| 摘要 |
<p>A circuit interruption device (10) comprises: a main branch (12); a secondary branch (14) having an electrical on-resistance which is higher than an electrical on-resistance of the main branch (12); and first and second terminals (16, 18) for connection, in use, to an electrical network (20), the main and secondary branches (12, 14) extending between the first and second terminals (16, 18); wherein the main branch (12) includes a switching apparatus (22) which is switchable to selectively allow current to flow in the main branch (12) in a normal mode of operation or commutate current from the main branch (12) to the secondary branch (14) in a fault mode of operation, and the secondary branch (14) includes at least one switching device (26), the or each switching device including at least one normally-on switching element, the secondary branch (14) further including a control unit in communication with the or each normally-on switching element, the secondary branch (14) further including a power extraction circuit which is electrically coupled with the control unit, wherein during the normal mode of operation the or each normally-on switching element is in an on-state to permit the secondary branch (14) to conduct current, and during the fault mode of operation the control unit controls the switching of the or each normally-on switching element to an off-state to inhibit current flow in the secondary branch (14), wherein the power extraction circuit extracts power from current flowing in the secondary branch (14) to drive the control unit.</p> |
