摘要:AbstractIn this paper, new definitions of Phase and Gain stability margins for a class of Nonlinear (NL) systems (a linear plant with a nonlinear control), specifically, in systems with control saturation, are proposed. The Gain and Phase stability margins are defined as the maximum increase in the gain and the maximum phase shift that can be added to the frequency characteristic of the linear plant such that there are no limit cycles predicted or the sufficient stability condition is satisfied. The algorithms for computing the defined stability margins are developed based on the Circle Criterion (CC) and the Describing-Function-Harmonic-Balance (DF-HB) technique. Both methods that computepracticalstability margins are compared and analysed. Case study of the system with control saturation demonstrates the efficacy of the proposed approach.
关键词:KeywordsStability margin analysisNonlinear system analysisDescribing functionsHarmonic BalanceGain MarginsPhase Margins