Loading of Hydrogen-Cooled Generators at Elevated Gas Pressures

This paper presents a study, based on calculations and tests, of the heating characteristics of hydrogen-cooled generators at elevated gas pressures, and discusses various criteria for determining the capability of generators at elevated pressures. It is shown that the assumption of constant temperature rise of the windings above cold gas temperature, as a basis for limiting the output at elevated hydrogen pressures (particularly the rise of the armature winding by embedded detector) is misleading, and that a more realistic basis of rating is the assumption of constant total temperature of the winding copper, for constant temperature of ingoing cooling water at different loads and hydrogen pressures.