Zero sequence current based line differential protection solution

A method for zero sequence differential protection of a transmission line of a power system, the method comprising:

• performing, by a zero sequence differential protection unit and using current measurements of each phase A, B, C from a local terminal and a remote terminal of the transmission line, internal fault detection of the transmission line;
• and
• performing, by a phase selection unit configured for using a comparison of differential values of the current measures for each phase, determination of whether any of the phases A, B, C of the transmission line is faulty or not,
• wherein a trip is initiated by the zero sequence differential protection unit when an internal fault is detected by the zero sequence differential protection unit and wherein the trip causes the phase selection unit to evaluate all the phases A, B, C to finalize the trip for any faulty phase.

A method for zero sequence differential protection of a transmission line of a power system, the method comprising:

• detecting an internal fault of the transmission line using current measurements of each phase A, B, C from a local terminal and a remote terminal of the transmission line;
• initiating a trip when the internal fault is detected;
• determining which of the phases A, B, C of the transmission line is faulty by comparing differential values of the current measurements for each phase;
• and
• finalizing the trip for any phase determined to be faulty.