磁耦合谐振式无线电能传输系统建模与分析

磁耦合谐振式无线电能传输技术具有传输距离中等、传输效率高、能穿过非磁导性障碍物传输电能等优点,使其有望取代电池为物联网中的传感器节点无线供电。本文通过研究磁耦合谐振式无线电能传输机理,构建了传输系统的集总参数电路模型,对各模型参数进行了理论计算,并根据模型对不同传输距离下系统的传输效率与负载功率进行了分析,得出了不同耦合状态下系统获得最大负载功率的条件。     

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.     

磁耦合谐振串串式无线电能传输研究

磁耦合谐振式无线电能传输技术作为一种新兴无线能量传输技术,具有传输距离远、传输功率大、传输效率高、无辐射性和穿透性等优点。基于等效电路模型建立了磁耦合谐振式无线输电串串式拓扑模型,给出了输出功率、传输效率的计算方法,搭建了磁耦合谐振式无线电能传输试验平台,通过仿真与实验,分析了线圈距离、工作频率、负载电阻以及系统谐振对输出功率、传输效率的作用规律,为磁耦合谐振式无线电能传输系统的设计及参数优化提供了理论依据。     

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.     

无线电能传输中电谐振耦合机理分析

针对在无线电能传输分析中多以磁耦合谐振技术为主,缺少对电谐振耦合机理的分析这一问题,文中根据对称性原理,提出无线电能传输机理中应该包含磁谐振耦合和电谐振耦合两种谐振耦合机理,并从电路的对偶性角度出发,给出了电谐振耦合电路模型并推导出传输功率增益的理论公式。通过对电路参数的分析得出了传输功率增益的变化规律,为无线电能传输系统的设计提供了参考。     

基于SG3525的谐振式DC-DC无线电能传输模块的设计

磁耦合谐振式无线电能传输具有传输距离远、效率大、功率高等特点,还能穿透障碍物传输,该技术的研究对于无线充电技术的发展具有重要意义。文章设计制作的磁耦合谐振式电能传输模块以SG3525芯片产生PWM控制的高频功率源,经物理上隔开的发射线圈与接收线圈实现无线能量的传输,接收电路再经整流和滤波,实现了DC-DC的无线电能传输。经测试,SG3525供电电压为15V且发射线圈与接收线圈间距为10厘米时,输出功率约为4W,传输效率约为46%;线圈间距最大为50cm时,仍可点亮LED灯。     

磁耦合谐振式无线电能传输技术新进展

随着科学技术的发展和进步,近些年来,无线电传输技术已经受到广泛的关注和应用。磁耦合谐振式无线电能传输是一种新型的无线电能传输方式,传输的距离为几十厘米,传输的效率高达85%以上。磁耦合谐振式无线电能传输技术集合多种学科技术,达到安全、高效和便捷的电能传输过程。本文通过对无线电能传输技术的介绍,对磁耦合谐共振式无线电能传输技术进行简述。     

基于磁耦合谐振的动态无线传能系统设计

利用磁场在谐振线圈的共振耦合,磁耦合谐振式无线传能技术可以提供中等距离和功率的传输。当收发回路耦合系数较高且处于过耦合状态时,系统发生频率分裂现象,激励源频率成为制约传输功率的重要因素。由于收发线圈之间的距离具有随机性的特点,负载接收功率和额定功率难以恰好匹配。为了提高能量的传输功率及其稳定性,经过系统建模和理论分析发现,可以采用罗耶振荡电路对最大传输功率频点进行实时跟踪,基于反馈链路的功率控制也是实现功率匹配的有效手段。实验结果表明,采用罗耶振荡器和前端升压电路顺利完成无线传能系统的频率跟踪和功率控制,实现在12 cm距离内5 W功率的稳定传输,从而验证了能量传输过程中优化控制的有效性。     

Selection of maximum power transfer region for resonant inductively coupled wireless charging system

In order to uphold the maximum power transfer in a resonant inductively coupled wireless power transfer system, an operating region has been proposed based on the coupling coefficient, frequency and electric load. The effectiveness of the proposed condition has been examined both theoretically and experimentally. The obtained results are in well agreement with each other. It has been seen that the operating frequency region is different for different electric loads corresponding to the coupling coefficient between the transmitter and receiver coils of the resonant inductive link. The operating frequency region shifts to lower frequency side for lower value of electric load at larger value of coupling coefficient even maintaining the optimum power transfer. The obtained knowledge reveals the design modus operandi through which an effective wireless charging system can be intended not only for low power device applications but also for high power EV charging.     

Analysis and design-optimization of LCC resonant inverter forhigh-frequency AC distributed power system

The analysis and design of an LCC resonant inverter for a 20 kHz AC distributed power system are presented. Several resonant converter topologies are assessed to determine their suitability for high efficiency power conversion, under resistive and reactive loads. Two LCC-resonant inverter designs were implemented. One with all switches operating with zero voltage switching (ZVS), and another with two switches operating with ZVS and two switches with zero current switching (ZCS). The experimental results are presented along with a performance comparison of the two versions     

用于激光无线能量传输的MPPT集成仿真系统

在激光无线能量传输（LWPT）中,传能激光波长、光功率和光电池温度对光电池的输出特性有显著影响,最大功率跟踪（MPPT）技术可解决上述等因素造成的功率失配问题,提升系统的DC-DC效率。构建了针对LWPT的MPPT集成仿真系统,耦合了波长、光功率和温度对GaAs光电池输出特性的综合影响,可以同时分析光电池在功率匹配、功率失配和MPPT调制等多种条件下的输出特性。基于该仿真系统,研究了光电池在不同波长、光功率和温度条件下的物理规律。波长增大时,在850 nm左右转换效率η_max达到最大值为50%,波长继续增大,光子能量小于GaAs禁带宽度导致η_max迅速下降。功率增大时,η_max基本不变,最大功率匹配电阻R_Lmax减小。温度升高时,η_max和R_Lmax均持续下降。此外,研究了光电池在功率失配时的输出特性,此时光电池的转换效率对比功率匹配时均有不同程度的下降。根据光电池的输出特性在仿真系统设计了MPPT电路,利用时间扰动算法进行最大功率跟踪。光电池在MPPT系统调制后均可工作在功率匹配时的最大功率点,且光电池能源利用率达到99.93%。研究结果对用于激光输能有重要指导意义。     

High power mode conversion for linearly polarized HE11 hybrid mode output

Efficient plasma heating by ECR-wave irradiation requires axisymmetric, narrow, pencil-like millimetre wave beams with well-defined polarization. The linearly polarized gaussian-like HE₁₁, mode satisfies these conditions best. This quasi-optical hybrid mode can be generated from TE_0n gyrotron mode compositions by the two multi-step mode conversion processes: (1) ΣTE_0n to TE₀₁ to TE₁₁ to HE₁₁ or (2) ΣTE_0n to TE₀₁ to TM₁₁ to HE₁₁. The first scheme has the advantage that the converters can all be made without bends, allowing an arbitrary choice and fast change of the polarization plane. The second scheme does not exhibit this advantage, but it is more suitable at very high frequencies (e.g. 140GHz) because efficient TE₀₁-to-TM₁₁ transducers can be made considerably shorter than serpentine TE₀₁-to-TE₁₁ mode converters. This paper presents computations on mode converter systems of the first type at 70GHz and of both types at 140GHz (ID = 27 · 8 mm for 200kW transmission lines). The structure of wall perturbations (phase-matched superposition of 2 or 3 different geometrical periods) in the rippled wall mode converters and the curvature distribution in the bent, smooth-walled TE₀₁-to-TM₁₁ mode transducer were optimized by numerically solving the corresponding coupled-mode differential equations. Computer-aided optimization of circumferentially corrugated mode converters has been achieved with a scattering matrix code employing the modal field expansion technique (modular analysis concept (MAC)). In all cases the predicted overall efficiency of the complete mode converter system from ΣTE_0n (predominantly TE₀₂ at 70GHz or TE₀₃ at 140GHz) to HE₁₁ in the desired polarization is approximately 95% at 70GHz and 92% at 140GHz (ohmic attenuation is included). Low-power measurements on the conversion efficiency of the various mode transducers are in excellent agreement with the predicted values. High-power operation has been successfully demonstrated using a pulsed 70GHz gyrotron (200kW, 100ms).     

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.     

基于谐振式功放的电能传输系统设计

由于谐振式电能传输系统的整体性能受功率源所约束,文中提出以最佳频率为参数,通过综合分析后选择功放作为功率源,利用谐振式电能传输子系统作为功放的谐振滤波,构成功放谐振式电能传输融合系统,不仅简化了电路,还提高了整个系统的效率。文中对融合系统进行了理论分析,导出了主要参量和系统效率的计算公式,给出了融合系统各部分的参数计算公式,设计、制作并测试了原型系统。其整体系统效率达到64.1%,传输功率达到2.46W,传输距离为0.14米,工作频率1.578MHz,这为小型化系统的完整设计提供了有益参考。     

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.     

Investigating an LCL load resonant inverter for inductive power transfer applications

A inductor/capacitor/inductor load resonant inverter is investigated for inductive power transfer applications. The inverter uses a variable frequency controller and operates in discontinuous current mode. The steady state operation of this system is determined by a power flow balance between the inverter and the resonant tank. The results are used to design a system to achieve maximum power transfer.     

Maximization of the output power in resonant frequency multipliers with ideal abrupt junction diodes

A general procedure is described to maximize the output power from a lossless abrupt-junction multi-idler varactor multiplier under resonant conditions. The approach is illustrated by several examples. It forms the basis of an iterative technique for optimizing the design of multipliers having lossy and nonabrupt junction varactors.