Transformer Maximum MVA Rating

What is the maximum and minimum MVA ratings of following transformers used in transmission and distribution of power-

1 .66KV/11KV transformers

2.132KV/11KV Transformer

  1. What is the criteria on which the manufacturers decides the MVA rating

asked 7/9/2013

2 Answers

Voltage grade wise Transformer rating depends on Supply company rules and regulations. Highest rating of Transformer in a particular voltage grade depends on % voltage drop allowed which depends on Amperage and distance/length of line.
For Example:
I need 500MVA at 50 Km then it may not be suitable through 11/0.4KVTransformer because of the higher voltage drop being huge current. This is the way to restrict highest rating of the transformer in a particular voltage grade.
Similarly for minimum rating.
answered 9/13/2013 Er. S K Pal 2
Er. S K Pal
  • Thanks for your reply.Can you guide
    1. What is the % voltage drop allowed for EHV systems considering maximum amperage and maximum distance allowed(thumb rule based )?
    2. Also is there a restriction on Maximum MVA rating for transformers for particular voltage grades like 31.5MVA in 66KV grade,100MVA in 220KV grade,315MVA in 400KV grade. There is manual on this subject by Dakshin Haryana Bijli Vitram Nigam Ltd,India which I can mail to you. - ram31 9/29/2013

The minimum transformer is 6.6 MVA and range can be as maximum as per the application keeping in view following factors a) Voltage drop, b) Distance, c) type of conductor and d) temperature.

answered 10/28/2013 Sathya Narayana JE E/M 46
Sathya Narayana JE E/M

Your Answer

In order to provide an answer to this question, you must Login

I am flagging this question because...

10 inform moderator flags remaining

I am deleting this question because...

I am flagging this answer because...

10 inform moderator flags remaining

Flagging a Post

You have already flagged this post. Clicking "Remove Flag" below will remove your flag, thus reducing the count by one as well.

I am deleting this answer because...

Differential protection, the good old days

This morning I was explaining how differential protection works to a junior engineer. To give him something to read I opened up the NPAG (Network Protection...

Fault Calculations - Typical Equipment Parameters

A frequent problem in fault calculations is the obtaining of equipment parameters.  While it is always preferable to use the actual parameters of the equipment...

Fault Calculation - Symmetrical Components

For unbalance conditions the calculation of fault currents is more complex. One method of dealing with this is symmetrical components. Using symmetrical...

Sony Pocket eBook Reader

For the past few years I have reading eBooks on my HTC touch phone. On and off I have debated buying an eReader and recently purchased a Sony PRS-300 ...

Alternating Current Circuits

Alternating current (a.c.) is the backbone of modern electrical power distribution. In this article I’ll be pulling some of the more important concepts...

Photovoltaic (PV) - Electrical Calculations

Photovoltaic (PV) cells (sometimes called solar cells) convert solar energy into electrical energy.  Every year more and more PV systems are installed...

Tech Topics/Application Notes - Siemens

There are a lot of interesting two page type notes on various medium voltage topics – switchgear, circuit breakers, bus systems etc. It is on the Siemens...

How a Digital Substation Works

Traditionally substations have used circuit breakers, current transformers (CT), voltage transformers (VT) and protection relays all wired together using...

Cable Sheath and Armour Loss

When sizing cables, the heat generated  by losses within any sheath or armour need to be evaluated. When significant, it becomes a factor to be considered...

LED Replacement Light Bulb

The inventor of the first visible light-emitting diode makes history again this year as it begins to show customers a 40-watt replacement GE Energy Smart...

Our website uses cookies so that we can provide a better experience.
To learn more about what cookies are and how to manage them visit