Research and design of power-supply coil for on-line monitoring system

Draw-out power supply is important in on-line monitoring system of high voltage grid and iron-core coil is one of the main ways. In this paper, simulation and experiments have been carried out to analyze electromagnetic properties of iron-core coil with different core structures. The field-circuit coupling model has been set up and the load characteristics have been calculated by Ansoft Maxwell software. From the simulation results, it can be found that slotted iron-core saturation began in the smaller primary current. As the current increases, when the iron core is fully saturated, output voltage wave of the coil with slotted core distorts more lightly, which means the energy-acquiring time increases. Comparing the output voltage peak-to-peak value of the coil with different iron-core structure, it can be concluded that slotting can effectively limit the amplitude of the narrow-pulse voltage at core saturation. Experiments have been carried out to analyze the output characteristics of iron-core coil for power supply with 100Ω resistor load, whose results are consistent with the simulation results.