- Life Time Assessment for Generator Stator Coils
- Rewinding Generator Stator Coil with Improved Cooling Performance
- Digital Wedge Tapping - Generator Stator Wedge Looseness Inspection
Life Time Assessment for Generator Stator Coils
The ground insulation of generator stator coils deteriorates due to the combined stress from thermal, electrical, mechanical, and environmental degradation during operation, reducing insulating performance with each year.
Focusing on the fact that the signs of deterioration in insulation differ depending on the types of mica tapes applied to the stator coil ground insulation, Mitsubishi Hitachi Power Systems (MHPS) established a method for diagnosing life time, making it possible to assess deterioration phenomena attuned to each mica tape type in an easy and precise way.
Rewinding Generator Stator Coil with Improved Cooling Performance
We have developed and applied a high-heat-transmission insulating system*1 that improves the heat transfer rate by 2-3 times over our previous products by producing high thermal conductivity in the generator stator coil insulation. The development of this technology enables higher output density in large-capacity generators, greater output and efficiency for existing generators through coil upgrades, and lower operating temperatures.
- Registered Trademark (Japan, United States): High Heat Transmission, or HHT.
Digital Wedge Tapping - Generator Stator Wedge Looseness Inspection
Electromagnetic vibrations are generated in a coil inserted into the slot of a generator stator. With the aim of inhibiting these electromagnetic vibrations, a structure that fixes the coil inside the slot by means of a wedge has been developed. It is very important to check the proper fixation condition of the wedge. Conventionally, a special hammer was used to perform a tap tone-based sensitivity inspection to determine whether the wedge was fixed properly in place. Now we have developed a wedge looseness inspection system*2 that converts the wedge tap tones into numerical information and quantitatively assesses wedge looseness, thus improving the precision and work efficiency of diagnostics.
- Registered Trademark (Japan, United States): Digital Wedge Tapper.
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