Title :
Effect of contact material on the extinction of vacuum arcs under line frequency and high frequency conditions
Author :
Heyn, D. ; Lindmayer, M. ; Wilkening, E.-D.
Author_Institution :
Inst. fuer Elektrische Energieanlagen, Tech. Univ., Braunschweig, Germany
Abstract :
In two different test arrangements, the influence of different contact materials (Cu/Cr and Cu/Cr with additives of Zn, Sb, and Li2O) on reignition or extinction of vacuum arcs is studied. The following line frequency conditions are achieved in a synthetic Weil-Dobke circuit transient recovery voltage: 36 kV, currents: 800-4800 A, 50 Hz. High-frequency (HF) currents are generated by means of an L-C circuit, with amplitudes of several hundred amperes and frequencies in the range of several hundred kilohertz. The reignition voltage at the HF current zeros and its statistical distribution are evaluated. Cu/Cr 75/25 shows the highest values, in agreement with the tendency at 50 Hz. Like at line frequency, the additives reduce the reignition voltage, and hence increase the reignition tendency. Cu/Cr with higher Cr content has a smaller breaking capacity
Keywords :
chromium alloys; circuit-breaking arcs; copper alloys; 0.8 to 4.8 kA; 36 kV; 50 Hz; CuCr contacts; CuCr-Li2O contacts; CuCrSb contacts; CuCrZn contacts; HF testing; additives; contact material effects; currents; extinction of vacuum arcs; high frequency conditions; line frequency conditions; line frequency testing; reignition tendency; reignition voltage; synthetic Weil-Dobke circuit; transient recovery voltage; vacuum arcs reignition; Additives; Chromium; Circuit testing; Frequency; Hafnium; Materials testing; Statistical distributions; Vacuum arcs; Voltage; Zinc;
Conference_Titel :
Electrical Contacts, 1990. Proceedings of the Thirty-Sixth IEEE Holm Conference on ... and the Fifteenth International Conference on Electrical Contacts
Conference_Location :
Montreal, Que.
DOI :
10.1109/HOLM.1990.113057
