Robust tracking system design for a synchronous reluctance motor – SynRM based on a new modified bat optimization algorithm

Abstract

This paper discusses optimal controller structure design for a Synchronous Reluctance Motor (SynRM). Optimization of controller parameters is based on a new modified BAT optimization algorithm (mBAT). SynRM is represented with a nonlinear dynamic model of a synchronous machine. All gathered nonlinearities of SynRM are taken into account in the controller’s design and optimization procedure with mBAT. A novel SynRM controller structure with a modified robust disturbance observer (mRDO) is presented. The modified mRDO ensures a higher level of stability margin, efficient disturbance rejection, and enables transparent controller parametrization and optimization. Controller synthesis is based on robust ℋ∞ pole-placement technique. The ℋ∞ robust criteria are presented in the form of spectral polynomials and their strong positivity conditions. Spectral polynomials (SP) can be directly used as objective functions in the mBAT optimization procedure. The mBAT algorithm, in terms of the derived SP introduces a novel approach to adaptive weighting function selection and modification of BAT velocity in the position formula. The new modification of the BAT algorithm is inspired by feedback control theory and Lyapunov exponential stability property. The proposed modification of the mBAT significantly increases the efficiency of the given optimization problem.