Page 756 - Basic Electrical Engineering

stator windings that are made on stator slots have not been shown in the
figures.

Figure 10.1 (a) Salient-pole-type synchronous machine; (b) cylindrical-type synchronous machine

Direct current supply is provided to the field windings so that the poles are

magnetized. Current to the rotating field windings is supplied through brush
and slip-ring arrangement. The field winding current, I produces the flux.
f
The rotor carrying the field poles with their windings carrying current is
rotated with the help of a prime mover, i.e., a turbine. Since the rotor is

rotating, current from fixed supply terminals is to be provided to the rotor
field windings through the brush and slip-ring arrangement.
A set of two brushes and slip rings are required to supply dc current to the

field windings. Three-phase armature windings are made on the stator slots,
and connections from these windings to the load can be taken directly. Thus,

we have a three-phase winding placed on the stator slots. Field poles are
formed on the rotor which are excited by supplying direct current using two

sets of brush and slip rings.
It may be noted that in a dc machine, the armature winding is made on the

rotor while the field poles are fixed on the stator. In synchronous machines,