Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

Register Log in
  • Congratulations cowski on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Search results for query: *

  1. nelvex

    Discharge resistor for synchronous motor

    We have a synchronous motor 3250 kW with brushless exciter with rotating diodes. The power resistor ~4 ohmi from rotating part must be replaced. I don't know the manufacturer. Anybody know a manufacturer of such power resistors fitted on the rotating part?
  2. nelvex

    Synchronous generator in compensator regime

    We have a 60 MW hydro-generator to be put into operation soon. I work on the design side and have a tests program for the generator. It is required that the generator can also operate in a synchronous compensation mode. I know the procedure. The water is removed from the turbine and the machine...
  3. nelvex

    Dust from brushes in hydrogenerator with excitation system

    We have an hydro generator with static excitation system. There are 14 brushes on one ring, so the problem is how can remove dust from these brushes. The excitation current is 1150 A. I want a simple solution. Is anybody which can help me?. Thanks is advance.
  4. nelvex

    Fast de-excitation brushless exciter

    I'm am referring to a large 180MVA power generator which is equipped with an brushless exciter. At a fault in the stator winding arc must extinguished quickly. Due to the large time constant of generator excitation circuit the electric arc in the stator winding can damage high enough until the...
  5. nelvex

    Fast de-excitation brushless exciter

    I searched in the net material for fast de-excitation brushless exciter, but is there anyone who knows more about this subject and if he saw somewhere applied this operating mode. Thank you.
  6. nelvex

    Shaft current transformer for hidrogenerator

    Hi, I got an answer, but the ABB say they no longer manufacture the relay abb Raric, although on their website is this relay. In the Raric prospectus is listed also the transformer relay. So far I have not received any response. Is it not important that relay?
  7. nelvex

    Brushes for hidrogenerators.

    I have several questions about the brushes that are used in hydrogenerators. I'm not referring here to those for static excitation but those that are used for protection and measurement. How many brushes of this type are used? It is a brush that makes contact with the machine shaft, is mounted...
  8. nelvex

    Shaft current transformer for hidrogenerator

    To protect hydrogenerators bearing it is used shaft current transformer installed around it and a relay attached to the transformer. I looked at various companies but I did not receive any answer. My question is if you can provide me the names of companies that produce these transformers and the...
  9. nelvex

    Hydro generator mechanical brake device

    Yes, the brakes are applied at 30% rated speed, but some beneficiaries require such a device. Dust with oil vapor deteriorates cooling the machine.
  10. nelvex

    Hydro generator mechanical brake device

    Dear Sirs do you have any information, solutions about how to collect the dust produced by the mechanical brake device at vertical hydro generators?.
  11. nelvex

    Electrical braking at hydrogenerators

    Thank you all for your answers. The intention is short circuiting the phases without using the phase resistances. electricpete: "GD2 = 85 tm2 ... what is tm2?" GD ^ 2 is Flywheel effect (tm2 .... tones x m ^ 2) GD ^ 2 = 4 x g x J wolf39 Armature Winding loss = 68 kW; stray losses = 29 kW...
  12. nelvex

    Electrical braking at hydrogenerators

    Thanks to the intervention of you, I would be glad if someone could possibly indicate a book or a site where the electrical braking for Hydro-generators is better presented. I must solve this problem and I must know more details about this (formulas, calculation, etc.). I know generally...
  13. nelvex

    Electrical braking at hydrogenerators

    We have an hydrogenerator with followings technical data; 16000 kVA, 6.3 kV, I stator=1466 A, n=500rpm., m=3 phase, R stator=0.010 ohm, GD2=85 tm2 and we want use electrical braking system by the short circuit method. When I calculated the time for braking the generator I found t=870 sec.. In my...
  14. nelvex

    Static excitation system and shaft current

    It is a relation between the current in the hydrogenerator shaft and static excitation system? I know that this current can destroy the isolation bearings. Is someone who knows more about this?

Part and Inventory Search

Back
Top