A DC electrical network comprising: a plurality of DC terminals, each DC terminal being operatively connectable to a converter; and a plurality of DC transmission paths, each DC transmission path being arranged to interconnect two or more of the plurality of DC terminals, each DC transmission path including a DC power transmission medium (16, 18, 19), each DC transmission path further including a switching apparatus operable to selectively block current from flowing in the corresponding DC transmission path, the DC electrical network further including: at least one active power electronic device connected in at least one of the plurality of DC transmission paths, the or each active power electronic device being configured to be operable to selectively vary an apparent impedance of the or each corresponding DC transmission path; and a detector configured to detect one or more faults occurring in the plurality of DC transmission paths; the DC electrical network further includes a control unit programmed to operate the or each active power electronic device to vary an apparent impedance of a faulty corresponding DC transmission path so as to force a current (I 1) flowing in the faulty corresponding DC transmission path to reduce to a target current level, the control unit being further programmed to operate the or each switching apparatus to block current from flowing in the faulty corresponding DC transmission path when the current flowing in the faulty corresponding DC transmission path is reduced to the target current level, wherein the target current level corresponds to a current threshold at or below which the switching apparatus can be operated to block current from flowing in the corresponding DC transmission path, characterised in that the or each active power electronic device is configured to be operable to selectively vary an apparent impedance of the or each corresponding DC transmission path and thereby direct current from at least one of the plurality of DC transmission paths to at least one other of the plurality of DC transmission paths, and the control unit is programmed to operate the or each active power electronic device to vary an apparent impedance of the faulty corresponding DC transmission path and thereby divert current from at least one of the plurality of DC transmission paths to at least one other of the plurality of DC transmission paths so as to force a current flowing in the faulty corresponding DC transmission path to reduce to the target current level. at least one active power electronic device connected in at least one of the plurality of DC transmission paths, the or each active power electronic device being configured to be operable to selectively vary an apparent impedance of the or each corresponding DC transmission path; and a detector configured to detect one or more faults occurring in the plurality of DC transmission paths; the DC electrical network further includes a control unit programmed to operate the or each active power electronic device to vary an apparent impedance of a faulty corresponding DC transmission path so as to force a current (I 1) flowing in the faulty corresponding DC transmission path to reduce to a target current level, the control unit being further programmed to operate the or each switching apparatus to block current from flowing in the faulty corresponding DC transmission path when the current flowing in the faulty corresponding DC transmission path is reduced to the target current level, wherein the target current level corresponds to a current threshold at or below which the switching apparatus can be operated to block current from flowing in the corresponding DC transmission path, characterised in that the or each active power electronic device is configured to be operable to selectively vary an apparent impedance of the or each corresponding DC transmission path and thereby direct current from at least one of the plurality of DC transmission paths to at least one other of the plurality of DC transmission paths, and the control unit is programmed to operate the or each active power electronic device to vary an apparent impedance of the faulty corresponding DC transmission path and thereby divert current from at least one of the plurality of DC transmission paths to at least one other of the plurality of DC transmission paths so as to force a current flowing in the faulty corresponding DC transmission path to reduce to the target current level.