DC GENERATOR
E.M.F EQUATION
Let
Φ = flux/pole in weber
Z = total number of armture conductors = No.of
slots x No.of conductors/slot
P = No.of generator poles
A = No.of parallel paths in armature
N = armature rotation in revolutions per minute
(r.p.m) E = e.m.f induced in any parallel path in armature
Generated e.m.f Eg = e.m.f generated in any one
of the parallel paths i.e E. Average e.m.f geneated /conductor = dΦ/dt volt
(n=1)
Now, flux cut/conductor in one revolution dΦ =
ΦP Wb No.of revolutions/second = N/60
Time for one revolution, dt = 60/N second
Hence, according to Faraday's Laws of
Electroagnetic Induction,
E.M.F
generated/conductor is
For a simplex wave-wound generator
No.of
parallel paths = 2
No.of
conductors (in series) in one path = Z/2
E.M.F. generated/path
is
For a simplex lap-wound generator
No.of
parallel paths = P
No.of
conductors (in series) in one path = Z/P
E.M.F.generated/path
In
general generated e.m.f
where A =
2 for simplex wave-winding A = P for simplex lap-winding
PRINCIPLE OF OPERATION
DC
generator converts mechanical energy into electrical energy. when a conductor
move in a magnetic field in such a way conductors cuts across a magnetic flux
of lines and emf produces in a generator and it is defined by faradays law of
electromagnetic induction emf causes current to flow if the conductor circuit
is closed.