Short circuit current limiter for limiting fault currents in power networks

摘要

The short circuit current limiter in a main current circuit has a current switch off unit (1) for interrupting the phase current, in the event of fault current and in an auxiliary current circuit has a quenching circuit assigned to the current switch off unit. Each bridge branch of the bridge circuit of the quenching circuit (3) has at least one switchable quenching element (T(QpA)....). A control unit (2,5,6) is connectable with each of the quenching elements. With a detected fault current, two quenching elements arranged in the diagonal lying opposite are controlled in such a manner that the discharge current of the quenching capacitor (C(Q)) superimposes the current (i(Q)) branched from the main circuit in the same direction in the auxiliary current circuit.