| Abstract |
This paper presents an alternative method, the "μ-Analysis", for studying the robustness of the well-known field-oriented control of induction machine. The method, based on the structured singular value analysis, is used to analyse the robust stability and robust performance of closed-loop systems, here the motor with its associated control law, against several simultaneous plant uncertainties. The purpose of this paper is to give the worst-case effects of motor parameter variations on the stability and performance of the field-oriented drive structure. Furthermore, the author shows that the unmodeled drive dynamics can be introduced as unstructured uncertainties by using frequency-weighting transfer functions. This paper develops the nominal transfer function matrix of the entire indirect vector control scheme and gives the uncertainty block structure to perform the linear fractional transformation commonly defined in "μ-Analysis" theory. Simulation results are discussed and demonstrate the effectiveness of the proposed method applied to an industrial AC-drive example. |
