- #1
girts
- 186
- 22
I have looked over the types of generators used in most power plants (Hydro, Nuclear, coal etc) and with different sized and rotor rpm's they all basically share the same principle of operation if I'm not mistaken, which is that the rotor gets supplied via brushes and slip rings with a DC "excitation" current which while flowing through the rotor coils sets up a B field or "pole=pairs" which then travel along the stator coils to induce AC current in them, the frequency of which is directly related to the rpm of the rotor and the number of pole pairs on the rotor.Now one way to keep the frequency unchanged while operating at different mechanical loads is to alter the DC current through the rotor which I assume is done in most if not all commercial power plant generators correct?
But I assume that it would be more beneficial (especially for some types of power plants like nuclear) to be able to run the reactor-steam turbine-generator set with the power level that is most efficient for a particular desired electrical output of the plant (night vs day peak loads)So my question is would a generator that has its rpm and output frequency independent from one another be more desirable or in other words could such a generator have any noticeable advances over current generators. If one can vary the rotor rpm but keep the same output frequency of the generator, well the lower rpm or higher rpm would still change the amplitude of the output (voltage) but that could be compensated with varying the strength of the generator's excitation B field.
I am thinking that wind generators would benefit largely from such a device as the rotor rpm and wind loads are varying in short periods of time, so from what I read under certain wind strength the generator becomes too inefficient as the rpm's drop very low.Can you say anything about this?
thank you.
But I assume that it would be more beneficial (especially for some types of power plants like nuclear) to be able to run the reactor-steam turbine-generator set with the power level that is most efficient for a particular desired electrical output of the plant (night vs day peak loads)So my question is would a generator that has its rpm and output frequency independent from one another be more desirable or in other words could such a generator have any noticeable advances over current generators. If one can vary the rotor rpm but keep the same output frequency of the generator, well the lower rpm or higher rpm would still change the amplitude of the output (voltage) but that could be compensated with varying the strength of the generator's excitation B field.
I am thinking that wind generators would benefit largely from such a device as the rotor rpm and wind loads are varying in short periods of time, so from what I read under certain wind strength the generator becomes too inefficient as the rpm's drop very low.Can you say anything about this?
thank you.