Differential protection using instrument transformer signal transducers

A method to provide protection for an electric power delivery system, comprising:

• electrically connecting secondary winding leads of a first current transformer in electrical communication with a first portion of the electric power delivery system to form a first electrically continuous secondary winding;
• electrically connecting secondary winding leads of a second current transformer in electrical communication with a second portion of the electric power delivery system to form a second electrically continuous secondary winding;
• obtaining a voltage signal corresponding with current in the first and second electrically continuous secondary windings using series-connected signal transducers in electrical communication with the first and second electrically continuous secondary windings;
• comparing the voltage signal against a predetermined threshold;
• integrating a voltage signal from one series-connected signal transducer to produce a signal corresponding with a current in the first portion of the electric power delivery system;
• determining a fault condition of the first conductor using the signal corresponding with the current in the first portion;
• and
• affect a protective action on the electric power delivery system when one or more of the following:
• the voltage signal exceeds the predetermined threshold;
• and a fault condition is determined.

A system to provide protection for an electric power delivery system, comprising:

• a first current transformer in electrical communication with a first portion of the electric power delivery system, the first current transformer comprising shorted leads to form a first electrically continuous secondary winding;
• a second current transformer in electrical communication with a second portion of the electric power delivery system, the second current transformer comprising shorted leads to form a second electrically continuous secondary winding;
• a first signal transducer in electrical communication with the electrically continuous secondary winding of the first current transformer, and comprising a first signal transducer output;
• a second signal transducer in electrical communication with the electrically continuous secondary winding of the second current transformer, and comprising a second signal transducer output;
• a protective device in electrical communication with the first and second signal transducer outputs, the protective device comprising:
• a protection module for determining a fault on the electric power delivery system using signals provided by the first signal transducer output and the second signal transducer output;
• and
• a monitored equipment interface to affect a protective action on the electric power delivery system upon determination of the fault.

A system to provide protection for an electric power delivery system, comprising:

• a first current transformer in electrical communication with a first portion of the electric power delivery system, the first current transformer comprising an electrically continuous secondary winding;
• a second current transformer in electrical communication with a second portion of the electric power delivery system, the second current transformer comprising an electrically continuous secondary winding;
• a first signal transducer in electrical communication with the electrically continuous secondary winding of the first current transformer, and comprising a first signal transducer output;
• a second signal transducer in electrical communication with the electrically continuous secondary winding of the second current transformer, and comprising a second signal transducer output;
• a protective device in electrical communication with the first and second signal transducer outputs, the protective device comprising:
• a differential protection module for determining a fault on the electric power delivery system, configured to
• compare a voltage signal from the signals provided by the first signal transducer output and the second signal transducer output against a predetermined threshold using an overvoltage protection module;
• and
• a monitored equipment interface to affect a protective action on the electric power delivery system upon determination of the fault.