Short-circuit current limiter for coupled power systems

Claim 1

AN ARRANGEMENT FOR LIMITING OVERLOAD CURRENTS IN A LINE BETWEEN TWO ALTERNATING CURRENT NETS WHICH NORMALLY OPERATE AT A GIVEN FREQUENCY, SAID ARRANGEMENT COMPRISING A SERIES-CIRCUIT TUNED TO HAVE A RESONANT FREQUENCY APPROXIMATELY EQUAL TO SAID GIVEN FREQUENCY AND COMPOSED OF INDUCTIVE REACTANCE MEANS AND CAPACITATIVE REACTANCE MEANS WHICH, DURING NORMAL OPERATION, HAVE APPROXIMATELY THE SAME VALUE THEREBY TO OFFER SUBSTANTIALLY NO IMPEDANCE TO A CURRENT THROUGH SAID LINE, SAID CAPACITATIVE REACTANCE MEANS COMPRISING A CAPACITOR AND A SHUNT PATH CONNECTED IN PARALLEL WITH SAID CAPACITOR, SAID SHUNT PATH COMPRISING AN OHMIC RESISTANCE AND A CLOSED CORE SATURABLE CHOKE, SAID SATURABLE CHOKE GOING SATURATED ABOVE A PREDETERMINED CURRENT VALUE THROUGH SAID LINE, SAID CAPACITATIVE REACTANCE MEANS THUS HAVING A CURRENT DEPENDENCY WHICH, ABOVE SAID PREDETERMINED CURRENT VALUE, SUBSTANTIALLY CHANGES THE REACTANCE OF SAID CAPACITATIVE REACTANCE MEANS THEREBY TO DETUNE SAID SERIES-CIRCUIT SO AS SUBSTANTIALLY TO INCREASE THE RESULTING TOTAL IMPEDANCE, THEREBY EFFECTIVELY TO LIMIT THE CURRENT THROUGH SAID LINE.