Virtual inductance for DC microgrids with constant power loads

Abstract

In this paper, we develop a decentralized controller with virtual inductance to improve the robustness of a DC microgrid with constant power loads (CPLs). It is well known that the key to the problem is increasing the damping in the system. The CPLs, on the other hand, exhibit a negative impedance effect that deteriorates the damping. To counteract the CPLs, various methods including centralized and droop control have been developed. However, existing work have strict requirements on information acquisition and impose significant influences on microgrid's operating points. Instead, this paper develops a decentralized controller with virtual inductance that can virtually increases the damping in a DC microgrid and effectively accomplish the robustness enhancement objective without shifting the operating points. A simulation example is shown to demonstrate the efficacy of the proposed method.