Construction of synchronous motor

 

Construction of synchronous motor

The construction of a synchronous motor (with salient pole rotor) is as shown in the figure at left. Just like any other motor, it consists of a stator and a rotor. 

The stator core is constructed with thin silicon lamination and insulated by a surface coating, to minimize the eddy current and hysteresis losses.

 The stator has axial slots inside, in which three phase stator winding is placed. The stator is wound with a three phase winding for a specific number of poles equal to the rotor poles. 

The rotor in synchronous motors is mostly of salient pole type. DC supply is given to the rotor winding  via slip-rings. 

The direct current excites the rotor winding and creates electromagnetic poles. In some cases permanent magnets can also be used.