Process for limiting the opening currents of the circuit breakers in a high-voltage switchgear, and application of the process

摘要

In a high-voltage switchgear, nodes (1, 2, ..., 8) are connected in the form of a ring via switching points (12, 23, ...) each containing a circuit breaker. In this system, the breaking currents of the circuit breakers should be limited when a short-circuited part (e.g. node 1) is disconnected from an intact part of the system, thus reducing the breaking capacity of the circuit breakers provided in the system. This is achieved by opening a switching point (e.g. 45) of the ring-connected nodes, between their contact leads and the unavailable node (e.g. 1) at least one available node (e.g. 2, 3, 4, 5, 6, 7, 8) is provided, via which a partial short-circuit current is fed into the ring. It is particularly advantageous) to open the switching point (e.g. 45) that divides the short-circuit current flowing to the short-circuited part (e.g. node 1) into two halves of approximately the same size, since then the maximum breaking current in the power-switching points (e.g. 12, 18) only has to be half of the maximum short-circuit current of the high-voltage system.