Exam Question

**(a) Sketch a schematic arrangement of a three phase alternator with star connection.**
A three-phase alternator generates three alternating voltages, mutually displaced by 120 electrical degrees in time phase. In a star (Y) connection, one end of each of the three phase windings is connected to a common point, known as the neutral point. The other ends of the three windings form the line terminals.
* **Stator Construction**: The stator is the stationary part, housing three sets of windings (coils) arranged at 120-degree intervals around the periphery. These windings are typically made of insulated copper conductors and are embedded in slots in the stator core, which is made of laminated steel to reduce eddy current losses.
* **Rotor Construction**: The rotor is the rotating part, which carries the field winding. This winding is excited by a DC current, creating a rotating magnetic field. The DC excitation can be supplied by a separate exciter or through a brushless excitation system.