As the core component of the inductively coupled wireless power transmission, loosely coupled transformer will make temperature rise rapidly in the process of electric transmission, and thus will affect its electrical performance and service life. In terms of its operation characteristics, the distribution characteristics of internal temperature of loosely coupled transformers and several influencing factors of thermal behavior are studied in the paper. The magnetic field model and circuit model based on mutual inductance structure of loosely coupled transformer were established, then its thermal model was established, and the process of its thermogenesis and thermolysis was analyzed, the electromagnetic field the coupling of thermology and electromagnetism was achieved. Finally, according to the coupling results, the internal temperature distribution of the loosely coupled transformer is analyzed and the influencing factors of its steady temperature rise are studied.
