Stator is the
important part of rotary system which you can mainly find in electric
motors, generators, biological rotors or sirens. The main purpose of
using stator is to keep the field aligned. The stator may act in a
different way as per the configuration of a spinning electromotive
device like field magnet or interacting with armature to create the
motion or may be for receiving influence from moving field coils on
the rotor.
The maximum value
of flux density in the air gap has some limitation which controlled
by the magnetic saturation in the stator and rotor iron and it is
typically around one tesla. Large synchronous generators are designed
in such a way so that it could bear the terminal voltage of several
thousand volts. Each stator coil for the stator winding machine
usually consists of a number of same types of coils placed in
sequential manner in slots on the stator surface and also connected
in series.
The voltages
which are induced in individual coils in the distributed winding are
sometimes displaced in time from each other. Thus, the result comes
out with the maximum winding is less than the voltage per coil
multiplied the number of coils. However, the waveform on the
automatic stator winding machine is still the form of approximately
like sine. The winding spans of the stator are mainly each of 60
degree. So, to make use of the whole periphery of stator surface, two
other same types of windings need to be inserted so that the voltage
induced into the winding should be equal in peak magnitude to the
windings of 60 degree arcs, but would be delayed in time by
approximately one third of the cycle. This is the three phase system
of stator winding machine and the waveforms for the three phase
stator winding machines will work well with electric motors,
generators and many other machines as well.
You will get so
many advantages for three phase arrangements. Any single winding or
phase definitely needs two conductors for transmission of its
electrical power to a load. At the first time, it may seems that six
conductors would require for the system. However, the waveform is
considered to be those of current flowing in three phase windings.
You can see that the sum of the three currents that are flowing on
the three phase Automatic stator winding is zero at every instant in
time. So as long as the three phases are loaded equally, the
terminals can be connected together to form a neutral point which may
either connected to ground or left open in some cases. So, the
purpose of the field windings of exciter is placed on stator and the
phase windings on its rotor.
