Design of induced power apparatus for monitoring system of dynamic increasing capacity of high-voltage transmission lines

This paper uses CT to gain the energy directly from the high-voltage power line, which is to address the problem of power supply for monitoring system of dynamic increasing capacity in high voltage side of transmission line. The draw-out power coil can induce voltage from the transmission line whose current ranges from 50 to 1000A. Then after rectifying, filtering, voltage reduction and voltage stabilization, it can finally output stable DC voltage of +5V. Single-chip microcomputer is selected to calculate secondary side´s voltage, and analog output square wave to control the switching transistor, in order to increase the current of the secondary side. The method of adding secondary-side current significantly increases the saturated current of coil. And in a accordance with the theoretical calculation, parameters such as coil structure, core material and winding turns are matched reasonably. The power supply based on this kind of draw-out power coil has undergone the overall testing, and it is verified-showing that it can work in a non-saturated and low-consumed status within the range of normal operating current, and provide a stable output. The equipment has also increased over-voltage protection circuit to avoid the damage of the impulse current or short-circuit current to power supply circuit. It solves the power supply of high voltage side of transmission line.