A Laboratory Test System for Multi-Relay Magnetic Resonance Coupled Insulator in Power Supply of Monitoring Devices for Transmission Tower

Multi-relay magnetic resonance coupled insulator combined with current transformer is a reliable solution for the power supply problem of the transmission line online monitoring device. However, it is difficult to test the multi-relay magnetic resonance coupled insulator and the current transformer on the operating transmission line. In this paper, a laboratory test system for multi-relay magnetic resonance coupled insulator and current transformer is proposed and its design consideration and detailed method are given. Firstly, a test system structure that can simultaneously provide high voltage and large current is proposed to simulate the actual transmission line environment, while the extracted power is transferred wirelessly to the high voltage terminal of tested insulator to avoid the insulation problem. Then the compensation topology of wireless transfer module is determined, and the compensation parameter is properly configured. Finally, the magnetic coupler and its arrangement are designed according to the insulation distance and the limit of no influence on test results. The effect of wireless power transfer is also verified by finite element analysis (FEA). The results of finite element simulation show that the proposed compensation parameter can ensure the constant current(CC) output characteristic with gain of 1, and the magnetic coupler design meet the requirements of insulation and decoupling.