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TEMISA Power Gen · Explainer

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Hydro generator repair and maintenance

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Hydro generator repair and maintenance: stator, salient-pole rotor and excitation. Scope follows the nameplate, history and condition.

Published · 58.2 seconds · English and Spanish captions

Email ventas@temisapowergen.mxWhatsApp

Short answer

What does hydro generator maintenance include?

Maintenance and rewinding start from the salient-pole electrical machine coupled to the hydraulic turbine. The narration uses 40 poles at 180 revolutions as an example of delivering 60 hertz, with pole excitation through slip rings. After years of moisture, dust and heat, stator insulation is assessed to decide on maintenance, repair or rewinding. TEMISA Power Gen builds that scope from the nameplate and the history, for generators from 1 to 365 MVA.

Video transcript

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  1. 00:00

    This dam in Chiapas

  2. 00:01

    is 261 meters tall,

  3. 00:03

    and the water it

  4. 00:04

    holds back drives

  5. 00:05

    eight generators of

  6. 00:06

    about 300 megawatts

  7. 00:07

    each.

  8. 00:08

    How does it work?

  9. 00:09

    The water drops

  10. 00:10

    through a penstock and

  11. 00:11

    reaches the spiral

  12. 00:12

    case,

  13. 00:12

    which spreads it

  14. 00:13

    around the turbine.

  15. 00:14

    The wicket gates open

  16. 00:15

    and close like blinds

  17. 00:16

    and control how much

  18. 00:17

    water gets in.

  19. 00:18

    The water pushes the

  20. 00:19

    blades of the Francis

  21. 00:20

    runner and leaves

  22. 00:21

    through the draft

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    tube.

  24. 00:22

    There is no gearbox

  25. 00:23

    here.

  26. 00:24

    The turbine turns

  27. 00:25

    slowly at a few

  28. 00:26

    hundred revolutions

  29. 00:26

    and drives the

  30. 00:27

    generator directly.

  31. 00:28

    To make 60 hertz

  32. 00:30

    at that speed,

  33. 00:31

    the rotor carries many

  34. 00:32

    salient poles.

  35. 00:33

    For example,

  36. 00:33

    40 poles at 180

  37. 00:35

    revolutions.

  38. 00:36

    That is why a

  39. 00:37

    hydrogenerator is

  40. 00:38

    huge,

  41. 00:38

    like a disc several

  42. 00:39

    meters wide.

  43. 00:40

    The excitation feeds

  44. 00:41

    the poles through slip

  45. 00:42

    rings,

  46. 00:43

    and the governor moves

  47. 00:44

    the wicket gates to

  48. 00:45

    hold the speed.

  49. 00:46

    After decades,

  50. 00:47

    moisture,

  51. 00:48

    dust,

  52. 00:48

    and heat wear down

  53. 00:49

    the stator insulation.

  54. 00:50

    At TEMISA Power Gen,

  55. 00:52

    we diagnose,

  56. 00:52

    repair,

  57. 00:53

    and rewind generators.

  58. 00:54

    Get a quote at

  59. 00:55

    temisapowergen.mx

Questions from plant owners

What does hydro generator maintenance include?

Assessment of the electrical machine coupled to the hydraulic turbine: stator, salient-pole rotor and excitation. The programme depends on the design, history and condition of the unit.

Do you rewind a hydro generator stator?

When the assessment supports it. The narration points to moisture, dust and heat as wear on stator insulation after decades of operation. The proposal separates maintenance, repair and rewinding.

Is the example of 40 poles at 180 revolutions my unit?

It is an example in the narration, used to explain 60 hertz at low speed. Pole count, speed and rating come from your generator nameplate and drawings.

How do I request an assessment?

Email ventas@temisapowergen.mx with the nameplate, vertical or horizontal arrangement, symptoms, history and outage window. Published generator service covers 1 to 365 MVA.

About the figures: Figures in the narration and in the on-screen graphics illustrate the example in the video. They are not the nameplate of a serviced generator and they are not acceptance limits.

About the footage: The video is an explainer animation. It does not document work on a customer's machine and it does not show a serial number.

Technical sources

  • ANDRITZ · Hydropower services — General hydropower maintenance reference already cited on the hydrogenerator service page. It does not describe a TEMISA job.

These references identify equipment families or background documents. They are not an endorsement by the publisher and they are not an assessment of your generator.

Narration of the TEMISA Power Gen explainer video.