Power Angle Characteristic of Salient Pole Machine
Neglecting the armature winding resistance, the power output of the generator is given by:
synchronous machine. This also shows that it is possible to generate an emf even if the excitation E0 is zero. However this magnitude is quite less compared with that obtained with a finite E0. Likewise It is clear from the above expression that the power is a little more than that for a cylindrical rotor synchronous machine, as the first term alone represents the power for a cylindrical rotor synchronous machine. A term in (sin 2s) is added into the power - angle characteristic of a non-salient pole we can show that the machine develops a torque - called the reluctance torque - as this torque is developed due to the variation of the reluctance in the magnetic circuit even if the excitation E0 is zero. Fig: shows the typical power angle characteristic of a salient pole alternator.