3.17 AC Generators Flashcards
What can alternating current waveforms sometimes be called?
‘Time-dependent signals’ or ‘periodic signals’
What is the most common alternating current waveform?
A sine waveform
What are the stationary parts in a AC generator called?
Stator
What are the rotating parts called in an AC generator?
Rotor
What are the three types of AC generators?
-permanent magnet generator
-rotating armature generator
-rotating field generator
What is the difference between a DC and a AC rotating armature generator?
The DC has a commutator whilst the AC has slip rings
Rotating armature is only used for?
DC generators
Rotating field is advantageous for ?
AC generators
A star / Y connection has how many wires?
4
A delta / mesh style connection has how many wires?
3
What type of wire connection is most commonly used in AC power distribution?
Star / Y
The line voltage is ____ times the phase voltage?
1.73 (√3)
If one phase becomes damaged or open in a delta / mesh connection, what is the capacity of the generator now?
57.7%
What are the modern high-output brushless generators called?
Permanent magnet generators (PMGs) or Brushless AC generators
What are the advantages of a brushless generator?
-lower maintenance cost
-high stability and consistency
-better performance at high altitudes
How do brushless generators transfer current from rotor to stator?
Electromagnetic induction
How does a brushless system induce voltage into the rotor?
Using magnetic flux lines
What type of connection do brushless generators uselessly use?
Star / Y connection
When using a three phase generator how wold you get 200V?
Connect any two main output terminals
When using a three phase generator how wold you get 115V?
By connecting one main output and ground
What is the generator control unit (GCU) used or?
It monitors and regulates the output to the desired amount
How does the generator control unit work?
By increasing or decreasing the exciter field
