Disturbance Based on Sliding Mode Control and State Observer for Three-Phase Three-Level T-Type Rectifiers

Abstract

This paper presents a new sliding mode control (SMC) strategy for three-phase three-level T-type rectifiers (3LT2), which can be applied in
distributed power supply system. First, a state observer (SOB) was designed based on linear matrix inequality (LMI) to identify the optimal
eigenvalues of the state-tracking error function. Second, fixed-time sliding mode control (FTSMC) was constructed to control the system.
Third, a disturbance observer (DOB) was created based on the error signals of the system outputs and observer outputs. The output signals
precisely converged to the predefined trajectories in a very short time, with small overshoots and steady-state errors. Fourth, the Lyapunov
condition was utilized to verify the corrections/stability of the proposed controller and observer. Matlab Simulink simulation was used to
show the power/effectiveness of FTSMC and compare with the PI (Proportional-Integral) controller.