Electrical link comprising an electrical protection device—voltage bias

A method for the secure supply of electric power to a user apparatus in a vehicle via an electrical link linking the user apparatus to a power source, the electrical link comprising:

• an electrical conductor surrounded by an insulating cover;
• an electrical protection device comprising:
• a conductive sleeve arranged around the insulating cover;
• a biasing module configured to apply a voltage-bias the conductive sleeve;
• a circuit breaker arranged on the conductor and configured to cut off a current transiting through the conductor;
• and
• a detection module comprising a comparator with a first input connected to the conductive sleeve and a second input connected to a reference voltage supplied by a DC voltage generator, and a microcontroller connected between an output of the comparator and the circuit breaker, the microcontroller being configured to send a command signal to the circuit breaker on the basis of an output signal received from the comparator,
• wherein the method comprises the following successive steps of:
• injection, by the biasing module, of a DC voltage into the conductive sleeve;
• comparison, by the comparator, of a voltage on the conductive sleeve and the reference voltage;
• monitoring, by the microcontroller, of the state of the output signal of the comparator, said state being either a first state indicative of a current leak out of the electrical conductor or a second state if not;
• activation of the circuit breaker by the microcontroller if the output signal of the comparator is in the first state,
• wherein the power source is a high-voltage direct-current power source and the biasing module applies a DC voltage with a polarity opposite to a polarity of a DC voltage supplied by the power source to the conductor.