A Novel Electric Insulation String Structure With High-Voltage Insulation and Wireless Power Transfer Capabilities

Abstract

High-voltage insulation (HVI) strings are commonly used to hold high-voltage electric cables and electrically isolate them from the grounded transmission tower. In this paper, a novel concept of an electric insulation string with HVI and wireless power transfer (WPT) capabilities is presented. Based on the concept of the domino-resonator WPT system, this new structure consists of coil resonators embedded inside totally sealed insulation discs, which are then connected in series to form the new insulation string structure with the simultaneous HVI and WPT functions. This structure allows energy harvested from the ac magnetic field around the high-voltage cable to be transmitted wirelessly to power an online monitoring system in high-voltage transmission tower continuously, thereby reducing the storage requirements of the battery. The design and analysis of this new WPT structure based on the dimensions of commercially available HVI rod are included. Practical measurements obtained from a hardware prototype of about 25 W have been obtained to confirm the WPT capability of the proposal. An energy efficiency of more than 60% has been achieved for a transmission distance of 1.1 m over a wide range of load.