Multi‐Load Constant Voltage Output of Domino Wireless Power Transfer System for Insulator Condition Monitoring

Insulator condition monitoring is a guarantee for the safe and stable operation of transmission lines. Operating in high‐voltage environments poses challenges for the power supply of insulator condition monitoring. The domino wireless power transfer (WPT) system achieves noncontact energy transfer via multi‐relay coils that inherently provide electrical insulation, thus providing a feasible approach. However, complex cross‐coupling relationships in domino coils shift resonant frequencies and alter reactive power exchange between nonadjacent coils, thereby affecting the system's output characteristics. To overcome the impact of cross‐coupling, this paper first analyzes the types of cross‐coupling and the methods to eliminate them. Based on the voltage and current output characteristics of each coil loop, it further discusses a coil configuration approach to achieve multi‐load constant‐voltage output for a domino‐WPT system. A five‐stage domino‐WPT system was designed and built to verify the proposed method. The experimental results show that as the load changes from 30 to 90 Ω, the constant‐voltage output of approximately 5 V is achieved for the three loads, respectively, verifying the effectiveness of the proposed method.