一种无线电能传输系统设计

本文针对基于E类放大器的磁耦合谐振式无线电能传输系统,根据电路互感理论建立系统耦合模型,详细推导了系统传输功率和传输效率的表达式;为了满足1MHz驱动的要求,提出了用高速大功率三极管推挽方式设计高频驱动的方法。在此基础上,成功设计并搭建无线电能传输系统,经实验证明,该设计最大传输功率15W,传输距离20cm,对无线电能传输中E类放大器的方法进行验证。     

无线电能传输中的问题探究

在日新月异的21世纪,电的应用也越发广阔,而无线电能传输的发展前景也越发光明。关于磁耦合谐振式的无线方面的电能传输所遇到的问题也日益需要解决。此研究以小功率的谐振式为背景,运用BTL来提高电源的利用率,在中频段使传输距离明显提高。与此同时,线圈的材质,品质因素等都有不同程度的影响。     

超声耦合无线电能传输用发射换能器优化设计

针对超声耦合无线电能传输系统研究的需要,对水下超声耦合无线电能传输系统发射换能器进行选型,确定换能器类型及工作频率。基于夹心式纵振压电换能器一维设计理论对发射换能器进行优化设计,在深入分析圆锥形前盖板延展系数对换能器振速比和等效机电耦合系数影响的基础上,选取的延展系数能同时兼顾换能器振速比和等效机电耦合系数均为较优值,并据此进一步确定换能器全部结构尺寸。实际测试结果表明,试制的发射换能器实际谐振频率为38.552 kHz,等效机电耦合系数为0.149,满足实际需要。     

无线电能传输装置设计

自从美国麻省理工学院于2007年发表其研究成果后,磁耦合谐振式无线电能传输技术就成了研究热点问题。本文分析了磁耦合谐振式无线电能传输技术的基本结构和工作原理。并基于软开关技术设计了一套无线电能传输装置。无线电能传输装置的电能损耗主要是发射线圈的驱动发热以及两线圈的传输损耗,软开关技术主要就是为了减小发射线圈的驱动部分的损耗,以达到提高传输效率的目的。     

无线电能传输磁耦合系统综述

综述了无线电能传输系统的关键部件——磁耦合系统的工作原理和特点及优化方法.结合目前磁耦合元件的研究现状和问题,探讨了磁耦合元件的关键技术、发展趋势和研究方向.     

E类变换器高频无线电能传输平台设计

本文以高频低功率下的谐振式无线电能传输作为电力电子教学实训案例,阐述了实训案例与电力电子教学内容的联系。通过实训,使学生加深对无线电能传输的电路拓扑、平面PCB线圈设计、硬件模块的理解。通过应用新型半导体材料GaN器件作为开关管,完成基于双E类DC-DC变换器的6.78MHz无线电能传输平台的实物搭建和测试,使学生具备初步的电路设计、分析与测试的能力,从而在教学上做到理论与实践相互结合。     

试论无线电能传输系统中传输功率和效率的影响因素

随着全球各国科学技术水平的不断发展和提高,国内外的专家和相关工作人员开始研究开发如何利用无线技术进行电能的传输。如果这项技术研究成功,将会促进科学技术的进一步发展。但在目前该技术推广的过程中,其所能够使用的电磁环境变得越来越复杂。文章针对影响无线电能传输系统中传输功率和效率的各种因素进行分析和探讨,希望为我国相关工作人员在这方面的研究提供一些具有参考性的资料。     

关于磁耦合谐振式无线电能传输分析

磁耦合谐振式是一种无线电能传输系统,可以最大程度使无线电能传输技术发挥出来。磁耦合谐振式是利用空间线圈感应原理和等效电路分析原理,能够更好地分析出电压频率曲线以及电能传输情况。此外,根据空间分配原理,合理摆放空间线圈,分析出空心线圈数值与方向的关系,提出无线电能过耦合、临界耦合和欠耦合3种状态。文章以有关实验为基础,与其他实验结果进行比对,具体得出无线传输电能的现实性状态,并且提出有关建议。     

基于磁耦合谐振的无线电能传输装置

在基于耦合谐振技术上,设计一种无线电能传输装置,采用软件对所设计的耦合谐振电路进行了建模与仿真,在此基础上实际制作了无线电能传输装置,实测效果良好.该设计方法简洁实用,但从效率角度考虑,有进一步改进的空间.     

Design of auto-tuning capacitive power transfer system for wireless power transfer

This paper presents the design of capacitive wireless power transfer systems based on a Class-E inverter approach. The main reason for adopting the Class-E inverter approach is because of its high efficiency, theoretically 100%. However, the operation of a Class-E inverter is highly sensitive to its circuit’s parameters. In a typical capacitive wireless power transfer application, the capacitive coupling distance between plates is subject to changes, and hence its power transfer efficiency is greatly affected if the Class-E inverter is properly tuned. This drawback motivates us to develop an auto frequency tuning algorithm for a Class-E inverter which maintains its power transfer efficiency in spite of the variations of capacitive coupling distances between plates and circuit’s parameters. Finally, simulation and experiment are carried out to verify the effectiveness of the auto frequency tuning algorithm.     

基于DE类功放的无线电能传输系统设计与分析

为了提高无线电能传输(WPT)的传输效率,提出了基于DE类功放的WPT系统。通过对WPT系统建立等效模型,得出了实现电路软开关的参数设计方法,在此基础上,利用拉普拉斯变换对DE类功放的动态过程建立了复频域模型,分析了耦合线圈距离变化对WPT系统的参数和性能的影响。最后利用PSpice仿真,得到所设计系统的最大传输效率为95.1%,功率为8.9 W,验证了理论分析和设计方法的正确性。     

Dynamic wireless power transfer in the presence of reflecting walls

Analog Integrated Circuits and Signal Processing - This paper investigates wireless power transmission (WPT) system efficiency of antenna arrays in free space and in fully enclosed boxes with...     

Retrodirective wireless power transfer for short and long range applications

Analog Integrated Circuits and Signal Processing - This paper applies the phase conjugation method which is equivalent to time reversal in the time, to wireless power transfer using two different...     

High-efficiency resonant coupled wireless power transfer via tunable impedance matching

For magnetic resonant coupled wireless power transfer (WPT), the axial movement of near-field coupled coils adversely degrades the power transfer efficiency (PTE) of the system and often creates sub-resonance. This paper presents a tunable impedance matching technique based on optimum coupling tuning to enhance the efficiency of resonant coupled WPT system. The optimum power transfer model is analysed from equivalent circuit model via reflected load principle, and the adequate matching are achieved through the optimum tuning of coupling coefficients at both the transmitting and receiving end of the system. Both simulations and experiments are performed to evaluate the theoretical model of the proposed matching technique, and results in a PTE over 80% at close coil proximity without shifting the original resonant frequency. Compared to the fixed coupled WPT, the extracted efficiency shows 15.1% and 19.9% improvements at the centre-to-centre misalignment of 10 and 70 cm, respectively. Applying this technique, the extracted S₂₁ parameter shows more than 10 dB improvements at both strong and weak couplings. Through the developed model, the optimum coupling tuning also significantly improves the performance over matching techniques using frequency tracking and tunable matching circuits.     

Time-modulated multi-tone antenna array for wireless information and power transfer

This paper aims to design a multi-tone radiator exploiting harmonic radiation characteristic of time-modulated antenna array for wireless information and power transmission (WIPT) and multi-operational WIPT receiver. The time-modulated linear antenna array (TMLAA) radiating simultaneously at modulating and harmonic frequencies separated in multiple switching periods is utilized as a multi-tone radiating system. TMLAA with suitable power in harmonic bands generates multi-tone radiation by employing an optimized switching sequence. The ON and OFF time instants of the TMLAA are optimized to suppress sidelobe level and enhance sideband level. A population-based optimization algorithm, teaching learning based optimization (TLBO), is employed to optimize the ON and OFF instants of the TMLAA to suppress sidelobe level and enhance sideband level. TLBO is utilized for a 16-element TMLAA with minimizing cost function to achieve the above objectives. The 16-element TMLAA with optimized switching radiates multi-tone beams with a minimum of 5 dB peak power difference exploited as WIPT. The purpose of multi-operation is accomplished by utilizing the Wilkinson power divider in the receiver system; its power dividing capability is analyzed using applied wave research (AWR). A voltage doubler type rectifier is modeled for DC generation and is tested using AWR. The DC generating capability is tested for fixed power available at various frequencies, and the fixed desired frequency with various available power levels is tested. The results show that the designed circuitry provides a maximum of 80% power conversion efficiency (PCE).     

非铁磁性介质中的磁谐振无线传能系统仿真

理论上磁谐振无线能量传输可以做到很高的效率,然而在实际情况下由于各种各样介质的影响,实测效率与理论值难以保持良好的一致性。为了解决实测效率与理论效率偏差较大的问题,提出了基于等效电路模型的非铁磁性介质中的磁谐振无线能量传输系统。从计算与仿真角度分析了不同介质的对线圈阻抗与谐振频率的影响,且计算与仿真结果吻合良好。提出了介质中高效率系统的设计步骤,优化后仿真结果表明可以提高30%以上的效率。     

Optimization of wireless information and power transfer in multiuser OFDM systems

Simultaneous wireless information and power transfer (SWIPT), which belongs to energy harvesting techniques, is an important research topic. In existing literature, two SWIPT schemes, namely the time switching (TS) scheme and the power splitting (PS) scheme are adopted. For multiuser orthogonal frequency division multiple (OFDM) systems, this paper proposes a new SWIPT scheme named as the subcarrier sharing (SS) scheme. Resource allocation algorithms for the SS scheme are then proposed for maximizing the sum rate under the minimum harvested energy constraint. We show that the SS scheme outperforms the existing TS and the PS schemes.     

Simultaneous wireless information and power transfer with fixed and adaptive modulation

Activating Wireless Power Transfer (WPT) in Radio-Frequency (RF) to provide on-demand energy supply to widely deployed Internet of Everything devices is a key to the next-generation energy self-sustainable 6G network. However, Simultaneous Wireless Information and Power Transfer (SWIPT) in the same RF bands is challenging. The majority of previous studies compared SWIPT performance to Gaussian signaling with an infinite alphabet, which is impossible to implement in any realistic communication system. In contrast, we study the SWIPT system in a well-known Nakagami-m wireless fading channel using practical modulation techniques with finite alphabet. The attainable rate-energy-reliability tradeoff and the corresponding rationale are revealed for fixed modulation schemes. Furthermore, an adaptive modulation-based transceiver is provided for further expanding the attainable rate-energy-reliability region based on various SWIPT performances of different modulation schemes. The modulation switching thresholds and transmit power allocation at the SWIPT transmitter and the power splitting ratios at the SWIPT receiver are jointly optimized to maximize the attainable spectrum efficiency of wireless information transfer while satisfying the WPT requirement and the instantaneous and average BER constraints. Numerical results demonstrate the SWIPT performance of various fixed modulation schemes in different fading conditions. The advantage of the adaptive modulation-based SWIPT transceiver is validated.