Modeling and Stability Analysis of DC Microgrid with Constant Power Loads

This paper presents modeling and stability analysis of droop controlled converter-based DC microgrids with constant power loads. The closed-loop control system is constituted by double loop control and droop control. Then a linearized small signal model of DC/DC boost converters with controller is derived, which can be easily extended to multiple connected converter system. In terms of this small signal model, stability and parametric sensitivity analysis are carried out with parameter variation according to the distribution of eigenvalues. Moveover, the Hopf bifurcation is identified when the system enters unstable operation states. Simulation results are provided to demonstrate the validity of the developed model and stability analysis in this paper.