Hydrogen-Cooled Generators

Highly Efficient & Reliable

Hydrogen's low density, high specific heat and thermal conductivity make it a superior coolant for rotating electrical machines, and it lends itself to a compact, highly efficient, reliable design. GE offers a complete line of hydrogen-cooled generators up to 514 MVA for either 50 or 60 Hz applications that are designed for maximum safety and reliability.

Hydrogen gas is circulated in a closed loop within the generator to remove heat from its active parts; then it is cooled by gas-to-water heat exchangers that are part of the stator frame

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Features & Benefits

The frame is tightly sealed to prevent gas leakage, and oil seals are installed on the shaft at each end of the stator to prevent leakage as the shaft emerges from the stator frame. The hydrogen-cooled generator's interior is completely sealed from the atmosphere, so dust, humidity, salt or chemicals have no effect on the machine. 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 its stator windings. This is a significant factor in the machine's reliability.

  • Class F insulation on both the rotor and stator provides dielectric and mechanical strength to ensure long life.
  • A direct-cooled field promotes uniform temperature distribution throughout the windings to lower temperature rise and prolong insulation life.
  • Retaining rings of 18-manganese / 18-chromium, non-magnetic stainless steel resist stress-corrosion cracking.
  • The stator winding support features top wedges and ripple springs to secure stator bars in the slot and eliminate bar vibration, maximizing insulation life and reducing maintenance requirements.
  • The plate-fin simplex coolers prolong life and simplify maintenance.
  • The low-loss stator core made of grain-oriented silicon steel minimizes electrical losses within the core to increase efficiency.

7FH2 Generator

The 7FH2 generator is an advanced, packaged design used primarily for application with GE 7F gas turbines and for down condenser steam turbine installations. 7FH2 features include:

  • A fully assembled package is available for delivery with the rotor already installed, along with lubricating oil piping and wiring routed in conduit. GE packaged turbine-generator sets can reduce installation time and cost by as much as 40 percent.
  • A factory assembled collector compartment houses the hydrogen control with autopurge, hydrogen and carbon dioxide manifolds, seal oil system, oil feed/drain piping, wiring and junction boxes to reduce on-site assembly.
  • The self-ventilated collector assembly features online removable brushes to simplify maintenance.
  • The location of the turning gear adds to the compactness of the overall gas turbine-generator installation.
  • A top-mounted terminal enclosure contains all neutral grounding equipment and current transformers.
  • The static start capability eliminates the need for a starting motor and torque converter in GE F technology gas turbine applications.

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