Stability and Stabilization for Amplidyne Electrical Systems via a Novel Negative-Definiteness Lemma

Abstract

It is arduous to determine the stability for amplidyne electrical systems (AESs) with time-varying delay. In this article, a novel approach with two independent tuning parameters is established to obtain the stability conditions for AESs with time-varying delay. The new method could optimize negative determination conditions by tuning two tuning parameters without producing extra decision variables. Some existing lemmas commonly employed in the literature are contained in the proposed method as exceptional cases. Then, an improved Lyapunov–Krasovskii (L–K) functional is proposed in which more delay and state information are employed. Based on the novel quadratic function negative-definiteness method and the proposed L–K functional, new delay-dependent stability and stabilization criteria are achieved for AESs with time-varying delay. Finally, numerical examples and simulation results are conducted to show the advantages of the proposed approach.