Wireless Power Transfer System Research Articles

A Decoupled Modulation Strategy for Constant Voltage/Current Wireless Charging System Under High Coils Misalignment

ABSTRACTOutput fluctuation and lower transmission efficiency under load and mutual inductance variation are hot concerned in the wireless charging system for power batteries. In this paper, a decoupled tracking strategy is proposed to realize constant voltage (CV) or current (CC) output and high transmission efficiency. The circuit model of series–series compensation network is built, and corresponding transmission characteristics can be derived. First, the load and mutual inductance value can be estimated by measuring the primary electrical information, including the inverter output voltage, current, and the phase error between them. Then load‐independent voltage or current output characteristics under coils misalignment can be maintained by tracking the optimal switching frequency of inverter part. In addition, the value of output voltage or current can be adjusted flexibly for different operation occasions by the employment of pulse‐width modulation. As a result, the load‐independent output characteristics realization and output adjustment can be decoupled. Based on only the primary measuring information, the CV/CC output can be maintained via the proposed hybrid control strategy when the coils misalignment and load variation happen, increasing the robustness of whole wireless power transfer (WPT) system. Furthermore, the soft switching of all power switches in the inverter part can be realized to reduce the switching loss. Compared with previous research, the proposed wireless charging system has a higher power density and a simplified control strategy. Finally, an experimental platform with 60‐V charging voltage and 3.6‐A charging current is built to verify the feasibility of the proposed sys‐tem and control method.

A Bidirectional Simultaneous Wireless Power and Data Transfer System with Non-Contact Slip Ring

A Bidirectional Simultaneous Wireless Power and Data Transfer System with Non-Contact Slip Ring

A Design Review for Biomedical Wireless Power Transfer Systems with a Three-Coil Inductive Link through a Case Study for NICU Applications

This paper outlines a design approach for biomedical wireless power transfer systems with a focus on three-coil inductive links for neonatal intensive care unit applications. The relevant literature has been explored to support the design approach, equations, simulation results, and the process of experimental analysis. The paper begins with a brief overview of various power amplifier classes, followed by an in-depth examination of the most common power amplifiers used in biomedical wireless power transfer systems. Among the traditional linear and switching amplifier classes, class-D and class-E switching amplifiers are highlighted for their enhanced efficiency and straightforward implementation in biomedical contexts. The impact of load variation on these systems is also discussed. This paper then explores the basic concepts and essential equations governing inductive links, comparing two-coil and multi-coil configurations. In the following, the paper discusses foundational coil parameters and provides theoretical and experimental analysis of both two-coil and multi-coil inductive links through step-by-step measurement techniques using lab equipment and addressing the relevant challenges. Finally, a case study for neonatal intensive care unit applications is presented, showcasing a wireless power transfer system operating at 13.56 MHz for powering a wearable device on a patient lying on a mattress. An inductive link with a transmitter coil embedded in a mattress is designed to supply power to a load at distances ranging from 4 cm to 12 cm, simulating the mattress-to-chest distance of an infant. the experimental results of a three-coil inductive link equipped with a Class-E power amplifier are reported, demonstrating power transfer efficiency ranging from 75% to 25% and power delivery to a 500 Ω-load varying from 340 mW to 25 mW over various distances.

Analysis of Control Strategy Based on P&G Algorithm for the Switching Component of Wireless Solar Power Transfer

Previous researchers have studied wireless power transfer (WPT), while the current study focused on converting DC voltage to AC voltage on the transmitting coil and transferring it to the receiving coil. Previous studies did not discuss the control technique to drive the switching component on the converter circuit, especially the change controller in DC voltage and current affecting the WPT performance. This paper discussed a control strategy based on the P&O algorithm for driving MOSFETs on the half H-bridge inverter of a wireless solar power transfer (WSPT) system. This system is constructed by PV modules as the main DC voltage source, a control strategy based on the perturb and observe (P&O) algorithm, a half H-bridge inverter, and a transmitting and receiving circuit. The WSPT system was modelled using MATLAB SIMULINK with various solar irradiance, and its performance was assessed. The results show that the change in the total output voltage and power of PV modules can be controlled by the P&O algorithm as the signal input of the PWM generator applied to drive the MOSFETs. There are no transient values of voltage waveform on the transmitting and receiving circuit when the transient total output voltage of PV modules occurs. It indicates that the P&O algorithm can effectively manage the PWM generator for its input signal, including the total output voltage and current produced by PV modules.

Asymmetrical Coils for High Efficiency Wireless Power Transfer System Under Various Angular Misalignments

Asymmetrical Coils for High Efficiency Wireless Power Transfer System Under Various Angular Misalignments

Optimization of Coreless PCB Coils Based on a Modified Taguchi Tuning Method for WPT of Pedelec

The printed circuit board (PCB) winding coil offers advantages such as small size, high precision, high repeatability, and low cost, making it conducive to the miniaturization of electronic equipment and a popular choice in wireless power transmission systems. This paper aims to clarify the correlation between induction parameters and inductive capabilities using the orthogonal array of the modified Taguchi method for Pedelec applications. The conventional Taguchi method typically achieves only local optimization; however, this paper considers practical application conditions and combines experimental data to establish the initial values of the orthogonal array, thereby achieving global optimization. Additionally, the tuning process of the Taguchi method replaces physical experiments with simulations, enhancing optimization speed and reducing hardware implementation costs. The performance index for the proposed modified Taguchi tuning method is selected as a combination of the quality factor (Q) and coupling coefficient (k) to minimize AC resistance and improve system efficiency. To validate the proposed method, the designed coils were implemented and tested in a WPT system based on S–S compensation with a half-bridge topology. The experimental results demonstrate that the optimized PCB coil parameters derived from the proposed tuning method accurately validate the method’s effectiveness and accuracy. From the measured results with the proposed modified tuning method, the system efficiency is increased by 43.87% and the system transmitting power is increased by 28.51%.

Analysis and Design of a 6.78 M Wireless Power Transfer System With Strong Misalignment Tolerance Based on Simplified Impedance Trajectory Tracing

Analysis and Design of a 6.78 M Wireless Power Transfer System With Strong Misalignment Tolerance Based on Simplified Impedance Trajectory Tracing

Mutual Inductance Calculation of Rectangular Coils at Arbitrary Position With Bilateral Finite Magnetic Shields in Wireless Power Transfer Systems

Mutual Inductance Calculation of Rectangular Coils at Arbitrary Position With Bilateral Finite Magnetic Shields in Wireless Power Transfer Systems

Research on parameter deviation modelling of dual LCC wireless power transfer system

Abstract In this paper, parameter deviation modelling analysis is performed based on the dual LCC compensation network of wireless power transfer (WPT) system. Firstly, the mutual inductive coupling model of the dual LCC compensation circuit is derived based on the fundamental wave analysis method; secondly, the parameter deviation is introduced into the circuit model for the errors existing in the inductive and capacitive components of the compensation network circuit of the actual wireless charging system, and the relation between the deviation and the amplitude of the branch currents, the phase angle and the output characteristics of system are obtained through the establishment of derivation model and the resistive deviation correction term is introduced; finally, the parameter deviation is verified through the simulation. The establishment of parameter deviation model increases the accuracy of the whole circuit model and provides the theoretical basis to reduce the negative influence of parameter deviation on transmission characteristics. The value of parameter deviation can be inverted through the phase angle, thus providing a basis for adjusting the resonant state of the compensation circuit.

Feedback Control-Free Dynamic Wireless Power Transfer System for AGVs

Feedback Control-Free Dynamic Wireless Power Transfer System for AGVs

High Power Density Self-Resonant Coupler for Flexible Surface Wireless Power Transfer System With Nanocrystalline Ribbon

High Power Density Self-Resonant Coupler for Flexible Surface Wireless Power Transfer System With Nanocrystalline Ribbon

Adaptive Tube-Based Model Predictive Control for the Receiving-Side DC–DC of Dynamic Wireless Power Transfer System

Adaptive Tube-Based Model Predictive Control for the Receiving-Side DC–DC of Dynamic Wireless Power Transfer System

Output Power Control Strategy for Omnidirectional Wireless Power Transfer System Based on Maximum Mutual Inductance Information Estimation

Output Power Control Strategy for Omnidirectional Wireless Power Transfer System Based on Maximum Mutual Inductance Information Estimation

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.