A Combined Analytical-Numerical Methodology for Predicting Subharmonic Oscillation in H-Bridge Inverters Under Double Edge Modulation

In this paper, a combined analytical-numerical methodology is developed for detecting subharmonic oscillation in H-bridge inverters with an LC filter and under double edge modulation. The prediction of this phenomenon is accomplished accurately by combining analytical expressions and computational procedures to determine the switching instants and the corresponding periodic orbits. Different approximate closed-form expressions for the stability boundary are derived revealing the effect of the parameters of the system on its dynamical behavior and showing that the stability boundary is different from the ones corresponding to single edge modulation strategies such as trailing edge and leading edge modulations. The theoretical results are validated by numerical simulations using a system-level switched model. Also, a prototype is implemented to validate he theoretical derivations and the numerical simulations getting a good matching.