Generation of Three-Phase Voltages
As per this diagram, this generator comprises of 2 poles and 3 phases. There are 3 coils present in the armature. They are named as nn’, mm’, andll’. The axes of all these coils face a displacement in space which is 120 electrical degrees from each other.
Now taking in consideration of both this graph and this diagram highlighted above, we can easily find out about the generated voltage. In certain instances when the highlighted field is rotated and excited, in those 3 phases generation of voltages can be observed. This observation is based as per Faraday’s law.
We can clearly see that the structuration of the fields as per this graph is in a specific way which pinpoints the distribution of flux. In accordance with this graph, this distribution is mainly sinusoidalon both sides of the poles.
As per this, the flux which is connected with any of the phases will have a curved variation with time. And the voltages which are sinusoidally distributed will get induced in 3 phases. This displacement of 3 waves in accordance with time will have an angular displacement of 120°. And the reason for such outcome is mainly on the grounds of phase displacement in space.
Instantaneous values regarding al 3 voltages are explained in equational format. According to this graph, the equation stands to be,
As per this 3 e.m.f.’s, the sum of all 3 will always come to be zero.
So, in this case, Resultant instantaneous e.m.f. is,