Design Strategies for Flywheel Energy Storage Systems in EV Fast Charging

With rising numbers of electric vehicles to curb greenhouse gas emissions, mitigating strain on the electrical grid from EV charging, specifically fast-charging applications, has become a significant challenge, especially since adapting grid infrastructure is not only complex but costly. Long service life, high power charge capacity, and the ability to mitigate peak loads to the electrical grid are some of the requirements for energy storage systems (ESS) to support electric vehicle fast charging. In this context, interest in flywheel energy storage systems (FESS) has been growing in recent years due to the favorable power characteristics and lack of cycle aging that FESS offer over electrochemical ESS such as second-life batteries. Typically, flywheel design has focused on small-scale transportation and large-scale grid frequency regulation applications. The present paper presents design strategies for FESS in fast-charging applications, which signifies a promising and innovative approach for reducing the strain that fast EV charging imposes on the electrical grid. This study considers design strategies to achieve low material and fabrication costs, a high safety standard, and operational advantages.