DYNAMIC LOAD SCHEDULING FOR ENERGY EFFICIENCY IN A MICROGRID

Abstract

Growing concerns over global warming and increasing fuel costs have pushed the traditional fuel-based centralized electrical grid to the forefront of mounting public pressure. These concerns will only intensify in the future, owing to the growth in electricity demand. Such growths require increased generation of electricity to meet the demand, and this means more carbon footprint from the electrical grid. To meet the growing demand economically by using clean sources of energy, the electrical grid needs significant structural and operational changes to cope with various challenges. Microgrids (µGs) can be an answer to the structural requirement of the electrical grid. µGs integrate renewables and serve local needs, thereby, reducing line losses and improving resiliency. However, stochastic nature of electricity harvest from renewables makes its integration into the grid challenging. The time varying and intermittentnature of renewables and consumer demand can be mitigated by the use of storages and dynamic load scheduling. Automated dynamic load scheduling constitutes the operational changes that could enable us to achieve energy efficiency in the grid.The current research works on automated load scheduling primarily focuses on scheduling residential and commercial building loads, while the current research on manufacturing scheduling is based on static approaches with very scarce literature on job shop scheduling. However, residential, commercial and, industrial sector, each contribute to about one-third of the total electricity consumption. A few researchworks have been done focusing on dynamic scheduling in manufacturing facilities for energy efficiency. In a smart grid scenario, consumers are coupled through electricitypool and storage. Thus, this research investigates the problem of integrating production line loads with building loads for optimal scheduling to reduce the total electricitycost in a µG.This research focuses on integrating the different types of loads from different types of consumers using automated dynamic load scheduling framework for sequential decision making. After building a deterministic model to be used as a benchmark, dynamic load scheduling models are constructed. Firstly, an intelligent algorithm is developed for load scheduling from a consumer’s perspective. Secondly, load scheduling model is developed based on central grid controller’s perspective. And finally, a reinforcement learning model is developed for improved load scheduling by sharingamong multiple µGs. The performance of the algorithms is compared against different well-known individualistic strategies, static strategies and, optimal benchmarksolutions. The proposed dynamic load scheduling framework is model free with minimum assumptions and it outperforms the different well-known heuristics and static strategies while obtains solutions comparable to the optimal benchmark solution.The future electrical grid is envisioned to be an interconnected network of µGs. In addition to the automated load scheduling in a µG, coordination among µGs bydemand and capacity sharing can also be used to mitigate stochastic nature of supply and demand in an electrical grid. In this research, demand and resource sharingamong µGs is proposed to leverage the interaction between the different µGs for developing load scheduling policy based on reinforcement learning.