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Recent content by timm33333

  1. timm33333

    Insulation Coordination

    Also does ferro-resonance only create temporary overvoltage (TOV), or does it also create other types of switching transients?
  2. timm33333

    Insulation Coordination

    Thanks for the information. Also I need some clarification that what are the acceptable values of transient voltages (in kV) of different types for switching transients. Switching transients are of several types including TOV (temporary overvoltage), TRV (transient recovery voltage), SFO (slow...
  3. timm33333

    Insulation Coordination

    I have a question regarding insulation coordination. The conventional insulation coordination study involves hand calculations of protective margins (PRL1, PRL2, PRS) of surge arrester. However there is also frequency scans based insulation coordination study done by software, which involves...
  4. timm33333

    Sizing of Gas Turbine Generators

    Simplified single line diagram is attached. About half of the loads are non-linear loads. https://files.engineering.com/getfile.aspx?folder=7e7cb663-dc5b-435b-bea1-3a0ff4cdb154&file=One_Line.jpeg
  5. timm33333

    Sizing of Gas Turbine Generators

    I am trying to figure out the sizing criteria of large gas turbine generators (GTG) when non-linear loads are present. Information is easily available on the web for sizing the small diesel generators, but not much information is available for large gas turbine generators. For sizing the small...
  6. timm33333

    Transmission Line Clearance

    Thanks everybody for information. I think 234(B)(1)(b) is for clearance from other supporting structures like the base of a surge arrester or CT. I think the correct rule would be 234(C)(1)(b), where a mechanical equipment (well-head) would come under the category of “other installations except...
  7. timm33333

    Transmission Line Clearance

    If we have to follow NESC: then which rule (or figure) of NESC should be used to find the minimum clearance between the “lowest phase conductor of 161kV line” and the “nearby structure/mechanical equipment”?
  8. timm33333

    Transmission Line Clearance

    I am trying to figure out which rule of NESC addresses the horizontal clearance between 161kV transmission line and an industrial facility (like a well pump). NESC rules 233(B) and 234(B) talk about horizontal clearances, and 233-3 talks about clearance envelope, but these are not clear. Also...
  9. timm33333

    Soil Resistivity Measurement

    I have a question regarding the soil resistivity measurement. Soil resistivity for the ground grid system of high voltage (HV) substations is measured as per IEEE-81. How about transmission lines, is it required that the soil resistivity be measured at the base of each tower of high voltage...
  10. timm33333

    Power Control by Reactive Power of Shunt Reactor

    We are controlling the reactive power by changing the taps of shunt reactor (not by varying excitation current of shunt reactor). My question is that what are the acceptable limits of voltage/current/power-factor/frequency (in percentages) which should be maintained while we vary the reactive...
  11. timm33333

    Power Control by Reactive Power of Shunt Reactor

    I am looking for the logic for the control of power system using the reactive power provided by 230kV shunt reactor. For example if the voltage is not within +/- 5%, then the taps of shunt reactor would be changed to bring the voltage within acceptable limits. Likewise if the current at the...
  12. timm33333

    HV Neutral Conductor

    What kind of connector can be used to connect the 600V (or bare) grounding cable to 15kV neutral bushing?
  13. timm33333

    HV Neutral Conductor

    As mentioned above, we are talking about the insulation of grounding electrode conductor which connects the star point of shunt reactor to ground. We are not talking about the insulation of neutral terminal of shunt reactor.
  14. timm33333

    HV Neutral Conductor

    """If insulation is applied for other than electrical safety reasons, 600V would be acceptable.""" I think electrical safety would not be an issue here because it is a grounding conductor which connects the star point of shunt reactor to the ground. However insulation might still be required to...
  15. timm33333

    HV Neutral Conductor

    IEC 60076-3, 7.4.2.1https://files.engineering.com/getfile.aspx?folder=3cfc9f30-21c8-485d-b7b9-f44dff9f37c2&file=Neutral.PNG

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