A fully distributed hierarchical control framework for coordinated operation of DERs in active distribution power networks

Abstract

In order to effectively accommodate large-scale distributed energy resources (DERs) in active distribution power networks, this paper proposes a fully distributed hierarchical framework to economically manage multiple DERs within three layers: the tertiary, the secondary generation regulation layer, and the primary frequency droop control layer. In the tertiary layer, a fully distributed dispatch strategy is designed to optimally allocate the active power base point of DERs in a center-free manner, with total generation and load imbalance locally estimated by individual DER using the discrete finite-time consensus algorithm. In the secondary layer, a distributed fair generation correction strategy is designed based on power sharing ratio to timely counterbalance the load deviations on top of the tertiary layer. In the primary layer, a droop controller is presented for DER, battery energy storage and controllable load to maintain satisfactory system frequency performance. The proposed hierarchical framework is a fully distributed generation coordinating approach, which could optimally control active power outputs of multiple DERs with the minimal cost while ensuring satisfactory system frequency, and is also robust to DERs' uncertainties. Case studies have demonstrated the effectiveness of proposed fully distributed hierarchical framework for optimally coordinating DERs power outputs and regulating system frequency.