Loading patent…
AssigneeAsea Brown Boveri AG
InventorsHans Bernhoff, Mikael Bergkvist, Mats Ekberg, Jan Isberg, Mats Leijon, Li Ming, Anders Sunesson, Dan Windmar, Bertil Berggren
Estimating the term…
This invention is related to a device and a method in an electric power plant for protection of an object (1) against over-currents from a network (3) or another equipment included in the high voltage plant, the device comprising a switching device (4) in a line (2) between the object and the network/equipment. The line (2) between the object and the network/equipment is connected to an arrangement (5) reducing over-currents towards the object (1), said arrangement (5) being actuatable for over-current reduction with the assistance of an over-current condition detecting arrangement (11-13) within a time period substantially less than the break-time of the switching device (4).
A device in an electric power plant for protection of an object connected to an electric power network or another equipment included in the electric power plant from fault-related over-currents, the device comprising a switching device in a line between the object and the network/equipment, wherein the line between the object and the switching device is connected to an over-current reducing arrangement, which is actuatable for over-current reduction with assistance of an over-current conditions detecting arrangement within a time period substantially shorter than the break-time of the switching device, wherein the over-current arrangement comprises an over-current diverter for diverting over-currents to earth or otherwise another unit having a lower potential than the network/equipment, said over-current diverter including switch means coupled between earth or said lower potential and the line between the object and the network/equipment.
A device according to claim 6, wherein said means for causing or at least initiating the electrode gap to assume electrical conductivity being arranged to cause the gap or a part thereof to assume the form of a plasma.
A method in an electric power plant for protection of an object connected to an electric power network or another equipment included in the electric power plant from fault-related over-currents, a switching device being placed in a line between the object and the network/equipment, wherein an over-current reducing arrangement connected to the line between the object and the switching device is activated for over-current reduction when over-current conditions have been detected by means of an arrangement for such detection, within a time period substantially less than the break-time of the switching device.
A device in an electric power plant for protection of an object connected to an electric power network or another equipment included in the electric power plant from fault-related over-currents, the device comprising a switching device in a line between the object and the network/equipment, the line between the object and the switching device being connected to an over-current reducing arrangement, which is actuatable for over-current reduction with assistance of an over-current conditions detecting arrangement within a time period substantially shorter than the break-time of the switching device, comprising a control unit connected to the over-current reducing arrangement and to the over-current conditions detecting arrangement, said control unit being arranged to control the over-current reducing arrangement to closing based upon information from the over-current conditions detecting arrangement when required for reasons of protection, and a further breaker arranged in the line between the switching device and the object, said further breaker being arranged between the over-current reducing arrangement and the object, wherein said control unit is arranged to control, based upon information from the over-current conditions detecting arrangement, the over-current reducing arrangement as well as the further breaker, and said control unit is arranged to control the further breaker to break when the over-current towards or away from the object has been reduced by means of the over-current reducing arrangement but substantially earlier than the switching device.
Dependencies are inferred from the claim text.