Three of hydrogen's outstanding properties- low density, high specific heat, and thermal conductivity - make it a superior coolant for rotating electrical machines. Hydrogen enables a compact, highly efficient, reliable design.
Hydrogen gas is circulated in a closed loop within the generator to remove heat from its active parts, and then it is cooled by gas-to-water heat exchangers that are part of the stator frame.
The hydrogen-cooled generator's interior is sealed from the atmosphere, so dust, humidity, salt or chemicals have little effect on the machines operation and reliability.
The absence of oxygen in its cooling gas means the generator's high-voltage insulation system will not be damaged by any corona activity in the generator's stator windings. This is a significant factor in the machine's reliability.
- The unit is designed to operate continuously, delivering power from the armature terminals, while maintaining hydrogen pressureand purity.
- Temperature detectors and other devices are installed in, or connected with, the machine to permit the measurement of the winding and hydrogen temperatures, as well as the hydrogen pressure and purity.
- The generator's stator is strong enough to limit destructive effects of an explosion of the hydrogen contents to only the generator casing and enclosed parts.