Search

Numerical simulations of detailed time-dependent behavior are performed on a simulation model in which a coupled system of nonequilibrium disk MHD generator and line-commutated inverter is connected to an infinite bus through the transmission line, showing that continuous operation of the system is usually possible even when a power line fault occurs near the system. Then, time-dependent swing simulations are carried out on another simulation model in which the MHD/inverter system and a synchronous generator are connected in parallel to an infinite bus through the common transmission line, revealing that the rotor angle swing of the synchronous generator caused by the power line fault can be effectively suppressed by the fast output power control of the MHD/inverter system. © 1999 Scripta Technica, Electr Eng Jpn, 127(3): 13–24, 1999 [ABSTRACT FROM AUTHOR]

Two-dimensional stability analyses for open-cycle supersonic disk MHD generators are carried out which take into account electrical boundary conditions. A method of r-θ two-dimensional linear stability analysis for supersonic disk MHD generators is proposed which examines the time growth rate of perturbations. The growth rate is determined by the characteristic equation which is derived from the electrical boundary conditions. Whether the perturbations grow or decay is judged diagrammatically in a way similar to the Nyquist method. A coal-fired outflow supersonic disk MHD generator of commercial scale is analyzed under several types of boundary conditions. The stability is much affected by the electrical boundary conditions and also by the azimuthal wavenumber of disturbances. Two-dimensional analysis has revealed an azimuthally nonuniform instability in one of the load sections of the generator, where no instability is found in the one-dimensional analysis. The analysis also shows that the instability can be suppressed by subdividing the load section with control electrodes. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 120(4): 23–30, 1997 [ABSTRACT FROM AUTHOR]