Inductive reactance device for use in symmetrical component analysers

Claim 1

A POLYPHASE SYMMETRICAL COMPONENT ANALYSER CIRCUIT ARRANGEMENT FOR PRODUCING OUTPUT SIGNALS CHARACTERISTIC OF THE SYMMETRICAL COMPONENTS OF A POLYPHASE SYSTEM, INCLUDING AT LEAST ONE INDUCTIVE REACTANCE DEVICE COMPRISING A PRIMARY WINDING HAVING FIRST AND SECOND END TERMINALS AND A SECONDARY WINDING MUTUALLY INDUCTIVELY COUPLED TO THE PRIMARY WINDING HAVING FIRST AND SECOND END TERMINALS, MEANS FOR PASSING A CURRENT FROM ONE OF THE PHASES OF THE POLYPHASE SYSTEM THROUGH THE SAID PRIMARY WINDING, MEANS INTERCONNECTING THE FIRST TERMINAL OF THE PRIMARY WINDING WITH THE FIRST TERMINAL OF THE SECONDARY WINDING SO THAT A FIRST VOLTAGE SIGNAL IS DEVELOPED BETWEEN THE FIRST AND SECOND TERMINALS OF THE PRIMARY WINDING AND A SECOND VOLTAGE SIGNAL IS DEVELOPED BETWEEN THE SECOND TERMINAL OF THE PRIMARY WINDING AND THE SECOND TERMINAL OF THE SECONDARY WINDING, THE FIRST AND SECOND VOLTAGE SIGNALS RESPECTIVELY LEADING AND LAGGING THE SAID CURRENT THROUGH THE PRIMARY WINDING, FIRST COMBINING MEANS CONNECTED TO RECEIVE THE SAID FIRST VOLTAGE SIGNAL AND SIGNALS DERIVED FROM CURRENTS FROM OTHER PHASES OF THE POLYPHASE SYSTEM SO AS TO PRODUCE AN OUTPUT SIGNAL CHARACTERISTIC OF THE POSITIVE-SEQUENCE SYMMETRICAL COMPONENTS OF THE POLYPHASE SYSTEM, AND SECOND COMBINING MEANS CONNECTED TO RECIEVE THE SAID SECOND VOLTAGE SIGNAL AND SIGNALS DERIVED FROM CURRENTS FROM OTHER PHASES OF THE POLYPHASE SYSTEM SO AS TO PRODUCE AN OUTPUT SIGNAL CHARACTERISTIC OF THE NEGATIVE-SEQUENCE COMPONENTS OF THE POLYPHASE SYSTEM.