Most commercial short circuit programs today rely on classical short circuit solution methods, which are characterized by:
• The use of the impedance (Z) matrix for modeling the sequence networks
• The use of equivalent circuits made up of sequence equivalents at the faulted buses
The classical methods work well for a limited number of fault connections, but it is extremely difficult to extend these methods to more general faults.
The solution in ASPEN OneLiner is based on an entirely new approach to short circuit computations developed recently by Vladimir Brandwajn and William F. Tinney.
V. Brandwajn and W.F. Tinney, "Generalized Method of Fault Analysis," IEEE Trans. on Power Apparatus and Systems, pp. 1301-06, June 1985.
The new method is characterized by:
• The use of the admittance (Y) matrix for modeling the sequence networks.
• The use of a phase equivalent at the faulted buses.
With this new method, any kind of fault, whether single or simultaneous, is solved with the same generality.
ASPEN OneLiner also exploits a number of phase-oriented solution techniques that are used within the Electromagnetic Transients Program (EMTP).