Stability Analysis of DC Microgrids with Constant Power Load under Distributed Control Method

摘要

DC microgrids are becoming popular as effective means to integrate variousrenewable energy resources. Constant power loads (CPLs) may yield instabilitydue to the negative impedance characteristic. This paper analyzes the stabilityof the DC microgrid in presence of CPL. Distributed generations (DGs) arecontrolled by using a distributed controller which aims at current sharing andvoltage recovery. For simplicity, a reduced order model is derived on thefundamental of neglecting the transient state of the DC/DC converter. Thepurpose of this paper is to analyze stability conditions and give thesuggestions to design control parameters. The stability conditions are obtainedby using inertia theorem. Moreover, this paper makes a further detailedresearch based on the existed theorems. Simulation results are provided toverify the effectiveness and validity of the proposed theorem.