Modelling and control of a power supply for a power line inspection robot

This paper investigates the modelling and controller design for the power supply of a power line inspection robot. The power supply is unusual because it is based on a current transformer principle, may operate at low secondary voltages, and must cope with very large changes in the line current. A proportional and integral (PI) controller is able to control the charging current via modulating the apparent resistance presented on the transformer secondary. Derivative action may be used to counter phase lag from moving average filtering of measured values. The contributions of the paper include a novel bridge configuration, insight into modeling and digital controller design for a current-fed convertor and further engineering insight into the development of a power line inspection robot.