Process and device for current switching with a fluid-driven liquid metal current switch

Liquid metal current switch for current limiting and/or circuit breaking, especially for executing the process as claimed in one of the preceding claims, comprising solid electrodes and a liquid metal tank with at least one channel for a liquid metal, in the first operating state between the solid electrodes there being a first current path for an operating current (I1) through the current switch and the first current path leading at least partially through the liquid metal which is in the first position (x1), wherein

• a) a dielectric fluid drive has a working fluid and a control and is designed for moving the liquid metal along one direction of motion (x) into at least one second position (x12, x2), the working fluid being dielectric and acting mechanically directly with a definable drive pressure (p1, p2) on one surface of the liquid metal, and
• b) in the liquid metal tank there is a dielectric and
• c) in the second operating state the liquid metal in at least one second position (x12, x2) is at least partially in series with the dielectric and thus forms a current-limiting and/or current-interrupting second current path in the current switch,
• d) for a given voltage level a maximum electrical resistance (Rx(x2)) of the dielectric being dimensioned to a finite value according to the current (I2) which is to be limited or to a dielectric insulation value for interrupting the current (I1, I2).

Electrical switchgear assembly, especially a high or medium voltage switchgear assembly, comprising a liquid metal current switch for current limiting and/or circuit breaking, especially for executing the process as claimed in one of the preceding claims, comprising solid electrodes and a liquid metal tank with at least one channel for a liquid metal, in the first operating state between the solid electrodes there being a first current path for an operating current (I1) through the current switch and the first current path leading at least partially through the liquid metal which is in the first position (x1), wherein

• a) a dielectric fluid drive has a working fluid and a control and is designed for moving the liquid metal along one direction of motion (x) into at least one second position (x12, x2), the working fluid being dielectric and acting mechanically directly with a definable drive pressure (p1, p2) on one surface of the liquid metal, and
• b) in the liquid metal tank there is a dielectric and
• c) in the second operating state the liquid metal in at least one second position (x12, x2) is at least partially in series with the dielectric and thus forms a current-limiting and/or current-interrupting second current path in the current switch,
• d) for a given voltage level a maximum electrical resistance (Rx(x2)) of the dielectric being dimensioned to a finite value according to the current (I2) which is to be limited or to a dielectric insulation value for interrupting the current (I1, I2).