【作者】 周雯琪；

【导师】 何湘宁； 马皓；

【作者基本信息】 浙江大学 ， 电气工程， 2008， 博士

【摘要】 感应耦合电能传输技术(ICPT)作为一个崭新的研究领域,近年来开始受到广泛关注。在ICPT系统中,能量可以通过电磁场,由一个静止的原边电源传给一个或多个可以运动的副边负载,由于其不需要经过导线接触,避免了可能由于接触引起的隐患,如火花,接触不良等。同时也可以使接头和连接器等免于维护,不受天气等外界环境的影响。ICPT除了在一般便携式电子设备中能够提供更为方便快捷的充电方式,用于电动汽车的供电,在某些特殊场合,如水下、矿井等较为危险的环境中,也受到了特别的青睐。随着各个领域对非接触式电能传输越来越多的需求,感应电能传输技术也越来越成为研究热点。本文以松散耦合变压器的等效模型为基础,对感应耦合电能传输电路的基本特性及其参数设计方法进行了研究,主要包括以下几个方面的内容:1.建立松散耦合变压器模型在感应耦合电能传输系统中,变压器由于耦合不紧密,存在较大的漏感,耦合系数很低,其特性与常规变压器有较大不同。在常规变压器等效模型的基础上,本文建立了松散耦合变压器的模型,阐明了其两种模型的磁通及各电气参数间的等效关系,并基于该模型分析了耦合系数、负载、线圈电阻等对松散耦合变压器传输特性的影响。对变压器参数的几种测量方法和不同测量方法可能引起的误差给出了理论分析和实验研究结果,并以此给出不同测量方法的适用场合。2.感应耦合电能传输电路的多谐振补偿设计方法为了提高功率传输能力,通常在松散耦合的变压器两侧以并联或串联的电容作为补偿,构成谐振电路。本文详细分析了各种补偿形式,包括仅在变压器一侧进行补偿的单谐振补偿结构(含原边串联补偿、原边并联补偿、副边串联补偿、副边并联补偿),和在变压器两侧同时进行补偿的多谐振补偿结构(含原边串联副边串联补偿、原边串联副边并联补偿、原边并联副边串联补偿、原边并联副边并联补偿等),并着重对其功率因数、电压增益、电流增益等进行分析研究,提出多谐振补偿结构能有效提高电路的功率因数,从而减小电路元件的应力和输入电源的功率等级。基于对多谐振补偿的研究结果,本文提出了一种通用的基于功率因数的多谐振补偿设计方法,该方法能够对系统进行有效的补偿,使得系统在不同负载下均具有较高的功率因数。3.电流型感应耦合电能传输电路的稳态及小信号建模基于理论分析和实验研究,分别建立了线性负载和整流桥负载两种情况下的电流型推挽感应耦合电能传输电路稳态模型,并考虑了磁芯损耗的影响,为电流型感应耦合电能传输系统参数优化设计提供了理论依据。基于电流型推挽感应耦合电能传输电路在不同阶段的动态方程分析,给出各阶段的谐振频率表达式,并着重讨论了电路参数对各谐振频率的影响,得出了实现频率表达式简化的条件及其结果,并通过实验进行了验证。在以一般平均法得到的稳态方程基础上,给出了电路的小信号模型。4.非接触式充电平台的设计作为感应耦合电能传输电路的一种具体应用,本文最后通过仿真和实验研究设计了一台用于便携式电子设备的非接触式充电平台实验装置。该充电平台利用无磁芯的平面变压器实现非接触式的电能传输,提出一种基于有限元分析(FEA)仿真的非接触式充电平台原边线圈优化布局方法,从而可以实现充电平面上方磁场分布的基本均匀。并基于多个绕组的变压器模型,对充电平台为多个负载同时供电的情况进行了电路分析。提出一种基于最大化功率因数原则的,多负载非接触式充电平台电路的参数设计方法,使得系统可以在不同的负载数目情况下均具有较高的功率因数,同时保持每个负载上的电压基本不变。与其他方法相比,该设计方法有利于实现在同样功率情况下具有较小的电路元件的电压、电流应力,提高元器件利用率。更多还原

【Abstract】 As an emerging research field, Inductively Coupled Power Transfer (ICPT) technology has attracted wide spread attention recently. In ICPT system, power could be transferred from a stable primary source to one or more movable secondary loads through magnetic field. As no wires are needed to transfer power in the system, dangers from contact such as spark, non-reliable connect could be avoided. At the same time, connectors are maintenance free, and free from bad weather or other poor environmental conditions. Besides convenient charging for consumer electronic devices and electrical vehicles, ICPT can be widely used for charging in special conditions, such as underwater, mining wells, etc. As there are more and more demands of non-contact power transfer in various fields, ICPT technology has been a popular research project.The dissertation mainly focuses on the basic characteristics and the parameter design method of ICPT system based on the model of loosely coupled transformer, including following aspects:1. Modeling of loosely coupled transformerIn ICPT system, there are large leakage inductances in the transformer due to the non-compact coupling, which results in a fairly low coupling coefficient, and the characteristics are much different from conventional transformers. Loosely coupled transformer model is built in this dissertation based on conventional transformer models; the equivalence of flux and electrical parameters between leakage inductance model and mutual inductance model is clarified. Based on the built model, the effect of coupling coefficient, load resistance and wire resistance to the transformer voltage and current transfer characteristic is analyzed in detail. Theoretical analysis and experimental results are given to elaborate different measure methods of transformer parameters and to clarify the differences during measurement in each method. And suggestions on how to appropriately choose the measure method are given.2. Multi-resonant compensation design method of ICPTTo improve the power transfer capability, series or parallel capacitors are usually used in either side of the transformer as compensation, which can help to constitute resonant circuit. Different compensation topologies are discussed in detail, including single-resonant compensation, which compensate on only one side of the transformer (including primary series compensation, primary parallel compensation, secondary series compensation and secondary parallel compensation), and multi-resonant compensation, which compensate on both sides of the transformer (including primary series secondary series compensation, primary series secondary parallel compensation, primary parallel secondary series compensation and primary parallel secondary parallel compensation, etc.). Analyses are focused on the power factor, voltage gain and current gain in each topology; the results show that compared with single-resonant compensation, multi-resonant compensation can greatly improve the power factor. As a result, the circuit components and the power source can be selected at a lower power rate. According to the analysis, a general design method based on power factor is proposed to perform circuit parameter design, with which the system can be effectively compensated, and a high power factor can be achieved under different load condition.3. Steady state and small-signal model of a current source ICPT systemBased on theoretical and experiment analysis, steady state model of the linear and rectifier load is built, respectively. Core loss of the circuit is discussed briefly. An optimization principal for ICPT system parameter design is proposed. Resonant frequencies of different stages in this circuit are discussed in detail based on the analysis of dynamic circuit equations. Several simplification conditions are obtained, and experimental results verified the analysis. Small signal model of the circuit is given based on the steady state operation point obtained from general average method.4. Non-contact charging platform designAs a practical application of ICPT, a non-contact charging platform for portable electronic devices is built through simulations and experiments. The charging platform uses coreless planar transformer to realize non-contact power transfer. An optimized primary winding structure design technique is proposed by Ansoft FEA simulation. Based on multi-winding transformer model, circuit analysis of charging for multi-loads is presented. Finally a parameter design procedure in light of maximizing the power factor is proposed, by which the power factor can achieve a high value at different load numbers, and the voltage on each load remains constant. Compared with other methods, the proposed method can lower the voltage and current stress of circuit components at the same power rate, and help to achieve efficient components utilization.更多还原