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...
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...
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
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...
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...
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”?
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...
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...
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...
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...
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.
"""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...
There is also IEC 60076-3 section 7.4 which says that for solidly grounded system, when transformer voltage is more than 72.5 kV then the test voltage for neutral terminal has to be minimum 38 kV (Um ≥ 17.5 kV). Um is maximum system voltage for which equipment maybe used.
It is not clear but...
NESC does not give information about neutral conductor. Which standard (IEEE or IEC) provides information about insulation level of neutral conductor for solidly grounded 230kV oil filled shunt reactor (or transformer)?
I have a question about the voltage rating of neutral conductor for solidly grounded 230kV shunt reactor. NEC 250.184(A)(1) states that for solidly grounded systems greater than 1kV, the insulation of neutral conductor has to be minimum 600V.
So for 230kV solidly grounded shunt reactor, the...
I have a question about reactive power compensators (Static VAR Compensator, Static STATCOM, and Dynamic Synchronous Condenser). Are all of these used to improve the voltage drop at the receiving end of transmission line? Also, do they provide capacitive-compensation or inductive-compensation...
Thanks. IEEE-80 figure B-2 shows a square substation yard for grounding, but it does not tell that how to determine the physical size (length X width) of the yard.
The substation has one transformer, one switchgear, and one control panel. Should we get the actual dimensions of the equipment...
