An Adaptive Compensated Virtual Impedance Method for Oscillation Suppression in DC Distribution Power Systems

Abstract

The oscillation problem in dc distribution power system is becoming increasingly prominent as the system scale expands. It is mainly caused by the system impedance mismatch. Traditionally, virtual impedance methods are employed to reconfigure the impedance and eliminate the oscillation. However, traditional solutions are generally criticized for unsatisfactory stability, poor dynamic performance, and low scalability. To overcome these drawbacks, an adaptive compensated virtual impedance (ACVI) method is proposed in this article. The proposed method can adapt to variable output power with significantly improved dynamic performance and stability. On top of this, an online source-side impedance estimation method is incorporated into the ACVI. It helps optimize the control parameters for adapting to different source impedances. Finally, the proposed method is implemented in a 48 V dc distribution power system. Experimental results demonstrate the effectiveness of the proposed ACVI method and its parameter optimization method.