Online Impedance-based Analysis for Power System Stability Assessment Using Transformer-less and Filter-less Switch-Mode Perturbation Generator

This paper proposes an online impedance-based analysis method for power systems, utilizing a switch-mode perturbation generator. The proposed approach employs frequency scanning with rectangular perturbations, which is achieved through single pulse switching of the dedicated inverter for perturbation generating. This method eliminates the need for filter inductors, which often limit the applicability of conventional techniques. Additionally, the inverter is designed to enable transformer-less operation. This paper presents comparative results from simulations and experiments using both sinusoidal and rectangular perturbations. The results show good agreement, demonstrating the basic feasibility of the proposed method.