Continuous conduction stability conditions for semi-quasi-Z-source inverters with resistive nonlinear loads

LISANDRO DE NICOLÓ; HERNAN HAIMOVICH; RICHARD H. MIDDLETON

Bariloche

Congreso; XV Reunión de Trabajo en Procesamiento de la Información y Control; 2013

Universidad Nacional de Río Negro

The recently introduced semi-quasi-Z-source inverter can be interpreted as a DC-DC converter whose input-output voltage gain may take any value between minus infinity and 1, depending on the applied duty cycle. In order to generate a sinusoidal voltage waveform at the output of this converter, a time-varying duty cycle needs to be applied. Application of a time-varying duty cycle that produces large-signal behavior requires careful consideration of stability issues. Previous work by the authors derived novel stability results for both the large-signal averaged and the switched models of the semi-quasi-Z-source inverter operating in continuous conduction mode and connected to a linear resistive load. In this paper, we focus on the switched model of the inverter and extend the previous results to the case of a purely resistive but nonlinear load. This extension is nontrivial because asymptotic stability depends on the restrictions imposed on switching.