Wireless Power Transfer System Research Articles

An efficient hybrid LC-S compensation topology for wireless power transfer system

An efficient hybrid LC-S compensation topology for wireless power transfer system

Medium-Duty Delivery Truck Integrated Bidirectional Wireless Power Transfer System With Grid and Stationary Energy Storage System Connectivity

Medium-Duty Delivery Truck Integrated Bidirectional Wireless Power Transfer System With Grid and Stationary Energy Storage System Connectivity

Integrated LCC-LCC Topology for WPT System With CC Output Regarding Air Gap and Load Variations

Integrated LCC-LCC Topology for WPT System With CC Output Regarding Air Gap and Load Variations

A Wide Output Voltage Range and High Efficiency Dual-Channel WPT System Employing Multimode Control Strategy

A Wide Output Voltage Range and High Efficiency Dual-Channel WPT System Employing Multimode Control Strategy

Switching Frequency Control Strategy of Inverter for Multifrequency Multiload WPT System Based on Hysteresis Current Control

Switching Frequency Control Strategy of Inverter for Multifrequency Multiload WPT System Based on Hysteresis Current Control

A Single-Transmitter Multi-Receiver Wireless Power Transfer System with High Coil Misalignment Tolerance and Variable Power Allocation Ratios

This article proposes a single-transmitter multi-receiver wireless power transfer (STMR-WPT) system, which uses a cross-overlapped bipolar coil as the transmitter and multiple square unipolar coils as the receivers. By using this structure, the magnetic field of the system can be adjusted to accommodate different coil misalignment conditions. In addition, the proposed system uses C-CLCs networks to achieve separate load power allocation. Thus, relay coils, complex multi-frequency transmission channels and multiple independent power supplies can be avoided. A mapping impedance-based circuit model was established to analyze the characteristics of the system, and then a single-frequency power allocation method was presented. Through this method, the STMR-WPT system can achieve load power allocation at any specified ratios under different mutual inductance and load impedance conditions. Finally, an experimental STMR-WPT system was built. The side lengths of the transmitter and receiver coils are 400 mm and 160 mm, respectively. The measurement results indicated that when the lateral or longitudinal coil misalignment varies within the range of 0~200 mm, the coupling coefficient decreases by a maximum of 6% compared to the initial value, and when the angular coil misalignment varies within the range of 0~90 degrees, the coupling coefficient decreases by a maximum of 22% compared to the initial value. In four different power allocation scenarios, the experimental STMR-WPT system successfully achieved the expected power allocation goals.

Extending the design space of minimized VA rating inductive wireless power transfer links operating in restricted sub-resonant frequency region with constant current output

Wireless power transfer systems are typically required to operate under varying geometrical positioning (vertical distance, misalignment) between the transmitter and receiver coils while supporting a load with non-constant characteristics. This creates the need for robust systems that can operate over a range of coupling coefficients under time-varying load. Widespread control methods utilized to support such an operation typically suffer from volt-ampere (VA) over-rating of the inductive wireless power transfer link (IWPTL) transmitter. Sub-resonant frequency control has proven to be an effective solution to this problem, attaining robust operation and minimized transmitter VA rating by utilizing operational frequency as the control variable for system output regulation under above-mentioned constraints. However, allowed operating frequency range is usually restricted in practical applications (e.g. to 79 kHz–90 kHz by SAE J2954 EV charging standard), limiting the misalignment tolerance of sub-resonant control method. Recently, extension of the classical sub-resonant control methodology was proposed in order to overcome this limitation. However, no clear guidelines were given for designing practical IWPTLs operating under extended sub-resonant control. To this end, this work bridges the gap between academical findings and practical applications by establishing generalized guidelines for designing sub-resonant controlled series-series (SS) compensated IWPTL with minimized transmitter VA rating, allowing to maximize misalignment tolerance under given operating frequency and output voltage ranges. The proposed methodology is accurately validated by simulations and experiments, demonstrate close correlation with analytical predictions. Experimental framework reveals that IWPTL operating under extended sub-resonant control methodology attains 50 % increase of tolerable coupling coefficients range compared to a classical system designed to operate under sub-resonant control under identical operating conditions while achieving nearly similar DC-to-DC efficiency.

Scalable networks of wireless bioelectronics using magnetoelectrics.

Networks of miniature bioelectronic implants would enable precise measurement and manipulation of the complex and distributed physiological systems in the body. For example, sensing and stimulation nodes throughout the heart, brain, or peripheral nervous system would more accurately track and treat disease or support prosthetic technologies with many degrees of freedom. A main challenge to creating this type of in-body bioelectronic network is the fact that wireless power and data transfer are often inefficient when communicating through biological tissues. This challenge is typically compounded as one increases the number of implants within the network. Here, we show that magnetoelectric wireless data and power transfer enable a network of millimeter-sized bioelectronic implants where the power transfer efficiency of the system improves as the number of implanted devices increases. Using this property, we demonstrate networks of wireless battery-free bioelectronics ranging from 1 to 6 implants where the wireless power transfer efficiency for the system increases from 0.2% to 1.3%, with each node in the network receiving 2.2 mW at a distance of 1 cm. We use this system for efficient and robust wireless data and power transfer to demonstrate proof-of-concept networks of miniature spinal cord stimulators and cardiac pacing devices in large animals. The scalability of this network architecture enabled by magnetoelectric wireless power transfer provides a platform for building wireless closed-loop networks of bioelectronic implants for next-generation electronic medicine.

An Integrated Double-Sided LCC Compensation Based Dual-Frequency Compatible WPT System with Constant-Current Output and ZVS Operation

This article presents an integrated double-sided inductance and double capacitances (DS-LCC) compensation based dual-frequency compatible wireless power transfer (WPT) system. A cascaded single-phase multi-frequency inverter (CSMI) is constructed to generate the independent dual-frequency power transfer signals. In order to achieve the load-independent constant-current output (CCO) at two frequencies, an integrated DS-LCC compensated topology is reconstructed. By configuring the frequency-selective resonating compensation (FSRC) network in the primary side, the power transfer signals at two frequencies can be superimposed into a single transmitting coil, reducing the cost and volume of the system. Furthermore, to implement zero-voltage switching (ZVS) of the CSMI throughout the entire power range, a general parameter design method of the proposed system is also introduced. A 1.5-kW experimental prototype is built to validate the practicability of the presented dual-frequency compatible WPT System. The system can supply power to different loads at two frequencies simultaneously with CCO and ZVS properties. The peak efficiency reaches 91.75% at a 1.2-kW output power.

High efficiency three‐dimensional wireless power transfer system using cylindrical transmitting coil

AbstractThree‐dimensional (3D) wireless power transfer (WPT) is an attractive methodology to improve the charging safety and flexibility of portable electronic equipment and to meet the charging demand brought by the increase of electronic equipment. Herein a 3D WPT system using a cylindrical transmitting coil excited by a single power source is proposed to improve flexibility and efficiency. Specifically, the coil size is designed and the circuit model is analyzed. A method for determining inductor parameters of Inductor‐Capacity‐Capacity compensation is designed to achieve high efficiency. The power transmission performance of the WPT system is validated through an experimental platform. The measured maximum power is more than 50 W, and the maximum DC‐DC efficiency is up to 82.3%. The system can simultaneously charge multiple loads with different receiving coils at different positions. The proposed WPT system can improve the flexibility of equipment charging without control, and provide a reference for the design of portable equipment high efficiency wireless chargers.

Self-decoupled coupler based dual-coupled LCC-LCC rotating wireless power transfer system with enhanced output power

Self-decoupled coupler based dual-coupled LCC-LCC rotating wireless power transfer system with enhanced output power

Optimizing Wireless Power Transfer Systems: A Simulation-Based Approach Using CST Studio Suite

In the rapidly evolving field of wireless power transfer (WPT), achieving systems that combine efficiency with reliability is crucial. This paper presents a simulation-based approach using CST Studio Suite to optimize WPT systems for wireless battery chargers in electric bikes. The study fixes the size of both the transmitter and receiver coils, the spacing between turns, and the number of coil turns, with a set distance of 20mm between the transmitter and receiver coils. CST Studio Suite is employed to determine the parameters of resonance capacitors and the optimal switching frequency to enhance WPT efficiency. This powerful simulation tool allows researchers and engineers to design resonance compensation circuits more effectively, optimizing power transfer efficiency. The simulation conducted with CST Studio Suite confirms its effectiveness in designing a WPT system, achieving an impressive peak efficiency of 99.61% at the resonant frequency. The paper demonstrates CST Studio Suite's capability to accurately predict WPT system performance by developing detailed electromagnetic models and fine-tuning simulation parameters to reflect real operating conditions. Iterative simulations resulted in optimized practices, validated by select results that highlight the method's effectiveness and showcase an optimal balance between system complexity and efficiency. These findings provide a strategic framework for future WPT system development, offering practical guidance for researchers and industry professionals aiming to advance WPT technology.

Advances in EV wireless charging technology – A systematic review and future trends

Current advancements in wireless power transfer systems have improved the viability of enhancing the scope of the driving journey of an Electric Vehicle. This paper addresses the prime aspects of wireless charging infrastructure using a systematic approach, such as compensation topologies, power converter circuit design, and power transfer methods. The exclusive wireless charging track on the road minimizes the size of the battery device and the charging duration of energy storage during driving. The ability to transmit high power through a coil placed on the road to the Electric Vehicle requires an appropriate design for the complete wireless power transmission module. This paper also presents advancements in the domain of wireless technologies and recommends upcoming opportunities and future research trends.

A series-parallel-compensated fractional-order wireless power transfer system with coupling independence and detuning insensitivity

A series-parallel-compensated fractional-order wireless power transfer system with coupling independence and detuning insensitivity

DAB-Based Bidirectional Wireless Power Transfer System with LCC-S Compensation Network under Grid-Connected Application

To realize two-way power transfer without physical connections under a grid-connected application, bidirectional wireless power transfer (BDWPT) is introduced. This paper proposes an LCC-S compensated BDWPT system based on dual-active-bridge (DAB) topology with the minimum component counts. LCC-S is designed to be a constant voltage (CV) network. To obtain the power transmission characteristics of the system, a mathematical model based on the fundamental harmonic approximation (FHA) method is established, and the result shows that the direction and amount of transfer power can be controlled by changing the magnitude of output voltages of either/both side of H-bridges. The reactive power of the system can be controlled to be zero when the output voltages of two H-bridges are in the same phase. Compared with DAB-based BDWPT systems with constant current (CC) compensation networks, the proposed structure has better transfer power regulation capability and easier control of the direction of power flow. A 1.1 kW experimental prototype is built in the laboratory to verify the characteristics of the proposed system. The results indicate that the power transfer characteristics of the proposed BDWPT system match its mathematical derivation results based on the FHA model.

Efficiency Optimization of LCL-Resonant Wireless Power Transfer Systems via Bidirectional Electromagnetic–Thermal Coupling Field Dynamics

This paper delved into the thermal dynamics and stability of Wireless Power Transfer (WPT) systems, with a focus on the temperature effects on the coil structure. Using the Finite Element Method (FEM), this study investigated both unidirectional and bidirectional coupling field simulations, assessing their impacts on the transmission efficiency of LCL-resonant WPT systems. The boundary conditions and processes of the electromagnetic–thermal coupling field related to coil loss were analyzed, as well as the dynamic thermal balance in the bidirectional coupling field model. It was found that there is a significant temperature variation across the coil, with the highest temperatures at the central position and the lowest at the edges. This temperature rise notably changed the electrical parameters of the system, leading to variations in its operating state and a reduction in transmission efficiency. A constant coil voltage control strategy was more effective in mitigating the temperature rise compared to a constant coil current strategy, providing valuable insight for enhancing the efficiency and stability of WPT systems.

Mechanism Analysis and Elimination of Multiple Pulse Phenomenon of Active Rectifier in Wireless Power Transfer Systems

Mechanism Analysis and Elimination of Multiple Pulse Phenomenon of Active Rectifier in Wireless Power Transfer Systems

Precise Parameterized Modeling of Coil Inductance in Wireless Power Transfer Systems

Precise Parameterized Modeling of Coil Inductance in Wireless Power Transfer Systems

Curved HSIW: an affordable performance for non-planar millimeter-wave applications

This paper introduces a Curved Hollow Substrate Integrated Waveguide (CHSIW) to address the growing demand for millimeter-wave applications, including communication, sensing, imaging, radar, and wireless power transfer systems. Leveraging advancements in integrated circuits and system-in-package (SiP) technology, the CHSIW tackles the challenges associated with hardware integration into curved structures. The design utilizes MultiJet Printing (MJP) for the M3 crystal dielectric substrate and a water laser cutter system for copper sheets, streamlining the fabrication process by eliminating complex via manufacturing steps through prefabricated through-hole vias. Operating in the frequency range of 21.7 GHz to 32 GHz, the CHSIW exhibits outstanding performance on curved surfaces, with measured average attenuation constants of 1.89 Np m−1 (16.42 dB m−1) and 1.95 Np m−1 (16.94 dB/m) for samples with radii of curvature of 166.8 mm and 125.1 mm, respectively. Beyond addressing technical challenges, the CHSIW presents a cost-effective and simplified fabrication process, positioning it as a breakthrough solution for diverse millimeter-wave applications, including future robotic and UAV communications. Furthermore, the proposed design and fabrication technique hold promise for the realization of conformal and free-form Hollow Substrate Integrated Waveguide (HSIW) devices in the future.

Laser wireless power transfer system design for lunar rover

In order to address the future power generation needs for scientific exploration of the lunar permanently shadowed regions, this paper proposes a laser wireless power transfer (LWPT) system from a power source at the illuminated rim of the crater to a photovoltaic laser receiver on a rover exploring inside the permanently shadowed region. To fill a gap between the conceptual design and an operational system, the required conditions were analyzed regarding the effects of beam alignment and shaping, wavelength-dependent conversion efficiency on the system level efficiency, and a ground-based prototype system was established. Electric–electric efficiency of 11.55% was measured at a ground transmission distance of 10 m. The study is complemented by discussing optimization analysis for subsequent research, can be more effective and employed in the future.