| 摘要 |
PROBLEM TO BE SOLVED: To provide a cathodic protection of pipelines, which allows the pipe-to-ground potential of a cathodic protection target to be maintained on a steady basis, reducing the ripple content ratio of protection current as low as possible so as to achieve steady control with high efficiency and less power loss.SOLUTION: The cathodic protection of pipelines detects the pipe-to-ground potential between a reference electrode Er disposed in the electrolyte around a pipeline P and the pipeline P, and controls the output voltage of an external powered cathodic protection device 1 for outputting the protection current from an anode connected to the pipeline P and disposed in the electrolyte around the pipeline on the basis of the detected pipe-to-ground potential. The method includes the steps of: outputting smoothed DC voltage from an AC power supply; and controlling the output voltage outputted in the step of outputting smoothed DC voltage. In the step of controlling the output voltage, the output voltage is controlled such that the detected pipe-to-ground potential falls within a predetermined fluctuation range of the pipe-to-ground potential. |
