This electrical protection system for a DC-current medium-voltage electrical circuit, comprising a disconnection module, for generating a counter-voltage greater than the voltage of the source for a current flowing therethrough that is equal to at most a few percent of the nominal current of the device, a resistive limitation module connected between a first terminal and a second terminal and configured so as to reduce the intensity of the output current of the protection system in order to limit the current between a value and upon a low impedance fault downstream of the device, and a primary switching module coupled in parallel across the disconnection module and the resistive module. The primary switching module is configured so as to switch between a first state in which the primary switching module is conductive and a second state in which the primary switching module forms a short circuit. Control means for controlling the primary switching module are configured so as to switch the primary switching module as soon as the current flowing in the first terminal reaches an upper limit value as lower value or a lower limit as upper value.