This paper presents a method to solve the problems of excessive system volume and security risks caused by the use of voltage-boosting devices in single-wire power transfer (SWPT) systems. The main contributions include putting forward the interpretation and understanding of the new SWPT principle, discussing the non-necessity of the boosting device as the theoretical basis, verifying the feasibility of non-high voltage energy transfer through finite element simulation, and optimizing the inductor-capacitor-inductor (LCL) topology to be symmetrical, which solves the problem of the different load output caused by different single-line connection modes while canceling the booster link. This method reduces the security risks and reduces the system's volume, which is more conducive to the application of engineering practice. Finally, a small-scale low-power SWPT experimental device was built to verify the feasibility of this method. The experiment shows that the load can receive about 2 V of voltage under the input condition of 12 V, which verifies the feasibility of this method.
In dynamic wireless power transfer (DWPT) systems employing transmitting (Tx) coil arrays, output power fluctuations aggravate battery charging current ripples and compromise system stability. To address this issue, this work proposes a CLC-S compensation topology based on a dual-input single-output (DISO) architecture along with a cooperative coil design methodology. Theoretical analysis of the DISO CLC-S compensation network reveals that equivalent mutual inductance fluctuation is the main cause of output power instability, and that cross-coupling between Tx coils can disrupt the zero-voltage-switching (ZVS) condition. Parameter sensitivity analysis identifies the Tx coil series compensation capacitance as the key tunable parameter decoupled from the system output power. Based on the ZVS boundary condition, a tuning strategy is proposed to suppress the cross-coupling effect. To minimize equivalent mutual inductance fluctuations, an analytical model for the mutual inductance between the receiving (Rx) coil and adjacent dual transmit (Tx) coils under lateral movement is proposed. The model enables the determination of the optimal center-to-center distance between Tx coils, and supports the design of an overlapping Tx coil layout. A 1.3 kW prototype is developed for validation. Test results demonstrate that, compared to a single-input single-output (SISO) system, the proposed solution reduces output power fluctuation by 85.87%, while full ZVS operation during dynamic charging is achieved. In this case, the average output power has been increased by 6.58%.
When AGVs are parked for wireless charging, misalignment and offset between the transmitting and receiving coils are prone to occur, which affects the charging power and efficiency. To address this issue, this paper proposes a novel flat cross-shaped self-decoupling electromagnetic coupler for AGVs that require strong anti-offset performance in a hybrid topology wireless charging system. Firstly, a hybrid topology combining CLC-S compensation topology and S-CLC compensation topology is proposed. The principle of achieving anti-offset, the load-independent output characteristics, and the safety of the system in a weak coupling state are analyzed. Secondly, a new magnetic coupling mechanism is proposed, which can eliminate all cross-couplings generated in the proposed hybrid topology. Finally, a 200 W output power experimental platform is built. The maximum DC-DC efficiency of the system is 89.13%. The maximum X-axis offset of the system reaches 53.46% of the coil size, the maximum Y-axis offset is 9.43% of the coil size, and the maximum Z-axis offset reaches-37.78% to +13.33% of the rated transmission distance. The load-independent constant voltage output characteristics of the proposed system and its safety in a weak coupling state are also verified.
In response to the limitations of traditional magnetic coupling wireless power transfer (MC-WPT) systems in multi-degree-of-freedom spatial energy transmission, this paper proposes a full-space MC-WPT system based on a multi-node architecture. The system employs three-dimensional orthogonal coils as nodes, supporting both centralized and distributed power transfer modes, along with a corresponding dynamic magnetic energy control method that allows flexible mode selection according to transmission requirements to enhance performance. By coordinately adjusting coil combinations and current amplitudes, the magnetic field strength and direction at any position within the effective energy transfer range can be precisely controlled, thereby eliminating ineffective transmission zones and achieving omnidirectional and high-efficiency energy transfer. Experimental results show that the errors in magnetic field direction and intensity under both transmission modes are below 10%, verifying the correctness and effectiveness of the proposed control method.
To resolve controversies over the specific principle of single-wire power transmission (SWPT), this study innovatively confirms the indispensable role of the single wire and identifies scalar waves as the potential energy carrier through structural analysis and simulation. Starting from the typical structure of SWPT systems, it analyzes representative models and verifies that the single wire is a core, irreplaceable component for directional energy transfer. The study further deduces that the energy carrier in SWPT may propagate as scalar waves by exploring electromagnetic field characteristics. Finally, Comsol simulations (200 m single wire, 100 V high-frequency input, 50 Omega load) intuitively show the electric and magnetic field distributions on the single wire, confirming that these fields exhibit the distribution characteristics of scalar waves, providing theoretical and simulation support for clarifying the SWPT principle.
Electromobility is a key step in reducing our dependence on fossil fuels, whose resources are gradually depleting. By using renewable energy sources to recharge electric vehicles, we can reduce carbon emissions from the transport sector. However, battery storage capacity remains a challenge, making a fast and safe recharging network essential for electric vehicle (EV) drivers. In recent years, several coil designs have been used for Dynamic Wireless Power Transfer (DWPT) charging. This study focuses on the design and analysis of the rectangular coil, as well as its integration into the DWPT system. In this research, the finite element method (FEM) was used to analyze the magnetic flux distribution in the rectangular coil, and to examine the impact of varying the distance between the receiver and transmitter coils. The aim is to determine the energy transfer limits of this coil for different sizes of electric vehicles, while assessing the effect of the ferrite plate associated with the coils. The aim of this work is to find the most functional and optimal configuration of magnetic couplers for a DWPT system. The main magnetic couplers adopted by the system were studied using the finite element method. The results have been analyzed in detail to identify the best option.
This paper presents a novel LCC primary compensation + series-series (S-S) secondary compensation multi-stage compensation topology to meet the requirement for self-adaptive switching between constant current (CC) and constant voltage (CV) modes in low-power wireless charging systems for inspection robots. A key advantage of the proposed topology is its ability to provide stable CC and CV outputs as required through a simple topological reconfiguration, without relying on additional control algorithms, which substantially simplifies the control logic. To verify the design's feasibility, an experimental platform targeting 63 V/7 A was constructed. Performance tests indicate that in CV mode, the system maintains a stable output of 67 V with a fluctuation of only 5%. Correspondingly, in CC mode, it delivers a stable current of 7 A with a mere 4.6% fluctuation. These results conclusively validate the effectiveness and rationality of the proposed LCC-S-S topology and its parameter design.
Existing wireless power transfer (WPT) systems often fail to simultaneously achieve constant-voltage (CV) and constant-current (CC) outputs when charging multiple devices. To address this limitation, this paper proposes a dual-load WPT system with CV and CC characteristics. The system comprises a full-bridge rectifier circuit for CC output and a novel half-wave rectifier circuit for CV output, along with a composite CV/CC control method to independently regulate power across the two output circuits. First, the power transfer characteristics of the proposed circuit topology are analyzed, and the operational principles of the novel half-wave rectifier are elucidated. Second, a transfer function model of the dual-load WPT system is established, and the composite CV/CC control strategy is introduced: feedforward PI control with phase-shift voltage regulation enables CC output for the full-bridge rectifier circuit, while PI control ensures CV output for the half-wave rectifier circuit. Finally, an experimental prototype is constructed to validate the power transfer characteristics and the composite CV/CC control method. Experimental results demonstrate the feasibility and stability of the proposed approach.
To address the limitations of conventional UAV charging methods, this paper presented a lightweight, high-efficiency, and high-power-density wireless charging system for unmanned aerial vehicles (UAVs) based on electric field coupling power transfer (ECPT) technology, which provides an effective solution that integrates high power, high efficiency, and low loss, offering significant engineering value for future UAV wireless charging systems. The system adopts a dual-sided LC compensation topology combined with a tightly coupled quadrupole plate structure. By analyzing the resonant characteristics and deriving optimal design parameters, efficient power transfer at a high operating frequency of 1.5 MHz is achieved. To improve the transfer efficiency, aluminum oxide ceramic is employed as the dielectric material, while analysis of the coupling capacitance and dielectric properties is presented to improve the mutual capacitance and coupling coefficient. Experimental results demonstrate that the proposed ECPT system achieves stable constant-current output with a maximum power conversion efficiency of 87%. A prototype successfully delivers a rated output power of 200 W, validating the system's feasibility and practicality for UAV applications.
This paper presents a metal foreign body detection method based on a Generative Adversarial Network (GAN). The proposed approach utilizes a generator to simulate the electromagnetic field distribution in an environment free of foreign bodies, while the discriminator is trained to differentiate between a typical environment and one containing foreign metal objects. Additionally, an electromagnetic signal detection method based on wavelet transform is introduced. By increasing the convolutional depth and adjusting the learning rate, the model's accuracy in detecting metal foreign bodies in complex environments is significantly enhanced. Simulation results demonstrate that this method achieves a high detection accuracy for metal foreign bodies composed of various materials, with an accuracy rate of 98.5% and a false alarm rate of less than 1.5%.
This paper proposes a high-power-density integrated undersea wireless power transfer (UWPT) system for underwater intelligent sensors, which features anti-offset capability and electromagnetic shielding compatibility. Firstly, the high-frequency inverter designed for the UWPT system integrates auxiliary power supplies, control circuitry, driving components, and semiconductor switching devices. By employing zero-voltage switching (ZVS) technology to minimize high-frequency switching losses, the design enables a more compact structure and enhanced reliability. Secondly, to achieve high transmission efficiency, this paper establishes a nonlinear rectifier bridge load equivalent model based on the proposed topology. It reveals the mechanism by which the rectifier diode voltage drop affects load conversion and quantitatively analyzes how system efficiency varies with load. This analysis helps reduce calculation errors in determining the optimal load. Furthermore, the adoption of ferrite cores enhances the coupling coefficient and reduces eddy current losses resulting from the leakage of high-frequency alternating magnetic fields in the circuit. Finally, a 100 W prototype is built with a 500 kHz switching frequency to validate the proposed design. Experimental results demonstrate that the UWPT system exhibits strong robustness in both air and salt water environments. The maximum efficiencies achieved are 91.4% in air, and 89.6% in salt water.
In the context of the deep integration of wireless communication and perception technology, this paper examines the resource allocation problem of an energy harvesting-assisted unmanned aerial vehicle (UAV) communication and perception integrated systems. Firstly, an energy harvesting-assisted UAV sensing integrated system was constructed, which consists of a sensing integrated base station, sensing terminals, and ground sensing energy stations. Then, based on the separate study of energy consumption models, communication models, and perception models, an integrated energy harvesting-assisted UAV sensing system model was established. Considering the optimization objectives of communication and perception, communication metrics were transformed into constraints and the research focussed on studying the perception performance of the system. A series of convex optimization methods were used to solve the conversion optimization problem, and the optimal energy harvesting time slot allocation was solved using the binary method. The established optimization model takes into account the deep coupling between the drone beamforming vector and the position decision variable. Finally, the optimal solution was obtained through alternating iterations using semi-definite programming (SDP), the Dinkelbach method, and the successful convex approximation (SCA) method. The simulation experiment fully verifies the effectiveness of the proposed algorithm.
Parity-time symmetric wireless power transfer (PT-WPT) systems exhibit fixed constant-power output, which fails to meet the power regulation requirements for applications such as drone wireless in-flight charging. To address this limitation, this paper proposes an autonomous pulse density modulation (APDM) strategy. Within the strong-coupling region, the constant-power level can be flexibly regulated by adjusting the pulse density without disrupting the 'gain-loss balance' of the PT-symmetric state, thereby adapting to multi-scenario power demands. First, a high-order primary-series (S) and secondary single-inductor-double-capacitor (SLDC) topology is designed to effectively expand the constant-power region of the system. Then, an APDM strategy with uniform energy injection is proposed, which optimizes pulse sequence distribution to suppress output current fluctuation and enable full-range zero voltage switching (ZVS). Experimental results demonstrate that the system maintains the robustness of PT symmetry against coupling fluctuations while achieving autonomous and flexible power regulation across the designed pulse density range, with efficiency maintained at 88% and stable ZVS implementation. These results confirm the superiority of the proposed solution in power regulation, significantly expanding the application potential of PT-WPT systems in multi-power-demand scenarios such as drones.
Planar spiral coils in high-frequency wireless power transfer systems suffer from increased loss due to skin and proximity effects. The PCB Litz wire structure is proposed to suppress eddy current losses and improve the quality factor. Optimized design parameters are obtained through theoretical analysis and electromagnetic simulations. Simulation results confirm reduced AC resistance in the kilohertz range and a higher quality factor compared with conventional solid-wire coils. The proposed approach provides an effective solution for high-performance and compact WPT systems.
Although wireless excitation improves the reliability of electrically excited synchronous motors (EESMs), the rotor field current cannot be directly measured due to the rotation of the rotor. Using the widely adopted S-N topology as a representative framework, this paper reveals the prediction principle of excitation current and proposes five distinct excitation current estimation methods. By comprehensive comparison, the method of estimating the excitation current using the input voltage and the RMS value of the primary current exhibits excellent characteristics across all aspects. It eliminates the need for high-frequency phase detection, is robust to load variation, and provides a reliable technical solution for the closed-loop control of wireless excitation systems. Sensitivity analysis shows that, within a normalized sweep of 0.90-1.10, the estimation error remains within an engineering-acceptable range, providing tolerance-setting and sensor-selection guidance. Experimental validation on an 80 kHz prototype achieves primary-side ZVS, and a maximum steady-state error of 2.4% over 1-4 A setpoints, demonstrating effectiveness and practical feasibility.
To solve the problem that wireless power transfer (WPT) systems with multiple transmitters require more inverters and involve complex phase synchronization control between inverters, a dual-output zero-voltage switching (ZVS) inverter is proposed. It can generate two identical output voltages to realize synchronous driving of two transmitter coils, thereby reducing the number of inverters and switches required by the system, and simplifying system control. The output voltage gain characteristics of the inverter are analyzed and compared with those of existing typical inverters in WPT systems. The equivalent mathematical model of the system is constructed, and the output power characteristics are analyzed. Meanwhile, the operating states for soft-switching are analyzed and calculated. Theoretical analysis and experimental results indicate that the WPT system based on the proposed inverter can maintain high transmission efficiency during the movement of the receiver coil, with the maximum efficiency exceeding 90%.
For medium-voltage SiC devices, there is a mutual restraint between the isolation capability and the coupling capacitance of the isolated gate drive power supply. It is the major bottleneck for structural compactness and insulation reliability. This paper innovatively proposes a loosely coupled transformer design scheme using wireless power transfer, achieving the collaborative optimization of high isolation performance and low coupling capacitance within a limited space. The research first establishes a theoretical model of coupling capacitance. Through parameter analysis, the key design variables that affect the performance of the isolation unit are identified. At the coil structure design level, the electric field boundary homogenization was introduced, significantly reducing the local electric field stress and solving the problem of electric field concentration at the triplet points. Furthermore, this paper conducts an indepth comparison of different insulating materials and insulation schemes, and proposes two isolation unit design schemes: local potting and overall potting. After verification through partial discharge tests and coupling capacitor performance tests, it was finally determined that the overall sealing and filling scheme was the optimal design. This scheme achieves a partial discharge inception voltage (PDIV) of 21.5 kV effective value, and a low coupling capacitance of 2.34 pF.
