[amp_mcq option1=”d.c. shunt machines” option2=”d.c. series machines” option3=”d.c. compound machines” option4=”any of the above” correct=”option4″]
The correct answer is D. any of the above.
Exciters of synchronous machines can be of three types:
- D.C. shunt machines: These are the most common type of exciter. They have a field winding that is connected to a D.C. source, such as a battery or a rectifier. The field current from the exciter creates a magnetic field that rotates with the rotor of the synchronous machine.
- D.C. series machines: These exciters have a field winding that is connected in series with the armature winding of the synchronous machine. The field current from the exciter creates a magnetic field that is proportional to the armature current. This type of exciter is used in applications where it is important to have a constant field current, such as in power generation.
- D.C. compound machines: These exciters have a field winding that is connected in shunt with the armature winding and a field winding that is connected in series with the armature winding. The field current from the shunt winding creates a constant field current, while the field current from the series winding creates a field current that is proportional to the armature current. This type of exciter is used in applications where it is important to have a variable field current, such as in adjustable-speed drives.