GT Excitation system

[speedtronic]

With reference to GE frame9E GT Excitation system(rotaduct/rotating diodes), Why DC excitation voltage is not directly applied to rotor?
I mean that DC excitation voltage coming from excitation panel is first applied to exciter stator & consequently on exciter rotor, we get AC voltage which is then again converted to DC voltage through rotating diodes which give this DC voltage to generator rotor? What if we apply DC voltage to generator rotor directly which is coming from excitation panel?

 

[Shakey]

With reference to GE frame9E GT Excitation system(rotaduct/rotating diodes), Why DC excitation voltage is not directly applied to rotor?
I mean that DC excitation voltage coming from excitation panel is first applied to exciter stator & consequently on exciter rotor, we get AC voltage which is then again converted to DC voltage through rotating diodes which give this DC voltage to generator rotor? What if we apply DC voltage to generator rotor directly which is coming from excitation panel?

well done, you just uninvented the brushless generator

What you have is a two stage brushless (a three stage is where the initial excitation comes from a permanaent magent on the rotor)

The power is applied to the exciter stator, which then induces ointo to the rotating pick up field, you are then rectifying, and applying the DC to the rotor field, which is then inducing into the three phase stator output windings.

Yoiu will find that the AVR is also in the excitation panel, and this senses the genny output, adjusting the excitation field accordingly.

This is how we have a brushless system - there is no connection between rotor and stator.

If you were to apply power to the rotor directly, then you would have to be using sliprings and brushes- with the obvious maintenance penalty that this will incur