Method and apparatus for current limiting by means of a liquid metal current limiter

A method for current limiting, in particular in electrical power supply networks, having a current limiting apparatus which has solid electrodes and a container with at least one channel for a liquid metal, in which an operating current is carried on a first current path through the current limiting apparatus between the solid electrodes and the first current path is at least partially passed through the liquid metal, which is located in a first position, in a first operating state, in which the liquid metal is moved along a movement direction to at least one second position in a second operating state, and is passed along a resistance element during the transition from the first position to the second position, and is connected in series with the resistance element in the at least one second position and in consequence a current-limiting second current path is formed through the current limiting apparatus and has a predeterminable electrical resistance, wherein:

• a) the resistance element is purely resistive, and the electrical resistance, in order to achieve a soft disconnection characteristic, rises non-linearly and continuously with the second position, wherein
• b) in logarithmic representation, the electrical resistance as a function of the second position first of all increases more than proportionally with the second position and then rises linearly with the second position in a phase in which the energy which is stored in a network inductance must be absorbed, and then, in a region in which the short-circuit current is already limited and greater electrical resistances are tolerable, changes once again to a more than proportionally rising function of the second position.