Integral Sliding Mode Control to Compensate Parametric Asymmetry and Modeling Errors in Z-Source Converter

Abstract

In the field of designing controllers, classical linear control methods are used extensively. These control methods are widely accepted due to availability of a well defined classical control theory, easy design methodologies and many other merits. These controllers perform efficiently at the operating point, how-ever, compromise in performance at transients and are likely to be less robust in comparison with their non linear counterparts. Integral sliding mode control (ISMC) technique leverages the advantages of linear control methods by amalgamating them with nonlinear sliding mode control (SMC). To enhance the potency of robustness, ISMC is designed with two controlling components. One is a linear nominal control such as PID, state feedback, Linear Quadratic Regulator (LQR) etc and the other one is a discontinuous SMC. The paper presents a technique to mitigate parametric asymmetry caused in impedance source (Z-source) converters. The proposed controller is a merger of Dual-loop PID control as the nominal control and nonlinear SMC. SMC deals with the disturbances like parametric variations and modelling errors whereas nominal controller governs the system dynamics. The effectiveness of the suggested controller has been validated through simulation results for parametric changes and disturbance compensation.