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 :
GE Ind & Power Syst., Schenectady, NY, USA
fDate :
1/1/1995 12:00:00 AM
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 :
arresters; ferroresonance; overvoltage protection; power system measurement; power system protection; power transformer protection; power transformer testing; transformer windings; design; ferroresonance; metal-oxide surge arresters; neutral shift; open-phasing; operating practices; self-generated overvoltages; ungrounded-wye delta transformer banks; Arresters; Capacitance; Circuit faults; Electrical equipment industry; Ferroresonance; Industrial power systems; Surges; Testing; Transformer cores; Windings;
Journal_Title :
Power Delivery, IEEE Transactions on
