Development of Floating Power Supply for Measurement System of High Voltage Power Line

Abstract

A measurement system of the high voltage power line without using an expensive insulation has been developed. The equipment is directly attached to the power line and floated in the air to insulate from the ground. In this paper, a ±5 V dual outputs power supply for the floating measurement system is presented. The power supply obtains energy from the current in the high voltage power line using an induction coil. The AC voltage induced by the coil is greatly changed from several volts to several hundred volts by the current in the high voltage power line and by the load of the power. Then, the AC voltage is roughly converted around 5 V by an AC-DC converter in order to absorb this large fluctuation of the AC input voltage. After that, the regulated ±5 V is supplied by a dual output DC-DC converter.By using the proposed power supply, it is confirmed that, the floating measurement system can monitor the signal of the power line current ranging from 50 to 300 A. The excellent characteristics are obtained by the steady-state and transient experiments of the proposed power supply.