Discussion on “motor-generators vs. synchronous converters, with special reference to operation on long-distance transmission lines.” at New York, March 22, 1907

In regard to the use of motor-generators or synchronous converters, the question seems to me to be one of voltage regulation. The requirements of a railway system fed from a general transmission system are best met as to first cost and efficiency of operation by the adoption of the synchronous converter, and its almost universal use in railway installations would seem to leave no room for argument. The requirements of a direct-current lighting load can also be best met by the adoption of the synchronous converter, provided the distribution system is used for lighting only. Where, however, the distribution system supplies a mixed lighting and railway load (or any other load occasioning extreme fluctuations) the lighting system should be fed through motor-generator sets in order to smooth out the effect of unavoidable voltage fluctuations. Taking this broad view of the situation, there is a well-defined field for both synchronous converters and motor-generator sets, the question of voltage regulation determining the choice of either type of apparatus.