On-Line LoadDispatching Control withSecurity Constraints atthe TohokuElectric PowerCompany
Hachiro Isoda, Yoshihiko Sato · 1985
transformation combines thethreereduced andmodified sequencesubsys¬ temsinto onephase-coordinate equivalent. Thisphase equiv¬ alent isfurther modified tocorrectly represent theremaining unbalanced networktopology changes. A solution ofthe completely modified phase coordinate nodalequivalent yields thepostfault nodalvoltages forthatsubsystem. Following this, thephase solution istransformed backintosequence coordinates andconverted into a small setofcompensating currents. Byperforming a repeat solution on thecompensat¬ ing currents withthefactorized sequence admittance matri¬ ces,thenodevoltages fortheentire faulted network, or selected portions thereof, can becomputed. Thesefinal operations arespeeded upbyrecovering sparse vectorsfrom theequivalencing steps andusing themina mid-compensa¬ tionscheme. Thecompensating currentscorrectly simulate anykindoffault, including those thatcreatemutualcouplings betweenthesequencenetworks, e.g., simultaneous unbal¬ ancedfaults. Node-oriented compensation, whichaccommodates shunt elements more efficiently thantheusualbranch-oriented approach, isused. Themethodhasthefollowing favorable attributes: