Modeling of switching frequency instabilities in buck-based DC-AC inverters by nonlinear time varying Poincaré mappings

In this paper we study the dynamical behavior of a full bridge DC-AC buck inverter controlled by fixed frequency and PWM. After showing that the system can undergo both period doubling and Neimark-Sacker bifurcation at the fast scale (switching period) by using the exact switching model, we derive an exact solution discrete-time model able to predict both instability phenomena. The model is obtained without making the quasi-static approximation and it can be used to obtain the useful region in the multidimensional design parameter space from time domain simulations in a very fast and accurate manner.