METHOD AND DEVICE FOR LIMITING ELECTRICITY WITH A SELF-OPERATED CURRENT LIMITER

摘要

The invention relates to a process and a device ( 1 ) for combined current limiting and circuit breaking and to a switchgear assembly with such a device ( 1 ). In a combined current limiter-circuit breaker ( 1 ) as claimed in the invention, a movable electrode ( 3, 3' ) on the one hand for current limitation is guided automatically along one resistance element ( 5 ) for the current limitation path ( 31 ) by an overcurrent-dependent electromagnetic force (FSUBmag/SUB) and on the other hand for circuit breaking is moved into a series arrangement with an insulator ( 8 ). Embodiments include the following, among others: Use of the Lorenz force for automatic current limiting; movable electrode ( 3, 3' ) implemented by liquid metal ( 3 ) or movable solid-state conductor ( 3' ); an electrical resistance (RSUBx/SUB) which increases nonlinearly in the direction of motion (x) for a gentle current limiting characteristic; and a resistance element ( 5 ) in the form of a dielectric matrix ( 5 ) with several channels ( 3 a) for the liquid metal ( 3 ). Advantages are among others: arc-free, reversible current limitation and current interruption, also suited for high voltages and currents, fast reaction times, low wear, and ease of maintenance.