“…The viability was successfully demonstrated in the 1992 New York trial, when the 115 kV 3Φ double-circuit Goudey-Oakdale line was transformed into a 93 kV 6Φ line and operated commercially for three years [9]. This trial accumulated valuable operational experience and instigated others to investigate the technical issues and challenges associated with 6Φ transmission, including tower design [5,[10][11][12], transformer configuration and ferroresonance [8,13,14], transient stability [15][16][17][18], economics [19], fault analysis [20,21], relay protection [22][23][24], electromagnetic field [6,7,12,[25][26][27], noise [6,7,[25][26][27] and insulation coordination [7,27]. One of the major technical challenges is the need to add transformers at each line end to convert the three-phases into six-phases operating at an elevated phase-to-neutral voltage.…”