Dear Forum Members,
My GSU transformer specification mentions that the " The transformer is required to demonstrate design and construction suitable for Seismic Zone 3, in conformance with IEEE Standard 693-2005."
The section 1.3 of IEEE Std 693-2005- IEEE Recommended Practice for Seismic...
Davidbeach,
Thanks for your reply. I was just trying to confirm, how to calculate 3 phase losses of Power Transformer when single phase losses are given. Three single phase GSU transformers are connected for a three phase application.
SG
PRC,
Thanks for the answer. My situation is exactly as you mentioned above. Single phase transformer bank is formed with same windings as of a three phase unit. The reality is that some vendors have given load losses and no load losses for a single phase unit and some have given for a three...
I have a GSU transformer with the following rating and would like to know if I am given a single phase no load and load losses or three phase no load and load losses, how to convert these losses between single phase and three phase GSU transformer and vice versa. I am in the process of selecting...
I would like to know the number of CTS that are generally required for a bushing of a delta-wye grounded Power transformer with the following rating:
54/72/90 MVA
13.8 kV/ 242 kV- Grounded Wye
Impedance=8.1%
Single phase but used in three phase application with three similar transformers.
The...
Hello,
I am trying to calculate heat loss by radiation from Transformer Tank. For this i need to calculate the transformer tank area. I am not sure wheather all the 6 sides of the transfomer contribute to the heat loss by radiation. Please let me know the actual formula to calculate transformer...
Hello,
I was wondering what would be the main criteria for selecting a vendor for a GSU Transformer of a hydropower plant.The specification writing for this transformer is almost complete and would be going to the bid soon. The bidding process will not be based on lowest bidder but rather on...
Hi PRC,
Thanks for the response. I aboslutely agree with what you just mentioned above. IEEE standard also says " the average temperature of the cooling air for any 24 h period shall not exceed 30C. Since transformer run continiously, now in my temperature rise calculation, do i need to add 40...
I am trying to review estimated temperature rise calculation for 260 MVA GSU transformer. Following is the transformer data.
260 MVA, 14.4 kV/242 kV,3-Phase, Percentage Impedence= 14.9 %
As per IEEE C57.12.00-2010, Section-5.11.1.1(Winding Tempertaure Rise): The average winding temperature...
What is the exact difference between NOMINAL RATING and CONTINIOUS RATING? What does the transformer name plate and the generator name plate shows; NOMINAL RATING OR CONTINIOUS RATING? When we say transformer is rated at some voltage and current; are we talking about NOMINAL RATING or CONTINIOUS...
Hello,
I am in the process of reviewing specification for a GSU transformer for a hydropower plant. As calculated, the primary current on the low voltage side(13.8 kv)is equal to 6521 amp and the secondary current on the high voltage side (241.5 kv) is equal to 373 amp. What ratio bushing CTs...
I am in the process of writing a specification for Governor of 112 MW hydropower plant.The old mechanical governor is going to be replaced with new digital governor. Now a days, we can find the vendor which supplies both the PLC based digital governor as well as Processor based digital governor...
Hello,
I am familiar with Transformer MVA rating being increased based on the type of cooling. For instance, Transformer with ONAF type cooling, will have two MVA ratings. One rating for the oil natural cooling by convection and other higher rating with air forced type cooling using fans.
Does...
Hello,
At one of our Hydro Power Plants, we are planning to replace the governor and exciter control system. I am the lead Electrical Engineer for this project. The governor will be replaced with PLC-based digital governor system. For the exciter, we may just change the controls (Automatic...
Actually i am reviewing a single phase, 90 MVA, 13.8 kv/132 kV ODWF power transformer specification. Is it possible to have a nitrogent blanket as well as Coservator tank with buchholz relay in the same transformer? As far as i know purpose of both is to keep Oil pressure constant inside the...
