NEWTON SOLUTION FOR THE STEADY-STATE INTERACTION OF AC DC SYSTEMS/

The steady-state interaction of a six-pulse converter with a Thevenin equivalent of the three-phase AC and DC systems is solved. The convert er is represented by harmonic phasor mismatch equations, and the inter action between the converter and AC and DC systems is embodied in the solution of harmonic mismatch equations for the converter terminal con ditions. Since there are a large number of simultaneous nonlinear equa tions to be solved, a sparse Newton-type solution is developed that ex ploits the harmonic three-port nature of the converter, and the relati vely weak interaction between switching angles and terminal harmonics. The resulting solution is fast, and closely matches a time domain sim ulation of the test system.