Nested three-layer optimisation method for magnetic coils used in 3 kW vehicle-mounted wireless power transfer system

• Published in: IET power electronics 2016-10, Vol.9 (13), p.2562-2570
• Main Authors: Wang, Zhenshi, Wei, Xuezhe, Dai, Haifeng
• Format: Article
• Language: English
• Subjects: boundary conditions; coils; coupling coefficient; Efficiency; electric parameters; electric vehicle charging design; Electric vehicles; FEM; finite element analysis; Finite element method; finite element model; Magnetic coils; magnetic flux; magnetic flux densities; Mathematical models; mutual inductances; nested three‐layer optimisation method; optimisation; optimisation flow; optimised structure parameters; Optimization; Parameters; parasitic resistances; power 3 kW; Power transfer; radiofrequency power transmission; self‐inductances; transfer efficiency improvement; vehicle‐mounted wireless power transfer system
• ISSN: 1755-4535; 1755-4543; 1755-4543
• DOI: 10.1049/iet-pel.2015.0840

Wireless power transfer is becoming more and more popular, especially for the charging design of electric vehicles. In this study, a novel nested three-layer optimisation method based on finite element model (FEM) is proposed to determine the structure of magnetic coils, which can increase the coupling coefficient, and hence, improve the transfer efficiency. The boundary conditions which consider practical situations for electric vehicles are first elaborated, then the optimisation flow is detailed and further analysed. Two magnetic coils are fabricated based on the optimised structure parameters, and their electric parameters, including self-inductances, mutual inductances as well as parasitic resistances, are measured and compared with those extracted from FEM, in addition, the magnetic flux densities around magnetic coils are also analysed. At last, a 3 kW prototype with 95% efficiency over a 20 cm transfer distance is achieved to validate this research results.