Dynamic Analysis and State Estimation of a Mixed Energy Source Microgrid

Battery energy storage (BES) has become very attractive to electric utilities due to its promising frequency response characteristics. Its fast response under disturbances is particularly appreciated, that is, the BES can take faster actions than traditional synchronous generators (SG) during abrupt load changes. This paper presents a dynamic analysis of an islanded mixed energy source microgrid, containing one BES and one synchronous generator based distributed energy resource. The dynamic model of voltage source converter (VSC) controller is developed, considering distributed droop control scheme. Besides, to track the dynamic behaviors of the system, an extended Kalman filter (EKF) algorithm is employed to derive dynamic state estimation (DSE). Case studies demonstrate the merit of BES in terms of absorbing the abrupt load changes. In addition, the effectiveness of proposed EKF based DSE strategy is validated, as the dynamic behaviors of system state are accurately tracked despite the existence of process and measurement noises.