A Shielding Scheme With Ferrite Magnetic Antennas for Three-Dimensional Couplers in Long Range IPT Systems for HV Insulator Applications

In this article, a shielding scheme based on ferrite magnetic antennas (SS-FMA) is proposed. The scheme can effectively provide a path for the magnetic field lines of three-dimensional couplers to be concentrated and conducted. The SS-FMA is considered to be applied for long range inductive power transfer (IPT) systems of post insulators to powering smart grid sensors and improve the efficiency under the influence of metal components. The negative influence of the aluminum flanges on the magnetic field distribution is analyzed. The suppression effects of the shielding scheme on the abovementioned influence have been analyzed. Parameters of the SS-FMA are optimized. The equivalent circuit model is established, and the abovementioned process is explained from the perspective of the circuit model. A prototype of a post insulator that includes IPT system and SS-FMA has been built. When the coils of the IPT system are attached to the flanges, the efficiency can still reach 47.8% under the influence of SS-FMA, which is an increase of 13.7% compared with no shielding scheme. When the coils are slightly away from the flanges, efficiency of the system including SS-FMA can be quickly improved to 54.3%.