Piecewise hysteresis-type control of a single phase active three-level rectifier with low THD

This paper is focused on the analysis and design of a switching control strategy to correct power factor, to regulate output voltage of a single-phase active three-level rectifier (SPATR) and to guarantee low harmonic distortion using a type of hysteresis current-mode control. The switching criterion is designed analyzing the stability of the switched linear system, to avoid information loss from sinusoidal signals during the whole period of operation. The main advantage of the proposed control is that it is capable of controlling the input current ripple and maintaining a low harmonic distortion. The approach uses switched linear models instead of average models, therefore its applicability is not restricted in a local set about the operating point. Simulations were carried out to demonstrate the advantages of the control as well as to compare its performance with other existing in the literature. Simulations of the SPATR and control algorithm were performed using the Matlab / Simulink environment.