A Time-Domain Stability Analysis Method for Grid-Connected Inverter With PR Control Based on Floquet Theory

The feedback control may cause the system to oscillate or even collapse due to its unreasonable parameters, so the stability analysis with considering the control parameters is very important. The traditional frequency-domain stability analysis method based on the small-signal modeling has limitations in the inverter stability analysis due to the existing power frequency and the complexity of the transfer functions. In this article, a time-domain stability analysis method for a grid-connected inverter with proportional-resonance (PR) control is first proposed based on Floquet theory. Meanwhile, a transfer function decomposition construction method is first proposed to obtain the time-domain model of the PR control in this article, which makes the traditional frequency-domain control be analyzed in the time domain. Furthermore, the comparison of calculation cost between the proposed stability analysis method based on the Floquet theory and the traditional frequency-domain stability analysis method is given. Finally, the simulation and experimental results prove the correctness and effectiveness of the proposed time-domain stability analysis method for the grid-connected inverter with the PR control. Therefore, this article provides a new way of the stability analysis for the grid-connected inverter.