IEEE Std C37.081a-1997
(Supplement to IEEE Std C37.081-1981)
Supplement to IEEE Guide for Synthetic
Fault Testing of AC High-Voltage Circuit
Breakers Rated on a Symmetrical Current
Basis
8.3.2: Recovery Voltage for Terminal
Faults; Asymmetrical Short-Circuit
Current
Sponsor
Switchgear Committee
of the
IEEE Power Engineering Society
Approved 9 December 1997
IEEE Standards Board
Abstract: The transient recovery voltage needs to be modified when interrupting asymmetrical currents.
The voltage rate R, the peak voltage E2 and the rate of change of current di/dt all change with the
asymmetrical current zero. Guidance is provided on how to make these corrections when compared to the
symmetrical case.
Keywords: asymmetrical current, correction factors, major current zeros, minor current zeros, X/R ratio