A differential protection system including a plurality of inputs power cables for transfer of power from electric power generators, such as wind power generators, to an output cable. Each input and output power cable is provided with a respective circuit breaker. The protection system includes a plurality of protection equipment unit each being adapted to be arranged at a respective one of the input cables or at the output cable, each protection equipment unit including a measuring unit for measuring the current and voltage of the cable, and including a control unit being operatively connectable to the circuit breaker of the respective power cable for selectively tripping the circuit breaker when the protection system discovers a differential fault. The protection system includes a charging current compensator for compensating the differential protection for charging currents of the cables of the transfer system.