Adaptive Sliding Mode Control for Interleaved Nx Multilevel Boost Converter

Abstract

Interleaved <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Nx</i> multilevel boost converter ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Nx</i> MBC) has the advantages of low current stress, high efficiency, and high voltage gain without extreme duty cycle. However, it is difficult to design a controller for interleaved <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Nx</i> MBC due to the high order of state-space equations. A reduced order state-space averaged model of the interleaved <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Nx</i> MBC is proposed to reduce the complexity of the model. For the case of constant power load (CPL), an adaptive sliding mode controller based on nonlinear disturbance observer is designed on the basis of its reduced order state-space averaged model. The nonlinear observer is used to estimate the output power and avoid sampling error caused by interference. In order to ensure the large signal stability of the system, an adaptive law is introduced into the sliding mode controller to suppress the chattering phenomenon. Simulation and experimental results show that the proposed control algorithm has good dynamic regulation characteristics when the CPL and input power supply are disturbed.