Control of dual-excitation generator using derivatives of rotor angle

The paper investigates the performance of a synchronous generator with two field windings, with separate voltage and angle regulators. The effects of continuous rotor velocity and acceleration feedback signals in the regulator loops are examined, and it is shown that different derivative gains must be used during steady-state and transient conditions to obtain the best performance. This is achieved by the introduction of some simple switching in the angle regulator, and is most effective when implemented at the peak of the first rotor-angle swing. Acceleration feedback is introduced in the governor system, and the results illustrate the significant improvements in transient performance which are possible with the fast governor systems which have been developed recently. Initial results were obtained by digital computer, and the proposed control schemes were then tested on a laboratory micromachine system.