21 - Multi-time-scale energy management of distributed energy resources in active distribution grids

Abstract

Recently, power system is undergoing two major transformations: (1) continuous displacement of conventional generating sources by renewables and (2) increased deployment of new loads in the existing electric grids due to electrification of heating, gas, and transportation sectors. These transformations impose various control and operational complexities, congest existing grids, and might negatively impact the power balancing by creating large and random fluctuations. To address the issues, an integrated control of flexible resources and distributed generations is required. This is addressed in this chapter using an integrated multi-time-scale energy management approach for active distribution networks. First, a day-ahead predictive dispatch is done using forecasted loads/generations, which is then adjusted using intraday control in order to compensate uncertainties stemming from forecast errors and/or unexpected grid events. Finally, an adaptive power management is performed near actual operation for constraint violations management in real time. The performance of the proposed methods is demonstrated using data from a real-world low-voltage distribution feeder in a simulation model set up in a DIgSILENT-MATLAB co-simulation environment. The proposed method not only maximizes deployment of flexibility from spatially distributed resources, but also enable single flexible resource to provide multiple grid support functionalities.