Q.1 A 5000 kVA, 6600 V , 3 - phase , star connected alternator has a resistance of 0.75 ohm per phase. Estimate by zero power factor method the regulation for a load of 500 A at power factor (a) unity, (b) 0.9 leading and (c) 0.71 lagging, form the open circuit and full load, zero power factor curves: Field current, A Open circuit voltage, V ZPF curve, V 32 3100 0 50 4900 1850 75 6600 4250 100 7500 5800 140 8300 7000
Synchronous Generator
In comparison to an asynchronous generator, it is a machine where the rotor speed is equal to the rotating magnetic field produced by the stator, i.e., mechanical speed is equal to the electrical speed, thus called synchronous, and not asynchronous.
Salient Pole Rotor
Salient pole rotor includes a large number of exposed poles mounted on a magnetic wheel. The construction of a bright pole is as shown in the image on the left. The proposed poles are made of metal laminations. The rotor winding is provided on these poles and is supported by pole shoes.
Q.1 A 5000 kVA, 6600 V , 3 - phase , star connected alternator has a resistance of 0.75 ohm per phase. Estimate by zero power factor method the regulation for a load of 500 A at power factor (a) unity, (b) 0.9 leading and (c) 0.71 lagging, form the open circuit and full load, zero power factor curves:
Field current, A |
Open circuit voltage, V |
ZPF curve, V |
32 |
3100 |
0 |
50 |
4900 |
1850 |
75 |
6600 |
4250 |
100 |
7500 |
5800 |
140 |
8300 |
7000 |
Step by step
Solved in 4 steps with 3 images