Large-Signal Stability Analysis of DC Power System With Shunt Active Damper

Abstract

This paper proposes a large-signal stabilization method for the dc power system with a constant power load (CPL), which is detrimental to system stability due to its negative incremental resistance (NIR). The proposed method utilizes a shunt active damper at the point of common coupling of the dc bus and controls it as a parallel set of a virtual capacitor, virtual inductor, and resistor. The Takagi-Sugeno fuzzy model is employed with the Lyapunov stability theorem to verify the asymptotic stability of the system and to estimate the region of asymptotic stability. Improvements on the dc-bus voltage stability are evaluated based on dc-bus voltage deviation or dc-bus capacitance reduction. The performance of the proposed shunt active damper is verified by simulation and experimental results.