Page 11 of 11 FirstFirst ... 91011
  1. #101
    Following from Jonathan's post #99

    Transformer Inrush - Open Electrical

  2. The Following User Says Thank You to EddyCurrent For This Useful Post:


  3. #102
    Quote Originally Posted by EddyCurrent View Post
    Following from Jonathan's post #99

    Transformer Inrush - Open Electrical
    Good article, but they could have expressed the final equation more clearly to demonstrate their point. Also, it's a bit pointless to solve the differential equation using Laplace transforms when you can trivially separate the variables. This is how I did it:

    From Faraday's law:

    Seperate variables:

    Use sin(A+B) identity to make it easy to integrate:

    Integrate:

    Use cos(A+B) identity to simplify:
    (1)
    When the transformer is switched on, we have the initial condition relating to the residual flux:

    So substitute this in to (1) to find constant, k:

    So the solution is:


    So now it's easier to see that the term is a constant, which introduces a DC offset that disappears when the switching angle is ... i.e at the peak voltage.
    Last edited by Jonathan; 13-01-2014 at 12:28 AM.
    Old router build log here. New router build log here. Lathe build log here.
    Electric motorbike project here.

  4. #103
    I used to like Laplace transforms but that was 40 years ago, I've never needed to use them since

  5. #104
    Quote Originally Posted by EddyCurrent View Post
    I used to like Laplace transforms but that was 40 years ago, I've never needed to use them since
    I much prefer the Lapdance performs. . Makes me constant, which introduces a DC offset that disappears when the switching angle is ...at the peak. .

Page 11 of 11 FirstFirst ... 91011

Similar Threads

  1. Denford Triac VMC year 2000 motors spec
    By suesi34e in forum Milling Machines, Builds & Conversions
    Replies: 1
    Last Post: 17-11-2013, 11:44 PM
  2. Advice on spindle inverter spec
    By badgerman in forum Spindles & Drive Motors
    Replies: 12
    Last Post: 15-09-2013, 09:26 PM
  3. Hiwin linear blocks HGW 20 CC - what preload to spec?
    By range3rrr in forum Rails, Guideways & Bearings
    Replies: 1
    Last Post: 24-08-2011, 11:44 PM
  4. FOR SALE: Servo Spec gearbox's ---- Any offer considered
    By Jimmybristol in forum Items For Sale
    Replies: 11
    Last Post: 30-05-2011, 11:04 PM
  5. System spec and Mach3
    By gorbo in forum Computer Hardware
    Replies: 5
    Last Post: 23-01-2011, 03:25 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •