A 35,000-kw. induction frequency converter

F. C. Hanker: There is some question as to the application of the machine described that I want to discuss, particularly on the basis of considerations that Mr. Shirley has outlined. He has given in his paper three considerations. If you will analyze them, you will find the first is applicable to either the synchronous unit or the type described. In the second, in the amount of inductive kv-a. returned to the system appears to be questionable whether the type described is as effective as the straight synchronous, because the induction machine must of necessity receive its magnetization from either the 25-cycle or the 60-cycle system, depending on the voltage condition. That means that you have to compensate for that excitation or magnetization from the line either through other apparatus connected to, say, the 25-cyele system, or an additional machine that would be supplied with the set. If you take existing conditions, it would net be very serious or very harmful to supply the magnetization from the 25-eycle systems but in other cases where the power factor of the 25-cycle load is much lower, then it is a handicap to the machine.