A Comparative Analytical Exposition on Idealized and Parasitic Modeling for Stability Analysis of a 1-Φ H-Bridge Inverter

In this paper, the analytical treatment on stability analysis of a single-phase voltage-mode controlled H-bridge voltage source inverter without and with parasitics is given. A combination of Filippov and Floquet method is used to unfold the slow- and fast-timescale instabilities. In this approach, the stability of the periodic orbit is obtained in terms of the state transition matrices across each topological mode and saltation matrices across each switching event. Qualitative results remain similar. However from a quantitative view-point, while onset of period-doubling bifurcation does not differ much, parasitics have a more profound effect on the onset of Hopf bifurcation. Since, the simplified ideal model predicts instability for a much lower value of bifurcation parameter, such pessimistic results would serve the objective of ensuring stability and design need of a power electronic engineer very well. Analytical results for stability curves in the parameter spaces have been validated by bifurcation diagrams, obtained through numerical simulations.