On Quality of Usage Provisioning for Electricity Scheduling in Microgrids

Microgrid is a promising component for future smart grid deployment. The balance of supply and demand of electricity is one of the most important requirements of microgrid management. In this paper, we investigate the grid stability problem from an admission control perspective, while guaranteeing the quality of usage (QoU) of local residents in a microgrid under both random electricity supply and demand. In particular, a QoU request is generated when the electricity demand exceeds the microgrid supply. The microgrid control center aims to maintain the QoU blocking probability around a target value by serving (i.e., switching to the macrogrid for extra electricity supply) or blocking QoU requests. The problem is formulated as a queue stability problem by introducing the concept of a QoU blocking virtual queue. Lyapunov optimization is then applied to derive an adaptive QoU scheduling algorithm with low complexity O(1. Furthermore, it is an online algorithm since it does not require any future knowledge of the electricity supply and demand processes. The stability of the algorithm is proven, and its performance is evaluated with trace-driven simulations under random or nonstationary QoU requests. The simulation results demonstrate the efficacy and robustness of the proposed QoU scheduling algorithm.