Synchronous Generators




Generators are the active elements in the network.They are connected by a shaft to turbines in any type of power plants - to have the same speed and the same torque.

Its speed must be constant and not to vary with load variation. It can be determined by the law:
             W=(120 f / P)                       
where:
                                                                              
W  (r.p.m) : revolution per minute.
P (poles)   : number of generator poles.
f       (Hz)    : frequency .

Modeling of Synchronous Generator  :


The model of synchronous generator is shown in the following figure:




where:

Vt        : Terminal voltage.
Eeff      : Effective emf.
d         : Power angle (rotor angle)
Ra        : Armature resistance.
Xs        : Synchronous reactance
Xa        : Armature reactance
XL        : Leakage reactance.
Ia          : Armature current
Cos j   : Power factor.

Noting that:
                        1 - Xs >> Ra    ,     (Xs / Ra > 10)
                        2 - Xs   = Xa + XL
                        3 - Emf. is always constant (neglecting any change in If).
                        4 - In some times, (Ra) is neglected w.r.t (Xs).

Mathematical model:


The mathematical model of synchronous generator is indicated in the following equation :


- Where  f is the angle between the voltage and the current (the power factor angle).      
SHARE

Ahmad Atiia

Hi. I’m Designer of Engineering Topics Blog. I’m Electrical Engineer And Blogger Specializing In Electrical Engineering Topics. I’m Creative.I’m Working Now As Maintenance Head Section In An Industrial Company.

  • Image
  • Image
    Blogger Comment
    Facebook Comment

0 comments:

Post a Comment