【作者】 李然；

【导师】 李琳；

【作者基本信息】 华北电力大学(北京) ， 电力系统及其自动化， 2018， 博士

【摘要】 无线电能传输技术是电气工程领域的研究热点之一,在受电设备摆脱电线束缚提高设备移动灵活性,防止供电线产生电火花和井下水下设备供电方面具有广阔的应用前景。由于磁耦合谐振式无线电能传输技术具有传输效率高、负载功率大、传输距离远等特点,近年来受到了国内外学者的广泛关注。但由于该技术属于新兴技术,在模型的构建、电能传输机理和实验等方面还有许多尚未解决的问题。论文主要针对磁耦合谐振式无线电能传输系统模型的构建、不同拓扑结构的电能传输特性、电能与信号的同步传输以及空间磁场的分布特性等方面开展理论和实验研究,主要研究工作如下。针对当前磁耦合谐振式无线电能传输系统的两种主流的分析方法——耦合模理论和集总电路理论进行了详细的探讨,并分别采用这两种理论建立了系统模型。采用耦合模理论建立无损振荡和有损振荡的描述方程,得出电能传输的必要条件,即收发谐振器之间为强耦合并且其谐振频率一致。为了便于从电路结构上描述磁耦合谐振式无线电能传输系统,建立系统的集总电路模型作为耦合模模型的补充,根据谐振器形成的不同谐振结构,建立了系统四种拓扑结构的电路模型,详细给出了谐振器串联谐振时系统正向传输参数的计算方法,探讨了不同耦合状态下的电能传输特性。根据磁耦合谐振式无线电能传输系统的工作频段,并考虑谐振器的寄生参数,提出采用部分元等效电路方法建立系统的等效模型。将谐振器以匝为单位进行部分元划分,每个剖分单元由其自感和损耗电阻表示,剖分单元之间由互电感和互电容相关联。推导了模型中剖分单元的部分电感、部分电容和部分电阻的计算方法,采用改进的节点电压法对模型进行求解,实现对谐振器固有谐振频率和系统电能传输能力的预测。设计了两种谐振器结构并完成了相关实验,同时在电磁场仿真软件FEKO中对实体结构进行仿真计算,结果表明了部分元建模方法的有效性。针对二线圈磁耦合谐振式无线电能传输系统的不同馈电方式,分析了其电能传输特性。电能传输线圈采用中点馈电和端点馈电时形成两种不同的谐振结构,对应的电能传输系统具有不同的拓扑结构,从集总等效电路出发,分析不同馈电方式时系统电能传输能力和效率,得到中点馈电时系统具有较高的电能传输能力和效率。构建谐振器实体结构,同时进行部分元建模分析和实验验证,验证了理论分析的正确性。为了在磁耦合谐振式无线电能传输系统中同步传输信号,提出了一种双频谐振器的设计方法,由此种结构的谐振器构成的双频段磁耦合谐振式无线电能传输系统可分别利用其两个频段传输电能和信号。接收端同时接收到电能和信号,为了提取信号,并且不影响系统电能传输效率,提出采用陷波电路实现信号波与电能波的分离方法。设计了双频谐振器并构建了双频段磁耦合谐振式无线电能传输系统,建立等效模型计算系统的电能传输和信号传输特性,同时进行相关实验,结果证明该双频段磁耦合谐振式无线电能传输系统可在接收端有效地提取信号,并且不影响系统电能传输。采用部分元等效模型计算磁耦合谐振式无线电能传输系统的空间磁场分布。将系统看做磁准静态系统,由部分元等效模型计算各个剖分单元上的电流分布,进而计算各个剖分单元的空间磁场分布,然后采用叠加法得到系统周围空间的磁场分布。对比分析了系统谐振状态和失谐状态下的空间磁场分布,同时在FEKO仿真软件中进行验证,证明了该方法的有效性。更多还原

【Abstract】 Wireless power transfer(WPT)technology is a hot issue in electrical engineering.This technology has wide field of application with good prospects at getting rid of the shackles of wires powered device aiming to improve the mobility flexibility of the device,preventing spark and powering the underpit and underwater device.WPT technology via magnetic resonant coupling(MRC)has the characteristics of high transfer efficiency,high load power,and long distance,which has received wide attention by the scholars at home and abroad in the last few years.Howerever,being an emerging approach,there are more unsolved questions about modeling,power transfer mechanism and experimental researches.This paper aims at establishing model for MRC-WPT system,analyzing the power transfer characteristics for systems with different topologies,transmitting power and signal synchronously,and researching the magnetic field distribution of the system.The main research works are as follows:Coupled mode theory and equivalent circuit model are the main modeling methods of MRC-WPT system,and detailed discussions about the two modeling method are carried out.In this paper,models for MRC-WPT system by coupled mode theory and equivalent circuit theory are buildt respectively.The lossless and loss system are analyzed by coupled mode model,and the necessary conditions of energy exchange and tansfer are obtained.More precisely,energy transfer is realized as the resonators is under strong coupling and resonant frequencies of the resonators are equal.Lumped circuit model of MRC-WPT system is built as supplement of coupled mode model to describe the system by circuit struture.According to the resonant structure of the resonator,this paper establishes four kinds of topology model for MRC-WPT system,and analyzes the caculation method of the system scattering parameter in detail to research power transfer characteistic of different coupling states while the resonator is as series resonance.According to the operating frequency band of the MRC-WPT system,and considering the parasitic parameter,the modeling method of partial element equivalent circuit(PEEC)is proposed.The segment unit of PEEC is one turn of the resonator,and each unit is modeled by its self-inductance and AC resistance.The links between different units are built by the turn-to-turn mutual inductances and parasitic capacitances.The partial inductance,partial capacitance and partial resistance of PEEC network are calculated by numerical integrals and analytical formulas,and PEEC model of MRC-WPT sysem is solved by the modified nodal analysis in frequency domain.This modeling method can predict resonant frequency and power transfer capability for MRC-WPT system.Two types of MRC-WPT resonators are designed in our laboratory and some experimental measurements are implemented,and the relevant parameters of the practical system are also simulated by FEKO.The expermental and simulated results show the effectiveness of PEEC modeling method.Aiming at the different feed modes,this paper analyzes the performances of MRC-WPT system with two-coil structure.As the resonator is fed at center or end,the resonator is as two diffenent resonant strutures,and the corresponding MRC-WPT systems are with different topology structures.The lumped equivalent circuits of the two-coil systems with two feed modes are built to analyze the power transfer capability and system efficiency,and the results show that the two-coil system gets high power transfer capability and efficiency as the resonator is fed at certer.The practical resonator and system were design,and PEEC calculation and experiments are implemented on the practical system.The results verify the correctness of theoretical analysis.In order to implement synchronous transfer of power and data in MRC-WPT system with one set of resonator,a design method of dual-band resonator is proposed.MRC-WPT system constituted by this dual-band resonator can provide two channels with different frequencies for power transfer and signal transmission.Power wave and signal wave are both received at receiving side,so notch circuit is proposed to separate signal wave and power wave and the power transfer is not influenced.Dual-band resonator and dual-band system are designed in this paper,equivalent model of the dual-band system is established to calculate the power transfer characteristic and signal transmission characteristic,and the relevant experiments are implemented meanwhile.The calculated and experimental results show that the dual-band system can receive signal effectively without affecting the power transfer.PEEC model is used to calculate the magnetic field of MRC-WPT system.The current distributions of all units are calculated by PEEC model,so the magnetic field distributions of all units can be calculated,then the magnetic field distributions of MRC-WPT system are obtained by superposition.The magnetic field distributions of MRC-WPT system are analyzed at resonant state and detuning state,and the magnetic field distributions are also simulated by FEKO,which verifies the effectiveness of the calculated method.更多还原