Title :
Self-generated overvoltages due to open-phasing of ungrounded-wye delta transformer banks
Author :
Walling, R.A. ; Hartana, R.K. ; Ros, W.J.
Author_Institution :
Dept. of Power Syst. Eng., GE Ind. & Power Syst., Schenectady, NY, USA
Abstract :
Disconnecting one phase of an ungrounded-wye delta transformer bank from the source can result in severe overvoltages due to neutral shift and ferroresonance. Neutral shift overvoltages are quantified and their impact on metal-oxide surge arresters are evaluated. Ferroresonance is shown by test data to occur when low-loss banks, 15 kV and higher, are open phased. Design and operating practices to eliminate or mitigate these self-generated overvoltages are discussed
Keywords :
circuit resonance; overvoltage; power transformers; surge protection; ferroresonance; metal-oxide surge arresters; neutral shift; open-phasing; self-generated overvoltages; ungrounded-wye delta transformer banks; Arresters; Capacitance; Circuit faults; Electrical equipment industry; Ferroresonance; Industrial power systems; Surges; Testing; Transformer cores; Windings;
Conference_Titel :
Transmission and Distribution Conference, 1994., Proceedings of the 1994 IEEE Power Engineering Society
Conference_Location :
Chicago, IL
Print_ISBN :
0-7803-1883-8
DOI :
10.1109/TDC.1994.328441
