previous post

RICH DAD POOR DAD BOOK REVIEW

-
  RICH  DAD  POOR  DAD  BOOK REVIEW This is amazing book.   • Explodes the myth that you need to earn a high income to become rich • Challenges the belief that your house is an asset • Shows parents why they can't rely on the school system to teach their kids about money • Defines once and for all an asset and a liability • Teaches you what to teach your kids about money for their future financial success It's been nearly 25 years since Robert Kiyosaki’s  Rich Dad Poor Dad  first made waves in the Personal Finance arena. It has since become the #1 Personal Finance book of all time... translated into dozens of languages and sold around the world. Rich Dad Poor Dad  is Robert's story of growing up with two dads — his real father and the father of his best friend, his rich dad — and the ways in which both men shaped his thoughts about money and investing. The book explodes the myth that you need to earn a high income to be rich and explains the difference between working
Post a Comment

Compensating Winding

-
Compensating Winding
  • The cross magnetizing armature reaction effect that causes concentration of flux under one pole tip is caused mainly by the conductors that lie under the pole are.
  • When the machines are heavily loaded, the flux density at these tips become very high resulting in higher than normal induced voltage between concerned adjacent commutator segments.
  • This may cause a spark over between adjacent commutator segments more so because these coils are physically close to the commutation zone where air temperature is high and favorable for spark over. This may lead to other segments also getting involved and resulting in fire over entire commutator segment.
  • Also if load is rapidly fluctuating (e.g. rolling machine), L(di/dt) voltage of coils may became high enough to start a spark over between adjacent commutator segments. This phenomenon will start from the coil under the pole center and it would have maximum.
  • This problem is more acute when load is decreasing in generator and increasing in motor.
  • The above problems may be overcome by use of compensating winding. Compensating winding consists of conductors embedded in pole faces and carry armature current in a direction opposite to armature conductor current under pole arc.


  • The compensating winding may be designed to completely neutralize the armature MMF of the conductors that lie under the pole are resulting into restoration of main field flux.
  • The presence of compensating winding reduces the duty of inter-pole winding to the extent of armature MMF of conductors under the pole are and therefore can be set to aid commutation.

  • For compensated machine
             Fcomp. = [ { (Z/2) / P } * { pole arc / pole pitch } * { Ia / A } ] AT/pole
       
             Ncomp = [ { (Z/2) / P } * { pole arc / pole pitch } * { 1 / A } ] turns

             Finterpole =  [ { (Z/2) / P } * { 1 - ( pole arc / pole pitch ) } * {Ia / A } + { ( Bint / μo ) * Linterpolar gap } ] AT/pole

  • Compensating winding reduces armature circuit inductance and therefore improves time response. Because it neutralizes AR under pole faces only.
  • It increase cost of the machine but works satisfactorily under all conditions.
Related topic>>>Inter-poles

Comments

Post a Comment

If you have any doubts, please let me know

Popular posts from this blog

Ideal Transformer (1-phase) Operation Under Load

-
Image
 What is Ideal Transformer ? An ideal transformer is a transformer with the following assumptions: Permeability of transformer is infinite. Iron loss in the transformer core are zero. Resistance of transformer winding is zero. No magnetic leakage flux, so coefficient of coupling is  1 . Magnetization curve of transformer is linear. Operation of Ideal transformer under load Schematic diagram of an ideal, 1-phase transformer under load When a finite impedance load Z L   is connected across the secondary terminals of a 1-phase transformer as shown in above figure, the load current I 2   flows through the secondary winding and the load. load current I 2   is given by:- I 2  = V 2 / Z L How will MMFs Produce ? A voltage source V 1   is connected to the primary winding. Due to this voltage V 1  primary current I 1   flowing through N 1   number of turns in the primary winding produces an MMF  N 1 .I 1   which creates the flux Ⲫ in the core. This flux links with the secondary coil and induc
Read more

RICH DAD POOR DAD BOOK REVIEW

-
  RICH  DAD  POOR  DAD  BOOK REVIEW This is amazing book.   • Explodes the myth that you need to earn a high income to become rich • Challenges the belief that your house is an asset • Shows parents why they can't rely on the school system to teach their kids about money • Defines once and for all an asset and a liability • Teaches you what to teach your kids about money for their future financial success It's been nearly 25 years since Robert Kiyosaki’s  Rich Dad Poor Dad  first made waves in the Personal Finance arena. It has since become the #1 Personal Finance book of all time... translated into dozens of languages and sold around the world. Rich Dad Poor Dad  is Robert's story of growing up with two dads — his real father and the father of his best friend, his rich dad — and the ways in which both men shaped his thoughts about money and investing. The book explodes the myth that you need to earn a high income to be rich and explains the difference between working
Read more