Excitation Control to Improve Powerline Stability

The influence of generator voltage regulators upon powerline stability is closely scrutinized by analog techniques. Contrary to common concepts, it is shown that high-speed control of excitation to maintain constant terminal voltage actually hampers rather than aids damping and powerline stability. It is further shown that damping and stability are greatly improved by supplementing excitation control with a specially derived function of frequency deviation. Results of the studies are verified in actual performance obtained in field tests.