This study is performed as part of the wide research on large scale coal fired MHD generation systems. Faults in the power transmission line give remarkable fluctuations to the MHD generator and to the transmission network. Then, it is required to take countermeasures for stable operation of the generation system. The fluctuations do not converge to a stable state after cutting off the fault line in the transmission line because the commutation failure occurs in the inverter system after the line faults. The effects of installed system dumping resistors(SDR) on the stability of an open cycle disk type MHD generator connected to power transmission lines are numerically studied. Usually the AC SDR is installed in the AC primary grid of the transmission line for system stability. The SDR is used to absorb the output energy of the synchronous generator and to get stability of the power transmission system when faults occur in the transmission line. In this paper, we propose to install the SDR in the DC lines between the MHD generator and the primary side of connected line commutated inverters. We show that the SDR is effective for system stability by a. time dependent numerical analysis. This study makes it clear that switching on the applied SDR using the thyristor switches in addition to cutting off the faulted transmission lines is effective to remove the fluctuations of the MHD generation system.