Vector computer implementation of power flow outage studies

An application of vector and parallel processing to power flow outage studies on large-scale networks is presented. Standard sparsity programming is not well suited to the capabilities of vector and parallel computers because of the extremely short vectors processed in load flow studies. In order to improve computational efficiency, the operations required to perform both forward/backward solution and power residual calculation are gathered in the form of long FORTRAN DO loops. Two algorithms are proposed and compared with the results of a program written for scalar processing. Simulations for the outage studies on IEEE standard networks and some different configurations of the Italian and European (UCPTE) EHV systems are run on a CRAY Y-MP8/432 vector computer (and partially on a IBM 3090/200S VF). The multitasking facility of the CRAY computer is also exploited in order to shorten the wall clock time required by a complete outage simulation