Hydrogen Cooling of Rotating Machines

Hydrogen cooled synchronous condensers now in use have a total rating of several hundred thousand kilovolt-amperes. During the last 2 years the use of hydrogen cooling has been extended frequency converters, and most recently to turbine generators. Several such machines now are being constructed. This method of cooling not only results in a reduction of machine losses and maintenance cost, but also makes feasible the construction of units with capacities greater than those of the existing air cooled units.