The EMF (Electromotive Force) equation of a DC generator is a fundamental formula derived from Faraday's Laws of Electromagnetic Induction, used to calculate the voltage generated by the machine. When the armature rotates within the magnetic field of the DC generator, it cuts magnetic flux lines, inducing an EMF in the armature conductors. The average generated EMF across the armature terminals is directly proportional to the magnetic flux per pole, the speed of the armature, and the number of conductors.

1. 24PEE303 – ELECTRICAL MACHINES I
UNIT - II
DC GENERATOR
DC GENERATOR – EMF EQUATION

2. DERIVATION OF EMF EQUATION OF DC GENERATOR
Let
Φ = Magnetic flux per pole in Wb
Z = Total number of armature conductors
P = Number of poles in the machine
A = Number of parallel paths
Where, A = P … for LaP Winding = 2 … for Wave Winding
N = Speed of armature in RPM
Eg = Generated EMF = EMF per parallel path

6. EMF CALCULATION EXAMPLE

7. LOAD/TERMINAL VOLTAGE EXAMPLE

8. EFFICIENCY EXAMPLE

9. ARMATURE REACTION PROBLEM