more accurate as changes in one property of the plurality of properties may be cross-referenced with changes in another property of the plurality of properties to detect an obstruction with high accuracy and a low rate of false-positives.

[0053] The directional antenna module may comprise: at least one antenna configured to transmit the power signal; and an array of antennae arranged around the at least one antenna, the array of antennae configured to transmit the shell signal. The array of antenna may surround the at least one antenna. The shell signal may be provided around the power signal by virtue of relative positions of the respective antennae in the array and the at least one antenna.

[0054] For each antenna of the array of antennae, a phase of a signal transmitted by the antenna may be adjusted such that the shell signal is formed through constructive interference of the signals from each antenna. In this way, a substantially continuous shell signal may be formed to encase the power signal. The controller may use a sensor fusion system to manage responses and interactions of the power signal and the shell signal. The safety system may comprise a safety shutdown system configured to terminate wireless power transfer in response to the detection of an unsafe operating condition of the power signal. An unsafe operating condition may comprise detection of an unsafe object is detected in the beam path. Further, an unsafe operating condition may comprise the beamforming circuit being unable to redirect the beam to avoid the unsafe object. The unsafe object may comprise an animal and / or person.

[0055] The safety shutdown system may comprise a plurality of power switching devices. The safety shutdown system may interact with the previously described sensor. In this instance, the sensor may comprise a camera. The camera may detect an object in the beam and an object recognition system may identify the object as unsafe. The beamforming circuit may indicate that the beam may not be redirected to avoid the object. Accordingly, the safety shutdown system may trigger a safety shutdown. In another example, the sensor may comprise a LiDAR sensor and a camera to detect objects in the beam. An adaptive algorithm module may be used to adjust the power signal to avoid the object. If the object cannot be avoided, the safety shutdown system may trigger a safety shutdown.

[0056] The safety system may comprise an active interference cancellation system configured to detect an interfering signal and transmit a cancelling signal configured to destructively interfere with the interfering signal.

[0057] The active interference cancellation system may comprise an array of antennae configured to transmit the cancelling signal. For each antenna in the array of antennae, a parameter of a signal transmitted by the antenna may be adjusted to promote a cancellation of the interfering signal. In this way, the safety system may act to protect any electrical or electronic systems operating near the power signal.

[0058] The active interference cancellation system may further comprise at least one of: an interference detection and mitigation component; a shielding and filtering integration component; a control system module (which may be a separate module or integrated into the described controller); a null steering module; and an adaptive algorithm module.

[0059] The interference detection and mitigation component may be configured to monitor the beam and the local environment for signs of EM interference. The control system module may be configured to adjust a direction or power of the beam, pause or terminate the transmission of wireless power, or execute a steering manoeuvre if an interfering signal is detected.

[0060] The shielding and filtering integration component may comprise a metal box or mesh configured to enclose the antennae to block EM waves. The shielding and filtering integration component may further comprise a band-pass filter configured to allow only signals in a predetermined frequency range to pass. The predetermined frequency range may be configured to include a frequency of the power signal.

[0061] The interference detection may be performed using a separate receiver or using the array of antennae of the active interference cancellation system. At least one of power, frequency, and phase of an interfering signal may be measured. Further, an estimate of a direction of the interfering signal may be made using, for example, direction of arrival (DOA) estimation. DOA estimation may involve measuring a time difference of arrival (TDOA) or a phase difference of arrival (PDOA) of an interfering signal at different individual antennae in the array.

[0062] Once a DOA of the interfering signal is estimated, the active interference cancellation system may be configured to adjust a phase and amplitude of a cancelling signal from each antenna in the array of antennae to create a cancelling signal in that direction. The cancelling signal, or null beam, may be configured to combine destructively with the interfering signal in the direction of the interfering signal via the null steering module.

[0063] The control system module may be configured to send phase and amplitude adjustment commands to each antenna in the array. The null steering module may use the adaptive algorithm module to continuously adjust the cancelling signal in response to changes in the interfering or the cancelling signal. The adaptive algorithm module may comprise techniques such as least mean squares (LMS) or recursive least squares (RLS) to minimise a power of an interfering signal in the direction of the interference.

[0064] The safety system may comprise: a camera configured to capture images of an area in a vicinity of the power signal. The camera may be a high-definition camera configured to capture high resolution images. The camera may be installed in a position to as to have a clear view of the receiver and at least part of the beam.

[0065] The safety system may comprise: an object recognition system configured to identify objects in the images captured by the camera. The object recognition system may identify objects in the images via machine learning.

[0066] The safety system may comprise: a central control module configured to determine a response based on the identified objects. The response may promote safe transmission of the power signal. The response determined by the central control module may correspond to the previously-described response. Rather than the safety system comprising the central control module, the controller of the receiver may perform the same function. The central control module may comprise a robotic guidance system.

[0067] The camera may be connected to the central control system and the object recognition system. The object recognition system may execute an artificial intelligence algorithm.

[0068] The object recognition system may execute an artificial intelligence algorithm which includes operation of an artificially intelligent (Al) model. The Al model may be an image recognition model. The Al model may be trained using training data comprising diverse images of various objects that may obstruct the beam during transmission. Each image may be annotated with a label or labels that indicate the content of the image. An example label may be “a vehicle”, or “people”. The training data may be divided into a training dataset and a validation dataset. The training dataset may be used to train the weights of the Al model. The validation dataset may be used to evaluate a performance, e.g. determine an accuracy, of the trained Al model. In use, the Al model may receive an input image and produces an output label based on the training performed. The Al model may be developed using a deep learning framework such as TensorFlow® or PyTorch®. The Al model may comprise a convolutional neural network (CNN) architecture such as ResNet or MobileNet. Hyperparameters of the model may be optimised during the training to improve accuracy and robustness of performance of the model. Such hyperparameters may include learning rate, batch size, and number of epochs.

[0069] The input images may be captured by the camera. The images may be still images taken from frames of a video captured by the camera. The input images may undergo image processing before being provided to the Al model. The input images may be resized, normalised and / or augmented. The Al model, after receiving the input image, provides an output label configured to indicate an identity of an obstacle present in the input image. In this way, the Al model may be used to perform image recognition.

[0070] The central control module may be configured to receive an output label from the Al model indicative of an obstacle in or near the power signal. The central control module may be configured to interpret the output label and determine a response. The response may comprise the previously described response.

[0071] Alternatively, a response may be to activate a signalling mechanism configured to alert operators to the presence of an obstacle. A further response may be to activate an alarm configured to act as a warning or deterrent. Further, a response may be to activate a shutdown mechanism to reduce a power density of the beam. An appropriate response may be determined depending on an identity of the obstacle.

[0072] The artificially intelligent object recognition system may also comprise a position sensor such as radar, LiDAR or other sensors that are configured to determine a position of an object. The central control module may use the output of the position sensor along with an interpretation of the output label to determine an appropriate response. Further data about an object, e.g. velocity, may be collected by further sensors and used by the central control module to determine an appropriate response.

[0073] The wireless power transfer system may further comprise: a data communication system for communicating data between the transmitter and receiver. The data communication system may utilise a communication technology selected from the group consisting of Bluetooth Low Energy (BLE), Zigbee, LoRa, LTE, and 5G.

[0074] The data communication system may ensure the transmitter and receiver co-operate with one another to be in constant communication. This constant communication may provide for dynamic position tracking ensuring power transfer efficiency between the transmitter and receiver is maximised.

[0075] The data communication system may comprise: a communication module at the transmitter for transmitting data to the receiver and / or receiving data from the receiver; and a communication module at the receiver for transmitting data to the transmitter and / or receiving data from the transmitter.

[0076] The communication modules at the transmitter and / or receiver may comprise an antenna or transducer for transmitting and / or receiving the data. The modules may further comprise associated control electronics.

[0077] The communication module modules may comprise data encryption mechanisms to secure the data before, during and after transmission. The communication module may comprise power management modules to operate in a low-power mode to minimize energy consumption during data collection.

[0078] The communication system may support applications comprising: charging electric vehicles, medical implants and devices, drones, mobile robots, and sensors, while also providing real-time monitoring and data analytics.

[0079] The transmitter and / or receiver may further comprise a location tracking module for collecting tracking data of the receiver, and wherein the collected tracking data is communicated to the transmitter. The location tracking module may comprise GPS and / or inertial measurement units (IMlls). The tracking data may comprise positional and movement data of the receiver. The tracking data may be used by controller to control beamforming of the antenna module.

[0080] The controller at the controller may be configured to: aggregate received data into data packets; and perform error-checking and acknowledgment protocols to ensure data integrity.

[0081] The transmitter and / or receiver may further comprise local storage configured to temporarily buffer received data. The data may be buffered before transmission to a remote server or cloud storage.

[0082] The transmitter and / or receiver may further comprise a cloud interface module configured to transmit buffered data to a cloud platform. The buffered data may be transmitted utilizing a communication technology selected from the group consisting of GSM, 3G, 4G LTE, and Wi-Fi.

[0083] The cloud interface module may implement secure transmission protocols, including HTTPS and MQTT, to transmit data to the cloud.

[0084] The cloud interface module may comprise an artificial intelligence module configured to analyze the data for trends, anomalies, and insights related to the operation and status of the transmitter and / or receiver.

[0085] The wireless power transfer system may further comprise a user interface module in the cloud platform to provide access to the collected data and analytics for users, enabling remote monitoring and management of the receiver devices.

[0086] The transmitter and receiver may be configured to establish a bi-directional communication link, the communication link allowing the transmitter to send control commands to the receiver. The bi-directional link may be established according to any of the described communication protocols. The control commands may be based on data, parameters, etc. collected by the previously-described sensor.

[0087] The transmitter may further comprise at least one of: a power source electrically connected to the signal generator; a power amplifier electrically connected to the signal generator; a capacitor, e.g., supercapacitor, electrically connected to the signal generator; and superconducting materials integrated within the transmitter.

[0088] The power source may comprise a power converter. The power source may be selected from the group consisting of a battery, solar panel, or electrical outlet. The transmitter may further comprise a mechanism to switch between multiple power sources (e.g., battery, solar panel, electrical outlet) based on availability and efficiency.

[0089] The power converter may convert alternating current to direct current and / or direct current to direct current, e.g. a step-up voltage converter.

[0090] The power source may further comprise a power amplifier. The power amplifier may amplify a signal output from the signal generator.

[0091] The supercapacitor may stabilise the power signal. The transmitter may comprise a plurality of supercapacitors. By using a supercapacitor or a plurality of supercapacitors, a large amount of energy may be stored for rapid release. In particular, supercapacitors may enable rapid power delivery for initial start-up or to meet peak power demands, e.g. demand spikes, during transmission. The supercapacitors may also act to smooth out fluctuations in power received from the power source by providing intermediate power storage. In this way, a consistent power may be delivered to the amplifier and a strain on the power source may be reduced.

[0092] The transmitter may further comprise a phasing circuit for adjusting a phase of the antenna. The phasing circuit may be software based. The phasing circuit may be integrated with the beamforming circuit. The phasing circuit may comprise a phase shifter.

[0093] The signal generator may comprise a high-frequency oscillator.

[0094] The receiver may further comprise: a power management system configured manage the received electrical power. The power management system may comprise a battery management system. The battery management system may manage power to a battery at the receiver.

[0095] The receiver may further comprise: one or more sensors selected from the group comprising: conditions sensor; battery status sensor; pressure sensor; temperature sensor; and motion sensor.

[0096] The receiver may further comprise: a controller, and wherein the controller in the receiver is configured to: process and format collected sensor data into data packets, perform error-checking and acknowledgment protocols to ensure data integrity during transmission; and perform preliminary interpretation of the data.

[0097] The receiver may further comprise: a data acquisition module in the receiver configured to collect data from the device being powered, wherein the data acquisition module includes: sensors and controllers.

[0098] The receiver may further comprise: superconducting materials integrated within the receiver.

[0099] The system may be configured for use in at least one of: transportation applications; healthcare applications; industrial automation; environmental monitoring; agricultural applications; defence applications; telecommunications infrastructure applications; marine and underwater applications; renewable energy applications; aerospace applications; and earth monitoring purposes. Transportation applications may comprise electric vehicle charging, public transit systems, and autonomous vehicle charging and power management. Healthcare application may comprise medical implant charging, wearable health monitors, and remote patient monitoring systems. Industrial automation may comprise powering autonomous robots, sensors, and machinery in manufacturing and warehousing environments. Environmental monitoring may comprise powering and communicating with sensors for air quality, water quality, and soil condition monitoring. Agricultural applications may comprise powering precision farming equipment, agricultural drones, and environmental sensors. Telecommunications infrastructure applications may comprise powering remote base stations, small cells, and distributed antenna systems. Marine and underwater applications may comprise powering autonomous underwater vehicles, marine sensors, and underwater communication systems. Renewable energy applications may comprise beaming power from space, emergency power and public safety response applications, power transfer over distances for electrification purposes, energy harvesting, portable power transportation, powering and communicating with sensors and drones in solar and wind farms for maintenance and monitoring. Aerospace applications may comprise powering and communicating with aircraft systems, spacecraft, and satellites. Earth monitoring purposes may comprise highspeed internet applications, satellite communication and global communication and internet coverage (even when used in whole or in part)and communicating with aircraft systems, spacecraft, and satellites.

[0100] While the system has been described as comprising a safety system comprising a shell signal generator for generating a shell signal encasing the power signal, one of skill in the art will appreciate that this feature may be excluded. The system may still comprise a safety system, but the safety system may detect impingement or predict impingement of the power signal based on other described features such as the camera and object recognition system. In this way, the safety system may provide for safe and reliable wireless power transfer.

[0101] According to another aspect there is provided a transmitter for transferring electrical power to a receiver of a wireless power transfer system via a power signal, the transmitter comprising: a signal generator for generating a power signal; a power amplifier for amplifying the power signal; a directional antenna module for transmitting the power signal to a receiver of the wireless power transfer system; a beamforming circuit for directing the transmitted power signal based on a position of the receiver; a controller for controlling the directional antenna module based on an output of the beamforming circuit; and a safety system comprising a shell signal generator for generating a shell signal encasing the power signal.

[0102] All features and effect described in connection with described wireless power transfer system may apply to the transmitter.

[0103] The directional antenna module of the transmitter may comprise a dielectric substrate. The dielectric substrate or other components of the transmitter may be impregnated with metamaterials. The use of metamaterials may enhance beam steering, increase efficiency and / or provide a more compact transmitter design. The directional antenna module of the transmitter may comprise metamaterials or patterns of metamaterials. The directional antenna module of the transmitter may be impregnated with metamaterials or patterns of metamaterials.

[0104] The transmitter may further comprise a power source. The power source may be electrically connected to the signal generator. The power source may provide power to the signal generator for generating the power signal. The power source may be selected from the group consisting of a battery, solar panel, or electrical outlet. The transmitter may further comprise a mechanism to switch between multiple power sources (e.g., battery, solar panel, electrical outlet) based on availability and efficiency.

[0105] The transmitter may further comprise a power converter. The power converter may be electrically connected to the signal generator. The power converter may be electrically connected to a power source, e.g., the described power source. The power converter may convert alternating current to direct current and / or direct current to direct current, e.g. a step-up voltage converter.

[0106] The power source may further comprise a power amplifier. The power amplifier may amplify a signal output from the signal generator According to another aspect there is provided a receiver for receiving electrical power from a power signal transmitted by a transmitter of a wireless power transfer system, the receiver comprising: a directional antenna module for receiving the power signal and a shell signal encasing the power signal; a sensor for monitoring a parameter of at least one of the power signal and the shell signal; and a communication module for communicating the parameter to a transmitter of the power signal.

[0107] All features and effect described in connection with described wireless power transfer system may apply to the receiver.

[0108] The directional antenna module of the receiver may comprise a dielectric substrate. The dielectric substrate or other components of the receiver may be impregnated with metamaterials. The use of metamaterials may enhance beam steering, increase efficiency and / or provide a more compact receiver design. The directional antenna module of the receiver may comprise metamaterials or patterns of metamaterials. The directional antenna module of the receiver may be impregnated with metamaterials or patterns of metamaterials.

[0109] According to another aspect there is provided a method of transferring power from a transmitter of a wireless power transfer system to a receiver of the wireless power transfer system, the method comprising: generating a power signal for wireless electrical power transfer; directing the power signal based on a position of the receiver; and controlling a directional antenna module of the transmitter based on the directing to transmit the power signal the receiver, the power signal encased in a shell signal.

[0110] All features and effect described in connection with described wireless power transfer system may apply to the method. The directional antenna module of the transmitter may comprise a dielectric substrate. The dielectric substrate or other components of the transmitter may be impregnated with metamaterials. The use of metamaterials may enhance beam steering, increase efficiency and / or provide a more compact transmitter design. The directional antenna module of the transmitter may comprise metamaterials or patterns of metamaterials. The directional antenna module of the transmitter may be impregnated with metamaterials or patterns of metamaterials.

[0111] The method may further comprise: encasing the power signal in the shell signal.

[0112] The method may further comprise: detecting a parameter of the receiver, power signal, and / or shell signal; and controlling the directional antenna module based on the monitored parameter.

[0113] The method may further comprise: triggering a response based on the detected parameter. The response may comprise at least one of: activating a deterrent alarm; redirecting the power signal; pausing transmission of the power signal; and terminating transmission of the power signal.

[0114] The response may comprise at least one of: activating a deterrent alarm; redirecting the power signal; pausing transmission of the power signal; and terminating transmission of the power signal.

[0115] According to another aspect there is provided a controller for performing any of the described methods. According to another aspect there is provided a controller comprising a memory having computer code stored thereon, and a processor configured to execute the compute code to perform any of the described methods.

[0116] According to another aspect there is provided a non-transitory computer-readable medium having computer program code stored thereon, the code executable by a processor to perform any of the described methods. According to another aspect there is provided a computer program product having computer program code executable by a processor to perform any of the described methods.

[0117] The system, transmitter, receiver and / or method may provide a sustainable and / or efficient solution for power transfer and data communication. The system may be applied in technical fields such as transportation, for example, vehicle charging, such as vehicle-to-vehicle charging or charging station-to-vehicle charging, energy generation and transmission, telecommunication and data transfer, including power beaming from space, household utilities and appliances, and healthcare and medical devices.

[0118] The system, transmitter, receiver and / or method may reduce a requirement for cabling. As a result, cabling associated emissions, safety risks and ongoing maintenance may be reduced or eliminated improving a cost, safety and sustainability of power transfer.

[0119] Further, production of electrical cabling contributes to global warming through carbon dioxide emissions produced during mining and material processing. Further, production of electrical cabling consumes many non-renewable resources. For example, crude oil may be used to produce plastic insulation of electrical cabling. By reducing, or even eliminating, a need for electrical cabling, the wireless power transfer system may have a positive environmental impact.

[0120] Further, the wireless power transfer system, transmitter, receiver and / or method may avoid a risk of electrocution associated with cabling. For example, cabling may become damaged through misuse, severe weather, or poor maintenance. Damaged cabling may expose users to dangerous electrical energy. By reducing a requirement for cabling, the wireless power transfer system may reduce an electrocution risk.

[0121] The wireless power transfer system, transmitter, receiver and / or method may allow solar energy harvested in space to be used on Earth. In particular, the transmitter may be electrically connected to a solar array located in space. The transmitter of the system may accordingly wirelessly transfer collected electrical energy from the solar array to a receiver located on surface. In this way, solar energy may be harvested at any time of day or night and through all seasons without a variation in availability and efficiency of Earth-bound solar farms. In addition, no land is required to harvest the energy. In this way, the wireless power transfer system may not remove land from nature, agriculture, residential or commercial use. This may be environmentally beneficial and improve energy production.

[0122] The wireless power transfer system, transmitter, receiver and / or method may reduce an infrastructure cost associated with electricity distribution, electrical cabling and / or electrical outlets. For example, the wireless power transfer system may charge electric vehicles equipped with compatible receivers directly. In this way, the wireless power transfer system may reduce a need for expensive electrical infrastructure. A maintenance of such electrical infrastructure may be reduced, further reducing cost. A risk of electrocution associated with maintenance of electrical infrastructure may also be reduced.

[0123] The wireless power transfer system, transmitter, receiver and / or method may improve a convenience of electric vehicle charging by charging vehicles equipped with compatible receivers directly. In other words, there may be no requirement for a vehicle to be charged at a specific charging point. In this way, the wireless power transfer system may encourage adoption of electric vehicles, thereby decarbonising transportation. In the same way, by charging vehicles equipped with compatible receivers directly, a driving range of electric vehicles may be increased. In other words, a distance travelled by such electric vehicles may be increased. The wireless power transfer system may make electric vehicle charging mobile and ubiquitous. Increasing the driving range of electric vehicles and reducing range anxiety among electric vehicle owners may further encourage adoption of electric vehicles.

[0124] The wireless power transfer system, transmitter, receiver and / or method may reduce a cost of electricity by making electricity more accessible, reducing an overhead cost of electricity suppliers and removing links in a supply chain between electricity generation and use. In this way, consumers may procure inexpensive electricity. Accordingly, consumers may adopt habits that rely on electricity rather than fossil fuel derived energy. For example, consumers may be more inclined to purchase and use electric vehicles. As such, the wireless power transfer system may promote the wide-spread adoption of electric vehicles. The wireless power transfer system, transmitter, receiver and / or method sustain life through providing power to medical implants such as pace-makers.

[0125] It should be understood that any features described in relation to one aspect, example or embodiment may also be used in relation to any other aspect, example or embodiment of the present disclosure. Other advantages of the present disclosure may become apparent to a person skilled in the art from the detailed description in association with the following drawings.

[0126] Brief Description of the Drawings

[0127] Embodiments will now be described more fully with reference to the accompanying drawings in which:

[0128] Figure 1 is a schematic block diagram of a wireless power transfer system in accordance with an aspect of the disclosure;

[0129] Figure 2 is a schematic block diagram of a safety system of the wireless power transfer system of Figure 1 ;

[0130] Figure 3 is a schematic diagram of a shell signal of the safety system of Figure 2.

[0131] Figure 4 is a flowchart of a method of operating a safety system according to an aspect of the disclosure; and

[0132] Figure 5 is a flowchart of a method of operating a safety system according to an aspect of the disclosure.

[0133] Detailed Description

[0134] The foregoing summary, as well as the following detailed description of certain examples will be better understood when read in conjunction with the appended drawings. As used herein, an element or feature introduced in the singular and preceded by the word "a" or "an" should be understood as not necessarily excluding the plural of the elements or features. Further, references to "one example" or “one embodiment” are not intended to be interpreted as excluding the existence of additional examples or embodiments that also incorporate the described elements or features. Moreover, unless explicitly stated to the contrary, examples or embodiments "comprising" or "having" or “including” an element or feature or a plurality of elements or features having a particular property may include additional elements or features not having that property. Also, it will be appreciated that the terms “comprises”, “has”, “includes” means “including but not limited to” and the terms “comprising”, “having” and “including” have equivalent meanings. It will also be appreciated that like reference characters will be used to refer to like elements throughout the description and drawings.

[0135] As used herein, the terms “adapted” and “configured” mean that the element, component, or other subject matter is designed and / or intended to perform a given function. Thus, the use of the terms “adapted” and “configured” should not be construed to mean that a given element, component, or other subject matter is simply “capable of” performing a given function but that the element, component, and / or other subject matter is specifically selected, created, implemented, utilized, and / or designed for the purpose of performing the function. It is also within the scope of the subject application that elements, components, and / or other subject matter that is described as being adapted to perform a particular function may additionally or alternatively be described as being configured to perform that function, and vice versa. Similarly, subject matter that is described as being configured to perform a particular function may additionally or alternatively be described as being operative to perform that function.

[0136] It will be understood that when an element is referred to as being “on,” “attached” to, “connected” to, “coupled” with, “contacting,” etc., another element, it can be directly on, attached to, connected to, coupled with or contacting the other element or intervening elements may also be present.

[0137] It should be understood that use of the word “exemplary”, unless otherwise stated, means ‘by way of example’ or ‘one example’, rather than meaning a preferred or optimal design or implementation.

[0138] Turning now to Figure 1 , a schematic block diagram of a wireless power transfer system 100 is illustrated. The system 100 is configured to transfer a directionally focused beam of wireless power. The system 100 comprises a transmitter 102 and a receiver 116.

[0139] The transmitter 102 comprises: a power source 104, a power converter 128, a high- frequency oscillator 106, a supercapacitor 130, a power amplifier 132, a beamforming circuit 110, a phasing circuit 112, controller 114 and high-gain directional antenna 126. One of skill in the art will appreciate, one of more of these features may be omitted. For example, any one of the power converter 128, supercapacitor 130 (or a plurality of supercapacitors) and power amplifier 132 may be omitted.

[0140] The power source 104 generates a power signal. The power signal may be an DC power signal. The power converter 128 is configured to receive electricity from the power source 104 for conversion. The power converter 128 converts an alternating current to a direct current, and / or a direct current to a direct current. The supercapacitor 130 or a plurality of supercapacitors is connected to an output of the power converter 128. The supercapacitor 130 or plurality of supercapacitors is charged from the output of the power converter 128 in order to store energy ready for rapid release. The power amplifier 132 amplifies the output of the high-frequency oscillator 106.

[0141] The high-gain directional antenna 126 receives the amplified power signal from the power amplifier 132. The high-gain directional antenna 126 provides a power signal 101. In this arrangement, the power signal comprises a microwave signal having narrow beam width. The beamforming circuit 110 directs and steers the power signal 101 towards the receiver 116. The beamforming circuit 110 tracks the position of the receiver 116 dynamically. The phasing circuit 112 may be connected to the beamforming circuit 110, and may determine and apply a phase shift to the high-gain directional antenna 126 for the desired beamforming to optimise power transfer to the receiver 116.

[0142] The control electronics 114, the beamforming circuit 110, and the phasing circuit 112 act to control outputs of the power converter 128, the high-frequency oscillator 106, the supercapacitor 130, the power amplifier 132 and the antenna 126 in order to cause the antenna 126 of the transmitter 102 to generate the power signal 101. In this way, the dontroller 114, the beamforming circuit 110, and the phasing circuit 112 may control properties of the power signal 101, such as a power density of the power signal 101.

[0143] The generated power signal 101 is transmitted from the transmitter 102 across a far field region 134 towards the receiver 116. The receiver 116 is configured to receive a power signal 101 from the transmitter 102 and convert the power signal 101 into a direct current electrical signal. The receiver 116 comprises: a high-gain directional antenna 118, an impedance matching circuit 136 electrically connected to a rectifier 120, a controller 122, a supercapacitor 138, and a battery management system 124. The receiver 116 further comprises a load 140 which in the illustrated arrangement comprises a battery 142.

[0144] The high-gain directional antenna 118 receives the power signal 101 transmitted by the high-gain directional antenna 126 of the transmitter 102. The impedance matching circuit 136 is configured to match a source impedance and a load impedance to maximise power transfer and minimise signal reflection. The rectifier 120 rectified the received AC power signal to a DC power signal. The supercapacitor 138 may comprise a plurality of supercapacitors and may be disposed between rectifier 120 and the battery management system 124. The supercapacitor 138 may be charged from the output of the rectifier 120 in order to store energy ready for rapid release or to stabilise the energy intake by the battery 142. The controller 122 controls operation of the battery management system 124, but may also controller the rectifier 120, antenna 118 and other components of the receiver 116.

[0145] The battery management system 124 of the receiver 116 is configured to manage the load of the battery 142 to optimise battery charging and power use. The load 140 is configured to store the electrical energy received by the receiver 116. The receiver 116 is configured to store received electrical power in the battery 142. The load 140 shown in Figure 1 comprises a battery 142, but one of skill in the art will appreciate other loads may be preferred. The battery 142 is controlled and monitored by the battery management system 124. Accordingly, the receiver 116 being configured to load the electrical power received means

[0146] In use, electrical power from the power source 104 of the transmitter 102 is converted by the power converter 128, transformed by the oscillator 106, stabilised by the supercapacitor 130, amplified by the power amplifier 132, and then transmitted by the antenna 126 as a power signal 101 across the far field region 134 towards the antenna 118 of the receiver 116. The beamforming circuit 110, phasing circuit 112 and controller 114 act to modify operation of the power converter 128, oscillator 106, supercapacitor 130, power amplifier 132 and antenna 126 of the transmitter 102 to influence generation of the power signal 101.

[0147] The power signal 101 from the transmitter 102 is received by the antenna 118 of the receiver 116, converted to a DC signal by the rectifier 120, and loaded into the battery 142. The impedance matching circuit 136 maximises power transfer. The supercapacitor 138 is controlled by the controller 122, which is in communication with the battery management system 124 which monitors and controls the battery 142 of the load 140.

[0148] In the illustrated arrangement, the transmitter 102 further comprises a safety system 150. The safety system 150 comprises a shell signal generator 152 and a sensor 154. The safety system 150 inhibits a power signal (e.g., the microwave signal) from adversely impacting a local environment, i.e. an environment along a signal path between the transmitter 102 and receiver 116. The shell signal generator 152 generates a shell signal encasing the power signal generated by the oscillator 106. The shell signal has a substantially hollow cross-sectional shape configured to receive the power signal. A frequency of the shell signal may be less than a frequency of the power signal.

[0149] The sensor 154 detects a parameter. While only a single sensor 154 is referred, one of skill in the art will appreciate the safety system 150 may comprise a plurality of sensors 154. In this arrangement, the parameter comprises a reflection caused by an object perturbing at least a portion of the shell signal generated by the shell signal generator 152.

[0150] While not shown the safety system 150 may comprise one or more of: an active interference cancellation system, a camera, a controller, and a safety shutdown system.

[0151] The active interference cancellation system comprises an array of antennae configured to transmit a cancelling signal. For each antenna in the array of antennae, a parameter of a signal transmitted by the antenna is adjusted to promote a cancellation of the interfering signal. In this way, the safety system 150 may act to protect any electrical or electronic systems operating near the power signal. The camera captures images of an area in a vicinity of the power signal. The camera may include object recognition software (or system) for identifying objects in the images.

[0152] In this arrangement, the controller comprises an embedded control system. However, one of skill in the art will appreciate the controller may be incorporated in the described controller 114 of the transmitter 102. The controller may control the oscillator 106 to stop the output of the power signal and / or the antenna 126 to steer the power signal to more efficiently transfer power to the receiver 116 based on the output of the sensor 154, camera, etc.

[0153] The safety shutdown system is configured to terminate wireless power transfer in response to the detection of an unsafe operating condition of the power signal. An unsafe operating condition may comprise detection of an unsafe object is detected in the beam path. Further, an unsafe operating condition may comprise the beamforming circuit being unable to redirect the beam to avoid the unsafe object. The unsafe object may comprise an animal and / or person.

[0154] The safety shutdown system may comprise a plurality of power switching devices. The safety shutdown system may interact with the previously described sensor 154 or camera. For example, if the camera detects an object in the beam, the safety shutdown system may trigger a safety shutdown of the oscillator 106 if beamforming is not possible.

[0155] As shown in Figure 1, the system 100 may further comprises a data communication system 160 for communicating data between the transmitter 102 and receiver 116. The data communication system 160 may be integrated into the transmitter 102 and receiver 116. For example, the data communication system 160 may comprise a communication module at the transmitter 102 for communicating data between the transmitter 102 and receiver 116, and a communication module at the receiver 116 for communicating data between the transmitter 102 and receiver 116.

[0156] While the safety system 150 has been described with reference to Figure 1, Figure 2 illustrates a safety system according to another arrangement. As illustrated in Figure 2, a safety system 300 for use in the described wireless power transfer system 100 comprises a first sensor 306, a second sensor 308 and a third sensor 310. In the illustrated arrangement, the first sensor 306 is camera, the second sensor 308 is a radar sensor and the third sensor 310 is a LiDAR sensor. The safety system 300 further comprises a controller 312, e.g., an embedded control system. The sensors 306, 308, 310 communicate with the controller 312.

[0157] The controller 312 interprets data supplied by the sensors 306, 308, 310 and determines a control signal 314 to send to the transmitter 102. The controller 312 analyses the supplied data to assess a risk posed by an object detected by the sensors 306, 308, 310. For example, the controller 312 estimates a trajectory of a detected object and predicts whether the object will interfere with the power signal 302, which in this arrangement comprises a microwave signal. If appropriate, the embedded control system 312 triggers a response by sending a control signal 314 to the transmitter 102 to cause the transmitter 102 to activate a deterrent alarm, redirect the power signal 302, pause transmission of the power signal 302, and / or terminate transmission of the power signal 302.

[0158] As shown in Figure 2, the power signal 302 may be obstructed by a variety of obstacles 304 (e.g., plants, animals, buildings and other fixed structures, vehicles and other moving objects, and other environmental elements) detected by the sensors 306, 308, 310. The sensors 306, 308, 310 detect the obstacles 304 and the controller 312 sends a control signal 314 to one or more of the oscillator 106, power amplifier 132, and antenna 126 to control generation of the power signal, i.e. pause the generation of the signal, redirect the signal, or lower the power of the signal.

[0159] While not shown in Figure 2, the safety system 150 (safety system 300 in Figure 2) may comprise the shell signal generator 152. The shell signal generator 152 generates a shell signal encasing the power signal generated by the oscillator 106. An exemplary beam 500 between the transmitter 102 and receiver 116 is illustrated in Figure 5.

[0160] The beam 500 comprises a shell signal 502 and a power signal 504, which in this arrangement comprises a microwave signal. The shell signal 502 is arranged to encase a power signal 504. Figure 5 shows a cross-section of the shell signal 502 and the power signal 504 to illustrate the encasing. As shown in Figure 5, any object crossing the path of the beam 500 will impact the shell signal 502 prior to impacting the power signal 504. In this way, the shell signal 502 may be used for object detection and to maximise power transfer from the transmitter 102 to the receiver 116.

[0161] The shell signal 502 and the power signal 504 are transmitted by the transmitter 102 towards the receiver 116. The shell signal 502 is transmitted from an array of antennae arranged on the transmitter 102 around a perimeter of the transmitter 102 such that the array of antennae encircle an antenna transmitting the power signal 504. The array antenna (or array of antennae) and the antenna transmitted the power signal 504 may both form part of the described high-gain antenna 126.

[0162] As shown in Figure 5, when an object 506 is shown obstructing an edge of the shell signal 502, the object 506 reflects a portion 508 of the shell signal 502 towards the transmitter 102. The portion 508 of the shell signal 502 is detected by a sensor at the transmitter 102, e.g., sensor 306, 308, 310 illustrated in Figure 3. The sensor may determine a location of the object 506 based on a property of the reflected portion 508 of the shell signal. For example, based on a power density of the reflected portion 508, time of flight, etc.

[0163] In response to detecting the object 506, a controller (e.g., controller 312) communicates (e.g., control signal 314) to the transmitter 102 to modify the transmission of the beam 500. For example, the controller 312 may communicate with the beamforming circuit 110 to redirect the beam 500. Additionally or alternatively, the controller 312 may communicate with the active interference cancellation system of the safety system 150 to initiate transmission of a cancelling signal, or null beam. Additionally or alternatively, the controller 312 may communicate with the transmitter 102 to activate a deterrent, or to modify a transmission of the beam 500. Modifying a transmission may comprise reducing a power of the transmission, pausing a transmission, or terminating a transmission.

[0164] Turning now to Figure 4, a flowchart 400 of a method of operating a safety system according to an aspect of the disclosure. Flowchart 400 illustrates how a property of the power signal may be monitored to detect obstruction to the power signal. Further, flowchart 400 illustrates how a property of a shell signal (e.g., shell signal 502) may be monitored to predict an obstruction to the power signal. The flowchart 400 illustrates a series of decisions that determine a response to a measured power density of the power signal received at the receiver 116. First, at termination block 402, the wireless power transfer system 100 operates to transfer power from the transmitter 102 to the receiver 116.

[0165] At decision block 404, an assessment of a need for calibration of a power density measurement takes place. This may comprise calculating a duration since a previous calibration and determining if the duration exceeds a predetermined threshold for allowable calibration intervals. Alternatively, this may comprise conducting a test, comparing a result to a known correct result, calculating a difference and determining if the difference exceeds a predetermined threshold for allowable drift. If calibration is required 406, a calibration is applied 408. If no calibration is required 410, or once a required calibration is applied 412, an assessment 422 of the measured power density takes place.

[0166] If the measured power density does not exceed 416 a predetermined reference value, transmission continues according to termination block 418. If the measured power density exceeds 420 a predetermined reference value, a further assessment 422 of the measured power density takes place. If the measured power density does not exceed 424 a predetermined safe threshold, an intensity of the beam is reduced 426. If the measured power density exceeds 428 a predetermined safe threshold, transmission of the beam is terminated 430.

[0167] In this way, when a power density of a beam is measured, three possible outcomes 418, 426, 430 are provided. The outcomes 418, 426, 430 are implemented by the controller 312 (the functions of which may incorporated into the controller 114) communicating a control signal 314 to the transmitter 102 to modify the transmission. The power density of the beam (e.g., beam 500) may be monitored constantly or measured at predetermined intervals. When the beam is unobstructed, the power density at the receiver 116 may remain within a calibrated range. An abrupt change in power density at the receiver 116 may indicate a presence of an obstruction. In this way, the controller 312 may provide an appropriate control signal 314 to the transmitter 102 without delay. Power density at the receiver 116 may be measured by measuring a power at a plurality of points on the receiver 116 using an array of power sensors, and a size of an area comprising the plurality of points. Power data is sent to the controller 312 which calculates a total power and a power density based on a known value for an area comprising the plurality of power sensors.

[0168] When a power density of a transmission is normal, i.e. below a calibrated power density 416, no modification 418 to the transmission is required. When a power density of a transmission is high, i.e. above 420 a calibrated power density, but below a safe threshold 424, a power density of the transmission is reduced 426. In this way, a power density of the transmission may be brought back into a normal range. When a power density of a transmission is very high, i.e. above 420 a calibrated power density and above 428a safe threshold, the transmission is terminated 430. In this way, a dangerous transmission may be terminated and may not cause harm or damage. Termination of the transmission may be performed by the described safety shutdown system.

[0169] While not shown in Figure 4, an amplitude of the power signal (e.g., power signal 504) may be additionally or alternatively modulated at the transmitter 102. Monitoring a modulation of an amplitude of the power signal measured at the receiver 116 may provide an indication of any obstruction in the power signal. Distortion of the amplitude modulated power signal may indicate a presence of an obstruction and may cause the controller 312 to trigger a response. Monitoring power density and amplitude modulation of the power signal at the receiver together may provide an accurate indication of obstruction of the power signal. Monitoring power density and amplitude modulation of a shell signal at the receiver together may provide an accurate indication of obstruction of the shell signal, and thereby predict an obstruction of the power signal.

[0170] With reference to Figure 5, a flowchart 200 of an operation of a safety system (e.g., system 150) of the wireless power transfer system 100 is shown. The flowchart 200 illustrates the series of decisions that are made during detection of an object in the beam and a determination of a response to the object. First, at termination block 202, the wireless power transfer system 100 is functioning to transfer power from the transmitter 102 to the receiver 116. At decision block 204, object detection takes place. If an object is not detected, line 206, transmission continues according to termination block 222. If an object is detected, line 208, a further decision 210 is made. At decision block 210, an assessment of a level of EM radiation with respect to a limit takes place. If the electromagnetic radiation does not exceed the limit, line 212, transmission continues according to termination block 222. If the electromagnetic radiation exceeds the limit, line 214, a further decision 216 is made. At decision block 216, an assessment of a risk to the beam takes place. If the risk to the beam is not high, line 218, transmission continues according to termination block 222. If the risk to the beam is high, line 220, transmission is reduced, paused or terminated according to termination block 224.

[0171] Flowchart 200 illustrates how an unsafe operation of the wireless power transfer system 100 is detected. To exhibit unsafe operation, an object must be detected 208, the EM radiation must exceed the limit 214 and the risk to the beam (e.g., beam 500) must be high 220. By following the flowchart 200, a safety of a transmission of wireless power over a long range is maintained.

[0172] At each decision block 204, 210, 216, a negative answer 206, 212, 218 permits transmission to continue 222, while an affirmative answer 208, 214, 220 leads to a further decision block 210, 216 or to a modification of the transmission 224. Accordingly, a modification of the transmission may only take place if an object is detected 208 and a level of electromagnetic radiation exceeds the limit 214 and the risk to the beam is high 220. In this way, the transmission is not modified unnecessarily and an efficiency of the transmission is maintained.

[0173] The described wireless power transfer system 100 may be used in any field or sector not described above. Further, while a particular wireless power transfer system 100 has been described, variations may be made as would be appreciated by one of skill in the art. For example, the wireless power transfer system 100 may comprise a number of receivers 116 for a signal transmitter 102 having multiple antennae 126. The transmitter 102 may accordingly transfer electrical power to more than one receiver 116. The wireless power transfer system 100 may transmit and direct a power signal in any suitable way. The received electrical power received may be loaded in any suitable way. The safety system 150 may comprise any suitable logic and may promote a safety of the wireless power transfer system 100 in any suitable way. As described to transfer power wirelessly in order to reduce a need for cabling, reducing associated emissions, costs and risks, the wireless power transfer system 100 is provided. Further, the wireless power transfer system 100 may improve a charging cost, range and convenience of electric vehicles, promoting adoption of electrical vehicles to decarbonise transport and provide sustainable travel.

[0174] Although embodiments have been described above with reference to the figures, those of skill in the art will appreciate that variations and modifications may be made without departing from the scope thereof as defined by the appended claims.

Claims

CLAIMS:

1. A wireless power transfer system comprising: a transmitter for transferring electrical power via a power signal, the transmitter comprising: a signal generator for generating a power signal; a power amplifier electrically connected to the signal generator; a directional antenna module for transmitting the power signal to a receiver of the wireless power transfer system; a beamforming circuit for directing the power signal based on a position of the receiver; a controller for controlling the directional antenna module based on an output of the beamforming circuit; and a safety system comprising a shell signal generator and antenna for generating and transmitting a shell signal encasing the power signal; and a receiver for receiving electrical power from the transmitter via the transmitted power signal, the receiver comprising a directional antenna module for receiving the power signal from the transmitter.

2. The wireless power transfer system of claim 1, wherein the safety system comprises a sensor for a detecting a parameter.

3. The wireless power transfer system of claim 2, wherein the sensor is configured to detect an object in the vicinity of the power signal.

4. The wireless power transfer system of claim 3, wherein the parameter comprises at least one of a distance of the object from the power signal; and a direction of the object relative to the power signal.

5. The wireless power transfer system of claim of any of claims 2 to 4, wherein the sensor comprises a radar sensor; a LiDAR sensor; and a camera.

6. The wireless power transfer system of any of claims 2 to 5, wherein the controller is configured to process data acquired by the sensor and estimate a trajectory of a detected object.

7. The wireless power transfer system of claim 6, wherein the controller is configured to predict whether the object will interfere with the power signal.

8. The wireless power transfer system of any preceding claim, wherein the controller is configured to trigger a response based on an output of the safety system.

9. The wireless power transfer system of claim 8, wherein the response comprises at least one of: activating a deterrent alarm; redirecting the power signal; pausing transmission of the power signal; and terminating transmission of the power signal.

10. The wireless power transfer system of any preceding claim, wherein the controller is configured to control the power signal such that a power of the power signal is maintained below a pre-determined threshold.

12. The wireless power transfer system of any preceding claim, wherein the safety system is configured to monitor a property of the power signal to detect obstruction or deviation of the power signal.

13. The wireless power transfer system of claim 12, wherein the property of the power signal comprises: power density; signal distortion; signal delay; amplitude modulation; polarisation; and signal strength.

14. The wireless power transfer system of any preceding claim, wherein the safety system is configured to monitor a property of the shell signal to detect obstruction or deviation of the shell signal.

15. The wireless power transfer system of claim 13, wherein the property of the shell signal comprises signal strength; power density; phase shift; signal delay; and frequency shift.

16. The wireless power transfer system of any preceding claim, wherein the directional antenna module comprises: at least one antenna configured to transmit the power signal; and an array of antennae arranged around the at least one antenna, the array of antennae configured to transmit the shell signal.

17. The wireless power transfer system of claim 16, wherein, for each antenna of the array of antennae, a phase of a signal transmitted by the antenna is adjusted such that the shell signal is formed through constructive interference of the signals from each antenna.

18. The wireless power transfer system of any preceding claim, wherein the safety system comprises a safety shutdown system configured to terminate wireless power transfer in response to the detection of an unsafe operating condition of the power signal.

19. The wireless power transfer system of any preceding claim, wherein the safety system comprises an active interference cancellation system configured to detect an interfering signal and transmit a cancelling signal configured to destructively interfere with the interfering signal.

20. The wireless power transfer system of claim 19, wherein the active interference cancellation system comprises an array of antennae configured to transmit the cancelling signal, and wherein, for each antenna in the array of antennae, a parameter of a signal transmitted by the antenna is adjusted to promote a cancellation of the interfering signal.

21. The wireless power transfer system of any preceding claim, wherein the safety system comprises: a camera configured to capture images of an area in a vicinity of the power signal; and an object recognition system configured to identify objects in the images captured by the camera.

22. The wireless power transfer system of any preceding claim, further comprising: a data communication system for communicating data between the transmitter and receiver.

23. The wireless power transfer system of claim 22, wherein the data communication system comprises:a communication module at the transmitter for transmitting data to the receiver and / or receiving data from the receiver; and a communication module at the receiver for transmitting data to the transmitter and / or receiving data from the transmitter.

24. The wireless power transfer system of any preceding claim, wherein the receiver further comprises a location tracking module for collecting tracking data of the receiver, and wherein the collected tracking data is communicated to the transmitter.

25. The wireless power transfer system of any preceding claim, wherein the transmitter and receiver are configured to establish a bi-directional communication link, the communication link allowing the transmitter to send control commands to the receiver.

26. The wireless power transfer system of any preceding claim, wherein the transmitter further comprises at least one of: a power source electrically connected to the signal generator; a supercapacitor electrically connected to the signal generator; and superconducting materials integrated within the transmitter.

27. The wireless power transfer system of any preceding claim wherein the transmitter further comprises a phasing circuit for adjusting a phase of the antenna.

28. The wireless power transfer system of any preceding claim, wherein the signal generator comprises a high-frequency oscillator.

29. The wireless power transfer system of any preceding claim, wherein the receiver further comprises: a power management system configured to manage the received electrical power.

30. The wireless power transfer system of any preceding claim, wherein the system is configured for use in at least one of: transportation applications; healthcare applications;industrial automation; environmental monitoring; agricultural applications; defence applications; telecommunications infrastructure applications; marine and underwater applications; renewable energy applications; aerospace applications; and earth monitoring purposes.

31. The wireless power transfer system of any preceding claim, wherein the directional antenna module of the transmitter and / or the receiver is impregnated with metamaterials.

32. The wireless power transfer system of any of claims 1 to 30, wherein the directional antenna module of the transmitter and / or the receiver comprises a metasurface-based phased array antenna.

33. A transmitter for transferring electrical power to a receiver of a wireless power transfer system, the transmitter comprising: a signal generator for generating a power signal; a power amplifier for amplifying the power signal; a directional antenna module for transmitting the power signal to a receiver of the wireless power transfer system; a beamforming circuit for directing the power signal based on a position of the receiver; a controller for controlling the directional antenna module based on an output of the beamforming circuit; and a safety system comprising a shell signal generator and antenna for generating and transmitting a shell signal encasing the power signal.

34. A receiver for receiving electrical power from a power signal transmitted by a transmitter of a wireless power transfer system, the receiver comprising: a directional antenna module for receiving the power signal and a shell signal encasing the power signal;a sensor for monitoring a parameter of at least one of the power signal and the shell signal; and a communication module for communicating the parameter to a transmitter of the power signal.

35. A method of transferring power from a transmitter of a wireless power transfer system to a receiver of the wireless power transfer system, the method comprising: generating a power signal for wireless electrical power transfer; directing the power signal based on a position of the receiver; and controlling a directional antenna module of the transmitter based on the directing to transmit the power signal the receiver, the power signal encased in a shell signal.

36. The method of claim 35, further comprising: encasing the power signal in the shell signal.

37. The method of claim 35 or 36, further comprising: detecting a parameter of the receiver, power signal, and / or shell signal; and controlling the directional antenna module based on the monitored parameter.

38. The method of claim 37, further comprising: triggering a response based on the detected parameter.

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