Abstract: A method and a differential protection apparatus for an electrical link in a medium, high or very high voltage power distribution network. This method, in which two differential protection devices are disposed at the two ends (A, B) of said link, includes a step during which a comparison is made between the current measured locally and the current measured remotely, after said devices have been resynchronized by phase shifting the data received from the end situated remotely by one half of the sum of the outward and return propagation times; and a second step during which, if an angular phase difference is found to exist between two currents after resynchronization, automatic compensation is effected by servocontrolling the angle of the current vectors.

Abstract: A method and a differential protection apparatus for an electrical link in a medium, high or very high voltage power distribution network. This method, in which two differential protection devices are disposed at the two ends (A, B) of said link, includes a step during which a comparison is made between the current measured locally and the current measured remotely, after said devices have been resynchronized by phase shifting the data received from the end situated remotely by one half of the sum of the outward and return propagation times; and a second step during which, if an angular phase difference is found to exist between two currents after resynchronization, automatic compensation is effected by servocontrolling the angle of the current vectors.