【作者】 王玉山；

【导师】 宋保维；

【作者基本信息】 西北工业大学 ， 兵器科学与技术， 2021， 博士

【摘要】 海洋蕴藏着丰富的资源,是未来世界各国争夺的主战场之一。水下航行器是探测与开发海洋的重要工具,但能源补给问题限制了水下航行器的工作效率。利用无线电能传输技术通过海底基站对水下航行器进行电能补给能够显著增强航行器的续航能力,提高工作效率,具有很好的应用前景。本文以磁谐振式无线电能传输(Magnetic Resonance Wireless Power Transfer,MRWPT)技术为研究对象,研究屏蔽结构在水下MRWPT系统中对传输性能的作用。本文首先对该技术的补偿电路和电磁特性进行了分析,在此基础上建立了水下MRWPT系统的等效电路模型,并研究了MRWPT系统的屏蔽结构,最后根据使用场景设计并验证了三种具有涡流抑制作用的耦合器结构,取得了良好的传输效果。本文的研究贡献主要包含以下四个方面:(1)MRWPT系统补偿电路研究。基于等效电路模型,本文首先研究了几种基础补偿方式的元器件数值计算方法及回路特性。结果表明串联补偿(S)和T型补偿时的谐振状态与负载或反射阻抗无关。基于此点,本文后续对比分析了S-S型、S-LCC型、LCC-S型和LCC-LCC型四种补偿结构。结果表明LCC-LCC型补偿结构具有恒流输出特性,可实现短路保护,且具有良好的调节能力,满足安全条件和后续研究中对线圈电流可调性的要求。(2)MRWPT系统电磁特性研究与建立水下MRWPT系统的电路模型。本文从两种边界条件的电磁场计算入手,推导了MRWPT系统周围电磁场的计算公式,得到了电磁场分布与电流模值比、频率之间的关系。基于电磁场计算,本文得到了涡流损耗、线圈电感、线圈间互感的计算方法,并通过对比海水介质中与空气介质中线圈所激发电磁场的不同,量化了涡流对耦合器阻抗和互感的影响,以此为基础建立水下MRWPT系统的等效电路模型,并提出了相位控制法来抑制涡流损耗。通过搭建试验装置对分析结果进行验证,试验结果表明该模型能够较好地反映水下MRWPT系统的传输特性,相位控制法具有良好的涡流抑制效果。(3)MRWPT系统屏蔽结构与水下系统涡损抑制研究。介质屏蔽的研究结果表明介质屏蔽中铝合金板的电磁屏蔽效果最好,但会导致线圈的电阻剧增且电感骤降;磁材料屏蔽效果不理想,但可以大幅增加互感系数;组合屏蔽方法不仅能有效减弱离散电磁场,还能使传输系统保持较高的传输效率。两种线圈屏蔽方法均会降低系统的等效互感,其中反向串联线圈的屏蔽效果可通过改变屏蔽线圈匝数来调节,而感应线圈的屏蔽效果可以通过在屏蔽回路串联阻抗进行调节。试验结果表明:屏蔽线圈匝数相同时,感应线圈屏蔽方法能降低65%左右的离散电磁场,强于反向串联线圈的40%,且使用感应线圈时系统的传输效率高于使用反向串联线圈。水下MRWPT系统涡损抑制研究结果表明,均匀场抑制法和屏蔽结构均能有效降低水下系统的涡流损耗,研究结果为后续实验研究奠定了基础。(4)基于屏蔽结构的水下MRWPT系统实验研究。涡流损耗在水下MRWPT系统中无法避免,通过屏蔽结构或补偿控制可降低海水中的离散电磁场。本文首先研究了一种三线圈结构的MRWPT系统,涡流损耗分析和等效电路研究均表明该结构具有良好的涡流损耗抑制作用,试验结果表明该三线圈结构使系统最高传输效率提高约5%。而后分别针对坐落式和环套式两种对接场景提出了相应的涡流损耗抑制方法。试验结果表明屏蔽线圈在谐振频率较高、涡流损耗比较严重的工况下具有良好的表现。当组合屏蔽耦合器与相位控制法结合使用时,系统的DC-DC传输效率可提高2.3%。航行器搭载试验和海洋环境试验表明,本文设计的环套式MRWPT系统能够稳定以输出功率1000W、传输效率87.5%进行电能传输。综上所述,本文对MRWPT系统的补偿电路、电磁特性及屏蔽结构进行了研究,建立并验证了水下MRWPT系统的电路模型,实验研究了屏蔽方法在抑制涡流损耗中的应用,得到了一系列研究结果,为MRWPT系统在水下环境中的应用提供了理论和技术支持,同时能够为解决其他工程问题提供一定参考。更多还原

【Abstract】 Oceans are rich in resources,which will be one of the main battlefields for in the future.Underwater vehicle is an important tool for ocean exploration and development,but the energy problem limits its efficiency.Wireless power transmission technology can be used to supply power to underwater vehicles from submarine base station and this method can significantly increase vehicle endurance,which has a good application prospect.In this dissertation,magnetic resonance wireless power transfer technology(MRWPT)has been studied,and the effect of shielding structure on transmission characteristics of underwater MRWPT system is studied.This dissertation first analyzes the compensation circuit and electromagnetic characteristics of MRWPT systems.Then the equivalent circuit model of the underwater MRWPT system is present,and the shielding structure is studied.Finally,according to the application scene,three kinds of coupler structures with eddy current suppression are designed and experimentally verified,and good transmission results are achieved.(1)Compensation circuits of MRWPT systems are studied.Based on the equivalent circuit model,this dissertation provides the numerical calculation methods and circuit characteristics of several basic compensation methods.The results show that the resonant state of series compensation(S)and T-type compensation is independent of the load or the reflection resistance.Therefore,S-S,S-LCC,LCC-S and LCC-LCC compensation structures are analyzed and results show that LCC-LCC compensation can keep the output current constant,and it preforms well in realizing short-circuit protection and adjustable ability,which can meet the safety conditions and the adjustable requirements of coil current in subsequent research.(2)The electromagnetic characteristics of MRWPT systems are studied and the circuit model of underwater MRWPT systems is established.In this dissertation,starting from the electromagnetic field calculation of two kinds of boundary conditions,the calculation formula of the electromagnetic field around MRWPT systems is derived,and the relationship between electromagnetic field distribution and current value ratio,frequency is obtained.Based on this,the calculation methods of eddy current loss,coil inductance and mutual inductance between coils are obtained.The influence of eddy current on the impedance and mutual inductance of coupler is quantified by comparing the electromagnetic fields excited by coils in seawater and air.Based on this,the equivalent circuit model of underwater MRWPT system is established,and the phase control method is proposed to suppress the eddy current loss.The experimental results show that the model can better reflect the transmission characteristics of underwater MRWPT systems,and the phase control method has good eddy current suppression effect.(3)Shielding structure is studied for MRWPT system.The results show that the aluminum alloy plate has the best electromagnetic shielding effect,but it will lead to a sharp increase in the resistance and a sharp decrease in the inductance of the coil.The shielding effect of magnetic material is not ideal,but the mutual inductance can be greatly increased.The combined shielding method can not only effectively reduce electromagnetic field,but also make the transmission system maintain high transmission efficiency.The shielding effect of reverse series coils can be adjusted by changing the turns of the shielding coil,while the shielding effect of inductive coils can be adjusted by series impedance in shielding circuits.The experimental results show that: when the number of turns of the shielding coil is the same,inductive coils can reduce the stray electromagnetic field(SEF)by about 65%,which is stronger than 40% of reverse series coils,and the transmission efficiency of the system with inductive coils is higher than that the system with reverse series coils.The simulation results show that the shielding structure has good adaptability in the underwater environment.(4)Experimental study on underwater MRWPT systems with shielding structure.Eddy current loss can’t be avoided in underwater MRWPT systems.Shielding structure can limit the SEF in seawater.The three-coil structure MRWPT system is studied.The results of eddy current loss and equivalent circuit analysis show that the structure can restrain eddy current effect.The test results show that the three-coil structure can improve the transmission efficiency by 5%.Then,eddy current suppression methods are proposed respectively for the two docking scenarios of the seated type and the loop type.The shielding coil has good performance under the condition that the frequency is high.When the combined shielding coupler and the phase control method are used,the DC-DC transmission efficiency of the system can be improved by2.3%.The experimental results show that the loop type MRWPT system proposed in this paper can achieve stable output power 1000 W and the transmission efficiency 87.5%.This dissertation studies the compensation circuit,electromagnetic characteristics and shielding structure of MRWPT systems,establishes and verifies the circuit model of underwater MRWPT system,and studies the application of shielding method for restraining eddy current loss by experiment.It provides theoretical and technical support for the application of MRWPT system in the underwater environment.更多还原