Bubbling phenomenon in a unipolar SPWM inverter

Abstract

Bubbling phenomenon, bifurcations, and high periodic solutions are present in different applications of power inverters and have been widely reported in the literature. In particular, in this paper we present the dynamic analysis of a buck-inverter power system with unipolar switching. By changing the PWM scheme from bipolar to unipolar, it is shown how bifurcations, chaos, and high periodic solutions are suppressed but the bubbling phenomenon is preserved. Even more, a less pronounced bubbling dynamics is achieved and only appearing on the sinusoidal signal's downward slope of 1T-periodic solutions. In addition, an algorithm is developed to observe the bubbling phenomenon in more detail by detecting the time-on of the switches in every system state. This approach shows the transition of the system states in a phase period and the affectation of the switching dynamics due to the bubbling phenomenon.