New modeling framework considering economy, uncertainty, and security for estimating the dynamic interchange capability of multi-microgrids

Abstract

The increasing integration of distributed generation introduces severe challenges to the secure and economical operation of multi-microgrids (MMGs). Therefore, an accurate and timely estimation of secure ranges for dynamic interchange adjustments is necessary for microgrid operators. This study develops a new modeling framework for estimating the interchange capability between MMGs and a distribution network (DN) to increase the situation awareness of the microgrid operator. This framework contains a two models, namely, (1) the proposed prediction model, which considers the economical operation, the robustness of power interchange, and the uncertainty of renewable resources on a microgrid level to obtain the operation states and predicted interchange capabilities, and (2) the correction model, which determines the available interchange capabilities (AICs) while considering the effect of security constraints and spinning reserve on the DN level. AICs ensure the control flexibility and security of microgrids. The approach based on model predictive control is used in this framework to optimize the system operation on the microgrid and DN levels. The point estimation method and second-order conic programming are used to solve the two-level model to guarantee a globally optimal solution and improved computational efficiency. Finally, a distribution system with multiple microgrids is applied to prove the effectiveness of the proposed framework.