改进型电动汽车无线充电磁耦合机构互操作性评价方法

Improved interoperability evaluation method for magnetic coupler of wireless EV charging

关键词:  电动汽车无线充电  磁耦合机构  互操作性  端口阻抗  失谐因子

Key words:  electric vehicle wireless charging  magnetic coupler  interoperability  interface impedance  detuning factor

摘要:

不同类型无线充电设备的互操作性是影响电动汽车无线充电技术普及的重要因素。互操作性指不同地面和车载设备匹配时,系统以规定效率输出额定功率的能力。针对现有互操作性评价方法存在评价判据不全面、评价结果准确性低等问题,引入表征系统谐振特性和负载特性的失谐因子与负载因子,提出一种基于双因子的互操作性评价方法。首先,分析基于传统地面侧与车辆侧端口阻抗的方法在评价系统效率方面的不足；随后,建立失谐因子和负载因子与系统功率、效率及电流限值之间的数学关系,根据国家标准限值推导可互操作的双因子区域及其边界函数,得到基于双因子的互操作性评价判据。实验结果表明,所提方法可从输出功率、系统效率和电流限值三方面综合评价互操作性,不仅解决了传统阻抗法评价判据不全面的问题,还提升了评价结果的准确性。

Abstract:

The interoperability of different assemblies is an essential factor affecting the popularization of wireless electric vehicle charging technology. Interoperability refers to the ability of the system to output rated power with specified efficiency when different ground and vehicle assemblies are paired. Aiming at the problems of incomplete evaluation criteria and low accuracy of evaluation results, this paper introduces the detuning factor and load factor representing the system resonance and load, respectively, and proposes an interoperability evaluation method based on two factors. Firstly, the limitations of the traditional evaluation method based on interface impedance are revealed. Secondly, the relationship between the detuning/load factors and system power, efficiency, and current limits are established. Then, according to the limits specified in national standards, the two factors’ interoperable region and its boundary functions are deduced, and the interoperability evaluation criterion based on the two factors is obtained. Experiments show that the proposed method can evaluate interoperability comprehensively from output power, system efficiency, and current limits. It not only solves the problem of incomplete evaluation criteria in the traditional method, but also improves the accuracy of interoperability evaluation results.