Energy Management and Control of a Flywheel Storage System for Peak Shaving Applications

Abstract

Peak shaving applications provided by energy storage systems enhance the utilization of existing grid infrastructure to accommodate the increased penetration of renewable energy sources. This work investigates the provision of peak shaving services from a flywheel energy storage system installed in a transformer substation. A lexicographic optimization scheme is formulated to define the flywheel power set-points by minimizing the transformer power limit violations and the flywheel energy losses. Convex functions that represent the flywheel power losses and its maximum power are derived and integrated in the proposed scheme. A two-level hierarchical control framework is introduced to operate the transformer-flywheel-system in a way that handles prediction errors and modelling inaccuracies. At the higher level, a model predictive controller is developed that solves the lexicographic optimization scheme using linear programming. At the lower-level, a secondary controller corrects the power set-points of the model predictive controller using realtime measurements. A software platform has been developed for integrating the proposed controllers in an experimental setup to test their effectiveness in a realistic testbed setting, and the flywheel system characteristics are experimentally identified. Simulation and experimental results validate and verify the modelling, identification, control and operation of a real flywheel system for peak shaving services.

Bi-level Energy Trading Model Incorporating Large-scale Biogas Plant and Demand Response Aggregator

“…Among multiple ESSs, mechanical ESSs that take advantage of kinetic and gravitational forces to store inputted energy is one of the large-scale ESS technologies and the most mature one. The modeling of the pumped-storage power plant [6]- [9], flywheel ESS [10], and compressed air ESS [11], [12] incorporating their respective physical boundary conditions and characteristics as well as their commercialized application in the energy market has been explored by many scholars. With respect to chemical ESSs, the hydrogen plant has been demonstrated as a promising massive ESS by converting power to hydrogen and methane through electrolyzation.…”

Control Strategy of Flywheel Energy Storage System Based on Primary Frequency Modulation of Wind Power

“…With the FESS in the power compensation phase, the control strategy of the power outer and current inner loops was used to perform real-time peak shaving for the power curve output by a wind turbine. When wind power is too great, the FESS uses the excess power to charge up; contrarily, the FESS compensates for fluctuating and/or extremely low wind power by discharging power more smoothly to the grid [21][22][23][24][25]. The FESS flow chart for the real-time compensation of wind power output by a wind turbine is shown in Figure 4.…”

Review of Peak Shaving Features of the Power Box

“…This is due to their characteristics of full depth discharge ability, longer lifetime, eco-friendly, cheaper maintenance costs, an efficiency rate of 85-90%, and high charging-discharging capability. [38] It has become difficult to manage the stored energy and generated power in a storage device properly. One of the efficient ways of energy management is the regulation of the generated power peak.…”