Synchronous Generators
Synchronous Generators
(OP)
Hello everybody,
Can you please explain me why synchronous generators operate normally run at a lagging power factor?
Thank you in advance
Can you please explain me why synchronous generators operate normally run at a lagging power factor?
Thank you in advance






RE: Synchronous Generators
In generator reference, supplying VArs is lagging and absorbing VArs is leading, just the opposite of what it is in a load reference. I find it better to think of it as when Watts and VArs are in the same direction it is lagging and when Watts and VArs are in the opposite direction it is leading, then you don't need to worry about generator reference or load reference.
Even when the generator is connected in parallel with other sources, the system generally needs VArs, so the generator is run to produce VArs, in other words a lagging power factor.
But the generator itself has no particular preference.
RE: Synchronous Generators
Pls. don’t mix with same type of motors. Generators must work possibly close to cos=1, and in base loading is inductive.
RE: Synchronous Generators
----------------------------------
Sometimes I only open my mouth to swap feet...
RE: Synchronous Generators
A generator operating at a lagging power factor is producing vars, not consuming them. Since most loads are lagging, the generator runs at a lagging power factor to provide the vars.
RE: Synchronous Generators
When a set is connected to the grid, the combination of all the generation in the system determines the system voltage. Any one small gen-set is makes very little contribution to the system voltage. Now the field strength determines the production of VARs. As the field strength on one machine is increased, the machine will supply more VARs to the system and the other machines making up the grid will supply correspondingly less. Total VARs consumed by the loads will remain the same. Smaller sets that are connected to the grid are often run in PF control mode so as not to overload the set with reactive current if the grid voltage drops and the small set tries to produce more reactive current than it's windings can handle safely.
RE: Synchronous Generators
The excitation voltage applied to the generator will determine the phase angle of the generated apparent power (S). Hence the utilities can exercise a level of control over the load they supply.