Machines Flashcards
What are salient pole rotors?
These low speed rotors are always a large diameter to accommodate the large number of poles required.
The poles are mounted on a large steel frame fixed to a revolving vertical shaft.
What is sychronisation?
The frequency of power produced by a synchronous generator must exactly match that of the system it supplies.
The output voltage and current must match
- system frequency
- system phase
- voltage magnitude
Coupling to the grid
Applying more torque to the rotor causes it to lead the stator field by a physical angle α and causes power to flow into the grid.
What is the frequency formula of voltage and current waveforms?
f = n*P/60
where P = pole pairs not poles! If given poles divide by two.
Power oscillates at double the frequency.
What is the slip formula?
s = (ns - nr) / ns