Stability study of DC DPS and the improvement with EDLC

Stability problems of DC Distributed Power System (DPS) arise with the widely use of tightly regulated power modules including: (i) negative impedance characteristic in small-signal sense of constant power load, (ii) the interaction among the power converters. The concept of impedance specifications for a stable DPS was introduced and explained. Electric Double-Layer Capacitor (EDLC) has high power density and small Equivalent Series Resistance (ESR). A viewpoint was brought forward originally in this paper that the output impedance of DC DPS will be reduced and system stability will be improved largely by linking EDLCs to the DC bus. It was proved valid and feasible in a design instance.