电动汽车无线充电系统松耦合变压器补偿技术与优化设计

发布时间：2019-03-29 11:54

【摘要】：随着电动汽车产业的迅速发展,充电基础设施的建设成为电动汽车普及与推广的重要前提。无线充电具有安全、方便等优势,是电动汽车充电技术领域研究的热点,而松耦合变压器作为车外与车内能量非接触传输的纽带,是无线充电系统中的关键部分,因此,对松耦合变压器进行优化设计,并以提高传输效率为目的,研究其补偿技术,具有重要的意义与广泛的应用前景。本文针对电动汽车松耦合变压器存在的原副边耦合系数低的问题,建立变压器磁路模型,通过补偿方案提高变压器传输效率,并针对松耦合直流变压器(DC Transformer,DCT)进行系统设计,主要工作如下:本文首先研究变压器工作原理,建立变压器磁路模型,通过ANSOFT软件对缠绕方式、空气气隙、水平侧移方式仿真得到磁感线分布规律。结合磁力线分布规律,对磁通进行分块,得到磁路模型,推导出耦合系数与磁阻的关系式。通过“三参数测量方法”对松耦合变压器参数进行测量得到耦合系数与空气间隙与水平侧移的关系。接着研究松耦合变压器原副边补偿技术,将原边高频逆变电路和松耦合变压器看作一个整体,组成松耦合DCT,通过对DCT的补偿进行定量分析,得到了能量传输效率、开关角频率和补偿参数的关系。在此基础上,提出了优化的补偿方案,加入补偿后的DCT能够等效为LLC-DCT,从而实现软开关,减少了电压应力,进一步提高变压器的效率。最后,对DCT系统进行设计,具体从补偿参数、绕组匝比、变压器参数以及开环控制模块硬件四个方面进行设计,搭建DCT的仿真模型和实验原理样机对结果进行验证。仿真和实验结果表明:所设计的原副边串串补偿DCT和未加补偿的DCT相比,能够有效提高传输效率,并减少功率器件的电压应力,优化后的DCT传输效率提高了2.248%。
[Abstract]:With the rapid development of electric vehicle industry, the construction of charging infrastructure has become an important prerequisite for the popularization and promotion of electric vehicles. Wireless charging has the advantages of safety and convenience, which is a hot spot in the field of electric vehicle charging technology. The loose coupling transformer is the key part of the wireless charging system as a non-contact transmission link between the outside and inside of the vehicle. In order to improve the transmission efficiency, the compensation technology of loosely coupled transformer is studied in order to improve the transmission efficiency. It is of great significance and wide application prospect to carry out the optimization design of the loosely coupled transformer. In this paper, the magnetic circuit model of transformer is established to improve the transmission efficiency of transformer through compensation scheme, aiming at the problem of low coupling coefficient of the original secondary side of the loose coupling transformer in electric vehicle, and aimed at the loose coupling DC transformer (DC Transformer,. DCT) carries on the system design, the main work is as follows: firstly, this paper studies the transformer working principle, establishes the transformer magnetic circuit model, through the ANSOFT software to the winding mode, the air gap, the horizontal side shift way simulation obtains the magnetic inductance line distribution rule. Combining with the distribution of magnetic force line, the magnetic flux is divided into blocks, and the magnetic circuit model is obtained. The relation between coupling coefficient and magnetoresistance is deduced. The relationship between coupling coefficient and air gap and horizontal lateral shift is obtained by measuring the parameters of loosely coupled transformer by "three-parameter measurement method". Secondly, the primary and secondary side compensation technology of loosely coupled transformer is studied. The primary high frequency inverter circuit and loose coupling transformer are regarded as a whole, and the loose coupling DCT, is composed of loose coupling transformer. The energy transmission efficiency is obtained by quantitatively analyzing the compensation of DCT. The relationship between switching angle frequency and compensation parameters. On the basis of this, an optimized compensation scheme is proposed. The compensation DCT can be equivalent to LLC-DCT, so as to realize soft switching, reduce voltage stress and further improve the efficiency of transformer. Finally, the DCT system is designed from four aspects: compensation parameters, winding turn ratio, transformer parameters and open-loop control module hardware. The simulation model and experimental principle prototype of DCT are built to verify the results. The simulation and experimental results show that compared with the uncompensated DCT, the original auxiliary side series compensation DCT can effectively improve the transmission efficiency, reduce the voltage stress of the power devices, and improve the transmission efficiency of the optimized DCT by 2.248%.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM910.6;TM714.3

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