Dynamic modelling and long-term simulation of ultracapacitor-type ESS integration in power grid

Abstract

A novel dynamic average-value model (AVM) of energy storage systems (ESS) integration in power grid for long-term control is developed and validated. It is expected to greatly improve the computational speed of power system dynamics in a long-term simulation. To end this, the development of the dynamic AVM of ESS integration including ultracapacitor, DC–DC converter, and voltage source converter is elaborated upon. A new control strategy which uses digital logic circuit is proposed to keep the ultracapacitors from overcharging without significantly increasing the charging time. To validate the proposed dynamic AVM and control strategy, case studies are carried out to perform the dynamics as affected by sudden changing of charging/discharging of ESS. The accuracy of the proposed model and controller is verified by the simulation results with that obtained from the detailed model implemented in MATLAB/Simulink. Moreover, the time-step size is enlarged greatly without sacrificing the accuracy, therefore the computational speed is improved significantly.

Keywords

• DC-DC power convertors
• energy storage
• power grids
• power filters
• logic circuits
• time-domain analysis
• supercapacitors
• dynamic modelling
• long-term simulation
• ultracapacitor-type ESS integration
• power grid
• dynamic average-value model
• energy storage systems integration
• long-term control
• computational speed
• power system dynamics
• dynamic AVM
• ESS integration including ultracapacitor
• DC–DC converter
• voltage source converter
• control strategy
• digital logic circuit
• ultracapacitors
• simulation results
• detailed model