Exploring the effect of grid impedance on the large signal stability of an inverter using Lyapunov functions

This paper investigates the large signal stability of a DC to AC inverter using a Lure-type Lyapunov function. The Lyapunov function is systematically calculated for an inverter modeled as an electrostatic machine. The calculated Lyapunov function takes into account the impedance between the inverter and the grid. The stability of the inverter was studied under three scenarios: purely inductive, slightly resistive and purely resistive grid impedance. Simulation results show that the grid impedance has a pronounced effect on the large signal stability of inverters.