As the sixth generation network(6G)emerges,the Internet of remote things(IoRT)has become a critical issue.However,conventional terrestrial networks cannot meet the delay-sensitive data collection needs of IoRT network...As the sixth generation network(6G)emerges,the Internet of remote things(IoRT)has become a critical issue.However,conventional terrestrial networks cannot meet the delay-sensitive data collection needs of IoRT networks,and the Space-Air-Ground integrated network(SAGIN)holds promise.We propose a novel setup that integrates non-orthogonal multiple access(NOMA)and wireless power transfer(WPT)to collect latency-sensitive data from IoRT networks.To extend the lifetime of devices,we aim to minimize the maximum energy consumption among all IoRT devices.Due to the coupling between variables,the resulting problem is non-convex.We first decouple the variables and split the original problem into four subproblems.Then,we propose an iterative algorithm to solve the corresponding subproblems based on successive convex approximation(SCA)techniques and slack variables.Finally,simulation results show that the NOMA strategy has a tremendous advantage over the OMA scheme in terms of network lifetime and energy efficiency,providing valuable insights.展开更多
Reconfigurable intelligent surface(RIS)employs passive beamforming to control the wireless propagation channel,which benefits the wireless communication capacity and the received energy efficiency of wireless power tr...Reconfigurable intelligent surface(RIS)employs passive beamforming to control the wireless propagation channel,which benefits the wireless communication capacity and the received energy efficiency of wireless power transfer(WPT)systems.Such beamforming schemes are classified as discrete and non-convex integer program-ming problems.In this paper,we propose a Monte-Carlo(MC)based random energy passive beamforming of RIS to achieve the maximum received power of electromagnetic(EM)WPT systems.Generally,the Gibbs sampling and re-sampling methods are employed to generate phase shift vector samples.And the sample with the maximum received power is considered the optimal solution.In order to adapt to the application scenarios,we develop two types of passive beamforming algorithms based on such MC sampling methods.The first passive beamforming uses an approximation of the integer programming as the initial sample,which is calculated based on the channel information.And the second one is a purely randomized algorithm with the only total received power feedback.The proposed methods present several advantages for RIS control,e.g.,fast convergence,easy implementation,robustness to the channel noise,and limited feedback requirement,and they are applicable even if the channel information is unknown.According to the simulation results,our proposed methods outperform other approxi-mation and genetic algorithms.With our methods,the WPT system even significantly improves the power effi-ciency in the nonline-of-sight(NLOS)environment.展开更多
The demand for electric vehicles has increased over the past few years.Wireless power transfer for electric vehicles provides more flexibility than traditional plug-in charging technology.Charging couplers are critica...The demand for electric vehicles has increased over the past few years.Wireless power transfer for electric vehicles provides more flexibility than traditional plug-in charging technology.Charging couplers are critical components in wireless power transfer systems.The thermal effect produced by the magnetic coupler in work will cause the temperature of the device to rise rapidly,affecting the work efficiency,transfer power,operation reliability,and service life.This paper modeled and analyzed each component's temperature distribution characteristics and thermal behavior.Firstly,the magnetic coupler's mutual inductance and magnetic circuit model are established,and the thermal model of the magnetic coupler analyzes the heat generation process.The thermal models of the coupler under three different magnetic core distributions are established,and the temperature rise of each component is obtained.The temperature rise of different parts of the coupler is verified by the temperature rise test structure of the experiment.展开更多
As one of the most attractive non-radiative power transfer mechanisms without cables,efficient magnetic resonance wireless power transfer(WPT)in the near field has been extensively developed in recent years,and promot...As one of the most attractive non-radiative power transfer mechanisms without cables,efficient magnetic resonance wireless power transfer(WPT)in the near field has been extensively developed in recent years,and promoted a variety of practical applications,such as mobile phones,medical implant devices and electric vehicles.However,the physical mechanism behind some key limitations of the resonance WPT,such as frequency splitting and size-dependent efficiency,is not very clear under the widely used circuit model.Here,we review the recently developed efficient and stable resonance WPT based on non-Hermitian physics,which starts from a completely different avenue(utilizing loss and gain)to introduce novel functionalities to the resonance WPT.From the perspective of non-Hermitian photonics,the coherent and incoherent effects compete and coexist in the WPT system,and the weak stable of energy transfer mainly comes from the broken phase associated with the phase transition of parity-time symmetry.Based on this basic physical framework,some optimization schemes are proposed,including using nonlinear effect,using bound states in the continuum,or resorting to the system with high-order parity-time symmetry.Moreover,the combination of non-Hermitian physics and topological photonics in multi-coil system also provides a versatile platform for long-range robust WPT with topological protection.Therefore,the non-Hermitian physics can not only exactly predict the main results of current WPT systems,but also provide new ways to solve the difficulties of previous designs.展开更多
This paper presents a four-plate undersea capacitive wireless power transfer(CPT)system for underwater applications such as autonomous underwater vehicles(AUVs).Generally,a CPT system transfers the power based on elec...This paper presents a four-plate undersea capacitive wireless power transfer(CPT)system for underwater applications such as autonomous underwater vehicles(AUVs).Generally,a CPT system transfers the power based on electric fields.The complex resonant compensation networks are used to make the CPT system work in the resonant condition.The resonant voltage is always very high.It will be a big challenge to the human safety.In this paper,a virtual electrons periodic reciprocating flow theory is proposed for the CPT system.In one switching cycle,the electrons firstly flow in the forward direction through the forward path and then flow in the inverse direction through the inverse path.The CPT system has been deeply studied with the vacuum dielectric or the air dielectric.However,for the CPT system,there are few papers to show the underwater application.In this paper,an undersea four-plate CPT system is designed and studied in the underwater condition.The two coupling capacitors and other elements of the CPT system could build a closed-loop path.A small value inductor is adapted as a resonant compensation network for the four-plate CPT system.The DC voltage is inverted to the AC voltage in the primary side with the single-phase full-bridge inverter.The resonant voltage is rectified to the DC voltage in the secondary side with the single-phase full-bridge diode rectifier.A 100 W power level CPT system is constructed to verify the theory analysis and the calculation.The theory analysis is verified by the simulated and experimental results.The stable output voltage and load power are achieved in this paper.展开更多
As a revolutionary hardware technology that can reconfigure the propagation environment,reconfigurable intelligent surfaces(RISs)have been regarded as a promising solution to enhance wireless networks.In this paper,we...As a revolutionary hardware technology that can reconfigure the propagation environment,reconfigurable intelligent surfaces(RISs)have been regarded as a promising solution to enhance wireless networks.In this paper,we consider a multiuser multiple-input single-output(MISO)wireless power transfer(WPT)system,which is assisted by several RISs.In order to improve energy efficiency and reduce hardware cost,we consider that the energy transmitter(ET)in the WPT system is equipped with a constant-envelope analog beamformer,instead of a digital beamformer.Focusing on user fairness,we study a minimum received power maximization problem by jointly optimizing the ET beamforming and the RIS phase shifts,subject to the constant-envelope constraints.We iteratively solve this non-convex maxmin problem by leveraging both the successive convex approximation(SCA)method and the alternating direction method of multipliers(ADMM)algorithm.Numerical results demonstrate the effectiveness of the proposed algorithm and show attractive performance gain brought by RISs.展开更多
Traditional magnetically coupled resonant wireless power transfer technology uses fixed distances between coils for research,to prevent fluctuations in the receiving voltage,and lead to reduce transmission efficiency....Traditional magnetically coupled resonant wireless power transfer technology uses fixed distances between coils for research,to prevent fluctuations in the receiving voltage,and lead to reduce transmission efficiency.This paper proposes a closed-loop control wireless communication wireless power transfer system with a wearable four-coil structure to stabilize the receiving voltage fluctuation caused by changes in the displacement between the coils.Test results show that the system can provide stable receiving voltage,no matter how the distance between the transmitting coil and the receiving coil is changed.When the transmission distance is 20 mm,the power transfer efficiency of the system can reach 18.5%under the open-loop state,and the stimulus parameters such as the stimulation period and pulse width can be adjusted in real time through the personal computer terminal.展开更多
The equivalent two-port network model of a middle range wireless power transfer(WPT) system was presented based on strongly coupled multiple resonators. The key parameters of the WPT system include self-inductance, re...The equivalent two-port network model of a middle range wireless power transfer(WPT) system was presented based on strongly coupled multiple resonators. The key parameters of the WPT system include self-inductance, resistance, parasitic capacitance, mutual inductance and S-parameters of coils & resonators were analyzed. The impedance matching method was used to optimize load power and transmission efficiency of the multi-resonator WPT system, and the impedance matching method was realized through adjusting the distances between the coils and resonators. Experiments show that the impedance matching method can effectively improve load power and transmission efficiency for middle range wireless power transfer systems with multiple resonators, at distances up to 3 times the coil radius with efficiency more than 70% and load power also close to 3.5 W.展开更多
Magnetic radiation phenomena appear inevitably in the magnetic-resonance wireless power transfer （MR-WPT） system, and regarding this problem the magnetic-shielding scheme is applied to improve the electromagnetic pe...Magnetic radiation phenomena appear inevitably in the magnetic-resonance wireless power transfer （MR-WPT） system, and regarding this problem the magnetic-shielding scheme is applied to improve the electromagnetic performance in engineering. In this study, the shielding effectiveness of a two-coil MR-WPT system for different material shields is analyzed in theory using Moser＇s formula and Schelkunoff＇s formula. On this basis a candidate magnetic-shielding scheme with a double-layer structure is determined, which has better shielding effectiveness and coils coupling coefficient. Finally, some finite element simulation results validate the correctness of the theoretical analysis, and the shielding effectiveness with the double-layer shield in maximum is 30？dB larger than the one with the single-layer case.展开更多
Wireless power transfer(WPT)technology is a popular choice for biomedical implant devices.The demands of higher efficiency and smaller implantation size are hard to compromise in previous studies.In the present work,a...Wireless power transfer(WPT)technology is a popular choice for biomedical implant devices.The demands of higher efficiency and smaller implantation size are hard to compromise in previous studies.In the present work,an implantable magnetic coupling resonant WPT system in-tegrated with a metasurface element working at 430 MHz is presented.Similar planar copper coil components for the transmitting and receiving structures are used to construct the primary system,and then the metasurface element is integrated to constitute the whole WPT system.The effects of the distances between the transmitting coil and skin surface,between the skin surface,and receiv-ing coil are discussed.The results show that the efficiency will be enhanced by 38-50 dB integrat-ing with the metasurface.展开更多
As different power has its own receivers,this paper analyzes and designs a multiple-receiver wireless power transfer(WPT)system systematically.The equivalent circuit model of the system is established to analyze the k...As different power has its own receivers,this paper analyzes and designs a multiple-receiver wireless power transfer(WPT)system systematically.The equivalent circuit model of the system is established to analyze the key parameters including transmitter power,receiver power,transmission efficiency,and each receiver power allocation.A control circuit is proposed to achieve the maximum transmission efficiency and transmitter power control and arbitrary receiver power allocation ratios for different receivers.Through the proposed control circuit,receivers with different loads can allocate appropriate power according to its power demand,the transmitter power and system efficiency do not vary with the change of the number of receivers.Finally,this control circuit is validated using a 130-kHz WPT system with three receivers whose power received is 3:10:12,and the overall system efficiency can reach as high as 55.5%.展开更多
By representing the Earth as a rotating spherical antenna several historic and scientific breakthroughs are achieved.Visualizing the Sun as a transmitter and the planets as receivers the solar system can be represente...By representing the Earth as a rotating spherical antenna several historic and scientific breakthroughs are achieved.Visualizing the Sun as a transmitter and the planets as receivers the solar system can be represented as a long wave radio system operating at Tremendously Low Frequency(TLF).Results again confirm that the“near-field”is Tesla’s“dynamic gravity”,better known to engineers as dynamic braking or to physicists as centripetal acceleration,or simply(g).Timewave theory is invented,and the relationship of reflected timewaves and time travel explored.A new law of the Sun is proposed as well as the merging of Einstein’s equation with acoustics and cosmic superstring theory.A new law of cosmic efficiency is also proposed that equates vibratory force and pressure with volume acceleration of the solar system.Lorentz force is broken down into centripetal and gravitational waves.Ten-dimensional cosmic superstring theory is espoused versus the aging three-dimensional Maxwellian model.Spherical antenna patterns for planets are presented and flux transfer frequency is calculated using distance to planets as wavelengths.The galactic grid operates at a Schumann Resonance of 7.83 Hz,which is derived from the science of dark energy and dark matter.The Sun and the planets are tuned to transmit and receive electrical power like resonating Tesla coils.The Earth’s stator winding has been modeled as a toroid tesla coil and the armature as a spherical armature.The equation for everything is born.展开更多
A wireless power transfer system for endoscopic micro-robot operating at 36 kHz is presented in this paper. The issue of patient＇ s health and safety regarding exposure to the electromagnetic field is addressed. The ...A wireless power transfer system for endoscopic micro-robot operating at 36 kHz is presented in this paper. The issue of patient＇ s health and safety regarding exposure to the electromagnetic field is addressed. The specific absorption rate and current density can be used to investigate the electromagnetic influences on the biological tissues surrounded by the wireless power launching coil. In view of this purpose, the limited close-ound solenoid electromagnetic model is built, the relationship between the electric intensity and the specific absorption rate and current density is deduced, and the simulation experiments are done. Experimental results show that the values of SAR and current density related to different tissue catalogs are all very small and do not exceed their own limits respectively when the resonance frequency of operation is 36 kHz.展开更多
A novel architecture for Wireless Power Transfer(WPT)module using monolithic components on GaN is presented in this paper.The design of such a WPT module receives DC power from solar panels,consists of photonic power ...A novel architecture for Wireless Power Transfer(WPT)module using monolithic components on GaN is presented in this paper.The design of such a WPT module receives DC power from solar panels,consists of photonic power converter(PPC),beamforming antenna,low pass filter,input matching network,rectifier,output matching network and logic circuit(off-chip)which are all integrated on a GaN chip.Our WPT components show excellent simulated performance,for example,our novel beam-forming antenna and multiple port wideband antenna have a gain of 8.7 dB and 7.3 dB respectively.We have added a band pass filter to the rectifier output which gives two benefits to the circuit.The first one is filtering circuit will remove unwanted harmonics before collecting DC power and second is filter will boost the efficiency of rectifier by optimizing the load impedance.Our proposed rectifier has RF-DC conversion efficiency of 74%and 67%with beam-forming antenna and multiple port wide band antenna respectively.Our WPT module is designed to charge a rechargeable battery(3 V and 1 mA)of a radio module which will be used between two antennas in future 5G networks.We believe our proposed WPT module architecture is unique and it is applicable to both microwave and millimeter wave systems such as 6G.展开更多
Wireless power transfer(WPT) to support mobile and portable devices is an emerging wireless technique.Among all kinds of approaches,magnetic resonance coupling(MRC) is an excellent one for mid-range WPT,which provides...Wireless power transfer(WPT) to support mobile and portable devices is an emerging wireless technique.Among all kinds of approaches,magnetic resonance coupling(MRC) is an excellent one for mid-range WPT,which provides better mobility,flexibility,and convenience due to its simplicity in hardware implementation and longer transmission distances.In this paper,we consider an MRCWPT system with multiple power transmitters,one intended power receiver and multiple unintended power receivers.We investigate the probabilistic robust beamforming designs and provide efficient algorithms to achieve the local optimums under two different criteria,i.e.,total source power minimization problem and min-max unintended receiving power restriction problem.As the problems are quite typical in robust design situations,our proposed robust beamformers can be conveniently applied to other probabilistic robust design problems,thus reduce the complexity as well as improve the beamforming performance.Numerical results demonstrate that the proposed algorithms can significantly improve the performance as well as the robustness of the WPT system.展开更多
It has been reported that, through the evanescent near fields, the strongly coupled magnetic resonance is able to achieve an efficient mid-range Wireless Power Transfer (WPT) beyond the characteristic size of the reso...It has been reported that, through the evanescent near fields, the strongly coupled magnetic resonance is able to achieve an efficient mid-range Wireless Power Transfer (WPT) beyond the characteristic size of the resonator. Recent studies on of the relay effect of the WPT allow more distant and flexible energy transmission. These new developments hold a promise to construct a fully wireless Body Sensor Network (wBSN) using the new mid-range WPT theory. In this paper, a general optimization strategy for a WPT network is presented by analysis and simulation using the coupled mode theory. Based on the results of theoretical and computational study, two types of thin-film resonators are designed and prototyped for the construction of wBSNs. These resonators and associated electronic components can be integrated into a WPT platform to permit wireless power delivery to multiple wearable sensors and medical implants on the surface and within the human body. Our experiments have demonstrated the feasibility of the WPT approach.展开更多
Due to the increasing commercial interest in autonomy and sustainability,this paper reviews and presents a comprehensive summary of the resonant-inductive power transmission(RPT)technology for autonomous mobile robots...Due to the increasing commercial interest in autonomy and sustainability,this paper reviews and presents a comprehensive summary of the resonant-inductive power transmission(RPT)technology for autonomous mobile robots.It outlines historic and recent research activities in wireless power transmission,covering the fundamental operation of microwave,capacitive and inductive power transfer technologies,state-of-the-art developments in RPT for high-power applications,current design and health standards,technological drawbacks,and possible future trends.In this paper,coupling-enhanced pad designs,adaptive tuning techniques,compensation network designs,and control techniques are explored.Major design issues such as coupling variation,frequency splitting,and bifurcation are reviewed.The difference between maximum power transfer and maximum energy efficiency is highlighted.Human exposure guidelines are summarized from documentations provided by the Institute of Electrical and Electronics Engineers(IEEE)and the International Commission on Non-ionizing Radiation Protection(ICNIRP).Other standards like WPC’s Qi and Airfuel design standards are also summarized.Finally,the possible trends of the relevant research and development,particularly dynamic charging,are discussed.The intention of this review is to encourage designs that will relieve robot operators of the burden of frequent manual recharging,and to reduce downtime and increase the productivity of autonomous mobile robots in industrial environments.展开更多
The optimization method by adjusting load and distances between two adjacent coils( or resonators) is presented on basis of wireless power transfer( WPT) system with relay resonators. 2-port network and impedance matc...The optimization method by adjusting load and distances between two adjacent coils( or resonators) is presented on basis of wireless power transfer( WPT) system with relay resonators. 2-port network and impedance matching theory are applied to analyzing power flow of incidence and reflection in WPT system,then setting up power flow model. The maximum power transmission efficiency can be obtained when the load and distance between secondary resonator and output coil meets impedance matching at 2-port network's output port. The simulation and experimental results shown the impedance matching method can effectively improve and maintain transmission efficiency by adjusting load and distances between coils or relay resonators.展开更多
This paper examines the properties of the double loop wireless power transmitter using numerical simulations. The double loop wireless power transmitter consists of two coupling and parallel loop antennas which transm...This paper examines the properties of the double loop wireless power transmitter using numerical simulations. The double loop wireless power transmitter consists of two coupling and parallel loop antennas which transmit field energy through resonant electromagnetic waves. This tech-nology can be applied in RFIDs (Radio Frequency Identification) and re-mote charging scenarios where wires cannot be applied to, including the wireless charging of drones and satellites.展开更多
基金supported by National Natural Science Foundation of China(No.62171158)the project“The Major Key Project of PCL(PCL2021A03-1)”from Peng Cheng Laboratorysupported by the Science and the Research Fund Program of Guangdong Key Laboratory of Aerospace Communication and Networking Technology(2018B030322004).
文摘As the sixth generation network(6G)emerges,the Internet of remote things(IoRT)has become a critical issue.However,conventional terrestrial networks cannot meet the delay-sensitive data collection needs of IoRT networks,and the Space-Air-Ground integrated network(SAGIN)holds promise.We propose a novel setup that integrates non-orthogonal multiple access(NOMA)and wireless power transfer(WPT)to collect latency-sensitive data from IoRT networks.To extend the lifetime of devices,we aim to minimize the maximum energy consumption among all IoRT devices.Due to the coupling between variables,the resulting problem is non-convex.We first decouple the variables and split the original problem into four subproblems.Then,we propose an iterative algorithm to solve the corresponding subproblems based on successive convex approximation(SCA)techniques and slack variables.Finally,simulation results show that the NOMA strategy has a tremendous advantage over the OMA scheme in terms of network lifetime and energy efficiency,providing valuable insights.
基金supported by National Nature Science Foundation of China(No.62171484)Zhuhai Fundamental and Application Research(No.ZH22017003210006PWC)Fundamental Research Funds for the Central Universities(No.21621420).
文摘Reconfigurable intelligent surface(RIS)employs passive beamforming to control the wireless propagation channel,which benefits the wireless communication capacity and the received energy efficiency of wireless power transfer(WPT)systems.Such beamforming schemes are classified as discrete and non-convex integer program-ming problems.In this paper,we propose a Monte-Carlo(MC)based random energy passive beamforming of RIS to achieve the maximum received power of electromagnetic(EM)WPT systems.Generally,the Gibbs sampling and re-sampling methods are employed to generate phase shift vector samples.And the sample with the maximum received power is considered the optimal solution.In order to adapt to the application scenarios,we develop two types of passive beamforming algorithms based on such MC sampling methods.The first passive beamforming uses an approximation of the integer programming as the initial sample,which is calculated based on the channel information.And the second one is a purely randomized algorithm with the only total received power feedback.The proposed methods present several advantages for RIS control,e.g.,fast convergence,easy implementation,robustness to the channel noise,and limited feedback requirement,and they are applicable even if the channel information is unknown.According to the simulation results,our proposed methods outperform other approxi-mation and genetic algorithms.With our methods,the WPT system even significantly improves the power effi-ciency in the nonline-of-sight(NLOS)environment.
文摘The demand for electric vehicles has increased over the past few years.Wireless power transfer for electric vehicles provides more flexibility than traditional plug-in charging technology.Charging couplers are critical components in wireless power transfer systems.The thermal effect produced by the magnetic coupler in work will cause the temperature of the device to rise rapidly,affecting the work efficiency,transfer power,operation reliability,and service life.This paper modeled and analyzed each component's temperature distribution characteristics and thermal behavior.Firstly,the magnetic coupler's mutual inductance and magnetic circuit model are established,and the thermal model of the magnetic coupler analyzes the heat generation process.The thermal models of the coupler under three different magnetic core distributions are established,and the temperature rise of each component is obtained.The temperature rise of different parts of the coupler is verified by the temperature rise test structure of the experiment.
基金supported by the National Key Research and Development Program of China (Grant No. 2016YFA0301101)the National Natural Science Foundation of China (Grant Nos. 91850206, 61621001, 2004284, 11674247, and 11974261)+3 种基金Shanghai Science and Technology Committee, China (Grant Nos. 18JC1410900 and 18ZR1442900)the China Postdoctoral Science Foundation (Grant Nos. 2019TQ0232 and 2019M661605)the Shanghai Super Postdoctoral Incentive ProgramFundamental Research Funds for the Central Universities, China
文摘As one of the most attractive non-radiative power transfer mechanisms without cables,efficient magnetic resonance wireless power transfer(WPT)in the near field has been extensively developed in recent years,and promoted a variety of practical applications,such as mobile phones,medical implant devices and electric vehicles.However,the physical mechanism behind some key limitations of the resonance WPT,such as frequency splitting and size-dependent efficiency,is not very clear under the widely used circuit model.Here,we review the recently developed efficient and stable resonance WPT based on non-Hermitian physics,which starts from a completely different avenue(utilizing loss and gain)to introduce novel functionalities to the resonance WPT.From the perspective of non-Hermitian photonics,the coherent and incoherent effects compete and coexist in the WPT system,and the weak stable of energy transfer mainly comes from the broken phase associated with the phase transition of parity-time symmetry.Based on this basic physical framework,some optimization schemes are proposed,including using nonlinear effect,using bound states in the continuum,or resorting to the system with high-order parity-time symmetry.Moreover,the combination of non-Hermitian physics and topological photonics in multi-coil system also provides a versatile platform for long-range robust WPT with topological protection.Therefore,the non-Hermitian physics can not only exactly predict the main results of current WPT systems,but also provide new ways to solve the difficulties of previous designs.
基金supported by the National Natural Science Foundation of China under grant no.52107205China Postdoctoral Science Foundation under grant no.2018M643700+2 种基金Scientific Research Project of Education Department of Shaanxi Province under grant no.18JS080Postdoctoral Research Program of Shaanxi Province under grant no.2018BSHYDZZ28Basic Research Project of Natural Science of Shaanxi Province under grant no.2020JQ-623.
文摘This paper presents a four-plate undersea capacitive wireless power transfer(CPT)system for underwater applications such as autonomous underwater vehicles(AUVs).Generally,a CPT system transfers the power based on electric fields.The complex resonant compensation networks are used to make the CPT system work in the resonant condition.The resonant voltage is always very high.It will be a big challenge to the human safety.In this paper,a virtual electrons periodic reciprocating flow theory is proposed for the CPT system.In one switching cycle,the electrons firstly flow in the forward direction through the forward path and then flow in the inverse direction through the inverse path.The CPT system has been deeply studied with the vacuum dielectric or the air dielectric.However,for the CPT system,there are few papers to show the underwater application.In this paper,an undersea four-plate CPT system is designed and studied in the underwater condition.The two coupling capacitors and other elements of the CPT system could build a closed-loop path.A small value inductor is adapted as a resonant compensation network for the four-plate CPT system.The DC voltage is inverted to the AC voltage in the primary side with the single-phase full-bridge inverter.The resonant voltage is rectified to the DC voltage in the secondary side with the single-phase full-bridge diode rectifier.A 100 W power level CPT system is constructed to verify the theory analysis and the calculation.The theory analysis is verified by the simulated and experimental results.The stable output voltage and load power are achieved in this paper.
基金supported by General Program of National Natural Science Foundation of China(No.62071090)Sichuan Science and Technology Program(No.2021YFH0014).
文摘As a revolutionary hardware technology that can reconfigure the propagation environment,reconfigurable intelligent surfaces(RISs)have been regarded as a promising solution to enhance wireless networks.In this paper,we consider a multiuser multiple-input single-output(MISO)wireless power transfer(WPT)system,which is assisted by several RISs.In order to improve energy efficiency and reduce hardware cost,we consider that the energy transmitter(ET)in the WPT system is equipped with a constant-envelope analog beamformer,instead of a digital beamformer.Focusing on user fairness,we study a minimum received power maximization problem by jointly optimizing the ET beamforming and the RIS phase shifts,subject to the constant-envelope constraints.We iteratively solve this non-convex maxmin problem by leveraging both the successive convex approximation(SCA)method and the alternating direction method of multipliers(ADMM)algorithm.Numerical results demonstrate the effectiveness of the proposed algorithm and show attractive performance gain brought by RISs.
基金supported by the National Natural Science Foundation of China(61674049,U19A2053)State Key Lab of ASIC and System(2019KF003)the Fundamental Research Funds for Central Universities(JZ2019HGTB0092)。
文摘Traditional magnetically coupled resonant wireless power transfer technology uses fixed distances between coils for research,to prevent fluctuations in the receiving voltage,and lead to reduce transmission efficiency.This paper proposes a closed-loop control wireless communication wireless power transfer system with a wearable four-coil structure to stabilize the receiving voltage fluctuation caused by changes in the displacement between the coils.Test results show that the system can provide stable receiving voltage,no matter how the distance between the transmitting coil and the receiving coil is changed.When the transmission distance is 20 mm,the power transfer efficiency of the system can reach 18.5%under the open-loop state,and the stimulus parameters such as the stimulation period and pulse width can be adjusted in real time through the personal computer terminal.
基金Project(61104088)supported by the National Natural Science Foundation of ChinaProject(12C0741)supported by Scientific Research Fund of Hunan Provincial Education Department,China
文摘The equivalent two-port network model of a middle range wireless power transfer(WPT) system was presented based on strongly coupled multiple resonators. The key parameters of the WPT system include self-inductance, resistance, parasitic capacitance, mutual inductance and S-parameters of coils & resonators were analyzed. The impedance matching method was used to optimize load power and transmission efficiency of the multi-resonator WPT system, and the impedance matching method was realized through adjusting the distances between the coils and resonators. Experiments show that the impedance matching method can effectively improve load power and transmission efficiency for middle range wireless power transfer systems with multiple resonators, at distances up to 3 times the coil radius with efficiency more than 70% and load power also close to 3.5 W.
基金Supported by the National Natural Science Foundation of China under Grant No 51377185
文摘Magnetic radiation phenomena appear inevitably in the magnetic-resonance wireless power transfer （MR-WPT） system, and regarding this problem the magnetic-shielding scheme is applied to improve the electromagnetic performance in engineering. In this study, the shielding effectiveness of a two-coil MR-WPT system for different material shields is analyzed in theory using Moser＇s formula and Schelkunoff＇s formula. On this basis a candidate magnetic-shielding scheme with a double-layer structure is determined, which has better shielding effectiveness and coils coupling coefficient. Finally, some finite element simulation results validate the correctness of the theoretical analysis, and the shielding effectiveness with the double-layer shield in maximum is 30？dB larger than the one with the single-layer case.
基金the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB32040200).
文摘Wireless power transfer(WPT)technology is a popular choice for biomedical implant devices.The demands of higher efficiency and smaller implantation size are hard to compromise in previous studies.In the present work,an implantable magnetic coupling resonant WPT system in-tegrated with a metasurface element working at 430 MHz is presented.Similar planar copper coil components for the transmitting and receiving structures are used to construct the primary system,and then the metasurface element is integrated to constitute the whole WPT system.The effects of the distances between the transmitting coil and skin surface,between the skin surface,and receiv-ing coil are discussed.The results show that the efficiency will be enhanced by 38-50 dB integrat-ing with the metasurface.
基金supported by the National Natural Science Foundation of China under Grant No.51574198Nanchong City 2018 Special Fund for City-School Cooperation under Grant No.18SXHZ0021
文摘As different power has its own receivers,this paper analyzes and designs a multiple-receiver wireless power transfer(WPT)system systematically.The equivalent circuit model of the system is established to analyze the key parameters including transmitter power,receiver power,transmission efficiency,and each receiver power allocation.A control circuit is proposed to achieve the maximum transmission efficiency and transmitter power control and arbitrary receiver power allocation ratios for different receivers.Through the proposed control circuit,receivers with different loads can allocate appropriate power according to its power demand,the transmitter power and system efficiency do not vary with the change of the number of receivers.Finally,this control circuit is validated using a 130-kHz WPT system with three receivers whose power received is 3:10:12,and the overall system efficiency can reach as high as 55.5%.
文摘By representing the Earth as a rotating spherical antenna several historic and scientific breakthroughs are achieved.Visualizing the Sun as a transmitter and the planets as receivers the solar system can be represented as a long wave radio system operating at Tremendously Low Frequency(TLF).Results again confirm that the“near-field”is Tesla’s“dynamic gravity”,better known to engineers as dynamic braking or to physicists as centripetal acceleration,or simply(g).Timewave theory is invented,and the relationship of reflected timewaves and time travel explored.A new law of the Sun is proposed as well as the merging of Einstein’s equation with acoustics and cosmic superstring theory.A new law of cosmic efficiency is also proposed that equates vibratory force and pressure with volume acceleration of the solar system.Lorentz force is broken down into centripetal and gravitational waves.Ten-dimensional cosmic superstring theory is espoused versus the aging three-dimensional Maxwellian model.Spherical antenna patterns for planets are presented and flux transfer frequency is calculated using distance to planets as wavelengths.The galactic grid operates at a Schumann Resonance of 7.83 Hz,which is derived from the science of dark energy and dark matter.The Sun and the planets are tuned to transmit and receive electrical power like resonating Tesla coils.The Earth’s stator winding has been modeled as a toroid tesla coil and the armature as a spherical armature.The equation for everything is born.
文摘A wireless power transfer system for endoscopic micro-robot operating at 36 kHz is presented in this paper. The issue of patient＇ s health and safety regarding exposure to the electromagnetic field is addressed. The specific absorption rate and current density can be used to investigate the electromagnetic influences on the biological tissues surrounded by the wireless power launching coil. In view of this purpose, the limited close-ound solenoid electromagnetic model is built, the relationship between the electric intensity and the specific absorption rate and current density is deduced, and the simulation experiments are done. Experimental results show that the values of SAR and current density related to different tissue catalogs are all very small and do not exceed their own limits respectively when the resonance frequency of operation is 36 kHz.
文摘A novel architecture for Wireless Power Transfer(WPT)module using monolithic components on GaN is presented in this paper.The design of such a WPT module receives DC power from solar panels,consists of photonic power converter(PPC),beamforming antenna,low pass filter,input matching network,rectifier,output matching network and logic circuit(off-chip)which are all integrated on a GaN chip.Our WPT components show excellent simulated performance,for example,our novel beam-forming antenna and multiple port wideband antenna have a gain of 8.7 dB and 7.3 dB respectively.We have added a band pass filter to the rectifier output which gives two benefits to the circuit.The first one is filtering circuit will remove unwanted harmonics before collecting DC power and second is filter will boost the efficiency of rectifier by optimizing the load impedance.Our proposed rectifier has RF-DC conversion efficiency of 74%and 67%with beam-forming antenna and multiple port wide band antenna respectively.Our WPT module is designed to charge a rechargeable battery(3 V and 1 mA)of a radio module which will be used between two antennas in future 5G networks.We believe our proposed WPT module architecture is unique and it is applicable to both microwave and millimeter wave systems such as 6G.
基金supported by National Natural Science Foundation of China(Grant No.61771185,61831013)Science and Technology Research Project of Henan Province(Grant No.182102210044)+1 种基金Key Scientific Research Program of Henan Higher Education(Grant No.18A510009)Beijing Municipal Natural Science Foundation(Grant No.4182030)
文摘Wireless power transfer(WPT) to support mobile and portable devices is an emerging wireless technique.Among all kinds of approaches,magnetic resonance coupling(MRC) is an excellent one for mid-range WPT,which provides better mobility,flexibility,and convenience due to its simplicity in hardware implementation and longer transmission distances.In this paper,we consider an MRCWPT system with multiple power transmitters,one intended power receiver and multiple unintended power receivers.We investigate the probabilistic robust beamforming designs and provide efficient algorithms to achieve the local optimums under two different criteria,i.e.,total source power minimization problem and min-max unintended receiving power restriction problem.As the problems are quite typical in robust design situations,our proposed robust beamformers can be conveniently applied to other probabilistic robust design problems,thus reduce the complexity as well as improve the beamforming performance.Numerical results demonstrate that the proposed algorithms can significantly improve the performance as well as the robustness of the WPT system.
文摘It has been reported that, through the evanescent near fields, the strongly coupled magnetic resonance is able to achieve an efficient mid-range Wireless Power Transfer (WPT) beyond the characteristic size of the resonator. Recent studies on of the relay effect of the WPT allow more distant and flexible energy transmission. These new developments hold a promise to construct a fully wireless Body Sensor Network (wBSN) using the new mid-range WPT theory. In this paper, a general optimization strategy for a WPT network is presented by analysis and simulation using the coupled mode theory. Based on the results of theoretical and computational study, two types of thin-film resonators are designed and prototyped for the construction of wBSNs. These resonators and associated electronic components can be integrated into a WPT platform to permit wireless power delivery to multiple wearable sensors and medical implants on the surface and within the human body. Our experiments have demonstrated the feasibility of the WPT approach.
基金partially funded by the Natural Sciences and Engineering Research Council of Canada(NSERC)through the Discovery Grant Program(RGPIN2018-05471 and RGPIN-2017-05762).
文摘Due to the increasing commercial interest in autonomy and sustainability,this paper reviews and presents a comprehensive summary of the resonant-inductive power transmission(RPT)technology for autonomous mobile robots.It outlines historic and recent research activities in wireless power transmission,covering the fundamental operation of microwave,capacitive and inductive power transfer technologies,state-of-the-art developments in RPT for high-power applications,current design and health standards,technological drawbacks,and possible future trends.In this paper,coupling-enhanced pad designs,adaptive tuning techniques,compensation network designs,and control techniques are explored.Major design issues such as coupling variation,frequency splitting,and bifurcation are reviewed.The difference between maximum power transfer and maximum energy efficiency is highlighted.Human exposure guidelines are summarized from documentations provided by the Institute of Electrical and Electronics Engineers(IEEE)and the International Commission on Non-ionizing Radiation Protection(ICNIRP).Other standards like WPC’s Qi and Airfuel design standards are also summarized.Finally,the possible trends of the relevant research and development,particularly dynamic charging,are discussed.The intention of this review is to encourage designs that will relieve robot operators of the burden of frequent manual recharging,and to reduce downtime and increase the productivity of autonomous mobile robots in industrial environments.
基金Human Provincial Natural Science Foudation of China(No.2016JJ4043)Youth Foundation of Education Bureau of Hunan Province,China(No.16B137)Science and Technology Projects of Loudi City,China
文摘The optimization method by adjusting load and distances between two adjacent coils( or resonators) is presented on basis of wireless power transfer( WPT) system with relay resonators. 2-port network and impedance matching theory are applied to analyzing power flow of incidence and reflection in WPT system,then setting up power flow model. The maximum power transmission efficiency can be obtained when the load and distance between secondary resonator and output coil meets impedance matching at 2-port network's output port. The simulation and experimental results shown the impedance matching method can effectively improve and maintain transmission efficiency by adjusting load and distances between coils or relay resonators.
文摘This paper examines the properties of the double loop wireless power transmitter using numerical simulations. The double loop wireless power transmitter consists of two coupling and parallel loop antennas which transmit field energy through resonant electromagnetic waves. This tech-nology can be applied in RFIDs (Radio Frequency Identification) and re-mote charging scenarios where wires cannot be applied to, including the wireless charging of drones and satellites.
