LINE DIFFERENTIAL PROTECTION SYSTEMS USING LOW POWER CURRENT SENSORS APPLIED TO EAF CIRCUITS

摘要

This companion paper to the three papers [1], [2], and [3] presented at the AISTech 2007, 2008, and 2009 conferences describes new differential protection solutions that use Rogowski Coil current sensors. This paper presents a novel solution for the protection of high-voltage power cables based on differential protection principles with currents measured by Rogowski Coil current sensors. This solution has been designed for general power line applications that may be two-source or single-source lines. This paper reviews protection system application on seven parallel connected in-service power cables that interface a 34.5 kV substation bus with a 90 MVA electric furnace transformer. The protection scheme has been subjected to extensive testing in a high power laboratory and in an operating electric arc furnace (EAF) circuit application that represents extreme power system operating conditions. All tests have verified the high dependability and security of the solution.