The optimum air gap length determination method to ensure maximum efficiency and non-saturation of the magnetic core output

Based on the study of the influence of the air gap length on the core characteristics, a method to determine the optimal air gap length of the core is proposed for energy harvesting of transmission lines. The equivalent model of the core is established, and the relationship between the optimal air gap length and the saturation primary current is derived. The simulation and experimental results show that when the air gap does not exceed 5% of the length of the magnetic circuit, the saturation characteristic model established in this paper can accurately calculate the optimal primary current with a calculation error of less than 5%. The air gap length corresponding to the optimal primary current is the optimal air gap length, and at the optimal air gap length, the core output efficiency is close to maximum, which has specific engineering utility value.