Fault analysis of midchannel power takeoff in diagonal conducting wall magnetohydrodynamic generators

The effects of loading faults on the midchannel power takeoff of a diagonal conducting wall magnetohydrodynamic generator are investigated. The fault analysis considers loading schemes for connecting multiple external loads to the channel. It is shown that applying the concept of diodes in series with power takeoff electrodes as implemented in the end regions is harmful or ineffective for the midchannel power takeoff, since it may trigger premature faults or cause the multiple loading to be ineffective. It is also shown that faults can be treated in the same manner as other off-design conditions in the power takeoff of the end region. Twodimensional calculations show that an open-circuit condition in the upstream load circuit results in a large current density at power takeoff anodes accompanied by a shorting current over the interframe insulators at the cathode. A short-circuit condition in the upstream load circuit causes a large current density at the power takeoff cathodes and drives a shorting current at the anode.