How can higher voltages and kilovolt-ampere ratings be achieved in commercial generators?

Higher voltages and kilovolt-ampere ratings in commercial generators can be achieved by using a revolving field and a stationary armature. In this design, the magnetic field is generated by the rotor (the revolving component), which produces a strong magnetic flux as it spins within the generator. The stationary armature, which is made up of coils of wire, is positioned in this rotating magnetic field.

When the rotor spins, it induces an alternating current (AC) in the stationary armature due to electromagnetic induction. The design leverages the fact that the relative motion between the magnetic field and the conductors induces a voltage according to Faraday's law of electromagnetic induction.

This configuration is advantageous because it allows for the generation of higher voltages without the need for excessive physical size or material in the armature. The voltage output can be increased by varying the speed of the rotor and the strength of the magnetic field, providing flexibility in design and operation for commercial applications.

In contrast, designs utilizing a stationary field can be less efficient in achieving the same voltage levels, and simply increasing the number of windings or using a larger magnetic field won't yield the same effectiveness as balancing the revolving field with a stationary armature setup.