Stability Analysis and Impedance Reshaping Methods for DC Distribution Systems with Multiple Voltage Sources

In recent years, impedance-based stability analysis and improvement methods have become very popular in DC distribution systems. However, the existing stability criteria such as the impedance-ratio and impedance-sum criteria, require the additional calculation of the number of right-half-plane (RHP) poles when applied in the DC distribution systems with multiple voltage sources, which makes the stability analysis complex. In this paper, a stability analysis method for a DC distribution system with two voltage sources and one converter-based load is proposed, which does not require evaluating the RHP poles. On this basis, an impedance reshaping strategy based on the first-order high-pass filter is proposed to suppress system oscillations. Finally, the feasibility of the proposed methods is verified through impedance analysis and experiments.