Decentralized State Estimation of Interconnected DC MGs with Constant Power Loads

Paper in proceeding, 2022

Advances in power electronics and avoiding the pollution of fossil fuel sources is leading to a propensity towards distributed generations in direct current microgrids (DC MGs). Emerging more complicated power grids requires advanced state-estimation methods to enhance the control and monitoring purposes. This work forces the issue of decentralized state estimation in a typical nonlinear interconnected DC MG. It is considered that each of the DC MGs contains a source and resistive and nonlinear constant power loads (CPLs) and connects to the other grids via a tie line. The state estimation is done for the case that the information of the other grids is not available. In this regard, a dual-extended Kalman filter (dual-EKF) is utilized to estimate the DC MG states and the effect of other grids. Since the dual-EKF is robust against stochastic noisy measurements and can be implemented with a low computational burden, it is a practical and effective approach for practice. To show the accuracy of the dual-EKF, it is applied on a two-area DC MG with resistive loads, CPLs, and buck converters.